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Vikas, Kumar R, Soni S. Measurement of anisotropy factor of nanoparticle embedded tumor phantoms for plasmonic photothermal therapeutics. JOURNAL OF BIOPHOTONICS 2024:e202400007. [PMID: 38894568 DOI: 10.1002/jbio.202400007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 05/07/2024] [Accepted: 05/11/2024] [Indexed: 06/21/2024]
Abstract
Measurement of anisotropy factor (g) in the presence of nanoparticles (NPs) is important for understanding light distribution for plasmonic photothermal cancer therapeutics. Here, anisotropy factor is investigated through bilayer phantoms (epidermal and dermal) of various thicknesses incorporated with gold nanorods (GNRs) concentrations of 10-40 μg/mL by using in-house developed goniometric setup. Results show that 10 μg/mL GNRs in the phantom increase g by ~50% (g = 0.9471) w.r.t. phantom without NPs. Higher concentrations (40 μg/mL) of GNRs decrease g by ~43% (g = 0.5341) w.r.t. phantom with 10 μg/mL GNRs. For 40 μg/mL GNRs phantom, the anisotropy factor reduces by 47% for phantom thickness from 600 to 1800 μm. Anisotropy factor of GNR embedded phantom increased by 44% by using glycerol (10%-40%). Incorporation of NPs in a tumor significantly affects g, a major parameter for light distribution. These measurements provide insights for light scattering based on nanoparticle doses for plasmonic photothermal therapeutics.
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Affiliation(s)
- Vikas
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
- Biomedical Applications Group, CSIR-Central Scientific Instruments Organisation, Chandigarh, India
| | - Raj Kumar
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
- Micro and Nano Optics Centre, CSIR-Central Scientific Instruments Organisation, Chandigarh, India
| | - Sanjeev Soni
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
- Biomedical Applications Group, CSIR-Central Scientific Instruments Organisation, Chandigarh, India
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Raj P, Wu L, Arora S, Bhatt R, Zuo Y, Fang Z, Verdoold R, Koch T, Gu L, Barman I. Engineering vascularized skin-mimetic phantom for non-invasive Raman spectroscopy. SENSORS AND ACTUATORS. B, CHEMICAL 2024; 404:135240. [PMID: 38524639 PMCID: PMC10956615 DOI: 10.1016/j.snb.2023.135240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
Recent advances in Raman spectroscopy have shown great potential for non-invasive analyte sensing, but the lack of a standardized optical phantom for these measurements has hindered further progress. While many research groups have developed optical phantoms that mimic bulk optical absorption and scattering, these materials typically have strong Raman scattering, making it difficult to distinguish metabolite signals. As a result, solid tissue phantoms for spectroscopy have been limited to highly scattering tissues such as bones and calcifications, and metabolite sensing has been primarily performed using liquid tissue phantoms. To address this issue, we have developed a layered skin-mimetic phantom that can support metabolite sensing through Raman spectroscopy. Our approach incorporates millifluidic vasculature that mimics blood vessels to allow for diffusion akin to metabolite diffusion in the skin. Furthermore, our skin phantoms are mechanically mimetic, providing an ideal model for development of minimally invasive optical techniques. By providing a standardized platform for measuring metabolites, our approach has the potential to facilitate critical developments in spectroscopic techniques and improve our understanding of metabolite dynamics in vivo.
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Affiliation(s)
- Piyush Raj
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Lintong Wu
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Saransh Arora
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Raj Bhatt
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Yi Zuo
- Department of Materials Science and Engineering, Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Zhiwei Fang
- Department of Materials Science and Engineering, Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
| | | | - Tanja Koch
- ams OSRAM Innovation and Engineering, Germany
| | - Luo Gu
- Department of Materials Science and Engineering, Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Ishan Barman
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21218, USA
- Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21218, USA
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Feng Y, Cao C, Shimada Y, Yasutomi K, Kawahito S, Kennedy GT, Durkin AJ, Kagawa K. Motion-resistant three-wavelength spatial frequency domain imaging system with ambient light suppression using an 8-tap CMOS image sensor. JOURNAL OF BIOMEDICAL OPTICS 2024; 29:016006. [PMID: 38239389 PMCID: PMC10795502 DOI: 10.1117/1.jbo.29.1.016006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 11/15/2023] [Accepted: 12/20/2023] [Indexed: 01/22/2024]
Abstract
Significance We present a motion-resistant three-wavelength spatial frequency domain imaging (SFDI) system with ambient light suppression using an 8-tap complementary metal-oxide semiconductor (CMOS) image sensor (CIS) developed at Shizuoka University. The system addresses limitations in conventional SFDI systems, enabling reliable measurements in challenging imaging scenarios that are closer to real-world conditions. Aim Our study demonstrates a three-wavelength SFDI system based on an 8-tap CIS. We demonstrate and evaluate the system's capability of mitigating motion artifacts and ambient light bias through tissue phantom reflectance experiments and in vivo volar forearm experiments. Approach We incorporated the Hilbert transform to reduce the required number of projected patterns per wavelength from three to two per spatial frequency. The 8-tap image sensor has eight charge storage diodes per pixel; therefore, simultaneous image acquisition of eight images based on multi-exposure is possible. Taking advantage of this feature, the sensor simultaneously acquires images for planar illumination, sinusoidal pattern projection at three wavelengths, and ambient light. The ambient light bias is eliminated by subtracting the ambient light image from the others. Motion artifacts are suppressed by reducing the exposure and projection time for each pattern while maintaining sufficient signal levels by repeating the exposure. The system is compared to a conventional SFDI system in tissue phantom experiments and then in vivo measurements of human volar forearms. Results The 8-tap image sensor-based SFDI system achieved an acquisition rate of 9.4 frame sets per second, with three repeated exposures during each accumulation period. The diffuse reflectance maps of three different tissue phantoms using the conventional SFDI system and the 8-tap image sensor-based SFDI system showed good agreement except for high scattering phantoms. For the in vivo volar forearm measurements, our system successfully measured total hemoglobin concentration, tissue oxygen saturation, and reduced scattering coefficient maps of the subject during motion (16.5 cm/s) and under ambient light (28.9 lx), exhibiting fewer motion artifacts compared with the conventional SFDI. Conclusions We demonstrated the potential for motion-resistant three-wavelength SFDI system with ambient light suppression using an 8-tap CIS.
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Affiliation(s)
- Yu Feng
- Shizuoka University, Graduate School of Integrated Science and Technology, Hamamatsu, Japan
| | - Chen Cao
- Shizuoka University, Research Institution of Electronics, Hamamatsu, Japan
| | - Yuto Shimada
- Shizuoka University, Graduate School of Integrated Science and Technology, Hamamatsu, Japan
| | - Keita Yasutomi
- Shizuoka University, Research Institution of Electronics, Hamamatsu, Japan
| | - Shoji Kawahito
- Shizuoka University, Research Institution of Electronics, Hamamatsu, Japan
| | - Gordon T. Kennedy
- University of California, Irvine, Beckman Laser Institute, Irvine, California, United States
| | - Anthony J. Durkin
- University of California, Irvine, Beckman Laser Institute, Irvine, California, United States
- University of California, Irvine, Biomedical Engineering Department, Irvine, California, United States
| | - Keiichiro Kagawa
- Shizuoka University, Research Institution of Electronics, Hamamatsu, Japan
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Kumar R, Soni S. Dynamic change in optical properties of a nanoparticle embedded tumor phantom for plasmonic photothermal cancer therapeutics. JOURNAL OF BIOPHOTONICS 2023; 16:e202200179. [PMID: 36151893 DOI: 10.1002/jbio.202200179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/27/2022] [Accepted: 09/15/2022] [Indexed: 06/16/2023]
Abstract
In this study, the temporal dynamic changes in optical properties of gold nanorods (GNR) embedded tumor phantom, during photothermal interaction, are reported for plasmonic photothermal therapeutics. Tumor mimicking bilayer phantoms were prepared by using 1% agarose incorporated with 0.1% coffee powder, 0.3% intralipid solution as epidermis layer; 3% intralipid solution and 0.3% human hemoglobin (Hb) powder as dermis layer. On incorporating GNRs of concentrations 10, 20, and 40 μg/ml within the phantom, the absorption coefficients increases 4-8 times, while there is minimal change in the reduced scattering coefficients. Further the absorption coefficient increased by ~8% with the incorporation of GNRs of concentration 40 μg/ml, while no considerable dynamic change in the optical properties is observed for the phantom embedded with GNRs of concentrations 10, and 20 μg/ml. The discussed results are useful for the selection of GNRs dose for pre-treatment planning of plasmonic photothermal cancer therapeutics.
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Affiliation(s)
- Raj Kumar
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
- Micro and Nano Optics Centre, CSIR-Central Scientific Instruments Organisation, Sector-30C, Chandigarh, India
| | - Sanjeev Soni
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
- Biomedical Applications Group, CSIR-Central Scientific Instruments Organisation, Sector-30C, Chandigarh, India
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Suarasan S, Campu A, Vulpoi A, Banciu M, Astilean S. Assessing the Efficiency of Triangular Gold Nanoparticles as NIR Photothermal Agents In Vitro and Melanoma Tumor Model. Int J Mol Sci 2022; 23:ijms232213724. [PMID: 36430201 PMCID: PMC9695152 DOI: 10.3390/ijms232213724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/24/2022] [Accepted: 11/04/2022] [Indexed: 11/09/2022] Open
Abstract
Photothermal therapy (PTT) is gaining a lot of interest as a cancer treatment option with minimal side effects due to the efficient photothermal agents employed. They are based on nanomaterials that, upon laser irradiation, absorb photon energy and convert it into heat to induce hyperthermia, which destroys the cancer cells. Here, the unique light-to-heat conversion features of three different gold nanotriangular nanoparticles (AuNTs) are evaluated with respect to their absorption properties to select the most efficient nanoheater with the highest potential to operate as an efficient photothermal agent. AuNTs with LSPR response in- and out- of resonance with the 785 nm near-infrared (NIR) excitation wavelength are investigated. Upon 15 min laser exposure, the AuNTs that exhibit a plasmonic response in resonance with the 785 nm laser line show the highest photothermal conversion efficacy of 80%, which correlates with a temperature increase of 22 °C. These photothermal properties are well-preserved in agarose-based skin biological phantoms that mimic the melanoma tumoral tissue and surrounding healthy tissue. Finally, in vitro studies on B16.F10 melanoma cells prove by fluorescence staining and MTT assay that the highest phototoxic effect after NIR laser exposure is induced by AuNTs with LSPR response in resonance with the employed laser line, thus demonstrating their potential implementation as efficient photothermal agents in PTT.
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Affiliation(s)
- Sorina Suarasan
- Nanobiophotonics and Laser Microspectroscopy Center, Interdisciplinary Research Institute in Bio-Nano-Sciences, Babes-Bolyai University, 42 T. Laurian Str., 400271 Cluj-Napoca, Romania
- Correspondence:
| | - Andreea Campu
- Nanobiophotonics and Laser Microspectroscopy Center, Interdisciplinary Research Institute in Bio-Nano-Sciences, Babes-Bolyai University, 42 T. Laurian Str., 400271 Cluj-Napoca, Romania
| | - Adriana Vulpoi
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute in Bio-Nano-Sciences, Babes-Bolyai University, 42 T. Laurian Str., 400271 Cluj-Napoca, Romania
| | - Manuela Banciu
- Center of Systems Biology, Biodiversity and Bioresources, Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babes-Bolyai University, 5-7 Clinicilor Str., 400006 Cluj-Napoca, Romania
| | - Simion Astilean
- Nanobiophotonics and Laser Microspectroscopy Center, Interdisciplinary Research Institute in Bio-Nano-Sciences, Babes-Bolyai University, 42 T. Laurian Str., 400271 Cluj-Napoca, Romania
- Department of Biomolecular Physics, Faculty of Physics, Babes-Bolyai University, 1 M. Kogalniceanu Str., 400084 Cluj-Napoca, Romania
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Nishidate I, Yasui R, Nagao N, Suzuki H, Takara Y, Ohashi K, Ando F, Noro N, Kokubo Y. RGB camera-based simultaneous measurements of percutaneous arterial oxygen saturation, tissue oxygen saturation, pulse rate, and respiratory rate. Front Physiol 2022; 13:933397. [PMID: 36200058 PMCID: PMC9527277 DOI: 10.3389/fphys.2022.933397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 08/25/2022] [Indexed: 11/24/2022] Open
Abstract
We propose a method to perform simultaneous measurements of percutaneous arterial oxygen saturation (SpO2), tissue oxygen saturation (StO2), pulse rate (PR), and respiratory rate (RR) in real-time, using a digital red–green–blue (RGB) camera. Concentrations of oxygenated hemoglobin (CHbO), deoxygenated hemoglobin (CHbR), total hemoglobin (CHbT), and StO2 were estimated from videos of the human face using a method based on a tissue-like light transport model of the skin. The photoplethysmogram (PPG) signals are extracted from the temporal fluctuations in CHbO, CHbR, and CHbT using a finite impulse response (FIR) filter (low and high cut-off frequencies of 0.7 and 3 Hz, respectively). The PR is calculated from the PPG signal for CHbT. The ratio of pulse wave amplitude for CHbO and that for CHbR are associated with the reference value of SpO2 measured by a commercially available pulse oximeter, which provides an empirical formula to estimate SpO2 from videos. The respiration-dependent oscillation in CHbT was extracted from another FIR filter (low and high cut-off frequencies of 0.05 and 0.5 Hz, respectively) and used to calculate the RR. In vivo experiments with human volunteers while varying the fraction of inspired oxygen were performed to evaluate the comparability of the proposed method with commercially available devices. The Bland–Altman analysis showed that the mean bias for PR, RR, SpO2, and StO2 were -1.4 (bpm), -1.2(rpm), 0.5 (%), and -3.0 (%), respectively. The precisions for PR, RR, Sp O2, and StO2 were ±3.1 (bpm), ±3.5 (rpm), ±4.3 (%), and ±4.8 (%), respectively. The resulting precision and RMSE for StO2 were pretty close to the clinical accuracy requirement. The accuracy of the RR is considered a little less accurate than clinical requirements. This is the first demonstration of a low-cost RGB camera-based method for contactless simultaneous measurements of the heart rate, percutaneous arterial oxygen saturation, and tissue oxygen saturation in real-time.
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Affiliation(s)
- Izumi Nishidate
- Tokyo University of Agriculture and Technology, Graduate School of Bio-Applications and Systems Engineering, Tokyo, Japan
- *Correspondence: Izumi Nishidate,
| | - Riku Yasui
- Tokyo University of Agriculture and Technology, Graduate School of Bio-Applications and Systems Engineering, Tokyo, Japan
| | - Nodoka Nagao
- Tokyo University of Agriculture and Technology, Graduate School of Bio-Applications and Systems Engineering, Tokyo, Japan
| | - Haruta Suzuki
- Tokyo University of Agriculture and Technology, Graduate School of Bio-Applications and Systems Engineering, Tokyo, Japan
| | | | | | | | | | - Yasuaki Kokubo
- Department of Neurosurgery, Faculty of Medicine, Yamagata University, Yamagata, Japan
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Helical Nanostructures of Ferroelectric Liquid Crystals as Fast Phase Retarders for Spectral Information Extraction Devices: A Comparison with the Nematic Liquid Crystal Phase Retarders. MATERIALS 2021; 14:ma14195540. [PMID: 34639937 PMCID: PMC8509210 DOI: 10.3390/ma14195540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 09/06/2021] [Accepted: 09/14/2021] [Indexed: 11/17/2022]
Abstract
Extraction of spectral information using liquid crystal (LC) retarders has recently become a topic of great interest because of its importance for creating hyper- and multispectral images in a compact and inexpensive way. However, this method of hyperspectral imaging requires thick LC-layer retarders (50 µm-100 µm and above) to obtain spectral modulation signals for reliable signal reconstruction. This makes the device extremely slow in the case of nematic LCs (NLCs), since the response time of NLCs increases proportionally to the square of the LC-layer thickness, which excludes fast dynamic processes monitoring. In this paper, we explore two approaches for solving the speed problem: the first is based on the use of faster nanospiral ferroelectric liquid crystals as an alternative to NLCs, and the second is based on using a passive multiband filter and focuses on multispectral extraction rather than hyperspectral. A detailed comparative study of nematic and ferroelectric devices is presented. The study is carried out using a 9-spectral bands passive spectral filter, covering the visible and near-infrared ranges. We propose the concept of multispectral rather than hyperspectral extraction, where a small number of wavelengths are sufficient for specific applications.
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Shao D, Liu C, Tsow F. Noncontact Physiological Measurement Using a Camera: A Technical Review and Future Directions. ACS Sens 2021; 6:321-334. [PMID: 33434004 DOI: 10.1021/acssensors.0c02042] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Using a camera as an optical sensor to monitor physiological parameters has garnered considerable research interest in biomedical engineering in recent decades. Researchers have explored the use of a camera for monitoring a variety of physiological waveforms, together with the vital signs carried by these waveforms. Most of the obtained waveforms are related to the human respiratory and cardiovascular systems, and in addition of being indicative of overall health, they can also detect early signs of certain diseases. While using a camera for noncontact physiological signal monitoring offers the advantages of low cost and operational ease, it also has the disadvantages such as vulnerability to motion and lack of burden-free calibration solutions in some use cases. This study presents an overview of the existing camera-based methods that have been reported in recent years. It introduces the physiological principles behind these methods, signal acquisition approaches, various types of acquired signals, data processing algorithms, and application scenarios of these methods. It also discusses the technological gaps between the camera-based methods and traditional medical techniques, which are mostly contact-based. Furthermore, we present the manner in which noncontact physiological signal monitoring use has been extended, particularly over the recent years, to more day-to-day aspects of individuals' lives, so as to go beyond the more conventional use case scenarios. We also report on the development of novel approaches that facilitate easier measurement of less often monitored and recorded physiological signals. These have the potential of ushering a host of new medical and lifestyle applications. We hope this study can provide useful information to the researchers in the noncontact physiological signal measurement community.
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Affiliation(s)
- Dangdang Shao
- Biodesign Institute, Arizona State University, Tempe, Arizona 85281, United States
| | - Chenbin Liu
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shenzhen, Guangdong 518116, China
| | - Francis Tsow
- Biodesign Institute, Arizona State University, Tempe, Arizona 518116, United States
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McDuff D, Nishidate I, Nakano K, Haneishi H, Aoki Y, Tanabe C, Niizeki K, Aizu Y. Non-contact imaging of peripheral hemodynamics during cognitive and psychological stressors. Sci Rep 2020; 10:10884. [PMID: 32616832 PMCID: PMC7331808 DOI: 10.1038/s41598-020-67647-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 05/26/2020] [Indexed: 11/27/2022] Open
Abstract
Peripheral hemodynamics, measured via the blood volume pulse and vasomotion, provide a valuable way of monitoring physiological state. Camera imaging-based systems can be used to measure these peripheral signals without contact with the body, at distances of multiple meters. While researchers have paid attention to non-contact imaging photoplethysmography, the study of peripheral hemodynamics and the effect of autonomic nervous system activity on these signals has received less attention. Using a method, based on a tissue-like model of the skin, we extract melanin [Formula: see text] and hemoglobin [Formula: see text] concentrations from videos of the hand and face and show that significant decreases in peripheral pulse signal power (by 36% ± 29%) and vasomotion signal power (by 50% ± 26%) occur during periods of cognitive and psychological stress. Via three experiments we show that similar results are achieved across different stimuli and regions of skin (face and hand). While changes in peripheral pulse and vasomotion power were significant the changes in pulse rate variability were less consistent across subjects and tasks.
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Affiliation(s)
| | - Izumi Nishidate
- Tokyo University of Agriculture and Technology, Tokyo, Japan
| | | | | | - Yuta Aoki
- Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Chihiro Tanabe
- Tokyo University of Agriculture and Technology, Tokyo, Japan
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Clancy NT, Jones G, Maier-Hein L, Elson DS, Stoyanov D. Surgical spectral imaging. Med Image Anal 2020; 63:101699. [PMID: 32375102 PMCID: PMC7903143 DOI: 10.1016/j.media.2020.101699] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 03/30/2020] [Accepted: 04/06/2020] [Indexed: 12/24/2022]
Abstract
Recent technological developments have resulted in the availability of miniaturised spectral imaging sensors capable of operating in the multi- (MSI) and hyperspectral imaging (HSI) regimes. Simultaneous advances in image-processing techniques and artificial intelligence (AI), especially in machine learning and deep learning, have made these data-rich modalities highly attractive as a means of extracting biological information non-destructively. Surgery in particular is poised to benefit from this, as spectrally-resolved tissue optical properties can offer enhanced contrast as well as diagnostic and guidance information during interventions. This is particularly relevant for procedures where inherent contrast is low under standard white light visualisation. This review summarises recent work in surgical spectral imaging (SSI) techniques, taken from Pubmed, Google Scholar and arXiv searches spanning the period 2013-2019. New hardware, optimised for use in both open and minimally-invasive surgery (MIS), is described, and recent commercial activity is summarised. Computational approaches to extract spectral information from conventional colour images are reviewed, as tip-mounted cameras become more commonplace in MIS. Model-based and machine learning methods of data analysis are discussed in addition to simulation, phantom and clinical validation experiments. A wide variety of surgical pilot studies are reported but it is apparent that further work is needed to quantify the clinical value of MSI/HSI. The current trend toward data-driven analysis emphasises the importance of widely-available, standardised spectral imaging datasets, which will aid understanding of variability across organs and patients, and drive clinical translation.
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Affiliation(s)
- Neil T Clancy
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), University College London, United Kingdom; Centre for Medical Image Computing (CMIC), Department of Medical Physics and Biomedical Engineering, University College London, United Kingdom.
| | - Geoffrey Jones
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), University College London, United Kingdom; Centre for Medical Image Computing (CMIC), Department of Computer Science, University College London, United Kingdom
| | | | - Daniel S Elson
- Hamlyn Centre for Robotic Surgery, Institute of Global Health Innovation, Imperial College London, United Kingdom; Department of Surgery and Cancer, Imperial College London, United Kingdom
| | - Danail Stoyanov
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), University College London, United Kingdom; Centre for Medical Image Computing (CMIC), Department of Computer Science, University College London, United Kingdom
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Borik S, Lyra S, Paul M, Antink CH, Leonhardt S, Blazek V. Photoplethysmography imaging:camera performance evaluation by means of an optoelectronic skin perfusion phantom. Physiol Meas 2020; 41:054001. [PMID: 32268307 DOI: 10.1088/1361-6579/ab87b3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Photoplethysmography imaging (PPGI) is a promising contactless camera-based method of non-invasive cardiovascular diagnostics. To achieve the best results, it is important to choose the most suitable camera for a specific application. The settings of the camera influence the quality of the detected signal. APPROACH The standard (European Machine Vision Association 2016 EMVA Standard 1288-Standard for Characterization of Image Sensors and Cameras pp 1-39 (available at: https://www.emva.org/wp-content/uploads/EMVA1288-3.1a.pdf)) for evaluating the imaging performance of machine vision cameras (MVC) helps at the initial decision of the sensor, but the camera should always be tested in terms of usability for a specific application. So far, PPGI lacks a standardized measurement scenario for evaluating the performance of individual cameras. For this, we realized a controllable optoelectronic phantom with artificial silicone skin allowing reproducible tests of cameras to verify their suitability for PPGI. The entire system is housed in a light-tight box. We tested an MVC, a digital single-lens reflex camera (DSLR) camera and a webcam. Each camera varies in used technology and price. MAIN RESULTS We simulated real PPGI measurement conditions simulating the ratio of pulse (AC) and non-pulse (DC) component of the photoplethysmographic signal and achieved AC/DC ratios of 0.5 % on average. An additional OLED panel ensures proper DC providing reproducible measurement conditions. We evaluated the signal morphological features, amplitude spectrum, signal-to-noise ratio (SNR) and spatially dependent changes of simulated subcutaneous perfusion. Here, the MVC proved to be the most suitable device. A DSLR is also suitable for PPGI, but a larger smoothing kernel is required to obtain a perfusion map. The webcam, as the weakest contender, proved to be very susceptible to any inhomogeneous illumination of the examined artificial skin surface. However, it is still able to detect cardiac rhythm. SIGNIFICANCE The result of our work is an optoelectronic phantom for reproducible testing of PPGI camera performance in terms of signal quality and measurement equipment costs.
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Affiliation(s)
- Stefan Borik
- Dept. of Electromagnetic and Biomedical Engineering, Faculty of Electrical Engineering and Information Technology, University of Zilina, Zilina, Slovakia
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Wang C, Chen X, Hong J, Meng L, Cheng W, Zhu X, Lu J, Li P. Extendable, large-field multi-modal optical imaging system for measuring tissue hemodynamics. BIOMEDICAL OPTICS EXPRESS 2020; 11:2339-2351. [PMID: 32499927 PMCID: PMC7249820 DOI: 10.1364/boe.386197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/26/2020] [Accepted: 03/30/2020] [Indexed: 05/08/2023]
Abstract
Simultaneous imaging of multiple hemodynamic parameters helps to evaluate the physiological and pathological status of biological tissue. To achieve multimodal hemodynamics imaging with a large field of view, an infinite conjugate relay lens system compatible with the standard C-Mount camera lens is designed to adapt one camera lens with multiple CCD/CMOS cameras for simultaneously multi-wavelength imaging. Using this relay lens system, dual wavelength reflectance imaging and laser speckle contrast imaging were combined to simultaneously detect the changes in blood flow, oxygenation, and hemoglobin concentrations. To improve the accuracy of hemoglobin concentration measurement with an LED illumination source, an integral algorithm is proposed that accounts for the dependence of differential pathlength factors (DPF) on hemoglobin concentrations and the integral effect of both the emission spectrum of the light source and the spectrum response of the detector. The imaging system is validated by both phantom and in vivo experiments, including the arterial occlusion, and the detection of blood volume pulse (BVP) and blood flow pulse (BFP) signal in human subjects. The system helps in the exploration of macroscopic tissue hemodynamics.
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Affiliation(s)
- Chen Wang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Xiao Chen
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Jiachi Hong
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Liangwei Meng
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Weimin Cheng
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Xuan Zhu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Jinling Lu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Pengcheng Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- HUST-Suzhou Institute for Brainsmatics, Suzhou 215125, China
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13
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Nishidate I, Minakawa M, McDuff D, Wares MDA, Nakano K, Haneishi H, Aizu Y, Niizeki K. Simple and affordable imaging of multiple physiological parameters with RGB camera-based diffuse reflectance spectroscopy. BIOMEDICAL OPTICS EXPRESS 2020; 11:1073-1091. [PMID: 32133238 PMCID: PMC7041446 DOI: 10.1364/boe.382270] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 01/15/2020] [Accepted: 01/15/2020] [Indexed: 05/11/2023]
Abstract
We propose a simple and affordable imaging technique to evaluate transcutaneously multiple physiological parameters by using a digital red-green-blue camera. In this method, the RGB-values were converted into tristimulus values in the CIE (Commission Internationale de l'Eclairage) XYZ color space, which is compatible with the common color spaces. Monte Carlo simulation for light transport in biological tissue was then performed to specify the relationship among the XYZ-values and the concentrations of oxygenated hemoglobin, deoxygenated hemoglobin, bilirubin, and melanin. The concentration of total hemoglobin and tissue oxygen saturation were also calculated from the estimated concentrations of oxygenated and deoxygenated hemoglobin. In vivo experiments with bile duct ligation in rats demonstrated that the estimated bilirubin concentration increased after ligation of the bile duct and reached around 22 mg/dl at 116 h after the onset of ligation, which corresponds to the ground truth value of bilirubin measured by a commercially available transcutaneous bilirubinometer. Experiments with rats while varying the fraction of inspired oxygen demonstrated that oxygenated hemoglobin and deoxygenated hemoglobin decreased and increased, respectively, as the fraction of inspired oxygen decreased. Consequently, tissue oxygen saturation dramatically decreased. We further extended the method to a non-contact imaging photo-plethysmograph and estimation of the percutaneous oxygen saturation. An empirical formula to estimate percutaneous oxygen saturation was derived from the pulse wave amplitudes of oxygenated and deoxygenated hemoglobin. The estimated percutaneous oxygen saturation dropped remarkably when a faction of inspired oxygen was below 19%, indicating the onset of hypoxemia due to hypoxia, whereas the tissue oxygen saturation decreased gradually according to the reduction of the faction of inspired oxygen. The results in this study indicate the potential of this method for imaging of multiple physiological parameters in skin tissue and evaluating an optical biomedical imaging technique that enables cost-effective, easy-to-use, portable, remotely administered, and/or point-of-care solutions.
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Affiliation(s)
- Izumi Nishidate
- Tokyo University of Agriculture and Technology, Graduate School of Bio-Applications & Systems Engineering, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Masashi Minakawa
- Tokyo University of Agriculture and Technology, Graduate School of Bio-Applications & Systems Engineering, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Daniel McDuff
- Microsoft Research, 4820 NE 36th Street, Building 99, Redmond, Washington 98052, USA
| | - MD. Abdul Wares
- Tokyo University of Agriculture and Technology, Graduate School of Bio-Applications & Systems Engineering, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
- Government of Bangladesh, Ministry of Fisheries and Livestock, Department of Livestock Services, Khamar Bari Road, Farmgate, Dhaka, 1209, Bangladesh
| | - Kazuya Nakano
- Chiba University, Center for Frontier Medical Engineering, 1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Hideaki Haneishi
- Chiba University, Center for Frontier Medical Engineering, 1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Yoshihisa Aizu
- Muroran Institute of Technology, College of Design and Manufacturing Technology, 27-1 Mizumoto-cho, Muroran, Hokkaido, 050-8585, Japan
| | - Kyuichi Niizeki
- Yamagata University, Graduate School of Bio-System Engineering, Jonan, Yonezawa-shi, Yamagata, 992-8510, Japan
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14
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Bauer JR, Thomas JB, Hardeberg JY, Verdaasdonk RM. An Evaluation Framework for Spectral Filter Array Cameras to Optimize Skin Diagnosis. SENSORS (BASEL, SWITZERLAND) 2019; 19:E4805. [PMID: 31694239 PMCID: PMC6864639 DOI: 10.3390/s19214805] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/31/2019] [Accepted: 11/01/2019] [Indexed: 01/02/2023]
Abstract
Comparing and selecting an adequate spectral filter array (SFA) camera is application-specific and usually requires extensive prior measurements. An evaluation framework for SFA cameras is proposed and three cameras are tested in the context of skin analysis. The proposed framework does not require application-specific measurements and spectral sensitivities together with the number of bands are the main focus. An optical model of skin is used to generate a specialized training set to improve spectral reconstruction. The quantitative comparison of the cameras is based on reconstruction of measured skin spectra, colorimetric accuracy, and oxygenation level estimation differences. Specific spectral sensitivity shapes influence the results directly and a 9-channel camera performed best regarding the spectral reconstruction metrics. Sensitivities at key wavelengths influence the performance of oxygenation level estimation the strongest. The proposed framework allows to compare spectral filter array cameras and can guide their application-specific development.
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Affiliation(s)
- Jacob Renzo Bauer
- The Norwegian Colour and Visual Computing Laboratory, Norwegian University of Science and Technology (NTNU), 2815 Gjøvik, Norway; (J.-B.T.); (J.Y.H.)
| | - Jean-Baptiste Thomas
- The Norwegian Colour and Visual Computing Laboratory, Norwegian University of Science and Technology (NTNU), 2815 Gjøvik, Norway; (J.-B.T.); (J.Y.H.)
| | - Jon Yngve Hardeberg
- The Norwegian Colour and Visual Computing Laboratory, Norwegian University of Science and Technology (NTNU), 2815 Gjøvik, Norway; (J.-B.T.); (J.Y.H.)
| | - Rudolf M. Verdaasdonk
- Biomedical Photonics and Imaging group, Faculty of Science and Technology, University of Twente, 7522NB Enschede, The Netherlands;
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15
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Paul M, Mota AF, Antink CH, Blazek V, Leonhardt S. Modeling photoplethysmographic signals in camera-based perfusion measurements: optoelectronic skin phantom. BIOMEDICAL OPTICS EXPRESS 2019; 10:4353-4368. [PMID: 31565494 PMCID: PMC6757484 DOI: 10.1364/boe.10.004353] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 06/26/2019] [Accepted: 06/28/2019] [Indexed: 06/10/2023]
Abstract
The remote acquisition of photoplethysmographic (PPG) signals via a video camera, also known as photoplethysmography imaging (PPGI), is not yet standardized. In general, PPGI is investigated with test persons in a laboratory setting. While these in-vivo tests have the advantage of generating real-life data, they suffer from the lack of repeatability and are comparatively effort-intensive because human subjects are required. Consequently, studying changes in signal morphology, for example, due to aging or pathological effects, is practically impossible. As a tool to study these effects, a hardware PPG simulator has been developed: this is a phantom which simulates and generates both 1D and locally resolved 2D optical PPG signals. Here, we demonstrate that it is possible to generate PPG-like signals with various signal morphologies by means of a purely optoelectronic setup, namely an LED array, and to analyze them by means of PPGI. Signals extracted via a camera show good agreement with simulated generated signals. In fact, the first phantom design is suitable to demonstrate this qualitatively.
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Affiliation(s)
- Michael Paul
- Medical Information Technology (MedIT), Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University, Aachen, Germany
| | - Ana Filipa Mota
- Medical Information Technology (MedIT), Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University, Aachen, Germany
| | - Christoph Hoog Antink
- Medical Information Technology (MedIT), Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University, Aachen, Germany
| | - Vladimir Blazek
- Medical Information Technology (MedIT), Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University, Aachen, Germany
- The Czech Institute of Informatics, Robotics and Cybernetics (CIIRC), Czech Technical University, Prague, Czech Republic
| | - Steffen Leonhardt
- Medical Information Technology (MedIT), Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University, Aachen, Germany
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16
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Zherebtsov E, Dremin V, Popov A, Doronin A, Kurakina D, Kirillin M, Meglinski I, Bykov A. Hyperspectral imaging of human skin aided by artificial neural networks. BIOMEDICAL OPTICS EXPRESS 2019; 10:3545-3559. [PMID: 31467793 PMCID: PMC6706048 DOI: 10.1364/boe.10.003545] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 06/06/2019] [Accepted: 06/11/2019] [Indexed: 05/06/2023]
Abstract
We developed a compact, hand-held hyperspectral imaging system for 2D neural network-based visualization of skin chromophores and blood oxygenation. State-of-the-art micro-optic multichannel matrix sensor combined with the tunable Fabry-Perot micro interferometer enables a portable diagnostic device sensitive to the changes of the oxygen saturation as well as the variations of blood volume fraction of human skin. Generalized object-oriented Monte Carlo model is used extensively for the training of an artificial neural network utilized for the hyperspectral image processing. In addition, the results are verified and validated via actual experiments with tissue phantoms and human skin in vivo. The proposed approach enables a tool combining both the speed of an artificial neural network processing and the accuracy and flexibility of advanced Monte Carlo modeling. Finally, the results of the feasibility studies and the experimental tests on biotissue phantoms and healthy volunteers are presented.
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Affiliation(s)
- Evgeny Zherebtsov
- Opto-Electronics and Measurement Techniques Research Unit, Faculty of Information Technology and Electrical Engineering, University of Oulu, PO Box 4500, 90014 Oulu, Finland
| | - Viktor Dremin
- Opto-Electronics and Measurement Techniques Research Unit, Faculty of Information Technology and Electrical Engineering, University of Oulu, PO Box 4500, 90014 Oulu, Finland
| | - Alexey Popov
- Opto-Electronics and Measurement Techniques Research Unit, Faculty of Information Technology and Electrical Engineering, University of Oulu, PO Box 4500, 90014 Oulu, Finland
| | - Alexander Doronin
- School of Engineering and Computer Science, Victoria University of Wellington, PO Box 600, 6140 Wellington, New Zealand
| | - Daria Kurakina
- Institute of Applied Physics of the Russian Academy of Sciences, 46 Ul’yanov Street, 603950 Nizhny Novgorod, Russia
| | - Mikhail Kirillin
- Institute of Applied Physics of the Russian Academy of Sciences, 46 Ul’yanov Street, 603950 Nizhny Novgorod, Russia
- Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Avenue, 603950 Nizhny Novgorod, Russia
| | - Igor Meglinski
- Opto-Electronics and Measurement Techniques Research Unit, Faculty of Information Technology and Electrical Engineering, University of Oulu, PO Box 4500, 90014 Oulu, Finland
- Institute of Engineering Physics for Biomedicine, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409 Moscow, Russia
| | - Alexander Bykov
- Opto-Electronics and Measurement Techniques Research Unit, Faculty of Information Technology and Electrical Engineering, University of Oulu, PO Box 4500, 90014 Oulu, Finland
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17
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Zaunseder S, Trumpp A, Wedekind D, Malberg H. Cardiovascular assessment by imaging photoplethysmography - a review. ACTA ACUST UNITED AC 2019; 63:617-634. [PMID: 29897880 DOI: 10.1515/bmt-2017-0119] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 05/04/2018] [Indexed: 12/12/2022]
Abstract
Over the last few years, the contactless acquisition of cardiovascular parameters using cameras has gained immense attention. The technique provides an optical means to acquire cardiovascular information in a very convenient way. This review provides an overview on the technique's background and current realizations. Besides giving detailed information on the most widespread application of the technique, namely the contactless acquisition of heart rate, we outline further concepts and we critically discuss the current state.
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Affiliation(s)
- Sebastian Zaunseder
- TU Dresden, Institute of Biomedical Engineering, Helmholtzstraße 18, Dresden, 01069 Saxony, Germany
| | - Alexander Trumpp
- TU Dresden, Institute of Biomedical Engineering, Helmholtzstraße 18, Dresden, 01069 Saxony, Germany
| | - Daniel Wedekind
- TU Dresden, Institute of Biomedical Engineering, Helmholtzstraße 18, Dresden, 01069 Saxony, Germany
| | - Hagen Malberg
- TU Dresden, Institute of Biomedical Engineering, Helmholtzstraße 18, Dresden, 01069 Saxony, Germany
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18
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Vahlsing T, Delbeck S, Leonhardt S, Heise HM. Noninvasive Monitoring of Blood Glucose Using Color-Coded Photoplethysmographic Images of the Illuminated Fingertip Within the Visible and Near-Infrared Range: Opportunities and Questions. J Diabetes Sci Technol 2018; 12:1169-1177. [PMID: 30222001 PMCID: PMC6232738 DOI: 10.1177/1932296818798347] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Noninvasive blood glucose assays have been promised for many years and various molecular spectroscopy-based methods of skin are candidates for achieving this goal. Due to the small spectral signatures of the glucose used for direct physical detection, moreover hidden among a largely variable background, broad spectral intervals are usually required to provide the mandatory analytical selectivity, but no such device has so far reached the accuracy that is required for self-monitoring of blood glucose (SMBG). A recently presented device as described in this journal, based on photoplethysmographic fingertip images for measuring glucose in a nonspecific indirect manner, is especially evaluated for providing reliable blood glucose concentration predictions.
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Affiliation(s)
- Thorsten Vahlsing
- Bundesanstalt für Materialforschung und
-prüfung (BAM), Acoustic and Electromagnetic Methods, Berlin, Germany
- Chair for Medical Information
Technology, Helmholtz Institute for Biomedical Engineering, RWTH Aachen University,
Aachen, Germany
| | - Sven Delbeck
- Interdisciplinary Center for Life
Sciences, South-Westphalia University of Applied Sciences, Iserlohn, Germany
| | - Steffen Leonhardt
- Chair for Medical Information
Technology, Helmholtz Institute for Biomedical Engineering, RWTH Aachen University,
Aachen, Germany
| | - H. Michael Heise
- Interdisciplinary Center for Life
Sciences, South-Westphalia University of Applied Sciences, Iserlohn, Germany
- H. Michael Heise, PhD, Interdisciplinary
Center for Life Sciences, South-Westphalia University of Applied Sciences,
Frauenstuhlweg 31, D-58644 Iserlohn, Germany.
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19
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Delbeck S, Vahlsing T, Leonhardt S, Steiner G, Heise HM. Non-invasive monitoring of blood glucose using optical methods for skin spectroscopy-opportunities and recent advances. Anal Bioanal Chem 2018; 411:63-77. [PMID: 30283998 DOI: 10.1007/s00216-018-1395-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 09/17/2018] [Accepted: 09/20/2018] [Indexed: 12/29/2022]
Abstract
Diabetes mellitus is a widespread disease with greatly rising patient numbers expected in the future, not only for industrialized countries but also for regions in the developing world. There is a need for efficient therapy, which can be via self-monitoring of blood glucose levels to provide tight glycemic control for reducing the risks of severe health complications. Advancements in diabetes technology can nowadays offer different sensor approaches, even for continuous blood glucose monitoring. Non-invasive blood glucose assays have been promised for many years and various vibrational spectroscopy-based methods of the skin are candidates for achieving this goal. Due to the small spectral signatures of the glucose hidden among a largely variable background, the largest signal-to-noise ratios and multivariate calibration are essential to provide the method applicability for self-monitoring of blood glucose. Besides multiparameter approaches, recently presented devices based on photoplethysmography with wavelengths in the visible and near-infrared range are evaluated for their potential of providing reliable blood glucose concentration predictions. Graphical abstract ᅟ.
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Affiliation(s)
- Sven Delbeck
- Interdisciplinary Center for Life Sciences, South-Westphalia University of Applied Sciences, Frauenstuhlweg 31, 58644, Iserlohn, Germany
| | - Thorsten Vahlsing
- Bundesanstalt für Materialforschung und -prüfung (BAM), Acoustic and Electromagnetic Methods, Unter den Eichen 87, 12205, Berlin, Germany.,Chair for Medical Information Technology, Helmholtz Institute of Biomedical Engineering, RWTH Aachen University, Pauwelsstr. 20, 52074, Aachen, Germany
| | - Steffen Leonhardt
- Chair for Medical Information Technology, Helmholtz Institute of Biomedical Engineering, RWTH Aachen University, Pauwelsstr. 20, 52074, Aachen, Germany
| | - Gerald Steiner
- Faculty of Medicine Carl Gustav Carus, Clinical Sensoring and Monitoring, Technical University of Dresden, Fetscherstraße 74, 01307, Dresden, Germany
| | - H Michael Heise
- Interdisciplinary Center for Life Sciences, South-Westphalia University of Applied Sciences, Frauenstuhlweg 31, 58644, Iserlohn, Germany.
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20
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Hypoperfusion following the injection of epinephrine in human forearm skin can be measured by RGB analysis but not with laser speckle contrast imaging. Microvasc Res 2018; 121:7-13. [PMID: 30153456 DOI: 10.1016/j.mvr.2018.08.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 07/19/2018] [Accepted: 08/25/2018] [Indexed: 11/20/2022]
Abstract
BACKGROUND The time taken for epinephrine to achieve its optimal effect during local anesthesia has recently become the subject of debate. The time from injection to commencement of surgery is traditionally quoted to be 7 to 10 min, while recent reports claim that it may take 30 min to achieve maximum hypoperfusion, which would prolong the time required for surgical procedures. The discrepancy may be related to difficulties associated with the techniques used to measure blood perfusion. The aim of this study was to test two methods of determining the time to maximum hypoperfusion. METHODS Laser speckle contrast imaging (LSCI) and red, green, blue (RGB) analysis of images obtained with a commercial digital camera, were used to monitor the effect of infiltration with commonly used local anesthetic preparations: lidocaine (20 mg/ml) + epinephrine (12.5 μg/ml), lidocaine (10 mg/ml) + epinephrine (5 μg/ml), and lidocaine (20 mg/ml) alone, in healthy subjects. RESULTS LSCI showed a paradoxical increase in signal after the injection of local anesthetics containing epinephrine, probably due to a change in the laser penetration depth resulting from blanching of the skin. However, RGB analysis of digital photographs gave more reliable results, showing skin blanching that corresponded to the expected effect of epinephrine in local anesthetics. The time to maximum effect was found to be 7 (range 5-10) minutes for 12.5 μg/ml epinephrine, and 9 (range 7-13) minutes for 5 μg/ml epinephrine in lidocaine. CONCLUSIONS RGB analysis of digital images proved to be a valid technique for monitoring the effect of local anesthetics with epinephrine in human skin. The technique requires only a commercial digital camera and constitutes a cheap, simple method. The optimal delay between epinephrine injection and incision, to minimize bleeding, was found to be 7 to 9 min, which is in good agreement with common surgical practice.
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21
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Mustari A, Nishidate I, Wares MA, Maeda T, Kawauchi S, Sato S, Sato M, Aizu Y. Agarose-based Tissue Mimicking Optical Phantoms for Diffuse Reflectance Spectroscopy. J Vis Exp 2018:57578. [PMID: 30199019 PMCID: PMC6231702 DOI: 10.3791/57578] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
This protocol describes how to make agarose-based tissue-mimicking phantoms and demonstrates how to determine their optical properties using a conventional optical system with an integrating sphere. Measuring systems for the acquisition of the diffuse reflectance and total transmittance spectra are constructed with a broadband white light source, a light guide, an achromatic lens, an integrating sphere, a sample holder, an optical fiber probe, and a multi-channel spectrometer. An acrylic mold consisting of two rectangular acrylic pieces and a U-shaped acrylic piece is constructed to create an epidermal phantom and a dermal phantom with whole blood. The application of a sodium dithionite (Na2S2O4) solution to the dermal phantom enables the researcher to deoxygenate hemoglobin in red blood cells distributed in the dermal phantom. The inverse Monte Carlo simulation with the diffuse reflectance and total transmittance spectra measured by a spectrometer with an integrating sphere is performed to determine the absorption coefficient spectrum µa(λ) and the reduced scattering coefficient spectrum µs'(λ) of each layer phantom. A two-layered phantom mimicking the diffuse reflectance of human skin tissue is also demonstrated by piling up the epidermal phantom on the dermal phantom.
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Affiliation(s)
- Afrina Mustari
- Graduate School of Bio-application & Systems Engineering, Tokyo University of Agriculture & Technology
| | - Izumi Nishidate
- Graduate School of Bio-application & Systems Engineering, Tokyo University of Agriculture & Technology;
| | - Md Abdul Wares
- Graduate School of Bio-application & Systems Engineering, Tokyo University of Agriculture & Technology; Department of Livestock Services, Ministry of Fisheries and Livestock, Government of Bangladesh
| | - Takaaki Maeda
- Department of Mechanical Engineering, Kushiro National College of Technology
| | - Satoko Kawauchi
- Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute
| | - Shunichi Sato
- Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute
| | - Manabu Sato
- Graduate School of Science and Engineering, Yamagata University
| | - Yoshihisa Aizu
- College of Design and Manufacturing Technology, Muroran Institute of Technology
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22
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Kim T, Visbal-Onufrak MA, Konger RL, Kim YL. Data-driven imaging of tissue inflammation using RGB-based hyperspectral reconstruction toward personal monitoring of dermatologic health. BIOMEDICAL OPTICS EXPRESS 2017; 8:5282-5296. [PMID: 29188120 PMCID: PMC5695970 DOI: 10.1364/boe.8.005282] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 10/19/2017] [Accepted: 10/19/2017] [Indexed: 05/05/2023]
Abstract
Sensitive and accurate assessment of dermatologic inflammatory hyperemia in otherwise grossly normal-appearing skin conditions is beneficial to laypeople for monitoring their own skin health on a regular basis, to patients for looking for timely clinical examination, and to primary care physicians or dermatologists for delivering effective treatments. We propose that mathematical hyperspectral reconstruction from RGB images in a simple imaging setup can provide reliable visualization of hemoglobin content in a large skin area. Without relying on a complicated, expensive, and slow hyperspectral imaging system, we demonstrate the feasibility of determining heterogeneous or multifocal areas of inflammatory hyperemia associated with experimental photocarcinogenesis in mice. We envision that RGB-based reconstructed hyperspectral imaging of subclinical inflammatory hyperemic foci could potentially be integrated with the built-in camera (RGB sensor) of a smartphone to develop a simple imaging device that could offer affordable monitoring of dermatologic health.
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Affiliation(s)
- Taehoon Kim
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | | | - Raymond L. Konger
- Departments of Pathology & Laboratory Medicine and Dermatology, Indiana University School of Medicine, IN 46202, USA
| | - Young L. Kim
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA
- Regenstrief Center for Healthcare Engineering, Purdue University, West Lafayette, IN 47907, USA
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23
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Baruch D, Abookasis D. Multimodal optical setup based on spectrometer and cameras combination for biological tissue characterization with spatially modulated illumination. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:46007. [PMID: 28425559 DOI: 10.1117/1.jbo.22.4.046007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 03/29/2017] [Indexed: 06/07/2023]
Abstract
The application of optical techniques as tools for biomedical research has generated substantial interest for the ability of such methodologies to simultaneously measure biochemical and morphological parameters of tissue. Ongoing optimization of optical techniques may introduce such tools as alternative or complementary to conventional methodologies. The common approach shared by current optical techniques lies in the independent acquisition of tissue’s optical properties (i.e., absorption and reduced scattering coefficients) from reflected or transmitted light. Such optical parameters, in turn, provide detailed information regarding both the concentrations of clinically relevant chromophores and macroscopic structural variations in tissue. We couple a noncontact optical setup with a simple analysis algorithm to obtain absorption and scattering coefficients of biological samples under test. Technically, a portable picoprojector projects serial sinusoidal patterns at low and high spatial frequencies, while a spectrometer and two independent CCD cameras simultaneously acquire the reflected diffuse light through a single spectrometer and two separate CCD cameras having different bandpass filters at nonisosbestic and isosbestic wavelengths in front of each. This configuration fills the gaps in each other’s capabilities for acquiring optical properties of tissue at high spectral and spatial resolution. Experiments were performed on both tissue-mimicking phantoms as well as hands of healthy human volunteers to quantify their optical properties as proof of concept for the present technique. In a separate experiment, we derived the optical properties of the hand skin from the measured diffuse reflectance, based on a recently developed camera model. Additionally, oxygen saturation levels of tissue measured by the system were found to agree well with reference values. Taken together, the present results demonstrate the potential of this integrated setup for diagnostic and research applications.
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Affiliation(s)
- Daniel Baruch
- Ariel University, Department of Electrical and Electronics Engineering, Ariel, IsraelbAriel University, Department of Physics, Ariel, Israel
| | - David Abookasis
- Ariel University, Department of Electrical and Electronics Engineering, Ariel, Israel
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24
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Feng W, Shi R, Zhang C, Yu T, Zhu D. Lookup-table-based inverse model for mapping oxygen concentration of cutaneous microvessels using hyperspectral imaging. OPTICS EXPRESS 2017; 25:3481-3495. [PMID: 28241562 DOI: 10.1364/oe.25.003481] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Hyperspectral imaging combining with skin optical clearing technique provides a possible way to non-invasively monitor hemodynamics of cutaneous microvessels. In order to estimate microvascular blood oxygen saturation, in this work, a lookup-table-based inverse model was developed to extract the microvascular optical and physiological properties using hyperspectral analysis. This approach showed a higher fitting degree than currently existing hyperspectral analysis methods (i.e. multiple linear regression and non-negative least square fit) in estimating blood oxygen saturation. Hypoxic stimulation experiment showed that calculated results were in accordance with physiological changes, and the relative changes of estimated oxygen saturation indicated this method appeared to be more sensitive to blood oxygen fluctuation. And a simulated blood model was used for verification here, indicating this method also showed a good accuracy in determining oxygen saturation from the simulated spectra.
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Akter S, Kawauchi S, Sato S, Aosasa S, Yamamoto J, Nishidate I. In vivo imaging of hepatic hemodynamics and light scattering property during ischemia-reperfusion in rats based on spectrocolorimetry. BIOMEDICAL OPTICS EXPRESS 2017; 8:974-992. [PMID: 28270997 PMCID: PMC5330569 DOI: 10.1364/boe.8.000974] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 01/11/2017] [Accepted: 01/14/2017] [Indexed: 05/13/2023]
Abstract
A red-green-blue camera-based imaging method is proposed for estimating spatial maps of concentrations of oxyhemoglobin (CHbO), deoxyhemoglobin (CHbR), total hemoglobin (CHbT), tissue oxygen saturation (StO2), and scattering power (b) in liver tissue. Hemodynamic responses to hepatic ischemia-reperfusion of in vivo rat liver tissues induced by portal triad occlusion were evaluated. Upon portal triad occlusion, this method yielded images of decreased CHbO, CHbT, StO2, and b, and increased CHbR followed by a progressive increase in CHbO and StO2 during reperfusion. Time courses of the changes in CHbO, CHbR, CHbT, and StO2 over different regions of interest (ROIs) revealed that ischemia results in an abrupt significant (P<0.05) reduction in CHbO, CHbT, and StO2 with a simultaneous increase in CHbR compared to the baseline level, indicative of the hemodynamic responses during hepatic ischemia-reperfusion. Upon reperfusion, there was a gradual increase in CHbO and StO2, and decrease in CHbR. The change in average scattering power b implies the presence of morphological alterations in the cellular and subcellular structures induced by ischemia or anoxia. This study shows the potential of monitoring spatiotemporal changes in hemodynamic parameters and morphological changes in studies of hepatic pathophysiology.
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Affiliation(s)
- Sharmin Akter
- Graduate School of Bio-Applications & Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
| | - Satoko Kawauchi
- Division of Biomedical Information Sciences, National Defense Medical College Research Institute, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Shunichi Sato
- Division of Biomedical Information Sciences, National Defense Medical College Research Institute, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Suefumi Aosasa
- Department of Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Junji Yamamoto
- Department of Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Izumi Nishidate
- Graduate School of Bio-Applications & Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
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Visualization of Venous Compliance of Superficial Veins Using Non-Contact Plethysmography Based on Digital Red-Green-Blue Images. SENSORS 2016; 16:s16121996. [PMID: 27897981 PMCID: PMC5190977 DOI: 10.3390/s16121996] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 11/02/2016] [Accepted: 11/19/2016] [Indexed: 11/17/2022]
Abstract
We propose the visualization of venous compliance (VC) using a digital red-green-blue (RGB) camera. The new imaging method, which transforms RGB values into VC, combines VC evaluation with blood concentration estimation from the RGB values of each pixel. We evaluate a non-contact plethysmography (NCPG) system for VC based on comparisons with conventional strain gauge plethysmography (SPG). We conduct in vivo measurements using both systems and investigate their differences by evaluating the VC. The results show that the two methods measure different blood vessels and that errors caused by interstitial fluid accumulation are negligible for the NCPG system, whereas SPG is influenced by such errors. Additionally, we investigate the relationship between VC and physical activity using NCPG.
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Kim T, Kim JI, Visbal-Onufrak MA, Chapple C, Kim YL. Nonspectroscopic imaging for quantitative chlorophyll sensing. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:16008. [PMID: 26790643 DOI: 10.1117/1.jbo.21.1.016008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 12/10/2015] [Indexed: 05/25/2023]
Affiliation(s)
- Taehoon Kim
- Purdue University, Weldon School of Biomedical Engineering, 206 South Martin Jischke Drive, West Lafayette, Indiana 47907, United States
| | - Jeong-Im Kim
- Purdue University, Department of Biochemistry, 175 South University Street, West Lafayette, Indiana 47907, United States
| | - Michelle A Visbal-Onufrak
- Purdue University, Weldon School of Biomedical Engineering, 206 South Martin Jischke Drive, West Lafayette, Indiana 47907, United States
| | - Clint Chapple
- Purdue University, Department of Biochemistry, 175 South University Street, West Lafayette, Indiana 47907, United States
| | - Young L Kim
- Purdue University, Weldon School of Biomedical Engineering, 206 South Martin Jischke Drive, West Lafayette, Indiana 47907, United StatescKyung Hee University, Department of Computer Science and Engineering, 1732, Deogyeong-daero, Yongin 17104, Republic of
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Huang J, Zhang S, Gnyawali S, Sen CK, Xu RX. Second derivative multispectral algorithm for quantitative assessment of cutaneous tissue oxygenation. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:036001. [PMID: 25734405 PMCID: PMC4347514 DOI: 10.1117/1.jbo.20.3.036001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 01/20/2015] [Indexed: 05/12/2023]
Abstract
We report a second derivative multispectral algorithm for quantitative assessment of cutaneous tissue oxygen saturation (StO₂). The algorithm is based on a forward model of light transport in multilayered skin tissue and an inverse algorithm for StO₂ reconstruction. Based on the forward simulation results, a parameter of a second derivative ratio (SDR) is derived as a function of cutaneous tissue StO₂. The SDR function is optimized at a wavelength set of 544, 552, 568, 576, 592, and 600 nm so that cutaneous tissue StO₂ can be derived with minimal artifacts by blood concentration, tissue scattering, and melanin concentration. The proposed multispectral StO₂ imaging algorithm is verified in both benchtop and in vivo experiments. The experimental results show that the proposed multispectral imaging algorithm is able to map cutaneous tissue StO₂ in high temporal resolution with reduced measurement artifacts induced by different skin conditions in comparison with other three commercial tissue oxygen measurement systems. These results indicate that the multispectral StO₂ imaging technique has the potential for noninvasive and quantitative assessment of skin tissue oxygenation with a high temporal resolution.
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Affiliation(s)
- Jiwei Huang
- The Ohio State University, Department of Biomedical Engineering, Columbus, Ohio 43210, United States
| | - Shiwu Zhang
- University of Science and Technology of China, Department of Precision Machinery and Precision Instrumentation, Hefei, Anhui 230027, China
| | - Surya Gnyawali
- The Ohio State University, Department of Surgery, Columbus, Ohio 43210, United States
| | - Chandan K. Sen
- The Ohio State University, Department of Surgery, Columbus, Ohio 43210, United States
| | - Ronald X. Xu
- The Ohio State University, Department of Biomedical Engineering, Columbus, Ohio 43210, United States
- University of Science and Technology of China, Department of Precision Machinery and Precision Instrumentation, Hefei, Anhui 230027, China
- Address all correspondence to: Ronald X. Xu, E-mail:
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Chen S, Lin X, Zhu C, Liu Q. Sequential weighted Wiener estimation for extraction of key tissue parameters in color imaging: a phantom study. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:127001. [PMID: 25467524 DOI: 10.1117/1.jbo.19.12.127001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 11/04/2014] [Indexed: 05/20/2023]
Abstract
Key tissue parameters, e.g., total hemoglobin concentration and tissue oxygenation, are important biomarkers in clinical diagnosis for various diseases. Although point measurement techniques based on diffuse reflectance spectroscopy can accurately recover these tissue parameters, they are not suitable for the examination of a large tissue region due to slow data acquisition. The previous imaging studies have shown that hemoglobin concentration and oxygenation can be estimated from color measurements with the assumption of known scattering properties, which is impractical in clinical applications. To overcome this limitation and speed-up image processing, we propose a method of sequential weighted Wiener estimation (WE) to quickly extract key tissue parameters, including total hemoglobin concentration (CtHb), hemoglobin oxygenation (StO2), scatterer density (α), and scattering power (β), from wide-band color measurements. This method takes advantage of the fact that each parameter is sensitive to the color measurements in a different way and attempts to maximize the contribution of those color measurements likely to generate correct results in WE. The method was evaluated on skin phantoms with varying CtHb, StO2, and scattering properties. The results demonstrate excellent agreement between the estimated tissue parameters and the corresponding reference values. Compared with traditional WE, the sequential weighted WE shows significant improvement in the estimation accuracy. This method could be used to monitor tissue parameters in an imaging setup in real time.
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Yoshida K, Nishidate I. Rapid calculation of diffuse reflectance from a multilayered model by combination of the white Monte Carlo and adding-doubling methods. BIOMEDICAL OPTICS EXPRESS 2014; 5:3901-20. [PMID: 25426319 PMCID: PMC4242026 DOI: 10.1364/boe.5.003901] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 10/08/2014] [Accepted: 10/09/2014] [Indexed: 05/13/2023]
Abstract
To rapidly derive a result for diffuse reflectance from a multilayered model that is equivalent to that of a Monte-Carlo simulation (MCS), we propose a combination of a layered white MCS and the adding-doubling method. For slabs with various scattering coefficients assuming a certain anisotropy factor and without absorption, we calculate the transition matrices for light flow with respect to the incident and exit angles. From this series of precalculated transition matrices, we can calculate the transition matrices for the multilayered model with the specific anisotropy factor. The relative errors of the results of this method compared to a conventional MCS were less than 1%. We successfully used this method to estimate the chromophore concentration from the reflectance spectrum of a numerical model of skin and in vivo human skin tissue.
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Estimation of melanin and hemoglobin using spectral reflectance images reconstructed from a digital RGB image by the Wiener estimation method. SENSORS 2013; 13:7902-15. [PMID: 23783740 PMCID: PMC3715247 DOI: 10.3390/s130607902] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 06/12/2013] [Accepted: 06/17/2013] [Indexed: 11/17/2022]
Abstract
A multi-spectral diffuse reflectance imaging method based on a single snap shot of Red-Green-Blue images acquired with the exposure time of 65 ms (15 fps) was investigated for estimating melanin concentration, blood concentration, and oxygen saturation in human skin tissue. The technique utilizes the Wiener estimation method to deduce spectral reflectance images instantaneously from an RGB image. Using the resultant absorbance spectrum as a response variable and the extinction coefficients of melanin, oxygenated hemoglobin and deoxygenated hemoglobin as predictor variables, multiple regression analysis provides regression coefficients. Concentrations of melanin and total blood are then determined from the regression coefficients using conversion vectors that are numerically deduced in advance by the Monte Carlo simulations for light transport in skin. Oxygen saturation is obtained directly from the regression coefficients. Experiments with a tissue-like agar gel phantom validated the method. In vivo experiments on fingers during upper limb occlusion demonstrated the ability of the method to evaluate physiological reactions of human skin.
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Balu M, Mazhar A, Hayakawa CK, Mittal R, Krasieva TB, König K, Venugopalan V, Tromberg BJ. In vivo multiphoton NADH fluorescence reveals depth-dependent keratinocyte metabolism in human skin. Biophys J 2013; 104:258-67. [PMID: 23332078 DOI: 10.1016/j.bpj.2012.11.3809] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 11/19/2012] [Accepted: 11/26/2012] [Indexed: 11/26/2022] Open
Abstract
We employ a clinical multiphoton microscope to monitor in vivo and noninvasively the changes in reduced nicotinamide adenine dinucleotide (NADH) fluorescence of human epidermal cells during arterial occlusion. We correlate these results with measurements of tissue oxy- and deoxyhemoglobin concentration during oxygen deprivation using spatial frequency domain imaging. During arterial occlusion, a decrease in oxyhemoglobin corresponds to an increase in NADH fluorescence in the basal epidermal cells, implying a reduction in basal cell oxidative phosphorylation. The ischemia-induced oxygen deprivation is associated with a strong increase in NADH fluorescence of keratinocytes in layers close to the stratum basale, whereas keratinocytes from epidermal layers closer to the skin surface are not affected. Spatial frequency domain imaging optical property measurements, combined with a multilayer Monte Carlo-based radiative transport model of multiphoton microscopy signal collection in skin, establish that localized tissue optical property changes during occlusion do not impact the observed NADH signal increase. This outcome supports the hypothesis that the vascular contribution to the basal layer oxygen supply is significant and these cells engage in oxidative metabolism. Keratinocytes in the more superficial stratum granulosum are either supplied by atmospheric oxygen or are functionally anaerobic. Based on combined hemodynamic and two-photon excited fluorescence data, the oxygen consumption rate in the stratum basale is estimated to be ∼0.035 μmoles/10(6) cells/h.
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Affiliation(s)
- Mihaela Balu
- Laser Microbeam and Medical Program, Beckman Laser Institute and Medical Clinic, University of California, Irvine, California, USA
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Xu RX, Allen DW, Huang J, Gnyawali S, Melvin J, Elgharably H, Gordillo G, Huang K, Bergdall V, Litorja M, Rice JP, Hwang J, Sen CK. Developing digital tissue phantoms for hyperspectral imaging of ischemic wounds. BIOMEDICAL OPTICS EXPRESS 2012; 3:1433-45. [PMID: 22741088 PMCID: PMC3370982 DOI: 10.1364/boe.3.001433] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 05/03/2012] [Accepted: 05/04/2012] [Indexed: 05/13/2023]
Abstract
Hyperspectral imaging has the potential to achieve high spatial resolution and high functional sensitivity for non-invasive assessment of tissue oxygenation. However, clinical acceptance of hyperspectral imaging in ischemic wound assessment is hampered by its poor reproducibility, low accuracy, and misinterpreted biology. These limitations are partially caused by the lack of a traceable calibration standard. We proposed a digital tissue phantom (DTP) platform for quantitative calibration and performance evaluation of spectral wound imaging devices. The technical feasibility of such a DTP platform was demonstrated by both in vitro and in vivo experiments. The in vitro DTPs were developed based on a liquid blood phantom model. The in vivo DTPs were developed based on a porcine ischemic skin flap model. The DTPs were projected by a Hyperspectral Image Projector (HIP) with high fidelity. A wide-gap 2nd derivative oxygenation algorithm was developed to reconstruct tissue functional parameters from hyperspectral measurements. In this study, we have demonstrated not only the technical feasibility of using DTPs for quantitative calibration, evaluation, and optimization of spectral imaging devices but also its potential for ischemic wound assessment in clinical practice.
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Affiliation(s)
- Ronald X. Xu
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - David W. Allen
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Jiwei Huang
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Surya Gnyawali
- Department of Surgery, The Ohio State University, Columbus, OH 43210, USA
| | - James Melvin
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Haytham Elgharably
- Department of Surgery, The Ohio State University, Columbus, OH 43210, USA
| | - Gayle Gordillo
- Department of Surgery, The Ohio State University, Columbus, OH 43210, USA
| | - Kun Huang
- Department of Biomedical Informatics, The Ohio State University, Columbus, OH 43210, USA
| | - Valerie Bergdall
- College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Maritoni Litorja
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Joseph P. Rice
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Jeeseong Hwang
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Chandan K. Sen
- Department of Surgery, The Ohio State University, Columbus, OH 43210, USA
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