1
|
Vera DA, García HA, Carbone NA, Waks-Serra MV, Iriarte DI, Pomarico JA. Retrieval of chromophore concentration changes in a digital human head model using analytical mean partial pathlengths of photons. JOURNAL OF BIOMEDICAL OPTICS 2024; 29:025004. [PMID: 38419755 PMCID: PMC10901244 DOI: 10.1117/1.jbo.29.2.025004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 01/25/2024] [Accepted: 01/26/2024] [Indexed: 03/02/2024]
Abstract
Significance Continuous-wave functional near-infrared spectroscopy has proved to be a valuable tool for assessing hemodynamic activity in the human brain in a non-invasively and inexpensive way. However, most of the current processing/analysis methods assume the head is a homogeneous medium, and hence do not appropriately correct for the signal coming from the scalp. This effect can be reduced by considering light propagation in a layered model of the human head, being the Monte Carlo (MC) simulations the gold standard to this end. However, this implies large computation times and demanding hardware capabilities. Aim In this work, we study the feasibility of replacing the homogeneous model and the MC simulations by means of analytical multilayered models, combining in this way, the speed and simplicity of implementation of the former with the robustness and accuracy of the latter. Approach Oxy- and deoxyhemoglobin (HbO and HbR, respectively) concentration changes were proposed in two different layers of a magnetic resonance imaging (MRI)-based meshed model of the human head, and then these changes were retrieved by means of (i) a typical homogeneous reconstruction and (ii) a theoretical layered reconstruction. Results Results suggest that the use of analytical models of light propagation in layered models outperforms the results obtained using traditional homogeneous reconstruction algorithms, providing much more accurate results for both, the extra- and the cerebral tissues. We also compare the analytical layered reconstruction with MC-based reconstructions, achieving similar degrees of accuracy, especially in the gray matter layer, but much faster (between 4 and 5 orders of magnitude). Conclusions We have successfully developed, implemented, and validated a method for retrieving chromophore concentration changes in the human brain, combining the simplicity and speed of the traditional homogeneous reconstruction algorithms with robustness and accuracy much more similar to those provided by MC simulations.
Collapse
|
2
|
Hartman ME. Prefrontal NIRS signal is unaffected by forehead Doppler flux during incremental cycling exercise. Clin Physiol Funct Imaging 2023; 43:393-403. [PMID: 37243413 DOI: 10.1111/cpf.12837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 05/17/2023] [Accepted: 05/24/2023] [Indexed: 05/28/2023]
Abstract
Near-infrared spectroscopy (NIRS) is used to measure tissue concentrations of oxyhemoglobin (O2 Hb) and deoxyhemoglobin (HHb). In the context of exercise, NIRS confers a higher signal-to-noise ratio than other neuroimaging techniques. However, part of the signal may be influenced by thermoregulatory hyperemia in the superficial cutaneous capillaries of the forehead. The degree to which NIRS signals during exercise reflect cerebral or extracerebral hemodynamic changes is a continuing source of controversy. However, the influence of skin blood flow may be attenuated depending on the NIRS technique (e.g., frequency domain machines with maximal optode separation distances >3.5 cm). The purpose of this study was to compare the changes in forehead skin blood flow and cerebral hemoglobin concentration during incremental exercise versus direct vasodilation of the forehead skin induced by gradual local heating. Thirty participants (12 females, 18 males; age: 20.8 ± 3.2 years; body mass index: 23.8 ± 3.7 kg·m-2 ) participated in the study. Forehead skin blood flow was quantified laser Doppler flux and absolute concentrations of cerebral O2 Hb and HHb were measured by NIRS. Local heating significantly increased the Doppler flux signal across time and these changes were significantly correlated with skin temperature. During incremental exercise, skin temperature, Doppler flux, O2 Hb and HHb increased however, the only significant change that was consistently correlated with Doppler flux was skin temperature. Therefore, a significant change in forehead skin blood flow may not significantly the NIRS hemoglobin data, depending on the type of NIRS device used.
Collapse
Affiliation(s)
- Mark E Hartman
- Department of Kinesiology, University of Rhode Island, Kingston, Rhode Island, USA
| |
Collapse
|
3
|
Sudakou A, Wabnitz H, Liemert A, Wolf M, Liebert A. Two-layered blood-lipid phantom and method to determine absorption and oxygenation employing changes in moments of DTOFs. BIOMEDICAL OPTICS EXPRESS 2023; 14:3506-3531. [PMID: 37497481 PMCID: PMC10368065 DOI: 10.1364/boe.492168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/29/2023] [Accepted: 05/29/2023] [Indexed: 07/28/2023]
Abstract
Near-infrared spectroscopy (NIRS) is an established technique for measuring tissue oxygen saturation (StO2), which is of high clinical value. For tissues that have layered structures, it is challenging but clinically relevant to obtain StO2 of the different layers, e.g. brain and scalp. For this aim, we present a new method of data analysis for time-domain NIRS (TD-NIRS) and a new two-layered blood-lipid phantom. The new analysis method enables accurate determination of even large changes of the absorption coefficient (Δµa) in multiple layers. By adding Δµa to the baseline µa, this method provides absolute µa and hence StO2 in multiple layers. The method utilizes (i) changes in statistical moments of the distributions of times of flight of photons (DTOFs), (ii) an analytical solution of the diffusion equation for an N-layered medium, (iii) and the Levenberg-Marquardt algorithm (LMA) to determine Δµa in multiple layers from the changes in moments. The method is suitable for NIRS tissue oximetry (relying on µa) as well as functional NIRS (fNIRS) applications (relying on Δµa). Experiments were conducted on a new phantom, which enabled us to simulate dynamic StO2 changes in two layers for the first time. Two separate compartments, which mimic superficial and deep layers, hold blood-lipid mixtures that can be deoxygenated (using yeast) and oxygenated (by bubbling oxygen) independently. Simultaneous NIRS measurements can be performed on the two-layered medium (variable superficial layer thickness, L), the deep (homogeneous), and/or the superficial (homogeneous). In two experiments involving ink, we increased the nominal µa in one of two compartments from 0.05 to 0.25 cm-1, L set to 14.5 mm. In three experiments involving blood (L set to 12, 15, or 17 mm), we used a protocol consisting of six deoxygenation cycles. A state-of-the-art multi-wavelength TD-NIRS system measured simultaneously on the two-layered medium, as well as on the deep compartment for a reference. The new method accurately determined µa (and hence StO2) in both compartments. The method is a significant progress in overcoming the contamination from the superficial layer, which is beneficial for NIRS and fNIRS applications, and may improve the determination of StO2 in the brain from measurements on the head. The advanced phantom may assist in the ongoing effort towards more realistic standardized performance tests in NIRS tissue oximetry. Data and MATLAB codes used in this study were made publicly available.
Collapse
Affiliation(s)
- Aleh Sudakou
- Nałęcz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Warsaw, Poland
| | - Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | - André Liemert
- Institut für Lasertechnologien in der Medizin und Meßtechnik an der Universität Ulm, Germany
| | - Martin Wolf
- Department of Neonatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Adam Liebert
- Nałęcz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Warsaw, Poland
| |
Collapse
|
4
|
Sun T, Piao D. Diffuse photon remission associated with the center-illuminated-area-detection geometry. II. Approach to the time-domain model. APPLIED OPTICS 2023; 62:3880-3891. [PMID: 37706697 DOI: 10.1364/ao.478322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 04/14/2023] [Indexed: 09/15/2023]
Abstract
This part proposes a model of time-dependent diffuse photon remission for the center-illuminated-area-detection (CIAD) geometry, by virtue of area integration of the radially resolved time-dependent diffuse photon remission formulated with the master-slave dual-source scheme demonstrated in Part I for steady-state measurements. The time-domain model is assessed against Monte Carlo (MC) simulations limiting to only the Heyney-Greenstein scattering phase function for CIAD of physical scales and medium properties relevant to single-fiber reflectance (SfR) and over a 2 ns duration, in compliance with the timespan of the only experimental report of SfR demonstrated with a 50 µm gradient index fiber. The time-domain model-MC assessments are carried out for an absorption coefficient ranging three orders of magnitude over [0.001,0.01,0.1,1]m m -1 at a fixed scattering, and a reduced scattering coefficient ranging three orders of magnitude over [0.01,0.1,1,10]m m -1 at a fixed absorption, among others. Photons of shorter and longer propagation times, relative to the diameter of the area of collection, respond differently to the scattering and absorption changes. Limited comparisons of MC between CIAD and a top-hat geometry as the idealization of SfR reveal that the time-domain photon remissions of the two geometries differ appreciably in only the early arriving photons.
Collapse
|
5
|
Sassaroli A, Blaney G, Fantini S. Novel data types for frequency-domain diffuse optical spectroscopy and imaging of tissues: characterization of sensitivity and contrast-to-noise ratio for absorption perturbations. BIOMEDICAL OPTICS EXPRESS 2023; 14:2091-2116. [PMID: 37206129 PMCID: PMC10191659 DOI: 10.1364/boe.485651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/08/2023] [Accepted: 03/28/2023] [Indexed: 05/21/2023]
Abstract
In frequency-domain (FD) diffuse optics it is known that the phase of photon-density waves (ϕ) has a stronger deep-to-superficial sensitivity ratio to absorption perturbations than the alternate current (AC) amplitude, or the direct current intensity (DC). This work is an attempt to find FD data types that feature similar or even better sensitivity and/or contrast-to-noise for deeper absorption perturbations than phase. One way is to start from the definition of characteristic function (Xt(ω)) of the photon's arrival time (t) and combining the real (ℜ ( X t ( ω ) ) = A C D C c o s ( ϕ ) ) and imaginary parts (ℑ [ X t ( ω ) ] = A C D C s i n ( ϕ ) ) with phase to yield new data types. These new data types enhance the role of higher order moments of the probability distribution of the photon's arrival time t. We study the contrast-to-noise and sensitivity features of these new data types not only in the single-distance arrangement (traditionally used in diffuse optics), but we also consider the spatial gradients, which we named dual-slope arrangements. We have identified six data types that for typical values of the optical properties of tissues and depths of interest, have better sensitivity or contrast-to-noise features than phase data and that can be used to enhance the limits of imaging of tissue in FD near infrared spectroscopy (NIRS). For example, one promising data type is ϕ - ℑ [ X t ( ω ) ] which shows, in the single-distance source-detector arrangement, an increase of deep-to-superficial sensitivity ratio with respect to phase by 41% and 27% at a source-detector separation of 25 and 35 mm, respectively. The same data type also shows an increase of contrast-to noise up to 35% with respect to phase when the spatial gradients of the data are considered.
Collapse
Affiliation(s)
- Angelo Sassaroli
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA
| | - Giles Blaney
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA
| | - Sergio Fantini
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA
| |
Collapse
|
6
|
Vera DA, García HA, Waks-Serra MV, Carbone NA, Iriarte DI, Pomarico JA. Reconstruction of light absorption changes in the human head using analytically computed photon partial pathlengths in layered media. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2023; 40:C126-C137. [PMID: 37132982 DOI: 10.1364/josaa.482288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Functional near infrared spectroscopy has been used in recent decades to sense and quantify changes in hemoglobin concentrations in the human brain. This noninvasive technique can deliver useful information concerning brain cortex activation associated with different motor/cognitive tasks or external stimuli. This is usually accomplished by considering the human head as a homogeneous medium; however, this approach does not explicitly take into account the detailed layered structure of the head, and thus, extracerebral signals can mask those arising at the cortex level. This work improves this situation by considering layered models of the human head during reconstruction of the absorption changes in layered media. To this end, analytically calculated mean partial pathlengths of photons are used, which guarantees fast and simple implementation in real-time applications. Results obtained from synthetic data generated by Monte Carlo simulations in two- and four-layered turbid media suggest that a layered description of the human head greatly outperforms typical homogeneous reconstructions, with errors, in the first case, bounded up to ∼20% maximum, while in the second case, the error is usually larger than 75%. Experimental measurements on dynamic phantoms support this conclusion.
Collapse
|
7
|
Meng S, Su H, Guo J, Wang L, Li T. Noninvasive optical monitoring of pulmonary embolism: a Monte Carlo study on visible Chinese human thoracic tissues. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:015001. [PMID: 36688229 PMCID: PMC9847892 DOI: 10.1117/1.jbo.28.1.015001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
Significance In recent years, the incidence rate of pulmonary embolism (PE) has increased dramatically. Currently, the correct diagnosis rate of PE in China is relatively low, and the diagnosis error rate and missed diagnosis rate were as high as about 80%. The most standard method of PE detection is pulmonary artery digital subtraction angiography (DSA), but pulmonary artery DSA is an invasive examination, and patients can have certain risks and discomfort. Noninvasive monitoring of PE remains challenging in cardiovascular medicine. Aim We attempt to study the light propagation in human thoracic tissues and explore the possibility of near-infrared spectroscopy (NIRS) in noninvasive detection of PE. Approach In this study, by utilizing the Monte Carlo simulation method for voxelized media and the Visible Chinese Human dataset, we quantified and visualized the photon migration in human thoracic region. The influence of the development (three levels) of PE on the light migration was observed. Results Results showed that around 4.6% light fluence was absorbed by the pulmonary tissue. The maximum signal sensitivity distribution reached 0.073% at the 2.8- to 3.1-cm light source-detector separation. The normalized light intensity was significantly different among different PE levels and formed a linear relationship (r 2 = 0.998 , p < 10 - 5 ). Conclusions The study found that photons could reach the pulmonary artery tissue, the light intensity was linearly related to the degrees of embolism, PE could be quantitatively diagnosed by NIRS. Meanwhile, the optimized distance in between the light source and detector, 2.8 to 3.1 cm, was recommended to be used in future potential noninvasive optical diagnosis of PE.
Collapse
Affiliation(s)
- Shuo Meng
- Chinese Academy of Medical Sciences, Institute of Biomedical Engineering, Peking Union Medical College, Tianjin, China
- Tiangong University, Tianjin, China
| | - Hengjie Su
- Chinese Academy of Medical Sciences, Institute of Biomedical Engineering, Peking Union Medical College, Tianjin, China
| | - Jianghui Guo
- Chinese Academy of Medical Sciences, Institute of Biomedical Engineering, Peking Union Medical College, Tianjin, China
- University of Electronic Science and Technology of China, Chengdu, China
| | - Lingxiao Wang
- Chinese Academy of Medical Sciences, Institute of Biomedical Engineering, Peking Union Medical College, Tianjin, China
| | - Ting Li
- Chinese Academy of Medical Sciences, Institute of Biomedical Engineering, Peking Union Medical College, Tianjin, China
- Chinese Institute for Brain Research, Beijing, China
| |
Collapse
|
8
|
Guo J, Meng S, Su H, Zhang B, Li T. Non-invasive optical monitoring of human lungs: Monte Carlo modeling of photon migration in Visible Chinese Human and an experimental test on a human. BIOMEDICAL OPTICS EXPRESS 2022; 13:6389-6403. [PMID: 36589576 PMCID: PMC9774858 DOI: 10.1364/boe.472530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/30/2022] [Accepted: 10/23/2022] [Indexed: 05/02/2023]
Abstract
The human lung was quantified and visualized by photon transport in this paper. A Monte Carlo (MC) simulation of voxelized media was used with the visible Chinese human (VCH). This study theoretically explored the feasibility of non-invasive optical detection of pulmonary hemodynamics, and investigated the optimal location of the light source in the lung photon migration and optimized the source-detector distance. The light fluence intensity showed that the photon penetration depth was 6-8.4 mm in the human lung. The optimal distance from the light source to the detector was 2.7-2.9 cm, but the optimal distance of the superior lobe of right lung was 3.3-3.5 cm. We then conducted experiments on diffuse light reflectance using NIRS on 14 volunteers. These measurements agree well with the simulation results. All the results demonstrated the great potential of non-invasive monitoring of pulmonary hemodynamics and contribute to the study of human lungs in the biomedical optics community.
Collapse
Affiliation(s)
- Jianghui Guo
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300192, China
- School of optoelectronic science and engineering, University of Electronic Science & Technology of China, Chengdu, 611731, China
| | - Shuo Meng
- Tiangong University, Tianjin, 300387, China
| | - Hengjie Su
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300192, China
| | - Bowen Zhang
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300192, China
| | - Ting Li
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300192, China
| |
Collapse
|
9
|
Ozana N, Lue N, Renna M, Robinson MB, Martin A, Zavriyev AI, Carr B, Mazumder D, Blackwell MH, Franceschini MA, Carp SA. Functional Time Domain Diffuse Correlation Spectroscopy. Front Neurosci 2022; 16:932119. [PMID: 35979338 PMCID: PMC9377452 DOI: 10.3389/fnins.2022.932119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/23/2022] [Indexed: 11/13/2022] Open
Abstract
Time-domain diffuse correlation spectroscopy (TD-DCS) offers a novel approach to high-spatial resolution functional brain imaging based on the direct quantification of cerebral blood flow (CBF) changes in response to neural activity. However, the signal-to-noise ratio (SNR) offered by previous TD-DCS instruments remains a challenge to achieving the high temporal resolution needed to resolve perfusion changes during functional measurements. Here we present a next-generation optimized functional TD-DCS system that combines a custom 1,064 nm pulse-shaped, quasi transform-limited, amplified laser source with a high-resolution time-tagging system and superconducting nanowire single-photon detectors (SNSPDs). System characterization and optimization was conducted on homogenous and two-layer intralipid phantoms before performing functional CBF measurements in six human subjects. By acquiring CBF signals at over 5 Hz for a late gate start time of the temporal point spread function (TPSF) at 15 mm source-detector separation, we demonstrate for the first time the measurement of blood flow responses to breath-holding and functional tasks using TD-DCS.
Collapse
Affiliation(s)
- Nisan Ozana
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States,*Correspondence: Nisan Ozana, ,
| | - Niyom Lue
- Massachusetts Institute of Technology Lincoln Laboratory, Lexington, MA, United States
| | - Marco Renna
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Mitchell B. Robinson
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States,Massachusetts Institute of Technology, Health Sciences and Technology Program, Cambridge, MA, United States
| | - Alyssa Martin
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Alexander I. Zavriyev
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Bryce Carr
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Dibbyan Mazumder
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Megan H. Blackwell
- Massachusetts Institute of Technology Lincoln Laboratory, Lexington, MA, United States
| | - Maria A. Franceschini
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Stefan A. Carp
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| |
Collapse
|
10
|
García HA, Vera DA, Waks Serra MV, Baez GR, Iriarte DI, Pomarico JA. Theoretical investigation of photon partial pathlengths in multilayered turbid media. BIOMEDICAL OPTICS EXPRESS 2022; 13:2516-2529. [PMID: 35519258 PMCID: PMC9045903 DOI: 10.1364/boe.449514] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 02/01/2022] [Accepted: 02/03/2022] [Indexed: 05/20/2023]
Abstract
Functional near infrared spectroscopy (fNIRS) is a valuable tool for assessing oxy- and deoxyhemoglobin concentration changes (Δ[HbO] and Δ[HbR], respectively) in the human brain. To this end, photon pathlengths in tissue are needed to convert from light attenuation to Δ[HbO] and Δ[HbR]. Current techniques describe the human head as a homogeneous medium, in which case these pathlengths are easily computed. However, the head is more appropriately described as a layered medium; hence, the partial pathlengths in each layer are required. The current way to do this is by means of Monte Carlo (MC) simulations, which are time-consuming and computationally expensive. In this work, we introduce an approach to theoretically calculate these partial pathlengths, which are computed several times faster than MC simulations. Comparison of our approach with MC simulations show very good agreement. Results also suggest that these analytical expressions give much more specific information about light absorption in each layer than in the homogeneous case.
Collapse
|
11
|
Fisher C, Harty J, Yee A, Li CL, Komolibus K, Grygoryev K, Lu H, Burke R, Wilson BC, Andersson-Engels S. Perspective on the integration of optical sensing into orthopedic surgical devices. JOURNAL OF BIOMEDICAL OPTICS 2022; 27:010601. [PMID: 34984863 PMCID: PMC8727454 DOI: 10.1117/1.jbo.27.1.010601] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 11/23/2021] [Indexed: 06/14/2023]
Abstract
SIGNIFICANCE Orthopedic surgery currently comprises over 1.5 million cases annually in the United States alone and is growing rapidly with aging populations. Emerging optical sensing techniques promise fewer side effects with new, more effective approaches aimed at improving patient outcomes following orthopedic surgery. AIM The aim of this perspective paper is to outline potential applications where fiberoptic-based approaches can complement ongoing development of minimally invasive surgical procedures for use in orthopedic applications. APPROACH Several procedures involving orthopedic and spinal surgery, along with the clinical challenge associated with each, are considered. The current and potential applications of optical sensing within these procedures are discussed and future opportunities, challenges, and competing technologies are presented for each surgical application. RESULTS Strong research efforts involving sensor miniaturization and integration of optics into existing surgical devices, including K-wires and cranial perforators, provided the impetus for this perspective analysis. These advances have made it possible to envision a next-generation set of devices that can be rigorously evaluated in controlled clinical trials to become routine tools for orthopedic surgery. CONCLUSIONS Integration of optical devices into surgical drills and burrs to discern bone/tissue interfaces could be used to reduce complication rates across a spectrum of orthopedic surgery procedures or to aid less-experienced surgeons in complex techniques, such as laminoplasty or osteotomy. These developments present both opportunities and challenges for the biomedical optics community.
Collapse
Affiliation(s)
- Carl Fisher
- Biophotonics@Tyndall, IPIC, Tyndall National Institute, Lee Maltings, Dyke Parade, Cork, Ireland
| | - James Harty
- Cork University Hospital and South Infirmary Victoria University Hospital, Department of Orthopaedic Surgery, Cork, Ireland
| | - Albert Yee
- University of Toronto, Sunnybrook Research Institute, Department of Surgery, Holland Bone and Joint Program, Division of Orthopaedic Surgery, Sunnybrook Health Sciences; Orthopaedic Biomechanics Laboratory, Physical Sciences Platform, Toronto, Canada
| | - Celina L. Li
- Biophotonics@Tyndall, IPIC, Tyndall National Institute, Lee Maltings, Dyke Parade, Cork, Ireland
| | - Katarzyna Komolibus
- Biophotonics@Tyndall, IPIC, Tyndall National Institute, Lee Maltings, Dyke Parade, Cork, Ireland
| | - Konstantin Grygoryev
- Biophotonics@Tyndall, IPIC, Tyndall National Institute, Lee Maltings, Dyke Parade, Cork, Ireland
| | - Huihui Lu
- Biophotonics@Tyndall, IPIC, Tyndall National Institute, Lee Maltings, Dyke Parade, Cork, Ireland
| | - Ray Burke
- Biophotonics@Tyndall, IPIC, Tyndall National Institute, Lee Maltings, Dyke Parade, Cork, Ireland
| | - Brian C. Wilson
- University of Toronto, Princess Margaret Cancer Centre/University Health Network, Department of Medical Biophysics, Toronto, Canada
| | - Stefan Andersson-Engels
- Biophotonics@Tyndall, IPIC, Tyndall National Institute, Lee Maltings, Dyke Parade, Cork, Ireland
- University College Cork, Department of Physics, Cork, Ireland
| |
Collapse
|
12
|
Liang Z. What Does Sleeping Brain Tell About Stress? A Pilot Functional Near-Infrared Spectroscopy Study Into Stress-Related Cortical Hemodynamic Features During Sleep. FRONTIERS IN COMPUTER SCIENCE 2021. [DOI: 10.3389/fcomp.2021.774949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
People with mental stress often experience disturbed sleep, suggesting stress-related abnormalities in brain activity during sleep. However, no study has looked at the physiological oscillations in brain hemodynamics during sleep in relation to stress. In this pilot study, we aimed to explore the relationships between bedtime stress and the hemodynamics in the prefrontal cortex during the first sleep cycle. We tracked the stress biomarkers, salivary cortisol, and secretory immunoglobulin A (sIgA) on a daily basis and utilized the days of lower levels of measured stress as natural controls to the days of higher levels of measured stress. Cortical hemodynamics was measured using a cutting-edge wearable functional near-infrared spectroscopy (fNIRS) system. Time-domain, frequency-domain features as well as nonlinear features were derived from the cleaned hemodynamic signals. We proposed an original ensemble algorithm to generate an average importance score for each feature based on the assessment of six statistical and machine learning techniques. With all channels counted in, the top five most referred feature types are Hurst exponent, mean, the ratio of the major/minor axis standard deviation of the Poincaré plot of the signal, statistical complexity, and crest factor. The left rostral prefrontal cortex (RLPFC) was the most relevant sub-region. Significantly strong correlations were found between the hemodynamic features derived at this sub-region and all three stress indicators. The dorsolateral prefrontal cortex (DLPFC) is also a relevant cortical area. The areas of mid-DLPFC and caudal-DLPFC both demonstrated significant and moderate association to all three stress indicators. No relevance was found in the ventrolateral prefrontal cortex. The preliminary results shed light on the possible role of the RLPCF, especially the left RLPCF, in processing stress during sleep. In addition, our findings echoed the previous stress studies conducted during wake time and provides supplementary evidence on the relevance of the dorsolateral prefrontal cortex in stress responses during sleep. This pilot study serves as a proof-of-concept for a new research paradigm to stress research and identified exciting opportunities for future studies.
Collapse
|
13
|
Forcione M, Chiarelli AM, Davies DJ, Perpetuini D, Sawosz P, Merla A, Belli A. Cerebral perfusion and blood-brain barrier assessment in brain trauma using contrast-enhanced near-infrared spectroscopy with indocyanine green: A review. J Cereb Blood Flow Metab 2020; 40:1586-1598. [PMID: 32345103 PMCID: PMC7370372 DOI: 10.1177/0271678x20921973] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Contrast-enhanced near-infrared spectroscopy (NIRS) with indocyanine green (ICG) can be a valid non-invasive, continuous, bedside neuromonitoring tool. However, its usage in moderate and severe traumatic brain injury (TBI) patients can be unprecise due to their clinical status. This review is targeted at researchers and clinicians involved in the development and application of contrast-enhanced NIRS for the care of TBI patients and can be used to design future studies. This review describes the methods developed to monitor the brain perfusion and the blood-brain barrier integrity using the changes of diffuse reflectance during the ICG passage and the results on studies in animals and humans. The limitations in accuracy of these methods when applied on TBI patients and the proposed solutions to overcome them are discussed. Finally, the analysis of relative parameters is proposed as a valid alternative over absolute values to address some current clinical needs in brain trauma care. In conclusion, care should be taken in the translation of the optical signal into absolute physiological parameters of TBI patients, as their clinical status must be taken into consideration. Discussion on where and how future studies should be directed to effectively incorporate contrast-enhanced NIRS into brain trauma care is given.
Collapse
Affiliation(s)
- Mario Forcione
- National Institute for Health Research Surgical Reconstruction and Microbiology Research Centre (NIHR-SRMRC), University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.,Neuroscience & Ophthalmology Research Group, Institute of Inflammation & Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Antonio M Chiarelli
- Department of Neuroscience Imaging and Clinical Science, Institute for Advanced Biomedical Technologies, University G. D'Annunzio of Chieti-Pescara, Chieti, Italy
| | - David J Davies
- National Institute for Health Research Surgical Reconstruction and Microbiology Research Centre (NIHR-SRMRC), University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.,Neuroscience & Ophthalmology Research Group, Institute of Inflammation & Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - David Perpetuini
- Department of Neuroscience Imaging and Clinical Science, Institute for Advanced Biomedical Technologies, University G. D'Annunzio of Chieti-Pescara, Chieti, Italy
| | - Piotr Sawosz
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Arcangelo Merla
- Department of Neuroscience Imaging and Clinical Science, Institute for Advanced Biomedical Technologies, University G. D'Annunzio of Chieti-Pescara, Chieti, Italy
| | - Antonio Belli
- National Institute for Health Research Surgical Reconstruction and Microbiology Research Centre (NIHR-SRMRC), University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.,Neuroscience & Ophthalmology Research Group, Institute of Inflammation & Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| |
Collapse
|
14
|
Wabnitz H, Contini D, Spinelli L, Torricelli A, Liebert A. Depth-selective data analysis for time-domain fNIRS: moments vs. time windows. BIOMEDICAL OPTICS EXPRESS 2020; 11:4224-4243. [PMID: 32923038 PMCID: PMC7449728 DOI: 10.1364/boe.396585] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/20/2020] [Accepted: 06/22/2020] [Indexed: 05/10/2023]
Abstract
Time-domain measurements facilitate the elimination of the influence of extracerebral, systemic effects, a key problem in functional near-infrared spectroscopy (fNIRS) of the adult human brain. The analysis of measured time-of-flight distributions of photons often relies on moments or time windows. However, a systematic and quantitative characterization of the performance of these measurands is still lacking. Based on perturbation simulations for small localized absorption changes, we compared spatial sensitivity profiles and depth selectivity for moments (integral, mean time of flight and variance), photon counts in time windows and their ratios for different time windows. The influence of the instrument response function (IRF) was investigated for all measurands and for various source-detector separations. Variance exhibits the highest depth selectivity among the moments. Ratios of photon counts in different late time windows can achieve even higher selectivity. An advantage of moments is their robustness against the shape of the IRF and instrumental drifts.
Collapse
Affiliation(s)
- Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Alessandro Torricelli
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Adam Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Trojdena 4, 02-109 Warsaw, Poland
| |
Collapse
|
15
|
Sudakou A, Yang L, Wabnitz H, Wojtkiewicz S, Liebert A. Performance of measurands in time-domain optical brain imaging: depth selectivity versus contrast-to-noise ratio. BIOMEDICAL OPTICS EXPRESS 2020; 11:4348-4365. [PMID: 32923048 PMCID: PMC7449735 DOI: 10.1364/boe.397483] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 07/03/2020] [Accepted: 07/03/2020] [Indexed: 05/25/2023]
Abstract
Time-domain optical brain imaging techniques introduce a number of different measurands for analyzing absorption changes located deep in the tissue, complicated by superficial absorption changes and noise. We implement a method that allows analysis, quantitative comparison and performance ranking of measurands under various conditions - including different values of reduced scattering coefficient, thickness of the superficial layer, and source-detector separation. Liquid phantom measurements and Monte Carlo simulations were carried out in two-layered geometry to acquire distributions of times of flight of photons and to calculate the total photon count, mean time of flight, variance, photon counts in time windows and ratios of photon counts in different time windows. Quantitative comparison of performance was based on objective metrics: relative contrast, contrast-to-noise ratio (CNR) and depth selectivity. Moreover, the product of CNR and depth selectivity was used to rank the overall performance and to determine the optimal source-detector separation for each measurand. Variance ranks the highest under all considered conditions.
Collapse
Affiliation(s)
- Aleh Sudakou
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Trojdena 4, 02-109 Warsaw, Poland
| | - Lin Yang
- Physikalisch-Technische Bundesanstalt, Abbestraße 2-12, 10587 Berlin, Germany
| | - Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt, Abbestraße 2-12, 10587 Berlin, Germany
| | - Stanislaw Wojtkiewicz
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Trojdena 4, 02-109 Warsaw, Poland
| | - Adam Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Trojdena 4, 02-109 Warsaw, Poland
| |
Collapse
|
16
|
Real-Time Dual-Wavelength Time-Resolved Diffuse Optical Tomography System for Functional Brain Imaging Based on Probe-Hosted Silicon Photomultipliers. SENSORS 2020; 20:s20102815. [PMID: 32429158 PMCID: PMC7287927 DOI: 10.3390/s20102815] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 01/12/2023]
Abstract
Near-infrared diffuse optical tomography is a non-invasive photonics-based imaging technology suited to functional brain imaging applications. Recent developments have proved that it is possible to build a compact time-domain diffuse optical tomography system based on silicon photomultipliers (SiPM) detectors. The system presented in this paper was equipped with the same eight SiPM probe-hosted detectors, but was upgraded with six injection fibers to shine the sample at several points. Moreover, an automatic switch was included enabling a complete measurement to be performed in less than one second. Further, the system was provided with a dual-wavelength (670 nm and 820 nm) light source to quantify the oxy- and deoxy-hemoglobin concentration evolution in the tissue. This novel system was challenged against a solid phantom experiment, and two in-vivo tests, namely arm occlusion and motor cortex brain activation. The results show that the tomographic system makes it possible to follow the evolution of brain activation over time with a 1s-resolution.
Collapse
|
17
|
Time-Gated Single-Photon Detection in Time-Domain Diffuse Optics: A Review. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10031101] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This work reviews physical concepts, technologies and applications of time-domain diffuse optics based on time-gated single-photon detection. This particular photon detection strategy is of the utmost importance in the diffuse optics field as it unleashes the full power of the time-domain approach by maximizing performances in terms of contrast produced by a localized perturbation inside the scattering medium, signal-to-noise ratio, measurement time and dynamic range, penetration depth and spatial resolution. The review covers 15 years of theoretical studies, technological progresses, proof of concepts and design of laboratory systems based on time-gated single-photon detection with also few hints on other fields where the time-gated detection strategy produced and will produce further impact.
Collapse
|
18
|
Xie D, Guo W. Measurement and Calculation Methods on Absorption and Scattering Properties of Turbid Food in Vis/NIR Range. FOOD BIOPROCESS TECH 2020. [DOI: 10.1007/s11947-020-02402-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
19
|
Gerega A, Wojtkiewicz S, Sawosz P, Kacprzak M, Toczylowska B, Bejm K, Skibniewski F, Sobotnicki A, Gacek A, Maniewski R, Liebert A. Assessment of the brain ischemia during orthostatic stress and lower body negative pressure in air force pilots by near-infrared spectroscopy. BIOMEDICAL OPTICS EXPRESS 2020; 11:1043-1060. [PMID: 32133236 PMCID: PMC7041453 DOI: 10.1364/boe.377779] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 05/26/2023]
Abstract
A methodology for the assessment of the cerebral hemodynamic reaction to normotensive hypovolemia, reduction in cerebral perfusion and orthostatic stress leading to ischemic hypoxia and reduced muscular tension is presented. Most frequently, the pilots of highly maneuverable aircraft are exposed to these phenomena. Studies were carried out using the system consisting of a chamber that generates low pressure around the lower part of the body - LBNP (lower body negative pressure) placed on the tilt table. An in-house developed 6-channel NIRS system operating at 735 and 850 nm was used in order to assess the oxygenation of the cerebral cortex, based on measurements of diffusely reflected light in reflectance geometry. The measurements were carried out on a group of 12 active pilots and cadets of the Polish Air Force Academy and 12 healthy volunteers. The dynamics of changes in cerebral oxygenation was evaluated as a response to LBNP stimuli with a simultaneous rapid change of the tilt table angle. Parameters based on calculated changes of total hemoglobin concentration were proposed allowing to evaluate differences in reactions observed in control subjects and pilots/cadets. The results of orthogonal partial least squares-discriminant analysis based on these parameters show that the subjects can be classified into their groups with 100% accuracy.
Collapse
Affiliation(s)
- Anna Gerega
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Stanislaw Wojtkiewicz
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Piotr Sawosz
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Michal Kacprzak
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Beata Toczylowska
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Karolina Bejm
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Franciszek Skibniewski
- Technical Department of Aeromedical Research and Flight Simulators, Military Institute of Aviation Medicine, Warsaw, Poland
| | - Aleksander Sobotnicki
- Department of Research and Development, Institute of Medical Technology and Equipment, Zabrze, Poland
| | - Adam Gacek
- Department of Research and Development, Institute of Medical Technology and Equipment, Zabrze, Poland
| | - Roman Maniewski
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Adam Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| |
Collapse
|
20
|
Fantini S, Blaney G, Sassaroli A. Transformational change in the field of diffuse optics: From going bananas to going nuts. JOURNAL OF INNOVATIVE OPTICAL HEALTH SCIENCES 2020; 13:1930013. [PMID: 36340430 PMCID: PMC9632641 DOI: 10.1142/s1793545819300131] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The concept of region of sensitivity is central to the field of diffuse optics and is closely related to the Jacobian matrix used to solve the inverse problem in imaging. It is well-known that, in diffuse reflectance, the region of sensitivity associated with a given source-detector pair is shaped as a banana, and features maximal sensitivity to the portions of the sample that are closest to the source and the detector. We have recently introduced a dual-slope method based on a special arrangement of two sources and two detectors, which results in deeper and more localized regions of sensitivity, resembling the shapes of different kinds of nuts. Here, we report the regions of sensitivity associated with a variety of source-detector arrangements for dual-slope measurements of intensity and phase with frequency-domain spectroscopy (modulation frequency: 140 MHz) in a medium with absorption and reduced scattering coefficients of 0.1 cm-1 and 12 cm-1, respectively. The main result is that the depth of maximum sensitivity, considering only cases that use source-detector separations of 25 and 35 mm, progressively increases as we consider single-distance intensity (2.0 mm), dual-slope intensity (4.6 mm), single-distance phase (7.5 mm), and dual-slope phase (10.9 mm). These results indicate the importance of dual-slope measurements, and even more so of phase measurements, when it is desirable to selectively probe deeper portions of a sample with diffuse optics. This is certainly the case in non-invasive optical studies of brain, muscle, and breast tissue, which are located underneath superficial tissue at variable depths.
Collapse
Affiliation(s)
- Sergio Fantini
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA
| | - Giles Blaney
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA
| | - Angelo Sassaroli
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA
| |
Collapse
|
21
|
Liu W, Chen W, Fang X, Li Y, Li T. Monte Carlo modeling of photon migration in realistic human thoracic tissues for noninvasive monitoring of cardiac hemodynamics. JOURNAL OF BIOPHOTONICS 2019; 12:e201900148. [PMID: 31251454 DOI: 10.1002/jbio.201900148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Revised: 06/23/2019] [Accepted: 06/27/2019] [Indexed: 06/09/2023]
Abstract
Noninvasive monitoring of cardiac hemodynamics remains challenging in cardiovascular medicine. The possibility of noninvasive optical monitoring of cardiac hemodynamics was theoretically investigated in this study. By utilizing the Monte Carlo simulation method for voxelized media (MCVM) and Visible Chinese Human dataset, we quantified and visualized the photon migration in human thoracic region. The light fluence distribution was showed to reach heart tissue (∼3 cm depth underbody surface) and 12% of the total fluence was absorbed by the myocardium. The proportion of spatial sensitivity distribution (SSD) in cardiac tissue to the total SSD reached 0.0195%. The portion of SSD increased following with cardiac diastole and diffuse reflectance deceased linearly with increasing cardiac volume. The optimal separation between the light source and detector was provided to be 3.5 to 4.0 cm for future development of noninvasive cardiac hemodynamics monitoring. A pilot experimental study was conducted to measure the diffuse reflectance light and fingertip photoplethysmography. These data suggest that the fluctuation period of near-infrared (NIR) diffuse reflectance was consistent with the cardiac cycle, while the fluctuation features of the NIR signal was not consistent with that of photoplethysmography. All results indicate the great potential of noninvasive optical monitoring of myocardial hemodynamics.
Collapse
Affiliation(s)
- Weichao Liu
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | | | - Xiang Fang
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Yingxin Li
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Ting Li
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| |
Collapse
|
22
|
Sawosz P, Liebert A. Method to improve the depth sensitivity of diffuse reflectance measurements to absorption changes in optically turbid medium. BIOMEDICAL OPTICS EXPRESS 2019; 10:5031-5041. [PMID: 31646028 PMCID: PMC6788621 DOI: 10.1364/boe.10.005031] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/30/2019] [Accepted: 08/30/2019] [Indexed: 05/24/2023]
Abstract
We have studied the spatial distributions of the sensitivity of time-resolved near-infrared diffuse reflectance measurement. Sensitivity factors representing a change of parameters of a measured optical signal induced by absorption perturbation in a certain voxel of the medium were simulated using the diffusion equation solution. The parameters were statistical moments of measured distributions of time of flight of photons (DTOFs) i.e., the total number of photons, mean time of flight and variance. The distributions of the sensitivity of statistical moments of DTOFs to a change in absorption were generated for various source-detector separations and various optical properties of the medium. Furthermore, differential sensitivity distributions for two different source-detector separations were calculated. A measurement geometry, in which two detection spots, separated by 5 mm, in combination with two sources was proposed. For this setup differences between the signals obtained for both detectors were calculated independently for both sources and afterward summed up for both source positions. Obtained differences in moments of DTOFs assessed at two source-detector separations and summed up for different positioning of the sources allowed to shape up the sensitivity profiles. Calculated sensitivity profiles show that positive sensitivities of the mean time of flight of photons and variance of the DTOF can be obtained. These positive sensitivity areas are located just between both detection spots and cover the compartment located deeply in the medium. The sensitivity in superficial compartments of the medium is negative and much smaller in amplitude. The proposed technique can be used for improved discrimination of optical signals related to the intracerebral change in absorption which remains a serious obstacle in the application of the NIRS technique in the assessment of brain oxygenation or perfusion.
Collapse
Affiliation(s)
- Piotr Sawosz
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Trojdena 4, 02-109 Warsaw, Poland
| | - Adam Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Trojdena 4, 02-109 Warsaw, Poland
| |
Collapse
|
23
|
Grosenick D, Wabnitz H, Macdonald R. Diffuse near-infrared imaging of tissue with picosecond time resolution. ACTA ACUST UNITED AC 2019; 63:511-518. [PMID: 29494335 DOI: 10.1515/bmt-2017-0067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 12/04/2017] [Indexed: 02/02/2023]
Abstract
Optical imaging of biological tissue in vivo at multiple wavelengths in the near-infrared (NIR) spectral range can be achieved with picosecond time resolution at high sensitivity by time-correlated single photon counting. Measuring and analyzing the distribution of times of flight of photons randomly propagated through the tissue has been applied for diffuse optical imaging and spectroscopy, e.g. of human breast tissue and of the brain. In this article, we review the main features and the potential of NIR multispectral imaging with picosecond time resolution and illustrate them by exemplar applications in these fields. In particular, we discuss the experimental methods developed at the Physikalisch-Technische Bundesanstalt (PTB) to record optical mammograms and to quantify the absorption and scattering properties from which hemoglobin concentration and oxygen saturation of healthy and diseased breast tissue have been derived by combining picosecond time-domain and spectral information. Furthermore, optical images of functional brain activation were obtained by a non-contact scanning device exploiting the null source-detector separation approach which takes advantage of the picosecond time resolution as well. The recorded time traces of changes in the oxy- and deoxyhemoglobin concentrations during a motor stimulation investigation show a localized response from the brain.
Collapse
Affiliation(s)
- Dirk Grosenick
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany, Phone: +49 30 3481-7302, Fax: +49 30 3481-7505
| | - Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), 10587 Berlin, Germany
| | - Rainer Macdonald
- Physikalisch-Technische Bundesanstalt (PTB), 10587 Berlin, Germany
| |
Collapse
|
24
|
Mahmoodkalayeh S, Ansari MA, Tuchin VV. Head model based on the shape of the subject's head for optical brain imaging. BIOMEDICAL OPTICS EXPRESS 2019; 10:2795-2808. [PMID: 31259052 PMCID: PMC6583357 DOI: 10.1364/boe.10.002795] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/24/2019] [Accepted: 05/09/2019] [Indexed: 05/05/2023]
Abstract
Optical imaging methods such as near-infrared spectroscopy and diffuse optical tomography rely on models to solve the inverse problem. Imaging an adult human head also requires a head model. Using a model, which makes describing the structure of the head better, leads to acquiring a more accurate absorption map. Here, by combining the key features of layered slab models and head atlases, we introduce a new two-layered head model that is based on the surface geometry of the subject's head with variable thickness of the superficial layer. Using the Monte Carlo approach, we assess the performance of our model for fitting the optical properties from simulated time-resolved data of the adult head in a null distance source-detector configuration. Using our model, we observed improved results at 70 percent of the locations on the head and an overall 20 percent reduction in relative error compared to layered slab model.
Collapse
Affiliation(s)
- Sadreddin Mahmoodkalayeh
- Department of Physics, Shahid Beheshti University, Velenjak, Tehran, Iran
- Laser and Plasma Research Institute, Shahid Beheshti University, 1983969411, Tehran, Iran
| | - Mohammad Ali Ansari
- Laser and Plasma Research Institute, Shahid Beheshti University, 1983969411, Tehran, Iran
| | - Valery V. Tuchin
- Research-Educational Institute of Optics and Biophotonics, Saratov State University, Saratov, Russia
- Interdisciplinary Laboratory of Biophotonics, Tomsk State University, Tomsk, Russia
- Laboratory of Laser Diagnostics of Technical and Living Systems, Institute of Precision Mechanics and Control of the Russian Academy of Sciences, Saratov, Russia
| |
Collapse
|
25
|
Abstract
This article reviews the past and current statuses of time-domain near-infrared spectroscopy (TD-NIRS) and imaging. Although time-domain technology is not yet widely employed due to its drawbacks of being cumbersome, bulky, and very expensive compared to commercial continuous wave (CW) and frequency-domain (FD) fNIRS systems, TD-NIRS has great advantages over CW and FD systems because time-resolved data measured by TD systems contain the richest information about optical properties inside measured objects. This article focuses on reviewing the theoretical background, advanced theories and methods, instruments, and studies on clinical applications for TD-NIRS including some clinical studies which used TD-NIRS systems. Major events in the development of TD-NIRS and imaging are identified and summarized in chronological tables and figures. Finally, prospects for TD-NIRS in the near future are briefly described.
Collapse
|
26
|
Kacprzak M, Sawosz P, Weigl W, Milej D, Gerega A, Liebert A. Frequency analysis of oscillations in cerebral hemodynamics measured by time domain near infrared spectroscopy. BIOMEDICAL OPTICS EXPRESS 2019; 10:761-771. [PMID: 30800513 PMCID: PMC6377883 DOI: 10.1364/boe.10.000761] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/23/2018] [Accepted: 12/23/2018] [Indexed: 05/21/2023]
Abstract
In this paper, we propose the application of time-domain near-infrared spectroscopy to the assessment of oscillations in cerebral hemodynamics. These oscillations were observed in the statistical moments of the distributions of time of flight of photons (DTOFs) measured on the head. We analyzed the zeroth and second centralized moments of DTOFs (total number of photons and variance) to obtain their spectra to provide parameters for the frequency components of microcirculation, which differ between the extracerebral and intracerebral layers of the head. Analysis of these moments revealed statistically significant differences between a control group of healthy subjects and a group of patients with severe neurovascular disorders, which is a promising result for the assessment of cerebral microcirculation and cerebral autoregulation mechanisms.
Collapse
Affiliation(s)
- Michal Kacprzak
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences Trojdena 4, 02-109 Warsaw, Poland
| | - Piotr Sawosz
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences Trojdena 4, 02-109 Warsaw, Poland
| | - Wojciech Weigl
- Anesthesiology and Intensive Care, Department of Surgical Sciences, Uppsala University, Akademiska Hospital, 751 85 Uppsala, Sweden
| | - Daniel Milej
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences Trojdena 4, 02-109 Warsaw, Poland
- Department of Medical Biophysics, Western University, London, Ontario N6A 5C1, Canada
- Imaging Division, Lawson Health Research Institute, London, Ontario N6A 4V2, Canada
| | - Anna Gerega
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences Trojdena 4, 02-109 Warsaw, Poland
| | - Adam Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences Trojdena 4, 02-109 Warsaw, Poland
| |
Collapse
|
27
|
Gerega A, Milej D, Weigl W, Kacprzak M, Liebert A. Multiwavelength time-resolved near-infrared spectroscopy of the adult head: assessment of intracerebral and extracerebral absorption changes. BIOMEDICAL OPTICS EXPRESS 2018; 9:2974-2993. [PMID: 29984079 PMCID: PMC6033559 DOI: 10.1364/boe.9.002974] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 04/27/2018] [Accepted: 05/17/2018] [Indexed: 05/23/2023]
Abstract
An optical technique based on diffuse reflectance measurement combined with indocyanine green (ICG) bolus tracking is extensively tested as a method for the clinical assessment of brain perfusion at the bedside. We report on multiwavelength time-resolved diffuse reflectance spectroscopy measurements carried out on the head of a healthy adult during the intravenous administration of a bolus of ICG. Intracerebral and extracerebral changes in absorption were estimated from an analysis of changes in statistical moments (total number of photons, mean time of flight and variance) of the distributions of times of flight (DTOF) of photons recorded simultaneously at 16 wavelengths from the range of 650-850 nm using sensitivity factors estimated by diffusion approximation based on a layered model of the studied medium. We validated the proposed method in a series of phantom experiments and in-vivo measurements. The results obtained show that changes in the concentration of the ICG can be assessed as a function of time of the experiment and depth in the tissue. Thus, the separation of changes in ICG concentration appearing in intra- and extracerebral tissues can be estimated from optical data acquired at a single source-detector pair of fibers/fiber bundles positioned on the surface of the head.
Collapse
Affiliation(s)
- Anna Gerega
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences Trojdena 4, 02-109 Warsaw, Poland
| | - Daniel Milej
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences Trojdena 4, 02-109 Warsaw, Poland
- Department of Medical Biophysics, Western University, London, Ontario N6A 5C1, Canada
- Imaging Division, Lawson Health Research Institute, London, Ontario N6A 4V2, Canada
| | - Wojciech Weigl
- Anesthesiology and Intensive Care, Department of Surgical Sciences, Uppsala University, Akademiska Hospital, 751 85 Uppsala, Sweden
| | - Michal Kacprzak
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences Trojdena 4, 02-109 Warsaw, Poland
| | - Adam Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences Trojdena 4, 02-109 Warsaw, Poland
| |
Collapse
|
28
|
Pagliazzi M, Sekar SKV, Colombo L, Martinenghi E, Minnema J, Erdmann R, Contini D, Mora AD, Torricelli A, Pifferi A, Durduran T. Time domain diffuse correlation spectroscopy with a high coherence pulsed source: in vivo and phantom results. BIOMEDICAL OPTICS EXPRESS 2017; 8:5311-5325. [PMID: 29188122 PMCID: PMC5695972 DOI: 10.1364/boe.8.005311] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 10/12/2017] [Accepted: 10/24/2017] [Indexed: 05/18/2023]
Abstract
Diffuse correlation spectroscopy (DCS), combined with time-resolved reflectance spectroscopy (TRS) or frequency domain spectroscopy, aims at path length (i.e. depth) resolved, non-invasive and simultaneous assessment of tissue composition and blood flow. However, while TRS provides a path length resolved data, the standard DCS does not. Recently, a time domain DCS experiment showed path length resolved measurements for improved quantification with respect to classical DCS, but was limited to phantoms and small animal studies. Here, we demonstrate time domain DCS for in vivo studies on the adult forehead and the arm. We achieve path length resolved DCS by means of an actively mode-locked Ti:Sapphire laser that allows high coherence pulses, thus enabling adequate signal-to-noise ratio in relatively fast (~1 s) temporal resolution. This work paves the way to the translation of this approach to practical in vivo use.
Collapse
Affiliation(s)
- M. Pagliazzi
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | | | - L. Colombo
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
| | - E. Martinenghi
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
| | - J. Minnema
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | | | - D. Contini
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
| | - A. Dalla Mora
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
| | - A. Torricelli
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, 20133 Milano, Italy
| | - A. Pifferi
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, 20133 Milano, Italy
| | - T. Durduran
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08015 Barcelona, Spain
| |
Collapse
|
29
|
Di Sieno L, Nissinen J, Hallman L, Martinenghi E, Contini D, Pifferi A, Kostamovaara J, Mora AD. Miniaturized pulsed laser source for time-domain diffuse optics routes to wearable devices. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-9. [PMID: 28823112 DOI: 10.1117/1.jbo.22.8.085004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 07/27/2017] [Indexed: 05/23/2023]
Abstract
We validate a miniaturized pulsed laser source for use in time-domain (TD) diffuse optics, following rigorous and shared protocols for performance assessment of this class of devices. This compact source (12×6 mm2) has been previously developed for range finding applications and is able to provide short, high energy (∼100 ps, ∼0.5 nJ) optical pulses at up to 1 MHz repetition rate. Here, we start with a basic level laser characterization with an analysis of suitability of this laser for the diffuse optics application. Then, we present a TD optical system using this source and its performances in both recovering optical properties of tissue-mimicking homogeneous phantoms and in detecting localized absorption perturbations. Finally, as a proof of concept of in vivo application, we demonstrate that the system is able to detect hemodynamic changes occurring in the arm of healthy volunteers during a venous occlusion. Squeezing the laser source in a small footprint removes a key technological bottleneck that has hampered so far the realization of a miniaturized TD diffuse optics system, able to compete with already assessed continuous-wave devices in terms of size and cost, but with wider performance potentialities, as demonstrated by research over the last two decades.
Collapse
Affiliation(s)
- Laura Di Sieno
- Politecnico di Milano, Dipartimento di Fisica, Milan, Italy
| | - Jan Nissinen
- University of Oulu, Circuits and Systems Research Unit, Oulu, Finland
| | - Lauri Hallman
- University of Oulu, Circuits and Systems Research Unit, Oulu, Finland
| | | | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, Milan, Italy
| | - Antonio Pifferi
- Politecnico di Milano, Dipartimento di Fisica, Milan, Italy
- Consiglio Nazionale delle Ricerche, Istituto di Fotonica e Nanotecnologie, Milano, Italy
| | - Juha Kostamovaara
- University of Oulu, Circuits and Systems Research Unit, Oulu, Finland
| | | |
Collapse
|
30
|
Carbone NA, Iriarte DI, Pomarico JA. GPU accelerated Monte Carlo simulation of light propagation in inhomogeneous fluorescent turbid media: application to whole field CW imaging. Biomed Phys Eng Express 2017. [DOI: 10.1088/2057-1976/aa7b8f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
31
|
Sawosz P, Wojtkiewicz S, Kacprzak M, Weigl W, Borowska-Solonynko A, Krajewski P, Bejm K, Milej D, Ciszek B, Maniewski R, Liebert A. Human skull translucency: post mortem studies. BIOMEDICAL OPTICS EXPRESS 2016; 7:5010-5020. [PMID: 28018721 PMCID: PMC5175548 DOI: 10.1364/boe.7.005010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 10/27/2016] [Accepted: 10/28/2016] [Indexed: 05/10/2023]
Abstract
Measurements of optical translucency of human skulls were carried out. An incandescent light source and a CCD camera were used to measure the distribution of light transmitted through the skull in 10 subjects post-mortem. We noticed that intra-individual differences in optical translucency may be up to 100 times but inter-individual translucency differences across the skull reach 105 times. Based on the measurement results, a "theoretical" experiment was simulated. Monte-Carlo calculations were used in order to evaluate the influence of the differences in optical translucency of the skull on results of NIRS measurements. In these calculations a functional stimulation was done, in which the oxyhemoglobin and deoxyhemoglobin concentrations in the brain cortex change by 5μM and -5μM respectively. The maximal discrepancies between assumed hemoglobin concentration changes and hemoglobin concentration changes estimated with Monte-Carlo simulation may reach 50% depending of the translucency of the skull.
Collapse
Affiliation(s)
- P Sawosz
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - S Wojtkiewicz
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - M Kacprzak
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - W Weigl
- Department of Surgical Sciences/Anaesthesiology and Intensive Care, Uppsala University, Akademiska Hospital, Uppsala, Sweden
| | | | - P Krajewski
- Forensic Medicine Department, Medical University of Warsaw, Warsaw, Poland
| | - K Bejm
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - D Milej
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - B Ciszek
- Department of Descriptive and Clinical Anatomy, Medical University of Warsaw, Warsaw, Poland
| | - R Maniewski
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - A Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| |
Collapse
|
32
|
Martelli F, Binzoni T, Sekar SKV, Farina A, Cavalieri S, Pifferi A. Time-domain Raman analytical forward solvers. OPTICS EXPRESS 2016; 24:20382-20399. [PMID: 27607645 DOI: 10.1364/oe.24.020382] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A set of time-domain analytical forward solvers for Raman signals detected from homogeneous diffusive media is presented. The time-domain solvers have been developed for two geometries: the parallelepiped and the finite cylinder. The potential presence of a background fluorescence emission, contaminating the Raman signal, has also been taken into account. All the solvers have been obtained as solutions of the time dependent diffusion equation. The validation of the solvers has been performed by means of comparisons with the results of "gold standard" Monte Carlo simulations. These forward solvers provide an accurate tool to explore the information content encoded in the time-resolved Raman measurements.
Collapse
|
33
|
Pifferi A, Contini D, Mora AD, Farina A, Spinelli L, Torricelli A. New frontiers in time-domain diffuse optics, a review. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:091310. [PMID: 27311627 DOI: 10.1117/1.jbo.21.9.091310] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 05/24/2016] [Indexed: 05/20/2023]
Abstract
The recent developments in time-domain diffuse optics that rely on physical concepts (e.g., time-gating and null distance) and advanced photonic components (e.g., vertical cavity source-emitting laser as light sources, single photon avalanche diode, and silicon photomultipliers as detectors, fast-gating circuits, and time-to-digital converters for acquisition) are focused. This study shows how these tools could lead on one hand to compact and wearable time-domain devices for point-of-care diagnostics down to the consumer level and on the other hand to powerful systems with exceptional depth penetration and sensitivity.
Collapse
Affiliation(s)
- Antonio Pifferi
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milan I-20133, ItalybIstituto di Fotonica e Nanotecnologie, Consiglio Nazionale per le Ricerche, Piazza Leonardo da Vinci 32, Milan I-20133, Italy
| | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milan I-20133, Italy
| | - Alberto Dalla Mora
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milan I-20133, Italy
| | - Andrea Farina
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale per le Ricerche, Piazza Leonardo da Vinci 32, Milan I-20133, Italy
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale per le Ricerche, Piazza Leonardo da Vinci 32, Milan I-20133, Italy
| | - Alessandro Torricelli
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, Milan I-20133, ItalybIstituto di Fotonica e Nanotecnologie, Consiglio Nazionale per le Ricerche, Piazza Leonardo da Vinci 32, Milan I-20133, Italy
| |
Collapse
|
34
|
Hoshi Y, Yamada Y. Overview of diffuse optical tomography and its clinical applications. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:091312. [PMID: 27420810 DOI: 10.1117/1.jbo.21.9.091312] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 06/13/2016] [Indexed: 05/23/2023]
Abstract
Near-infrared diffuse optical tomography (DOT), one of the most sophisticated optical imaging techniques for observations through biological tissue, allows 3-D quantitative imaging of optical properties, which include functional and anatomical information. With DOT, it is expected to be possible to overcome the limitations of conventional near-infrared spectroscopy (NIRS) as well as offering the potential for diagnostic optical imaging. However, DOT has been under development for more than 30 years, and the difficulties in development are attributed to the fact that light is strongly scattered and that diffusive photons are used for the image reconstruction. The DOT algorithm is based on the techniques of inverse problems. The radiative transfer equation accurately describes photon propagation in biological tissue, while, because of its high computation load, the diffusion equation (DE) is often used as the forward model. However, the DE is invalid in low-scattering and/or highly absorbing regions and in the vicinity of light sources. The inverse problem is inherently ill-posed and highly undetermined. Here, we first summarize NIRS and then describe various approaches in the efforts to develop accurate and efficient DOT algorithms and present some examples of clinical applications. Finally, we discuss the future prospects of DOT.
Collapse
Affiliation(s)
- Yoko Hoshi
- Hamamatsu University School of Medicine, Department of Biomedical Optics, Institute for Medical Photonics Research, Preeminent Medical Photonics Education and Research Center, 1-20-1 Handayama, Higashi-ku, Hamamatsu 431-3192, Japan
| | - Yukio Yamada
- University of Electro-Communications, Brain Science Inspired Life Support Research Center, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan
| |
Collapse
|
35
|
Bhatt M, Ayyalasomayajula KR, Yalavarthy PK. Generalized Beer-Lambert model for near-infrared light propagation in thick biological tissues. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:76012. [PMID: 27436050 DOI: 10.1117/1.jbo.21.7.076012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 06/20/2016] [Indexed: 05/08/2023]
Abstract
The attenuation of near-infrared (NIR) light intensity as it propagates in a turbid medium like biological tissue is described by modified the Beer–Lambert law (MBLL). The MBLL is generally used to quantify the changes in tissue chromophore concentrations for NIR spectroscopic data analysis. Even though MBLL is effective in terms of providing qualitative comparison, it suffers from its applicability across tissue types and tissue dimensions. In this work, we introduce Lambert-W function-based modeling for light propagation in biological tissues, which is a generalized version of the Beer–Lambert model. The proposed modeling provides parametrization of tissue properties, which includes two attenuation coefficients μ0 and η. We validated our model against the Monte Carlo simulation, which is the gold standard for modeling NIR light propagation in biological tissue. We included numerous human and animal tissues to validate the proposed empirical model, including an inhomogeneous adult human head model. The proposed model, which has a closed form (analytical), is first of its kind in providing accurate modeling of NIR light propagation in biological tissues.
Collapse
Affiliation(s)
- Manish Bhatt
- Indian Institute of Science, Medical Imaging Group, Department of Computational and Data Sciences, C V Raman Avenue, Bengaluru 560012, India
| | | | - Phaneendra K Yalavarthy
- Indian Institute of Science, Medical Imaging Group, Department of Computational and Data Sciences, C V Raman Avenue, Bengaluru 560012, India
| |
Collapse
|
36
|
There's plenty of light at the bottom: statistics of photon penetration depth in random media. Sci Rep 2016; 6:27057. [PMID: 27256988 PMCID: PMC4891734 DOI: 10.1038/srep27057] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 05/03/2016] [Indexed: 12/15/2022] Open
Abstract
We propose a comprehensive statistical approach describing the penetration depth of light in random media. The presented theory exploits the concept of probability density function f(z|ρ, t) for the maximum depth reached by the photons that are eventually re-emitted from the surface of the medium at distance ρ and time t. Analytical formulas for f, for the mean maximum depth 〈zmax〉 and for the mean average depth reached by the detected photons at the surface of a diffusive slab are derived within the framework of the diffusion approximation to the radiative transfer equation, both in the time domain and the continuous wave domain. Validation of the theory by means of comparisons with Monte Carlo simulations is also presented. The results are of interest for many research fields such as biomedical optics, advanced microscopy and disordered photonics.
Collapse
|
37
|
Abstract
Near-infrared spectroscopy (NIRS) was originally designed for clinical monitoring of tissue oxygenation, and it has also been developed into a useful tool in neuroimaging studies, with the so-called functional NIRS (fNIRS). With NIRS, cerebral activation is detected by measuring the cerebral hemoglobin (Hb), where however, the precise correlation between NIRS signal and neural activity remains to be fully understood. This can in part be attributed to the situation that NIRS signals are inherently subject to contamination by signals arising from extracerebral tissue. In recent years, several approaches have been investigated to distinguish between NIRS signals originating in cerebral tissue and signals originating in extracerebral tissue. Selective measurements of cerebral Hb will enable a further evolution of fNIRS. This chapter is divided into six sections: first a summary of the basic theory of NIRS, NIRS signals arising in the activated areas, correlations between NIRS signals and fMRI signals, correlations between NIRS signals and neural activities, and the influence of a variety of extracerebral tissue on NIRS signals and approaches to this issue are reviewed. Finally, future prospects of fNIRS are described.
Collapse
Affiliation(s)
- Y Hoshi
- Institute for Medical Photonics Research, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan.
| |
Collapse
|
38
|
Re R, Contini D, Zucchelli L, Torricelli A, Spinelli L. Effect of a thin superficial layer on the estimate of hemodynamic changes in a two-layer medium by time domain NIRS. BIOMEDICAL OPTICS EXPRESS 2016; 7:264-78. [PMID: 26977338 PMCID: PMC4771447 DOI: 10.1364/boe.7.000264] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 12/16/2015] [Accepted: 12/16/2015] [Indexed: 05/09/2023]
Abstract
In order to study hemodynamic changes involved in muscular metabolism by means of time domain fNIRS, we need to discriminate in the measured signal contributions coming from different depths. Muscles are, in fact, typically located under other tissues, e.g. skin and fat. In this paper, we study the possibility to exploit a previously proposed method for analyzing time-resolved fNIRS measurements in a two-layer structure with a thin superficial layer. This method is based on the calculation of the time-dependent mean partial pathlengths. We validated it by simulating venous and arterial arm cuff occlusions and then applied it on in vivo measurements.
Collapse
Affiliation(s)
- Rebecca Re
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Lucia Zucchelli
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Alessandro Torricelli
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | | |
Collapse
|
39
|
Martelli F, Del Bianco S, Spinelli L, Cavalieri S, Di Ninni P, Binzoni T, Jelzow A, Macdonald R, Wabnitz H. Optimal estimation reconstruction of the optical properties of a two-layered tissue phantom from time-resolved single-distance measurements. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:115001. [PMID: 26524677 DOI: 10.1117/1.jbo.20.11.115001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 09/25/2015] [Indexed: 05/02/2023]
Abstract
In this work, we have tested the optimal estimation (OE) algorithm for the reconstruction of the optical properties of a two-layered liquid tissue phantom from time-resolved single-distance measurements. The OE allows a priori information, in particular on the range of variation of fit parameters, to be included. The purpose of the present investigations was to compare the performance of OE with the Levenberg–Marquardt method for a geometry and real experimental conditions typically used to reconstruct the optical properties of biological tissues such as muscle and brain. The absorption coefficient of the layers was varied in a range of values typical for biological tissues. The reconstructions performed demonstrate the substantial improvements achievable with the OE provided a priori information is available. We note the extreme reliability, robustness, and accuracy of the retrieved absorption coefficient of the second layer obtained with the OE that was found for up to six fit parameters, with an error in the retrieved values of less than 10%. A priori information on fit parameters and fixed forward model parameters clearly improves robustness and accuracy of the inversion procedure.
Collapse
Affiliation(s)
- Fabrizio Martelli
- Università degli Studi di Firenze, Dipartimento di Fisica e Astronomia, Via G. Sansone 1, Sesto Fiorentino 50019, Firenze, Italy
| | - Samuele Del Bianco
- Istituto di Fisica Applicata Nello Carrara del Consiglio Nazionale delle Ricerche, Via Madonna del Piano 10, Sesto Fiorentino 50019, Italy
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, Milano 20133, Italy
| | - Stefano Cavalieri
- Università degli Studi di Firenze, Dipartimento di Fisica e Astronomia, Via G. Sansone 1, Sesto Fiorentino 50019, Firenze, Italy
| | - Paola Di Ninni
- Università degli Studi di Firenze, Dipartimento di Fisica e Astronomia, Via G. Sansone 1, Sesto Fiorentino 50019, Firenze, Italy
| | - Tiziano Binzoni
- University of Geneva, Département de Neurosciences Fondamentales, 1, rue Michel-Servet 1211 Genève 4, SwitzerlandeUniversity Hospital, Département de l'Imagerie et des Sciences de l'Information Médicale, 1, 4 rue Gabrielle-Perret-Gentil, 1211 Geneva 14, S
| | - Alexander Jelzow
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Rainer Macdonald
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| |
Collapse
|
40
|
Konecky SD, Wilson RH, Hagen N, Mazhar A, Tkaczyk TS, Frostig RD, Tromberg BJ. Hyperspectral optical tomography of intrinsic signals in the rat cortex. NEUROPHOTONICS 2015; 2:045003. [PMID: 26835483 PMCID: PMC4718192 DOI: 10.1117/1.nph.2.4.045003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 10/19/2015] [Indexed: 05/20/2023]
Abstract
We introduce a tomographic approach for three-dimensional imaging of evoked hemodynamic activity, using broadband illumination and diffuse optical tomography (DOT) image reconstruction. Changes in diffuse reflectance in the rat somatosensory cortex due to stimulation of a single whisker were imaged at a frame rate of 5 Hz using a hyperspectral image mapping spectrometer. In each frame, images in 38 wavelength bands from 484 to 652 nm were acquired simultaneously. For data analysis, we developed a hyperspectral DOT algorithm that used the Rytov approximation to quantify changes in tissue concentration of oxyhemoglobin ([Formula: see text]) and deoxyhemoglobin (ctHb) in three dimensions. Using this algorithm, the maximum changes in [Formula: see text] and ctHb were found to occur at [Formula: see text] and [Formula: see text] beneath the surface of the cortex, respectively. Rytov tomographic reconstructions revealed maximal spatially localized increases and decreases in [Formula: see text] and ctHb of [Formula: see text] and [Formula: see text], respectively, with these maximum changes occurring at [Formula: see text] poststimulus. The localized optical signals from the Rytov approximation were greater than those from modified Beer-Lambert, likely due in part to the inability of planar reflectance to account for partial volume effects.
Collapse
Affiliation(s)
- Soren D. Konecky
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Laser Microbeam and Medical Program, 1002 Health Sciences Road, Irvine, California 92612, United States
| | - Robert H. Wilson
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Laser Microbeam and Medical Program, 1002 Health Sciences Road, Irvine, California 92612, United States
| | - Nathan Hagen
- Rice University, Department of Biomedical Engineering, 6500 Main Street, Houston, Texas 77030, United States
| | - Amaan Mazhar
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Laser Microbeam and Medical Program, 1002 Health Sciences Road, Irvine, California 92612, United States
- University of California, Irvine, Department of Biomedical Engineering, 5200 Engineering Hall, Irvine, California 92697, United States
| | - Tomasz S. Tkaczyk
- Rice University, Department of Biomedical Engineering, 6500 Main Street, Houston, Texas 77030, United States
| | - Ron D. Frostig
- University of California, Irvine, Department of Neurobiology and Behavior, 2205 McGaugh Hall, Irvine, California 92697, United States
- University of California, Irvine, Department of Biomedical Engineering, 5200 Engineering Hall, Irvine, California 92697, United States
| | - Bruce J. Tromberg
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Laser Microbeam and Medical Program, 1002 Health Sciences Road, Irvine, California 92612, United States
- University of California, Irvine, Department of Biomedical Engineering, 5200 Engineering Hall, Irvine, California 92697, United States
- Address all correspondence to: Bruce J. Tromberg, E-mail:
| |
Collapse
|
41
|
Effects of Increasing Neuromuscular Electrical Stimulation Current Intensity on Cortical Sensorimotor Network Activation: A Time Domain fNIRS Study. PLoS One 2015; 10:e0131951. [PMID: 26158464 PMCID: PMC4497661 DOI: 10.1371/journal.pone.0131951] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 06/08/2015] [Indexed: 11/29/2022] Open
Abstract
Neuroimaging studies have shown neuromuscular electrical stimulation (NMES)-evoked movements activate regions of the cortical sensorimotor network, including the primary sensorimotor cortex (SMC), premotor cortex (PMC), supplementary motor area (SMA), and secondary somatosensory area (S2), as well as regions of the prefrontal cortex (PFC) known to be involved in pain processing. The aim of this study, on nine healthy subjects, was to compare the cortical network activation profile and pain ratings during NMES of the right forearm wrist extensor muscles at increasing current intensities up to and slightly over the individual maximal tolerated intensity (MTI), and with reference to voluntary (VOL) wrist extension movements. By exploiting the capability of the multi-channel time domain functional near-infrared spectroscopy technique to relate depth information to the photon time-of-flight, the cortical and superficial oxygenated (O2Hb) and deoxygenated (HHb) hemoglobin concentrations were estimated. The O2Hb and HHb maps obtained using the General Linear Model (NIRS-SPM) analysis method, showed that the VOL and NMES-evoked movements significantly increased activation (i.e., increase in O2Hb and corresponding decrease in HHb) in the cortical layer of the contralateral sensorimotor network (SMC, PMC/SMA, and S2). However, the level and area of contralateral sensorimotor network (including PFC) activation was significantly greater for NMES than VOL. Furthermore, there was greater bilateral sensorimotor network activation with the high NMES current intensities which corresponded with increased pain ratings. In conclusion, our findings suggest that greater bilateral sensorimotor network activation profile with high NMES current intensities could be in part attributable to increased attentional/pain processing and to increased bilateral sensorimotor integration in these cortical regions.
Collapse
|
42
|
Baker WB, Parthasarathy AB, Ko TS, Busch DR, Abramson K, Tzeng SY, Mesquita RC, Durduran T, Greenberg JH, Kung DK, Yodh AG. Pressure modulation algorithm to separate cerebral hemodynamic signals from extracerebral artifacts. NEUROPHOTONICS 2015; 2:035004. [PMID: 26301255 PMCID: PMC4524732 DOI: 10.1117/1.nph.2.3.035004] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 07/01/2015] [Indexed: 05/18/2023]
Abstract
We introduce and validate a pressure measurement paradigm that reduces extracerebral contamination from superficial tissues in optical monitoring of cerebral blood flow with diffuse correlation spectroscopy (DCS). The scheme determines subject-specific contributions of extracerebral and cerebral tissues to the DCS signal by utilizing probe pressure modulation to induce variations in extracerebral blood flow. For analysis, the head is modeled as a two-layer medium and is probed with long and short source-detector separations. Then a combination of pressure modulation and a modified Beer-Lambert law for flow enables experimenters to linearly relate differential DCS signals to cerebral and extracerebral blood flow variation without a priori anatomical information. We demonstrate the algorithm's ability to isolate cerebral blood flow during a finger-tapping task and during graded scalp ischemia in healthy adults. Finally, we adapt the pressure modulation algorithm to ameliorate extracerebral contamination in monitoring of cerebral blood oxygenation and blood volume by near-infrared spectroscopy.
Collapse
Affiliation(s)
- Wesley B. Baker
- University of Pennsylvania, Department of Physics and Astronomy, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
- Address all correspondence to: Wesley B. Baker, E-mail:
| | - Ashwin B. Parthasarathy
- University of Pennsylvania, Department of Physics and Astronomy, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
| | - Tiffany S. Ko
- University of Pennsylvania, Department of Physics and Astronomy, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
| | - David R. Busch
- University of Pennsylvania, Department of Physics and Astronomy, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
- Children’s Hospital of Philadelphia, Division of Neurology, 3401 Civic Center Boulevard, Philadelphia, Pennsylvania 19104, United States
| | - Kenneth Abramson
- University of Pennsylvania, Department of Physics and Astronomy, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
| | - Shih-Yu Tzeng
- University of Pennsylvania, Department of Physics and Astronomy, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
- National Cheng Kung University, Department of Photonics, No. 1, University Road, Tainan City 701, Taiwan
| | - Rickson C. Mesquita
- University of Campinas, Institute of Physics, 777 R. Sergio Buarque de Holanda, Campinas 13083-859, Brazil
| | - Turgut Durduran
- ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, Av. Carl Friedrich Gauss 3, Castelldefels (Barcelona) 08860, Spain
| | - Joel H. Greenberg
- University of Pennsylvania, Department of Neurology, 3450 Hamilton Walk, Philadelphia, Pennsylvania 19104, United States
| | - David K. Kung
- Hospital of the University of Pennsylvania, Department of Neurosurgery, 3400 Spruce Street, Philadelphia, Pennsylvania 19104, United States
| | - Arjun G. Yodh
- University of Pennsylvania, Department of Physics and Astronomy, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
| |
Collapse
|
43
|
Liebert A, Milej D, Weigl W, Gerega A, Kacprzak M, Maniewski R. Fluorescence-based method for assessment of blood-brain barrier disruption. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2013:3040-2. [PMID: 24110368 DOI: 10.1109/embc.2013.6610181] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We report on a fluorescence-based optical method for assessment of blood-brain barrier in humans. The technique is based on monitoring of fluorescence light excited in the dye circulating in the brain. Measurements were carried out in healthy volunteers and in patients with disruption of the blood-brain barrier with the use of time-resolved method during inflow and washout of indocyanine green after its intravenous injection. We show large differences in the fluorescence signals - in healthy subjects a fast washout of the dye can be observed whereas in patients the washout is significantly prolonged. We conclude that the monitoring of the fluorescence signals during injection of exogenous optical contrast agent can be used for the assessment of the condition of blood-brain barrier at the bedside. The technique may be of benefit for diagnosis of the patients suffering from damage of the blood-brain barrier and in monitoring of therapies used in such patients.
Collapse
|
44
|
Mora AD, Martinenghi E, Contini D, Tosi A, Boso G, Durduran T, Arridge S, Martelli F, Farina A, Torricelli A, Pifferi A. Fast silicon photomultiplier improves signal harvesting and reduces complexity in time-domain diffuse optics. OPTICS EXPRESS 2015; 23:13937-46. [PMID: 26072763 DOI: 10.1364/oe.23.013937] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We present a proof of concept prototype of a time-domain diffuse optics probe exploiting a fast Silicon PhotoMultiplier (SiPM), featuring a timing resolution better than 80 ps, a fast tail with just 90 ps decay time-constant and a wide active area of 1 mm2. The detector is hosted into the probe and used in direct contact with the sample under investigation, thus providing high harvesting efficiency by exploiting the whole SiPM numerical aperture and also reducing complexity by avoiding the use of cumbersome fiber bundles. Our tests also demonstrate high accuracy and linearity in retrieving the optical properties and suitable contrast and depth sensitivity for detecting localized inhomogeneities. In addition to a strong improvement in both instrumentation cost and size with respect to legacy solutions, the setup performances are comparable to those of state-of-the-art time-domain instrumentation, thus opening a new way to compact, low-cost and high-performance time-resolved devices for diffuse optical imaging and spectroscopy.
Collapse
|
45
|
Mora AD, Contini D, Arridge S, Martelli F, Tosi A, Boso G, Farina A, Durduran T, Martinenghi E, Torricelli A, Pifferi A. Towards next-generation time-domain diffuse optics for extreme depth penetration and sensitivity. BIOMEDICAL OPTICS EXPRESS 2015; 6:1749-60. [PMID: 26137377 PMCID: PMC4467698 DOI: 10.1364/boe.6.001749] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 03/20/2015] [Accepted: 03/20/2015] [Indexed: 05/18/2023]
Abstract
Light is a powerful tool to non-invasively probe highly scattering media for clinical applications ranging from oncology to neurology, but also for molecular imaging, and quality assessment of food, wood and pharmaceuticals. Here we show that, for a paradigmatic case of diffuse optical imaging, ideal yet realistic time-domain systems yield more than 2-fold higher depth penetration and many decades higher contrast as compared to ideal continuous-wave systems, by adopting a dense source-detector distribution with picosecond time-gating. Towards this aim, we demonstrate the first building block made of a source-detector pair directly embedded into the probe based on a pulsed Vertical-Cavity Surface-Emitting Laser (VCSEL) to allow parallelization for dense coverage, a Silicon Photomultiplier (SiPM) to maximize light harvesting, and a Single-Photon Avalanche Diode (SPAD) to demonstrate the time-gating capability on the basic SiPM element. This paves the way to a dramatic advancement in terms of increased performances, new high impact applications, and availability of devices with orders of magnitude reduction in size and cost for widespread use, including quantitative wearable imaging.
Collapse
Affiliation(s)
- Alberto Dalla Mora
- Dipartimento di Fisica, Politecnico di Milano,
Italy
- These authors contributed equally to this work
| | - Davide Contini
- Dipartimento di Fisica, Politecnico di Milano,
Italy
- These authors contributed equally to this work
| | - Simon Arridge
- Department of Computer Science, University College London,
United Kingdom
| | - Fabrizio Martelli
- Dipartimento di Fisica e Astronomia, Università degli Studi di Firenze,
Italy
| | - Alberto Tosi
- Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano,
Italy
| | - Gianluca Boso
- Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano,
Italy
| | - Andrea Farina
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche,
Italy
| | | | | | | | - Antonio Pifferi
- Dipartimento di Fisica, Politecnico di Milano,
Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche,
Italy
| |
Collapse
|
46
|
Time-Domain Diffuse Optical Imaging of Tissue by Non-contact Scanning. SPRINGER SERIES IN CHEMICAL PHYSICS 2015. [DOI: 10.1007/978-3-319-14929-5_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
|
47
|
Baker WB, Parthasarathy AB, Busch DR, Mesquita RC, Greenberg JH, Yodh AG. Modified Beer-Lambert law for blood flow. BIOMEDICAL OPTICS EXPRESS 2014; 5:4053-75. [PMID: 25426330 PMCID: PMC4242038 DOI: 10.1364/boe.5.004053] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 10/14/2014] [Accepted: 10/15/2014] [Indexed: 05/18/2023]
Abstract
We develop and validate a Modified Beer-Lambert law for blood flow based on diffuse correlation spectroscopy (DCS) measurements. The new formulation enables blood flow monitoring from temporal intensity autocorrelation function data taken at single or multiple delay-times. Consequentially, the speed of the optical blood flow measurement can be substantially increased. The scheme facilitates blood flow monitoring of highly scattering tissues in geometries wherein light propagation is diffusive or non-diffusive, and it is particularly well-suited for utilization with pressure measurement paradigms that employ differential flow signals to reduce contributions of superficial tissues.
Collapse
Affiliation(s)
- Wesley B. Baker
- Dept. Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104,
USA
| | | | - David R. Busch
- Dept. Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104,
USA
- Div. of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104,
USA
| | - Rickson C. Mesquita
- Institute of Physics, University of Campinas, Campinas, SP 13083-859,
Brazil
| | - Joel H. Greenberg
- Dept. Neurology, University of Pennsylvania, Philadelphia, PA 19104,
USA
| | - A. G. Yodh
- Dept. Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104,
USA
| |
Collapse
|
48
|
Sieno LD, Mora AD, Boso G, Tosi A, Pifferi A, Cubeddu R, Contini D. Diffuse optics using a dual window fast-gated counter. APPLIED OPTICS 2014; 53:7394-401. [PMID: 25402904 DOI: 10.1364/ao.53.007394] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
In this paper we demonstrate the advantages of a fast-gated counter in achieving high count-rate and reducing costs of timing equipment in a time-resolved diffuse optical spectroscopy setup. We experimentally prove the equivalence between the fast-gated counter we developed and a traditional time-correlated single-photon counting setup in terms of depth sensitivity and signal-to-noise ratio. Additionally, we show the suitability of this device for bilayer analysis and to estimate the absorption coefficient of homogeneous diffusing media. Finally, we present a proof-of-principle arterial occlusion measurement on a healthy volunteer to validate the proposed approach in a real application. Fast-gated counters can dramatically reduce both costs and complexity in time-resolved multichannel systems, while achieving high count-rate, thus offering a great advantage in applications like brain and muscle functional imaging.
Collapse
|
49
|
Buttafava M, Boso G, Ruggeri A, Dalla Mora A, Tosi A. Time-gated single-photon detection module with 110 ps transition time and up to 80 MHz repetition rate. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:083114. [PMID: 25173253 DOI: 10.1063/1.4893385] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We present the design and characterization of a complete single-photon counting module capable of time-gating a silicon single-photon avalanche diode with ON and OFF transition times down to 110 ps, at repetition rates up to 80 MHz. Thanks to this sharp temporal filtering of incoming photons, it is possible to reject undesired strong light pulses preceding (or following) the signal of interest, allowing to increase the dynamic range of optical acquisitions up to 7 decades. A complete experimental characterization of the module highlights its very flat temporal response, with a time resolution of the order of 30 ps. The instrument is fully user-configurable via a PC interface and can be easily integrated in any optical setup, thanks to its small and compact form factor.
Collapse
Affiliation(s)
- Mauro Buttafava
- Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy
| | - Gianluca Boso
- Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy
| | - Alessandro Ruggeri
- Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy
| | - Alberto Dalla Mora
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy
| | - Alberto Tosi
- Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy
| |
Collapse
|
50
|
Selb J, Boas DA, Chan ST, Evans KC, Buckley EM, Carp SA. Sensitivity of near-infrared spectroscopy and diffuse correlation spectroscopy to brain hemodynamics: simulations and experimental findings during hypercapnia. NEUROPHOTONICS 2014; 1:015005. [PMID: 25453036 PMCID: PMC4247161 DOI: 10.1117/1.nph.1.1.015005] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 06/12/2014] [Accepted: 06/25/2014] [Indexed: 05/18/2023]
Abstract
Near-infrared spectroscopy (NIRS) and diffuse correlation spectroscopy (DCS) are two diffuse optical technologies for brain imaging that are sensitive to changes in hemoglobin concentrations and blood flow, respectively. Measurements for both modalities are acquired on the scalp, and therefore hemodynamic processes in the extracerebral vasculature confound the interpretation of cortical hemodynamic signals. The sensitivity of NIRS to the brain versus the extracerebral tissue and the contrast-to-noise ratio (CNR) of NIRS to cerebral hemodynamic responses have been well characterized, but the same has not been evaluated for DCS. This is important to assess in order to understand their relative capabilities in measuring cerebral physiological changes. We present Monte Carlo simulations on a head model that demonstrate that the relative brain-to-scalp sensitivity is about three times higher for DCS (0.3 at 3 cm) than for NIRS (0.1 at 3 cm). However, because DCS has higher levels of noise due to photon-counting detection, the CNR is similar for both modalities in response to a physiologically realistic simulation of brain activation. Even so, we also observed higher CNR of the hemodynamic response during graded hypercapnia in adult subjects with DCS than with NIRS.
Collapse
Affiliation(s)
- Juliette Selb
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Department of Radiology, Optics Division, 149 13th Street, Charlestown, Massachusetts 02129, United States
- Address all correspondence to: Juliette Selb, E-mail:
| | - David A. Boas
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Department of Radiology, Optics Division, 149 13th Street, Charlestown, Massachusetts 02129, United States
| | - Suk-Tak Chan
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Department of Radiology, Optics Division, 149 13th Street, Charlestown, Massachusetts 02129, United States
| | - Karleyton C. Evans
- Massachusetts General Hospital, Harvard Medical School, Department of Psychiatry, 149 13th Street, Charlestown, Massachusetts 02129, United States
| | - Erin M. Buckley
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Department of Radiology, Optics Division, 149 13th Street, Charlestown, Massachusetts 02129, United States
| | - Stefan A. Carp
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Department of Radiology, Optics Division, 149 13th Street, Charlestown, Massachusetts 02129, United States
| |
Collapse
|