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Beatty R, Mendez KL, Schreiber LHJ, Tarpey R, Whyte W, Fan Y, Robinson ST, O'Dwyer J, Simpkin AJ, Tannian J, Dockery P, Dolan EB, Roche ET, Duffy GP. Soft robot-mediated autonomous adaptation to fibrotic capsule formation for improved drug delivery. Sci Robot 2023; 8:eabq4821. [PMID: 37647382 DOI: 10.1126/scirobotics.abq4821] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 08/02/2023] [Indexed: 09/01/2023]
Abstract
The foreign body response impedes the function and longevity of implantable drug delivery devices. As a dense fibrotic capsule forms, integration of the device with the host tissue becomes compromised, ultimately resulting in device seclusion and treatment failure. We present FibroSensing Dynamic Soft Reservoir (FSDSR), an implantable drug delivery device capable of monitoring fibrotic capsule formation and overcoming its effects via soft robotic actuations. Occlusion of the FSDSR porous membrane was monitored over 7 days in a rodent model using electrochemical impedance spectroscopy. The electrical resistance of the fibrotic capsule correlated to its increase in thickness and volume. Our FibroSensing membrane showed great sensitivity in detecting changes at the abiotic/biotic interface, such as collagen deposition and myofibroblast proliferation. The potential of the FSDSR to overcome fibrotic capsule formation and maintain constant drug dosing over time was demonstrated in silico and in vitro. Controlled closed loop release of methylene blue into agarose gels (with a comparable fold change in permeability relating to 7 and 28 days in vivo) was achieved by adjusting the magnitude and frequency of pneumatic actuations after impedance measurements by the FibroSensing membrane. By sensing fibrotic capsule formation in vivo, the FSDSR will be capable of probing and adapting to the foreign body response through dynamic actuation changes. Informed by real-time sensor signals, this device offers the potential for long-term efficacy and sustained drug dosing, even in the setting of fibrotic capsule formation.
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Affiliation(s)
- Rachel Beatty
- Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, University of Galway, Galway, Ireland
- SFI Centre for Advanced Materials and BioEngineering Research (AMBER), Trinity College Dublin, Dublin, Ireland
| | - Keegan L Mendez
- Harvard-MIT Program in Health Sciences and Technology, Cambridge, MA, USA
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Lucien H J Schreiber
- Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, University of Galway, Galway, Ireland
| | - Ruth Tarpey
- Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, University of Galway, Galway, Ireland
- CÚRAM, Centre for Research in Medical Devices, University of Galway, Galway, Ireland
- Biomedical Engineering, School of Engineering, University of Galway, Galway, Ireland
| | - William Whyte
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yiling Fan
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Scott T Robinson
- Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, University of Galway, Galway, Ireland
- SFI Centre for Advanced Materials and BioEngineering Research (AMBER), Trinity College Dublin, Dublin, Ireland
| | - Joanne O'Dwyer
- Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, University of Galway, Galway, Ireland
| | - Andrew J Simpkin
- School of Mathematical and Statistical Sciences, University of Galway, Galway, Ireland
| | - Joseph Tannian
- Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, University of Galway, Galway, Ireland
| | - Peter Dockery
- Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, University of Galway, Galway, Ireland
| | - Eimear B Dolan
- Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, University of Galway, Galway, Ireland
- CÚRAM, Centre for Research in Medical Devices, University of Galway, Galway, Ireland
- Biomedical Engineering, School of Engineering, University of Galway, Galway, Ireland
| | - Ellen T Roche
- Harvard-MIT Program in Health Sciences and Technology, Cambridge, MA, USA
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Garry P Duffy
- Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, University of Galway, Galway, Ireland
- SFI Centre for Advanced Materials and BioEngineering Research (AMBER), Trinity College Dublin, Dublin, Ireland
- CÚRAM, Centre for Research in Medical Devices, University of Galway, Galway, Ireland
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Abasi S, Aggas JR, Garayar-Leyva GG, Walther BK, Guiseppi-Elie A. Bioelectrical Impedance Spectroscopy for Monitoring Mammalian Cells and Tissues under Different Frequency Domains: A Review. ACS MEASUREMENT SCIENCE AU 2022; 2:495-516. [PMID: 36785772 PMCID: PMC9886004 DOI: 10.1021/acsmeasuresciau.2c00033] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 08/05/2022] [Accepted: 08/05/2022] [Indexed: 05/13/2023]
Abstract
Bioelectrical impedance analysis and bioelectrical impedance spectroscopy (BIA/BIS) of tissues reveal important information on molecular composition and physical structure that is useful in diagnostics and prognostics. The heterogeneity in structural elements of cells, tissues, organs, and the whole human body, the variability in molecular composition arising from the dynamics of biochemical reactions, and the contributions of inherently electroresponsive components, such as ions, proteins, and polarized membranes, have rendered bioimpedance challenging to interpret but also a powerful evaluation and monitoring technique in biomedicine. BIA/BIS has thus become the basis for a wide range of diagnostic and monitoring systems such as plethysmography and tomography. The use of BIA/BIS arises from (i) being a noninvasive and safe measurement modality, (ii) its ease of miniaturization, and (iii) multiple technological formats for its biomedical implementation. Considering the dependency of the absolute and relative values of impedance on frequency, and the uniqueness of the origins of the α-, β-, δ-, and γ-dispersions, this targeted review discusses biological events and underlying principles that are employed to analyze the impedance data based on the frequency range. The emergence of BIA/BIS in wearable devices and its relevance to the Internet of Medical Things (IoMT) are introduced and discussed.
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Affiliation(s)
- Sara Abasi
- Center
for Bioelectronics, Biosensors and Biochips (C3B®), Department
of Biomedical Engineering, Texas A&M
University, 400 Bizzell Street, College Station, Texas 77843, United States
- Cell
Culture Media Services, Cytiva, 100 Results Way, Marlborough, Massachusetts 01752, United States
| | - John R. Aggas
- Center
for Bioelectronics, Biosensors and Biochips (C3B®), Department
of Biomedical Engineering, Texas A&M
University, 400 Bizzell Street, College Station, Texas 77843, United States
- Test
Development, Roche Diagnostics, 9115 Hague Road, Indianapolis, Indiana 46256, United
States
| | - Guillermo G. Garayar-Leyva
- Center
for Bioelectronics, Biosensors and Biochips (C3B®), Department
of Biomedical Engineering, Texas A&M
University, 400 Bizzell Street, College Station, Texas 77843, United States
- Department
of Electrical and Computer Engineering, Texas A&M University, 400 Bizzell Street, College Station, Texas 77843, United States
| | - Brandon K. Walther
- Center
for Bioelectronics, Biosensors and Biochips (C3B®), Department
of Biomedical Engineering, Texas A&M
University, 400 Bizzell Street, College Station, Texas 77843, United States
- Department
of Cardiovascular Sciences, Houston Methodist
Institute for Academic Medicine and Houston Methodist Research Institute, 6670 Bertner Avenue, Houston, Texas 77030, United States
| | - Anthony Guiseppi-Elie
- Center
for Bioelectronics, Biosensors and Biochips (C3B®), Department
of Biomedical Engineering, Texas A&M
University, 400 Bizzell Street, College Station, Texas 77843, United States
- Department
of Electrical and Computer Engineering, Texas A&M University, 400 Bizzell Street, College Station, Texas 77843, United States
- Department
of Cardiovascular Sciences, Houston Methodist
Institute for Academic Medicine and Houston Methodist Research Institute, 6670 Bertner Avenue, Houston, Texas 77030, United States
- ABTECH Scientific,
Inc., Biotechnology Research Park, 800 East Leigh Street, Richmond, Virginia 23219, United
States
- . Tel.: +1(804)347.9363.
Fax: +1(804)347.9363
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Utilization of dielectric properties for assessment of liver ischemia-reperfusion injury in vivo and during machine perfusion. Sci Rep 2022; 12:11183. [PMID: 35778457 PMCID: PMC9249774 DOI: 10.1038/s41598-022-14817-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 06/13/2022] [Indexed: 11/20/2022] Open
Abstract
There is a shortage of donor livers and patients consequently die on waiting lists worldwide. Livers are discarded if they are clinically judged to have a high risk of non-function following transplantation. With the aim of extending the pool of available donor livers, we assessed the condition of porcine livers by monitoring the microwave dielectric properties. A total of 21 livers were divided into three groups: control with no injury (CON), biliary injury by hepatic artery occlusion (AHEP), and overall hepatic injury by static cold storage (SCS). All were monitored for four hours in vivo, followed by ex vivo plurithermic machine perfusion (PMP). Permittivity data was modeled with a two-pole Cole–Cole equation, and dielectric properties from one-hour intervals were analyzed during in vivo and normothermic machine perfusion (NMP). A clear increasing trend in the conductivity was observed in vivo in the AHEP livers compared to the control livers. After four hours of NMP, separations in the conductivity were observed between the three groups. Our results indicate that dielectric relaxation spectroscopy (DRS) can be used to detect and differentiate liver injuries, opening for a standardized and reliable point of evaluation for livers prior to transplantation.
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Oshin EA, Guo S, Jiang C. Determining tissue conductivity in tissue ablation by nanosecond pulsed electric fields. Bioelectrochemistry 2021; 143:107949. [PMID: 34583212 PMCID: PMC8643318 DOI: 10.1016/j.bioelechem.2021.107949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 09/10/2021] [Accepted: 09/15/2021] [Indexed: 02/03/2023]
Abstract
Nanosecond pulsed electric field (nsPEF) causes the permeabilization of the cell membrane and has been used to non-thermally treat cancerous tissues. As increased permeabilization in membranes were reported to be accompanied by impedance changes, the ablation effect of nsPEF on tissues can be monitored via the changes in tissue conductivity. In this study, effects of nsPEF on biological tissues were evaluated by determining the conductivities of potato and 4 T1-luc breast tumor tissues ex vivo from a murine model subjected to multiple 100-ns, 1-10 kV pulses. Using a four-needle electrode system with a calibrated electrode constant of 1.1 ± 0.1 cm, the conductivities of tissues was determined from both the network-analyzer measurement, before and after treatment, and voltage-current measurement in real-time. The conductivity of the potato tissue was measured for a frequency range of 0.1-3 MHz, and it increased with increasing pulse number and voltage amplitude. The conductivity of the tumor tissue was also observed to increase with pulse number and pulse voltage over a similar frequency range. In addition, the linear correlation between the ablation area in a treated potato tissue and the conductivity change in the tissue suggests that conductivity analysis of biological tissue under treatment could be a fast and sensitive approach to evaluate the effectiveness of a nsPEF treatment.
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Affiliation(s)
- Edwin A. Oshin
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA,Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA, USA
| | - Siqi Guo
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA
| | - Chunqi Jiang
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA,Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA, USA
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Anumba DOC, Stern V, Healey JT, Dixon S, Brown BH. Value of cervical electrical impedance spectroscopy to predict spontaneous preterm delivery in asymptomatic women: the ECCLIPPx prospective cohort study. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2021; 58:293-302. [PMID: 32798253 DOI: 10.1002/uog.22180] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 07/30/2020] [Accepted: 08/03/2020] [Indexed: 06/11/2023]
Abstract
OBJECTIVES Preterm birth (PTB) accounts for two-thirds of deaths of structurally normal babies and is associated with substantial lifetime healthcare costs. Prevention of PTB remains limited by the modest accuracy of prediction methods, namely transvaginal ultrasound (TVS) cervical length (CL) measurement and quantitative cervicovaginal fetal fibronectin (FFN) estimation. We report the first substantive study detailing the predictive performance of a cervical probe device based on electrical impedance spectroscopy (EIS) for PTB - the EleCtriCaL Impedance Prediction of Preterm birth by spectroscopy of the cervix (ECCLIPPx) study. We aimed to compare the accuracy of cervical EIS-based prediction of spontaneous PTB with that of prediction using TVS-CL and FFN in asymptomatic women in the mid-trimester. METHODS We studied asymptomatic women with a singleton pregnancy at 20-22 weeks' and 26-28 weeks' gestation. EIS was performed using a Sheffield Mark 5.0 device that makes measurements in the frequency range 76 Hz to 625 kHz using a small probe housing tetrapolar electrodes. TVS-CL and FFN were also measured. The associations of cervical EIS, TVS-CL and FFN with spontaneous delivery before 37 weeks and before 32 weeks were determined by multivariate linear and non-linear logistic regression analysis. Areas under the receiver-operating-characteristics curves (AUC) plots of sensitivity against specificity were used to compare the predictive performance of all parameters, both in isolation and in combination. RESULTS Of the 365 asymptomatic women studied at 20-22 weeks who were not receiving treatment, 29 had spontaneous PTB, 14 had indicated PTB and 322 had term birth. At the higher frequencies assessed, cervical EIS predicted spontaneous PTB before 37 weeks with an AUC of 0.76 (95% CI, 0.71-0.81), compared with AUCs of 0.72 (95% CI, 0.66-0.76) for TVS-CL and 0.62 (95% CI, 0.56-0.72) for FFN. Combining all three assessments improved the prediction of spontaneous PTB before 37 weeks (AUC, 0.79 (95% CI, 0.74-0.83)) compared with TVS-CL and FFN alone. Incorporating a history of spontaneous PTB (defined as previous mid-trimester miscarriage or spontaneous PTB (14 to < 37 weeks)) into the cervical EIS prediction model improved the accuracy of prediction of spontaneous PTB before 37 weeks (AUC, 0.83 (95% CI, 0.78-0.87)) and before 32 weeks (AUC, 0.86 (95% CI, 0.82-0.90)). CONCLUSIONS Mid-trimester cervical EIS assessment predicts spontaneous PTB. Larger confirmatory studies investigating its potential clinical utility and to inform effective preventive interventions are required. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
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Affiliation(s)
- D O C Anumba
- Academic Unit of Reproductive and Developmental Medicine, Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK
| | - V Stern
- Academic Unit of Reproductive and Developmental Medicine, Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK
| | - J T Healey
- Medical Physics and Clinical Engineering, University of Sheffield, Sheffield, UK
| | - S Dixon
- School of Health and Related Research (ScHARR), University of Sheffield, Sheffield, UK
| | - B H Brown
- Medical Physics and Clinical Engineering, University of Sheffield, Sheffield, UK
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Wang H, Wang L, Yang L, Shi X, Wen Z, Dong X. Exploring the relationship between the dielectric properties and viability of human normal hepatic tissues from 10 Hz to 100 MHz based on grey relational analysis and BP neural network. Comput Biol Med 2021; 134:104494. [PMID: 34058511 DOI: 10.1016/j.compbiomed.2021.104494] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 11/19/2022]
Abstract
Liver is an important parenchyma organ, and its tissue viability plays an important role in liver transplantation and liver ischemic injury assessment. Dielectric property is a useful biophysical feature that provides insights into the structure and composition of biological tissues. This work aims to establish the relationship between the dielectric properties and viability of human normal hepatic tissues and explore the possibility of evaluating tissue viability by using dielectric properties. First, data on dielectric properties and tissue viability (including cell morphology and enzyme indicators) were collected from human liver tissues at 0.25-24 h after isolation. Grey relational analysis was conducted to select dielectric property and tissue viability indices that were highly correlated with prolonged ex vivo time as the inputs and outputs, respectively, of back-propagation (BP) neural network analysis. Finally, a BP neural network was developed with the Levenberg-Marquardt algorithm to explore the possibility of using dielectric properties as the basis for tissue viability evaluation. Results showed that the mean relative error for prediction was 2.40%, indicating that the model showed potential in forecasting liver tissue viability by applying dielectric properties.
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Affiliation(s)
- Hang Wang
- School of Aerospace Medicine, Air Force Medical University, Xi'an, China.
| | - Lei Wang
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, China
| | - Lin Yang
- School of Aerospace Medicine, Air Force Medical University, Xi'an, China
| | - Xuetao Shi
- School of Biomedical Engineering, Air Force Medical University, Xi'an, China
| | - Zhihong Wen
- School of Aerospace Medicine, Air Force Medical University, Xi'an, China
| | - Xiuzhen Dong
- School of Biomedical Engineering, Air Force Medical University, Xi'an, China.
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7
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Zimmermann J, van Rienen U. Ambiguity in the interpretation of the low-frequency dielectric properties of biological tissues. Bioelectrochemistry 2021; 140:107773. [PMID: 33862548 DOI: 10.1016/j.bioelechem.2021.107773] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 02/04/2021] [Accepted: 02/08/2021] [Indexed: 10/22/2022]
Abstract
The frequency-dependent behaviour of the dielectric properties of biological tissues in the frequency range below 1 kHz has been under debate since the past century. Here, we reanalyse the raw data of the main resource of the dielectric properties of biological tissues in impedance representation. Employing a Kramers-Kronig validity test and parameter estimation techniques, we can describe the data by two physical parametric models that correspond to opposing biophysical interpretations: on the one hand the data can be explained only by intrinsic tissue properties, but on the other hand evidence for electrode-specific effects can be found for all tissues under investigation. The first interpretation would justify the continued use of a parametric model comprising four Cole-Cole dispersions, which describe the dielectric properties from extremely low to very high frequencies. As an alternative that is in accordance with the second interpretation, we suggest to omit the slowest of the four dispersions in the model and increase the static conductivity to account for a frequency-independent conductivity below 1 kHz.
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Affiliation(s)
- Julius Zimmermann
- Institute of General Electrical Engineering, University of Rostock, D-18051 Rostock, Germany.
| | - Ursula van Rienen
- Institute of General Electrical Engineering, University of Rostock, D-18051 Rostock, Germany; Department Life, Light & Matter, University of Rostock, D-18051 Rostock, Germany; Department of Ageing of Individuals and Society, Interdisciplinary Faculty, University of Rostock, D-18051 Rostock, Germany.
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Abstract
We study long-term electrical resistance dynamics in mycelium and fruit bodies of oyster fungi P. ostreatus. A nearly homogeneous sheet of mycelium on the surface of a growth substrate exhibits trains of resistance spikes. The average width of spikes is c. 23[Formula: see text]min and the average amplitude is c. 1[Formula: see text]k[Formula: see text]. The distance between neighboring spikes in a train of spikes is c. 30[Formula: see text]min. Typically, there are 4–6 spikes in a train of spikes. Two types of electrical resistance spikes trains are found in fruit bodies: low frequency and high amplitude (28[Formula: see text]min spike width, 1.6[Formula: see text]k[Formula: see text] amplitude, 57[Formula: see text]min distance between spikes) and high frequency and low amplitude (10[Formula: see text]min width, 0.6[Formula: see text]k[Formula: see text] amplitude, 44[Formula: see text]min distance between spikes). The findings could be applied in monitoring of physiological states of fungi and future development of living electronic devices and sensors.
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Affiliation(s)
| | - Alessandro Chiolerio
- Center for Sustainable Future Technologies, Istituto Italiano di Tecnologia, Torino, Italy
| | - Georgios Sirakoulis
- Department of Electrical and Computer Engineering, Democritus University of Thrace, Xanthi, Greece
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Kim JJ, Andrew TL. Real-time and noninvasive detection of UV-Induced deep tissue damage using electrical tattoos. Biosens Bioelectron 2020; 150:111909. [PMID: 31786020 DOI: 10.1016/j.bios.2019.111909] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 11/15/2019] [Accepted: 11/19/2019] [Indexed: 11/29/2022]
Abstract
Understanding longterm deep tissue damage caused by UV radiation is imperative for ensuring the health and safety of living organisms that are regularly exposed to radiation sources. While existing UV dosimeters can quantify the cumulative amount of radiation to which an organism is exposed, these sensors cannot reveal the presence and extent of internal tissue damage caused by such exposure. Here we describe a method that uses conducting polymer tattoos to detect UV radiation-induced deep tissue damage in living organisms using bioimpedance analysis (BIA), which allows for noninvasive, real-time measurements of body composition and point-of-care assessment of clinical condition. To establish a performance baseline for this method, we quantify the effects of UVA radiation on live plant leaves. Low-energy UVA waves penetrate further into biological tissue, as compared to UVB, UVC and ionizing radiation, and cause longlasting deep tissue damage that cannot be immediately and readily detected using surface-sensitive techniques, such as photogrammetry and epidermal sensors. We show that single-frequency bioimpedance analysis allows for sensitive, real-time monitoring of UVA damage: as UVA dose increases, the bioimpedance of a plant leaf measured at a frequency of 1 kHz linearly decreases until the extent of radiation damage saturates and the specimen is effectively necrotized. We establish a strong correlation between radiation fluence, internal biological damage and the bioimpedance signal measured using our conducting polymer tattoos, which supports the efficacy of our method as a new type of internal biodosimetry.
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Affiliation(s)
- Jae Joon Kim
- Departments of Chemistry and Chemical Engineering, University of Massachusetts Amherst, Amherst, MA, 01003, United States
| | - Trisha L Andrew
- Departments of Chemistry and Chemical Engineering, University of Massachusetts Amherst, Amherst, MA, 01003, United States.
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Clark-Matott J, Nagy JA, Sanchez B, Taylor R, Riveros D, Abraham NA, Simon DK, Rutkove SB. Altered muscle electrical tissue properties in a mouse model of premature aging. Muscle Nerve 2019; 60:801-810. [PMID: 31531861 DOI: 10.1002/mus.26714] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 09/07/2019] [Accepted: 09/11/2019] [Indexed: 01/31/2023]
Abstract
INTRODUCTION Improved methods are needed to detect and quantify age-related muscle change. In this study we assessed the electrical properties of muscle impacted by acquired mitochondrial DNA mutations via the PolG mouse, which exhibits typical age-associated features, and the impact of a potential therapy, nicotinamide mononucleotide (NMN). METHODS The gastrocnemii of 24 PolG and 30 wild-type (WT) mice (8 PolG and 17 WT treated with NMN) were studied in an electrical impedance-measuring cell. Conductivity and relative permittivity were determined from the impedance data. Myofiber cross-sectional area (CSA) was quantified histologically. RESULTS Untreated PolG mice demonstrated alterations in several impedance features, including 50-kHz relative permittivity and center frequency. A potential effect of NMN was also observed in these parameters in PolG but not WT animals. Impedance values correlated with myofiber CSA. DISCUSSION Electrical impedance is sensitive to myofiber features considered characteristic of aging and to the impact of a potential therapy.
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Affiliation(s)
- Joanne Clark-Matott
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Janice A Nagy
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Benjamin Sanchez
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Rebecca Taylor
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Daniela Riveros
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Neeta A Abraham
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - David K Simon
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Seward B Rutkove
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
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Lueck S, Preusse C, Delis A, Schaefer M. Development of cell oedema in piglet hearts during ischaemia monitored by dielectric spectroscopy. Bioelectrochemistry 2019; 129:54-61. [DOI: 10.1016/j.bioelechem.2019.04.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/29/2019] [Accepted: 04/29/2019] [Indexed: 11/30/2022]
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12
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Yuan P, Jiang T, Hirasaka K, Wang Y, Matsuo K, Miyazaki R, Tachibana K, Taniyama S. Application of Bio-Impedance Analysis to Estimate the Condition of Yellowtail (Seriola quinqueradiata) Muscle at Different Storage Temperatures. Bioelectromagnetics 2019; 40:488-497. [PMID: 31392747 DOI: 10.1002/bem.22211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 07/19/2019] [Indexed: 11/06/2022]
Abstract
Changes in impedance at 2 kHz, adenosine triphosphate (ATP) content, and muscle contraction were evaluated in yellowtail during 0 (ice), 5, 10, 15, and 20°C storage. Histological changes during ice storage were also measured. At any temperature, although impedance increased with both rigor mortis and ATP consumption during early storage, it began to decrease rapidly when ATP was almost depleted. Moreover, temporarily increasing impedance had a strong relationship with ATP content; decreasing impedance had a significant correlation with storage temperature after ATP depletion. Furthermore, impedance increased with narrowing of intercellular spaces when sarcolemma was intact and decreased with expansion of intercellular spaces when sarcolemma was leaky. Meanwhile, changes of sarcolemma and intercellular spaces were accompanied by ATP change. Thus, ATP is one significant physiological factor for impedance change, and temperature greatly influenced impedance after depletion of ATP. Results suggest that impedance analysis can be used as a convenient and nondestructive method to diagnose condition of tissue at different storage temperatures. Bioelectromagnetics. 2019;40:488-497. © 2019 Bioelectromagnetics Society.
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Affiliation(s)
- Pengxiang Yuan
- College of Food and Pharmacy, Zhejiang Ocean University, ZhouShan, China.,Grauate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki, Japan
| | - Tong Jiang
- Grauate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki, Japan
| | - Katsuya Hirasaka
- Grauate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki, Japan
| | - Yao Wang
- Grauate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki, Japan
| | - Kazuki Matsuo
- Grauate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki, Japan
| | - Riho Miyazaki
- Department of Food Dietetics, Higashi Chikushi Junior College, Kitakyushu, Japan
| | - Katsuyasu Tachibana
- Grauate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki, Japan
| | - Shigeto Taniyama
- Grauate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki, Japan
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Kubisz L, Hojan-Jezierska D, Szewczyk M, Majewska A, Kawałkiewicz W, Pankowski E, Janus M, Cwajda-Białasik J, Mościcka P, Jawień A. In vivo electrical impedance measurement in human skin assessment. PURE APPL CHEM 2019. [DOI: 10.1515/pac-2018-1106] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Structural and chemical alterations in living tissue are reflected in electrical impedance changes. However, due to the complexity of skin structure, the relation between electrical parameters and physiological/pathological conditions is difficult to establish. The impedance dispersion reflects the clinical status of the examined skin tissue and, therefore, it is frequently used in a non-invasive evaluation of exposing skin to various factors. The method has been used to assess the effect of the fish collagen on the skin of patients suffering from the leg ulcer. Therefore, from a number of different approaches to skin electrical impedance dispersion, the one considered to be safe was selected and applied. This paper presents a short review of different technical approaches to in vivo electrical impedance measurements, as well as an analysis of the results and the effect of fish collagen locally administered on human skin.
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Affiliation(s)
- Leszek Kubisz
- Department of Biophysics, Chair of Biophysics , Poznan University of Medical Sciences in Poznań , Poznań , Poland
| | - Dorota Hojan-Jezierska
- Department of Hearing Healthcare Profession, Chair of Biophysics , Poznan University of Medical Sciences in Poznań , Poznań , Poland
| | - Maria Szewczyk
- Department of Vascular Surgery and Angiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz , Nicolaus Copernicus University in Torun , Bydgoszcz , Poland
- Department of Perioperative Nursing, Department of Surgical Nursing and Chronic Wound Care , Nicolaus Copernicus University , Ludwic Rydygier Collegium Medicum in Bydgoszcz , Bydgoszcz , Poland
- Outpatient Department for Chronic Wound Management , University Hospital No 1 in Bydgoszcz , Bydgoszcz , Poland
| | - Anna Majewska
- Department of Hearing Healthcare Profession, Chair of Biophysics , Poznan University of Medical Sciences in Poznań , Poznań , Poland
| | - Weronika Kawałkiewicz
- Department of Biophysics, Chair of Biophysics , Poznan University of Medical Sciences in Poznań , Poznań , Poland
| | - Edward Pankowski
- Department of Biophysics, Chair of Biophysics , Poznan University of Medical Sciences in Poznań , Poznań , Poland
| | - Marta Janus
- Department of Biophysics, Chair of Biophysics , Poznan University of Medical Sciences in Poznań , Poznań , Poland
| | - Justyna Cwajda-Białasik
- Department of Vascular Surgery and Angiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz , Nicolaus Copernicus University in Torun , Bydgoszcz , Poland
- Department of Perioperative Nursing, Department of Surgical Nursing and Chronic Wound Care , Nicolaus Copernicus University , Ludwic Rydygier Collegium Medicum in Bydgoszcz , Bydgoszcz , Poland
- Outpatient Department for Chronic Wound Management , University Hospital No 1 in Bydgoszcz , Bydgoszcz , Poland
| | - Paulina Mościcka
- Department of Vascular Surgery and Angiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz , Nicolaus Copernicus University in Torun , Bydgoszcz , Poland
- Department of Perioperative Nursing, Department of Surgical Nursing and Chronic Wound Care , Nicolaus Copernicus University , Ludwic Rydygier Collegium Medicum in Bydgoszcz , Bydgoszcz , Poland
- Outpatient Department for Chronic Wound Management , University Hospital No 1 in Bydgoszcz , Bydgoszcz , Poland
| | - Arkadiusz Jawień
- Department of Vascular Surgery and Angiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz , Nicolaus Copernicus University in Torun , Bydgoszcz , Poland
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Cottet J, Kehren A, Lasli S, van Lintel H, Buret F, Frénéa-Robin M, Renaud P. Dielectrophoresis-assisted creation of cell aggregates under flow conditions using planar electrodes. Electrophoresis 2019; 40:1498-1509. [PMID: 30706961 DOI: 10.1002/elps.201800435] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 01/20/2019] [Accepted: 01/30/2019] [Indexed: 12/13/2022]
Abstract
We present a microfluidic platform allowing dielectrophoresis-assisted formation of cell aggregates of controlled size and composition under flow conditions. When specific experimental conditions are met, negative dielectrophoresis allows efficient concentration of cells towards electric field minima and subsequent aggregation. This bottom-up assembly strategy offers several advantages with respect to the targeted application: first, dielectrophoresis offers precise control of spatial cell organization, which can be adjusted by optimizing electrode design. Then, it could contribute to accelerate the establishment of cell-cell interactions by favoring close contact between neighboring cells. The trapping geometry of our chip is composed of eight electrodes arranged in a circle. Several parameters have been tested in simulations to find the best configurations for trapping in flow. Those configurations have been tested experimentally with both polystyrene beads and human embryonic kidney cells. The final design and experimental setup have been optimized to trap cells and release the created aggregates on demand.
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Affiliation(s)
- Jonathan Cottet
- Univ Lyon, Ecole Centrale de Lyon, Université Claude Bernard Lyon 1, INSA Lyon, CNRS, Ampère, Ecully, France.,École Polytechnique Fédérale de Lausanne, EPFL-STI-IMT-LMIS4, Station 17, CH-1015, Lausanne, Switzerland
| | - Alexandre Kehren
- École Polytechnique Fédérale de Lausanne, EPFL-STI-IMT-LMIS4, Station 17, CH-1015, Lausanne, Switzerland
| | - Soufian Lasli
- École Polytechnique Fédérale de Lausanne, EPFL-STI-IMT-LMIS4, Station 17, CH-1015, Lausanne, Switzerland
| | - Harald van Lintel
- École Polytechnique Fédérale de Lausanne, EPFL-STI-IMT-LMIS4, Station 17, CH-1015, Lausanne, Switzerland
| | - François Buret
- Univ Lyon, Ecole Centrale de Lyon, Université Claude Bernard Lyon 1, INSA Lyon, CNRS, Ampère, Ecully, France
| | - Marie Frénéa-Robin
- Univ Lyon, Ecole Centrale de Lyon, Université Claude Bernard Lyon 1, INSA Lyon, CNRS, Ampère, Ecully, France
| | - Philippe Renaud
- École Polytechnique Fédérale de Lausanne, EPFL-STI-IMT-LMIS4, Station 17, CH-1015, Lausanne, Switzerland
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15
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Tronstad C, Strand-Amundsen R. Possibilities in the Application of Machine Learning on Bioimpedance Time-series. JOURNAL OF ELECTRICAL BIOIMPEDANCE 2019; 10:24-33. [PMID: 33584879 PMCID: PMC7531209 DOI: 10.2478/joeb-2019-0004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Indexed: 05/16/2023]
Abstract
The relation between a biological process and the changes in passive electrical properties of the tissue is often non-linear, in which developing prediction models based on bioimpedance spectra is not trivial. Relevant information on tissue status may also lie in characteristic developments in the bioimpedance spectra over time, often neglected by conventional methods. The aim of this study was to explore possibilities in machine learning methods for time series of bioimpedance spectra, where we used organ ischemia as an example. Based on published data on the development of the bioimpedance spectrum during liver ischemia, a simulation model was made and used to generate sets of synthetic data with different levels of organ-to-organ variation, measurement noise and drift. Three types of artificial neural networks were employed in learning to predict the ischemic duration, based on the simulated datasets. The simulated prediction performance was very dependent on the amount of training examples, the organ-to-organ variation and the selection of input variables from the bioimpedance spectrum. The performance was also affected by noise and drift in the measurement, but a recurrent neural network with long short-term memory units could obtain good predictions even on noisy and drifting measurements. This approach may be relevant for further exploration on several applications of bioimpedance having the purpose of predicting a biological state based on spectra measured over time.
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Affiliation(s)
- Christian Tronstad
- Department of Clinical and Biomedical Engineering, Oslo University Hospital - Rikshospitalet, Oslo, Norway
- E-mail:
| | - Runar Strand-Amundsen
- Department of Clinical and Biomedical Engineering, Oslo University Hospital - Rikshospitalet, Oslo, Norway
- Sensocure AS, Skoppum, Norway
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16
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Shiffman C. Scaling and the frequency dependence of Nyquist plot maxima of the electrical impedance of the human thigh. Physiol Meas 2017; 38:2203-2221. [PMID: 29044047 DOI: 10.1088/1361-6579/aa9470] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To define and elucidate the properties of reduced-variable Nyquist plots. APPROACH Non-invasive measurements of the electrical impedance of the human thigh. A retrospective analysis of the electrical impedances of 154 normal subjects measured over the past decade shows that 'scaling' of the Nyquist plots for human thigh muscles is a property shared by healthy thigh musculature, irrespective of subject and the length of muscle segment. Here the term scaling signifies the near and sometimes 'perfect' coalescence of the separate X versus R plots into one 'reduced' Nyquist plot by the simple expedient of dividing R and X by X m , the value of X at the reactance maximum. To the extent allowed by noise levels one can say that there is one 'universal' reduced Nyquist plot for the thigh musculature of healthy subjects. MAIN RESULTS There is one feature of the Nyquist curves which is not 'universal', however, namely the frequency f m at which the maximum in X is observed. That is found to vary from 10 to 100 kHz. depending on subject and segment length. Analysis shows, however, that the mean value of 1/f m is an accurately linear function of segment length, though there is a small subject-to-subject random element as well. Also, following the recovery of an otherwise healthy victim of ankle fracture demonstrates the clear superiority of measurements above about 800 kHz, where scaling is not observed, in contrast to measurements below about 400 kHz, where scaling is accurately obeyed. SIGNIFICANCE The ubiquity of 'scaling' casts new light on the interpretation of impedance results as they are used in electrical impedance myography and bioelectric impedance analysis.
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Affiliation(s)
- Carl Shiffman
- Physics department, Northeastern University, Boston, MA, United States of America
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17
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Yan Q, Jin G, Ma K, Qin M, Zhuang W, Sun J. Magnetic inductive phase shift: a new method to differentiate hemorrhagic stroke from ischemic stroke on rabbit. Biomed Eng Online 2017; 16:63. [PMID: 28558773 PMCID: PMC5450218 DOI: 10.1186/s12938-017-0354-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Accepted: 05/22/2017] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND The major therapy for ischemic stroke is thrombolytic treatment, but severe consequences occur when this method is used to treat hemorrhagic stroke. Currently, computed tomography and magnetic resonance imaging are used to differentiate between two types of stroke, but these two methods are ineffective for pre-hospital care. METHODS We developed a new brain diagnostic device for rabbits based on electromagnetic induction to non-invasively differentiate two types of stroke. The device includes two coils and a phase difference measurement system that detects the magnetic inductive phase shift (MIPS) value to reflect the tissue's condition. The hemorrhage model was established through the injection of autologous blood into the internal capsule of a rabbit's brain. Ischemia was induced in the brain of a rabbit by bilateral carotid artery occlusion. Two types of animal models were measured with our device. RESULTS The MIPS value gradually decreased with increasing injected blood and increased with ischemia time. The MIPS changes induced by the two types of strokes were exact opposites, and the absolute values of MIPS variation in the hemorrhagic and the ischemic groups were significantly larger than those of the normal control group (P < 0.05). CONCLUSIONS The tested technique can differentiate ischemic stroke from hemorrhagic stroke on rabbit brain in a non-invasive, continuous, and bulk monitoring manner by using a simple and inexpensive apparatus.
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Affiliation(s)
- Qingguang Yan
- College of Biomedical Engineering, Third Military Medical University, Chongqing, 400030 China
| | - Gui Jin
- College of Biomedical Engineering, Third Military Medical University, Chongqing, 400030 China
| | - Ke Ma
- College of Biomedical Engineering, Third Military Medical University, Chongqing, 400030 China
| | - Mingxin Qin
- College of Biomedical Engineering, Third Military Medical University, Chongqing, 400030 China
| | - Wei Zhuang
- College of Biomedical Engineering, Third Military Medical University, Chongqing, 400030 China
| | - Jian Sun
- College of Biomedical Engineering, Third Military Medical University, Chongqing, 400030 China
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18
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Wang JY, Healey T, Barker A, Brown B, Monk C, Anumba D. Magnetic induction spectroscopy (MIS)-probe design for cervical tissue measurements. Physiol Meas 2017; 38:729-744. [PMID: 28448273 DOI: 10.1088/1361-6579/aa6b4e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Gradiometers have the advantage of increasing measuring sensitivity, which is particularly useful in magnetic induction spectroscopy (MIS) for bio-impedance measurements. Traditional gradiometers use a pair of field sensing coils equally distant and on opposite sides of a drive coil, which provides high immunity to interference. In this paper, a ferrite-cored coaxial gradiometer probe of 29 mm diameter has been developed for measuring the impedance spectra of cervical tissues in vivo. APPROACH It consists of a ferrite rod with outer ferrite confinement screening in order to eliminate the signals from surrounding tissue. The magnetic screening efficiency was compared with an air-cored gradiometer probe. For both gradiometer probes, a drive coil and two sensing coils were wound on a borosilicate glass former aligned coaxially with two sensing coils equidistant from the drive coil. The signal sensitivity of those two MIS gradiometers has been measured using saline samples with a conductivity range between 0.1 and 1.1 S m-1. Finite element methods using COMSOL Multiphysics have been used to simulate the distribution of sensitivity to conductivity over the face of each probe and with depth. MAIN RESULTS The ferrite-cored probe has a sensitivity confined to the volume defined by the gap between the ferrite core and outer tube of ferrite while the air-cored probe without any magnetic shielding had a wide sensitivity over the face and the side of the probe. Four saline samples and one of distilled water with conductivities from 0.1 to 1.1 S m-1 have been used to make conductivity measurements at frequencies of 50 kHz, 100 kHz, and 300 kHz. The measurement accuracy of the air-cored MIS probe was 0.09 S m-1 at 50 kHz, improving to 0.05 S m-1 at 300 kHz. For the ferrite-cored MIS probe, the measurement accuracy was 0.28 S m-1 at 50 kHz, improving to 0.04 S m-1 at 300 kHz. SIGNIFICANCE In vivo measurements on human hand have been performed using both types of gradiometers and the conductivity is consistent with reported data.
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Affiliation(s)
- Jau-Yi Wang
- Academic Unit of Reproductive and Development Medicine, Jessop Wing, University of Sheffield and Sheffield Teaching Hospitals NHS Trust, Sheffield S10 2SF, United Kingdom
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19
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Strand-Amundsen RJ, Reims HM, Tronstad C, Kalvøy H, Martinsen ØG, Høgetveit JO, Ruud TE, Tønnessen TI. Ischemic small intestine—in vivoversusex vivobioimpedance measurements. Physiol Meas 2017; 38:715-728. [DOI: 10.1088/1361-6579/aa67b7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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20
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Abstract
A specific device and system has been developed and tested for clinical monitoring of gastric mucosal reactance in the critically ill as an early warning of splanchnic hypoperfusion associated with shock and sepsis. This device has been proven effective in clinical trials and is expected to become commercially available next year. The system uses a combination nasogastric tube and impedance spectroscopy probe as a single catheter. Because this device has a double function, the question is: Does enteral feeding or suction affect the gastric reactance measurements? This study was designed to evaluate the effect of feeding and suction on the measurement of gastric impedance spectroscopy in healthy volunteers. Impedance spectra were obtained from the gastric wall epithelia of 18 subjects. The spectra were measured for each of the following conditions: postinsertion of gastric probe, during active suction, postactive suction, and during enteral feeding (236 ml of nutritional supplement). Impedance spectra were reproducible in all volunteers under all conditions tested. There was a slight increase in impedance parameters after suction, and a decrease in impedance after feeding; however, these observed differences were insignificant compared to patient-to-patient variability, and truly negligible compared with previously observed changes associated with splanchnic ischemia in critically ill patients. Our results demonstrate that suction or feeding when using the impedance spectro-metry probe/nasogastric tube does not significantly interfere with gastric impedance spectrometer measurements.
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21
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Amorós-Figueras G, Jorge E, García-Sánchez T, Bragós R, Rosell-Ferrer J, Cinca J. Recognition of Fibrotic Infarct Density by the Pattern of Local Systolic-Diastolic Myocardial Electrical Impedance. Front Physiol 2016; 7:389. [PMID: 27630580 PMCID: PMC5006502 DOI: 10.3389/fphys.2016.00389] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 08/22/2016] [Indexed: 11/13/2022] Open
Abstract
Myocardial electrical impedance is a biophysical property of the heart that is influenced by the intrinsic structural characteristics of the tissue. Therefore, the structural derangements elicited in a chronic myocardial infarction should cause specific changes in the local systolic-diastolic myocardial impedance, but this is not known. This study aimed to characterize the local changes of systolic-diastolic myocardial impedance in a healed myocardial infarction model. Six pigs were successfully submitted to 150 min of left anterior descending (LAD) coronary artery occlusion followed by reperfusion. 4 weeks later, myocardial impedance spectroscopy (1–1000 kHz) was measured at different infarction sites. The electrocardiogram, left ventricular (LV) pressure, LV dP/dt, and aortic blood flow (ABF) were also recorded. A total of 59 LV tissue samples were obtained and histopathological studies were performed to quantify the percentage of fibrosis. Samples were categorized as normal myocardium (<10% fibrosis), heterogeneous scar (10–50%) and dense scar (>50%). Resistivity of normal myocardium depicted phasic changes during the cardiac cycle and its amplitude markedly decreased in dense scar (18 ± 2 Ω·cm vs. 10 ± 1 Ω·cm, at 41 kHz; P < 0.001, respectively). The mean phasic resistivity decreased progressively from normal to heterogeneous and dense scar regions (285 ± 10 Ω·cm, 225 ± 25 Ω·cm, and 162 ± 6 Ω·cm, at 41 kHz; P < 0.001 respectively). Moreover, myocardial resistivity and phase angle correlated significantly with the degree of local fibrosis (resistivity: r = 0.86 at 1 kHz, P < 0.001; phase angle: r = 0.84 at 41 kHz, P < 0.001). Myocardial infarcted regions with greater fibrotic content show lower mean impedance values and more depressed systolic-diastolic dynamic impedance changes. In conclusion, this study reveals that differences in the degree of myocardial fibrosis can be detected in vivo by local measurement of phasic systolic-diastolic bioimpedance spectrum. Once this new bioimpedance method could be used via a catheter-based device, it would be of potential clinical applicability for the recognition of fibrotic tissue to guide the ablation of atrial or ventricular arrhythmias.
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Affiliation(s)
- Gerard Amorós-Figueras
- Department of Cardiology, Hospital de la Santa Creu i Sant Pau, Institut d'Investigació Biomèdica - Sant Pau, Universitat Autònoma de Barcelona Barcelona, Spain
| | - Esther Jorge
- Department of Cardiology, Hospital de la Santa Creu i Sant Pau, Institut d'Investigació Biomèdica - Sant Pau, Universitat Autònoma de Barcelona Barcelona, Spain
| | - Tomás García-Sánchez
- Electronic and Biomedical Instrumentation Group, Department of Electronics Engineering, Universitat Politècnica de Catalunya Barcelona, Spain
| | - Ramón Bragós
- Electronic and Biomedical Instrumentation Group, Department of Electronics Engineering, Universitat Politècnica de Catalunya Barcelona, Spain
| | - Javier Rosell-Ferrer
- Electronic and Biomedical Instrumentation Group, Department of Electronics Engineering, Universitat Politècnica de Catalunya Barcelona, Spain
| | - Juan Cinca
- Department of Cardiology, Hospital de la Santa Creu i Sant Pau, Institut d'Investigació Biomèdica - Sant Pau, Universitat Autònoma de Barcelona Barcelona, Spain
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22
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Pena-Mercado E, Garcia-Lorenzana M, Arechaga E, la Rosa CHGD, Beltran NE. Gastric mucosa injury quantification in an ischemia - Reperfusion experimental model. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2016:2303-2306. [PMID: 28324964 DOI: 10.1109/embc.2016.7591190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Gastric ischemia - reperfusion (I/R) injury is an important clinical problem, which is developed in more than 80% of critically ill patients. I/R is caused by interruption of blood supply to an organ or tissue followed by blood reflow into the exposed area, leading to multiple organ failure and death. Gastric reactance has been proposed to measure tissue injury caused by ischemia. The present study evaluates a new method to quantify gastric tissue damage due to I/R, and assess its relation to gastric reactance changes. Twenty Wistar rats were randomly assigned to 4 groups: control, ischemia, I/R 30 min, I/R 1 h. Local gastric ischemia was induced by clamping the celiac artery for 30 min and reperfusion was done for 30-60 min. In all groups, gastric impedance was measured, and then gastric mucosa samples were taken for light microscopy. There were statistical significant differences (p <;0.05) among the groups with respect to the index of gastric injury proposed, which was greater in I/R 1 h group. Also, impedance parameters increased in I/R groups with respect to control, and ischemia groups. The proposed index of gastric injury allowed gastric mucosa damage quantification, and it was related with gastric impedance increase, which is an objective method to evaluate tissue injury.
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23
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Haandbæk N, Bürgel SC, Rudolf F, Heer F, Hierlemann A. Characterization of Single Yeast Cell Phenotypes Using Microfluidic Impedance Cytometry and Optical Imaging. ACS Sens 2016. [DOI: 10.1021/acssensors.6b00286] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Niels Haandbæk
- Department
of Biosystems Science and Engineering, ETH Zurich, 4058, Basel, Switzerland
| | - Sebastian C. Bürgel
- Department
of Biosystems Science and Engineering, ETH Zurich, 4058, Basel, Switzerland
| | - Fabian Rudolf
- Department
of Biosystems Science and Engineering, ETH Zurich, 4058, Basel, Switzerland
| | - Flavio Heer
- Zurich Instruments AG, Technoparkstrasse
1, 8005, Zurich, Switzerland
| | - Andreas Hierlemann
- Department
of Biosystems Science and Engineering, ETH Zurich, 4058, Basel, Switzerland
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Rodriguez S, Ollmar S, Waqar M, Rusu A. A Batteryless Sensor ASIC for Implantable Bio-Impedance Applications. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2016; 10:533-544. [PMID: 26372646 DOI: 10.1109/tbcas.2015.2456242] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The measurement of the biological tissue's electrical impedance is an active research field that has attracted a lot of attention during the last decades. Bio-impedances are closely related to a large variety of physiological conditions; therefore, they are useful for diagnosis and monitoring in many medical applications. Measuring living tissues, however, is a challenging task that poses countless technical and practical problems, in particular if the tissues need to be measured under the skin. This paper presents a bio-impedance sensor ASIC targeting a battery-free, miniature size, implantable device, which performs accurate 4-point complex impedance extraction in the frequency range from 2 kHz to 2 MHz. The ASIC is fabricated in 150 nm CMOS, has a size of 1.22 mm × 1.22 mm and consumes 165 μA from a 1.8 V power supply. The ASIC is embedded in a prototype which communicates with, and is powered by an external reader device through inductive coupling. The prototype is validated by measuring the impedances of different combinations of discrete components, measuring the electrochemical impedance of physiological solution, and performing ex vivo measurements on animal organs. The proposed ASIC is able to extract complex impedances with around 1 Ω resolution; therefore enabling accurate wireless tissue measurements.
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25
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Strand-Amundsen RJ, Tronstad C, Kalvøy H, Gundersen Y, Krohn CD, Aasen AO, Holhjem L, Reims HM, Martinsen ØG, Høgetveit JO, Ruud TE, Tønnessen TI. In vivo characterization of ischemic small intestine using bioimpedance measurements. Physiol Meas 2016; 37:257-75. [PMID: 26805916 DOI: 10.1088/0967-3334/37/2/257] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The standard clinical method for the assessment of viability in ischemic small intestine is still visual inspection and palpation. This method is non-specific and unreliable, and requires a high level of clinical experience. Consequently, viable tissue might be removed, or irreversibly damaged tissue might be left in the body, which may both slow down patient recovery. Impedance spectroscopy has been used to measure changes in electrical parameters during ischemia in various tissues. The physical changes in the tissue at the cellular and structural levels after the onset of ischemia lead to time-variant changes in the electrical properties. We aimed to investigate the use of bioimpedance measurement to assess if the tissue is ischemic, and to assess the ischemic time duration. Measurements were performed on pigs (n = 7) using a novel two-electrode setup, with a Solartron 1260/1294 impedance gain-phase analyser. After induction of anaesthesia, an ischemic model with warm, full mesenteric arterial and venous occlusion on 30 cm of the jejunum was implemented. Electrodes were placed on the serosal surface of the ischemic jejunum, applying a constant voltage, and measuring the resulting electrical admittance. As a control, measurements were done on a fully perfused part of the jejunum in the same porcine model. The changes in tan δ (dielectric parameter), measured within a 6 h period of warm, full mesenteric occlusion ischemia in seven pigs, correlates with the onset and duration of ischemia. Tan δ measured in the ischemic part of the jejunum differed significantly from the control tissue, allowing us to determine if the tissue was ischemic or not (P < 0.0001, F = (1,75.13) 188.19). We also found that we could use tan δ to predict ischemic duration. This opens up the possibility of real-time monitoring and assessment of the presence and duration of small intestinal ischemia.
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Affiliation(s)
- R J Strand-Amundsen
- Department of Clinical and Biomedical Engineering, Oslo University Hospital - Rikshospitalet, Postboks 4950 Nydalen, 0424 Oslo, Norway. Department of Physics, University of Oslo, Postboks 1048 Blindern, 0316 Oslo, Norway
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26
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Garcia-Sanchez T, Jorge E, Amoros-Figueras G, Bragos R, Cinca J, Rosell-Ferrer J. Myocardial contractility assessed by dynamic electrical impedance measurements during dobutamine stress. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:6548-51. [PMID: 26737793 DOI: 10.1109/embc.2015.7319893] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In this study, the electrical impedance of myocardial tissue is measured dynamically during the cardial cycle. The multisine-based approach used to perform electrical impedance spectroscopy (EIS) measurements allows acquiring complete spectral impedance information of the tissue dynamics during contraction. Measurements are performed in situ in the left ventricule of swines during contractility stress tests induced by dobutamine infusion. Additionally, the ECG and the left ventricular (LV) pressure are also acquired synchronously to the impedance signals. The calculated impedance magnitude exhibits a periodic behavior during tissue contraction. The amplitude (peak-to-peak) of this signal is quantified and the compared to the maximum first derivative of the LV pressure (dP/dtmax) that is used as an indicator of contractility variations. The results show a linear correlation between impedance amplitude and dP/dtmax during dobutamine-increased contractility. The present work demonstrates how fast EIS measurements during heart contraction can represent a feasible method to assess changes in myocardial contractility.
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Hernández-Balaguera E, López-Dolado E, Polo JL. Obtaining electrical equivalent circuits of biological tissues using the current interruption method, circuit theory and fractional calculus. RSC Adv 2016. [DOI: 10.1039/c5ra24535d] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The current interruption method allows a real-time estimation of the physiological state of tissues from their electrical properties.
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Affiliation(s)
- E. Hernández-Balaguera
- Escuela de Ingeniería Industrial de Toledo
- Universidad de Castilla-La Mancha
- 45071 Toledo
- Spain
| | | | - J. L. Polo
- Escuela de Ingeniería Industrial de Toledo
- Universidad de Castilla-La Mancha
- 45071 Toledo
- Spain
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Jorge E, Amorós-Figueras G, García-Sánchez T, Bragós R, Rosell-Ferrer J, Cinca J. Early detection of acute transmural myocardial ischemia by the phasic systolic-diastolic changes of local tissue electrical impedance. Am J Physiol Heart Circ Physiol 2015; 310:H436-43. [PMID: 26608340 DOI: 10.1152/ajpheart.00754.2015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 11/19/2015] [Indexed: 11/22/2022]
Abstract
Myocardial electrical impedance is influenced by the mechanical activity of the heart. Therefore, the ischemia-induced mechanical dysfunction may cause specific changes in the systolic-diastolic pattern of myocardial impedance, but this is not known. This study aimed to analyze the phasic changes of myocardial resistivity in normal and ischemic conditions. Myocardial resistivity was measured continuously during the cardiac cycle using 26 different simultaneous excitation frequencies (1 kHz-1 MHz) in 7 anesthetized open-chest pigs. Animals were submitted to 30 min regional ischemia by acute left anterior descending coronary artery occlusion. The electrocardiogram, left ventricular (LV) pressure, LV dP/dt, and aortic blood flow were recorded simultaneously. Baseline myocardial resistivity depicted a phasic pattern during the cardiac cycle with higher values at the preejection period (4.19 ± 1.09% increase above the mean, P < 0.001) and lower values during relaxation phase (5.01 ± 0.85% below the mean, P < 0.001). Acute coronary occlusion induced two effects on the phasic resistivity curve: 1) a prompt (5 min ischemia) holosystolic resistivity rise leading to a bell-shaped waveform and to a reduction of the area under the LV pressure-impedance curve (1,427 ± 335 vs. 757 ± 266 Ω·cm·mmHg, P < 0.01, 41 kHz) and 2) a subsequent (5-10 min ischemia) progressive mean resistivity rise (325 ± 23 vs. 438 ± 37 Ω·cm at 30 min, P < 0.01, 1 kHz). The structural and mechanical myocardial dysfunction induced by acute coronary occlusion can be recognized by specific changes in the systolic-diastolic myocardial resistivity curve. Therefore these changes may become a new indicator (surrogate) of evolving acute myocardial ischemia.
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Affiliation(s)
- Esther Jorge
- Department of Cardiology, Hospital de la Santa Creu i Sant Pau, Institute of Biomedical Research Sant Pau, Universitat Autonoma de Barcelona, Barcelona, Spain; and
| | - Gerard Amorós-Figueras
- Department of Cardiology, Hospital de la Santa Creu i Sant Pau, Institute of Biomedical Research Sant Pau, Universitat Autonoma de Barcelona, Barcelona, Spain; and
| | - Tomás García-Sánchez
- Electronic and Biomedical Instrumentation Group, Department of Electronics Engineering, Universitat Politecnica de Catalunya, Barcelona, Spain
| | - Ramón Bragós
- Electronic and Biomedical Instrumentation Group, Department of Electronics Engineering, Universitat Politecnica de Catalunya, Barcelona, Spain
| | - Javier Rosell-Ferrer
- Electronic and Biomedical Instrumentation Group, Department of Electronics Engineering, Universitat Politecnica de Catalunya, Barcelona, Spain
| | - Juan Cinca
- Department of Cardiology, Hospital de la Santa Creu i Sant Pau, Institute of Biomedical Research Sant Pau, Universitat Autonoma de Barcelona, Barcelona, Spain; and
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Sanchez B, Li J, Yim S, Pacheck A, Widrick JJ, Rutkove SB. Evaluation of Electrical Impedance as a Biomarker of Myostatin Inhibition in Wild Type and Muscular Dystrophy Mice. PLoS One 2015; 10:e0140521. [PMID: 26485280 PMCID: PMC4618134 DOI: 10.1371/journal.pone.0140521] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 09/28/2015] [Indexed: 12/14/2022] Open
Abstract
Objectives Non-invasive and effort independent biomarkers are needed to better assess the effects of drug therapy on healthy muscle and that affected by muscular dystrophy (mdx). Here we evaluated the use of multi-frequency electrical impedance for this purpose with comparison to force and histological parameters. Methods Eight wild-type (wt) and 10 mdx mice were treated weekly with RAP-031 activin type IIB receptor at a dose of 10 mg kg−1 twice weekly for 16 weeks; the investigators were blinded to treatment and disease status. At the completion of treatment, impedance measurements, in situ force measurements, and histology analyses were performed. Results As compared to untreated animals, RAP-031 wt and mdx treated mice had greater body mass (18% and 17%, p < 0.001 respectively) and muscle mass (25% p < 0.05 and 22% p < 0.001, respectively). The Cole impedance parameters in treated wt mice, showed a 24% lower central frequency (p < 0.05) and 19% higher resistance ratio (p < 0.05); no significant differences were observed in the mdx mice. These differences were consistent with those seen in maximum isometric force, which was greater in the wt animals (p < 0.05 at > 70 Hz), but not in the mdx animals. In contrast, maximum force normalized by muscle mass was unchanged in the wt animals and lower in the mdx animals by 21% (p < 0.01). Similarly, myofiber size was only non-significantly higher in treated versus untreated animals (8% p = 0.44 and 12% p = 0.31 for wt and mdx animals, respectively). Conclusions Our findings demonstrate electrical impedance of muscle reproduce the functional and histological changes associated with myostatin pathway inhibition and do not reflect differences in muscle size or volume. This technique deserves further study in both animal and human therapeutic trials.
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Affiliation(s)
- Benjamin Sanchez
- Department of Neurology, Division of Neuromuscular Diseases, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215-5491, United States of America
- * E-mail:
| | - Jia Li
- Department of Neurology, Division of Neuromuscular Diseases, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215-5491, United States of America
| | - Sung Yim
- Department of Neurology, Division of Neuromuscular Diseases, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215-5491, United States of America
| | - Adam Pacheck
- Department of Neurology, Division of Neuromuscular Diseases, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215-5491, United States of America
| | - Jeffrey J. Widrick
- Division of Genetics and Genomics, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02215-5491, United States of America
| | - Seward B. Rutkove
- Department of Neurology, Division of Neuromuscular Diseases, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215-5491, United States of America
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Beltran NE, Sacristan E. Gastrointestinal ischemia monitoring through impedance spectroscopy as a tool for the management of the critically ill. Exp Biol Med (Maywood) 2015; 240:835-45. [PMID: 25711880 PMCID: PMC4935395 DOI: 10.1177/1535370215571876] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Accepted: 12/16/2014] [Indexed: 12/14/2022] Open
Abstract
Impedance spectroscopy (IS) has been proposed as a tool for monitoring mucosal tissue ischemia and damage in the gut of critically ill patients resulting from shock and hypoperfusion. A specific device and system have been developed and tested for this specific application over the past 12 years by our research group. This paper reviews previously published studies as well as unpublished experimental results, and puts the whole in context and perspective to help understand this technology. Results presented include summaries of gastric reactance measurement understanding, in vivo measurements in animal models, clinical significance of the measurement, and future perspectives of clinical use of this technology. All of the experimental work done to date has been designed to determine the evolving device prototypes' performance and limitations from an instrumentation point of view. Although there are still questions to be answered with regard to the IS measurement, we conclude that we have reached enough confidence in the measurement and the device's performance and safety to begin clinically oriented research to learn how this technology may be useful in the diagnosis and management of different populations of the critically ill.
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Affiliation(s)
- Nohra E Beltran
- Department of Process and Technology, Universidad Autonoma Metropolitana - Cuajimalpa, Mexico City 05300, Mexico National Center for Medical Instrumentation and Imaging Research, Universidad Autonoma Metropolitana - Iztapalapa, Mexico City, 09340, Mexico
| | - Emilio Sacristan
- National Center for Medical Instrumentation and Imaging Research, Universidad Autonoma Metropolitana - Iztapalapa, Mexico City, 09340, Mexico
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31
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Wang H, He Y, Yan Q, You F, Fu F, Dong X, Shi X, Yang M. Correlation between the dielectric properties and biological activities of human ex vivo hepatic tissue. Phys Med Biol 2015; 60:2603-17. [PMID: 25761728 DOI: 10.1088/0031-9155/60/6/2603] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Dielectric properties are vital biophysical features of biological tissues, and biological activity is an index to ascertain the active state of tissues. This study investigated the potential correlation between the dielectric properties and biological activities of human hepatic tissue with prolonged ex vivo time through correlation and regression analyses. The dielectric properties of 26 cases of normal human hepatic tissue at 10 Hz to 100 MHz were measured from 15 min after isolation to 24 h at 37 °C with 90% humidity. Cell morphologies, including nucleus area (NA) and alteration rate of intercellular area (ICAR), were analyzed as indicators of biological activities. Conductivity, complex resistivity, and NA exhibited opposing changes 1 h after isolation. Relative permittivity and ex vivo time were not closely correlated (p > 0.05). The dielectric properties measured at low frequencies (i.e. <1 MHz) were more sensitive than those measured at high frequencies in reflecting the biological activity of ex vivo tissue. Highly significant correlations were found between conductivity, resistivity and the ex vivo time (p < 0.05) as well as conductivity and the cell morphology (p < 0.05). The findings indicated that establishing the correlation between the dielectric properties and biological activities of human hepatic tissue is of great significance for promoting the role of dielectric properties in biological science, particularly in human biology.
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Affiliation(s)
- Hang Wang
- Department of Biomedical Engineering, Fourth Military Medical University, 169 West Changle Road, 710032, Xi'an, People's Republic of China
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32
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Sanchez B, Louarroudi E, Pintelon R. Time-invariant measurement of time-varying bioimpedance using vector impedance analysis. Physiol Meas 2015; 36:595-620. [DOI: 10.1088/0967-3334/36/3/595] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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33
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Podtaev S, Nikolaev D, Samartsev V, Gavrilov V, Tsiberkin K. Frequency and temperature dependence of skin bioimpedance during a contralateral cold test. Physiol Meas 2015; 36:561-77. [PMID: 25690397 DOI: 10.1088/0967-3334/36/3/561] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A study of the α- and β-dispersion of skin bioimpedance dependence on temperature and micro-hemodynamics is presented. The vascular tone changes during the cold test are verified by the wavelet-analysis of skin temperature signals obtained simultaneously with impedance measurements. Thirty three normal healthy subjects of 28 ± 7 years old were entered into the study. The tetra-polar electrode system was used to record the resistance and reactance; measurements were carried out at 67 frequencies, in a frequency range from 2 Hz to 50 kHz. It has been found that the impedance decreases with vasodilation and increases with vasoconstriction. The high values of correlation among thermal oscillation amplitudes and Nyquist diagram parameters prove the impedance dependence on blood flow in three frequency bands corresponding to the myogenic, neurogenic and endothelial vascular tone regulation mechanisms. Using an equivalent RC circuit, we obtained the changes in the Nyquist diagram matching the experimental data. The proposed descriptive α-dispersion model can be used to study mechanisms responsible for intercellular interaction.
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Affiliation(s)
- S Podtaev
- Institute of Continuous Media Mechanics, Korolyov str.1, Perm 614013, Russia
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34
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Farraha M, Nguyen DT, Barry MA, Lu J, McEwan AL, Pouliopoulos J. Investigating the utility of in vivo bio-impedance spectroscopy for the assessment of post-ischemic myocardial tissue. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2014:1111-4. [PMID: 25570157 DOI: 10.1109/embc.2014.6943789] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Increased myocardial structural heterogeneity in response to ischemic injury following myocardial infarction (MI) is purported as the mechanism of ventricular arrhythmogenesis. Current modalities for in vivo assessment of structural heterogeneity for identification of arrhythmogenic substrate are limited due to the complex nature of the structural microenvironment post-MI. We investigated the utility of in vivo bio-impedance spectroscopy (BIS) in a large post-infarct animal model for differentiation between normal and infarcted tissue. We also investigated the quantitative effects of adipose and collagen on BIS assessment of myocardium. The results indicate that the degree of myocardial injury following chronic post-infarction remodeling could be reliably quantified (performed in triplicates) using BIS. Furthermore, the presence of intramyocardial adipose tissue that develops in conjunction with collagen within the infarct zone had a greater and significant influence on BIS then collagen tissue alone. These preliminary results indicate a potential role of BIS for quantitative assessment and characterization of complex arrhythmogenic substrates in ischemic cardiomyopathy.
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35
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Haandbæk N, With O, Bürgel SC, Heer F, Hierlemann A. Resonance-enhanced microfluidic impedance cytometer for detection of single bacteria. LAB ON A CHIP 2014; 14:3313-24. [PMID: 24984254 DOI: 10.1039/c4lc00576g] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
This paper reports on a novel impedance-based cytometer, which can detect and characterize sub-micrometer particles and cells passing through a microfluidic channel. The cytometer incorporates a resonator, which is constructed by means of a discrete inductor in series with the measurement electrodes in the microfluidic channel. The use of a resonator increases the sensitivity of the system in comparison to state-of-the-art devices. We demonstrate the functionality and sensitivity of the cytometer by discriminating E. coli and B. subtilis from beads of similar sizes by means of the resonance-enhanced phase shift of the current through the microfluidic channel. The phase shift can be correlated to size and dielectric properties of the measured objects.
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Affiliation(s)
- Niels Haandbæk
- ETH Zurich, Dept. of Biosystems Science and Engineering, Mattenstrasse 26, Basel, CH-4058, Switzerland.
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36
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Sanchez B, Li J, Bragos R, Rutkove SB. Differentiation of the intracellular structure of slow- versus fast-twitch muscle fibers through evaluation of the dielectric properties of tissue. Phys Med Biol 2014; 59:2369-80. [PMID: 24743385 DOI: 10.1088/0031-9155/59/10/2369] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Slow-twitch (type 1) skeletal muscle fibers have markedly greater mitochondrial content than fast-twitch (type 2) fibers. Accordingly, we sought to determine whether the dielectric properties of these two fiber types differed, consistent with their distinct intracellular morphologies. The longitudinal and transverse dielectric spectrum of the ex vivo rat soleus (a predominantly type 1 muscle) and the superficial layers of rat gastrocnemius (predominantly type 2) (n = 15) were measured in the 1 kHz-10 MHz frequency range and modeled to a resistivity Cole-Cole function. Major differences were especially apparent in the dielectric spectrum in the 1 to 10 MHz range. Specifically, the gastrocnemius demonstrated a well-defined, higher center frequency than the soleus muscle, whereas the soleus muscle showed a greater difference in the modeled zero and infinite resistivities than the gastrocnemius. These findings are consistent with the fact that soleus tissue has larger and more numerous mitochondria than gastrocnemius. Evaluation of tissue at high frequency could provide a novel approach for assessing intracellular structure in health and disease.
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Affiliation(s)
- B Sanchez
- Department of Neurology, Division of Neuromuscular Diseases, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215-5491, USA
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37
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Zhang L, Shi X, You F, Liu P, Dong X. Improved circuit model of open-ended coaxial probe for measurement of the biological tissue dielectric properties between megahertz and gigahertz. Physiol Meas 2013; 34:N83-96. [PMID: 24021242 DOI: 10.1088/0967-3334/34/10/n83] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This note describes an improved equivalent circuit analysis model for open-ended coaxial probes for measurement of the dielectric properties of biological tissues below the gigahertz level. Some parameters in the conventional model that influence the measurement results were found to be still relative to the dielectric properties of the test sample and the terminal admittance of the probe was found to be dependent on the frequency. This was not found to be the case with the conventional model. According to the simulation results in frequency range from 30 MHz to 1 GHz, a polynomial expression was found to fit the frequency-admittance curve for terminal admittance and the equivalent circuit expression of probe terminal admittance was finally modified. The simulated annealing algorithm was used to calculate the dielectric properties of the new expression. The accuracy of the improved model was validated through a simulation test and experiment based on a series of solutions over 30 MHz-1 GHz. The new model was compared to the conventional model and was found to provide more accurate permittivity estimation over a wider frequency range than the conventional model if said range was between megahertz and gigahertz.
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Affiliation(s)
- Liang Zhang
- College of Science, National University of Defense Technology, Changsha 410073, People's Republic of China
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38
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Beltran NE, Garcia LE, Garcia-Lorenzana M. Gastric tissue damage analysis generated by ischemia: bioimpedance, confocal endomicroscopy, and light microscopy. BIOMED RESEARCH INTERNATIONAL 2013; 2013:824682. [PMID: 23841094 PMCID: PMC3697240 DOI: 10.1155/2013/824682] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 06/04/2013] [Indexed: 11/24/2022]
Abstract
The gastric mucosa ischemic tissular damage plays an important role in critical care patients' outcome, because it is the first damaged tissue by compensatory mechanism during shock. The aim of the study is to relate bioimpedance changes with tissular damage level generated by ischemia by means of confocal endomicroscopy and light microscopy. Bioimpedance of the gastric mucosa and confocal images were obtained from Wistar male rats during basal and ischemia conditions. They were anesthetized, and stain was applied (fluorescein and/or acriflavine). The impedance spectroscopy catheter was inserted and then confocal endomicroscopy probe. After basal measurements and biopsy, hepatic and gastric arteries clamping induced ischemia. Finally, pyloric antrum tissue was preserved in buffered formaldehyde (10%) for histology processing using light microscopy. Confocal images were equalized, binarized, and boundary defined, and infiltrations were quantified. Impedance and infiltrations increased with ischemia showing significant changes between basal and ischemia conditions (P < 0.01). Light microscopy analysis allows detection of general alterations in cellular and tissular integrity, confirming gastric reactance and confocal images quantification increments obtained during ischemia.
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Affiliation(s)
- Nohra E Beltran
- Departamento de Procesos y Tecnologia, Universidad Autonoma Metropolitana, Cuajimalpa. Artificios 40, Colonia Hidalgo, 01120 Ciudad de Mexico, DF, Mexico.
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39
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Dielectric behavior of gelatine–glycosaminoglycans blends: An impedance analysis. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2013; 33:2455-9. [DOI: 10.1016/j.msec.2013.01.057] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 12/26/2012] [Accepted: 01/23/2013] [Indexed: 01/11/2023]
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40
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Shiffman CA. Circuit modeling of the electrical impedance: part III. Disuse following bone fracture. Physiol Meas 2013; 34:487-502. [PMID: 23587651 DOI: 10.1088/0967-3334/34/5/487] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Multifrequency measurements of the electrical impedance of muscle have been extended to the study of disuse following bone fracture, and analyzed using the five-element circuit model used earlier in the study of the effects of disease. Eighteen subjects recovering from simple fractures on upper or lower limbs were examined (ten males, eight females, aged 18-66). Muscles on uninjured contralateral limbs were used as comparison standards, and results are presented in terms of the ratios p(injured)/p(uninjured), where p stands for the circuit parameter r1, r2, r3, 1/c1 or 1/c2. These are strikingly similar to the diseased-to-healthy ratios for patients with neuromuscular disease, reported in part I of this series. In particular, r1 is virtually unaffected and the ratios for r2, r3, 1/c1 and 1/c2 can be as large as in serious disease. Furthermore, the same pattern of relationships between the parameters is found, suggesting that there is a common underlying mechanism for the impedance changes. Atrophy and fibrosis are examined as candidates for that mechanism, but it is argued that their effects are too small to explain the observed changes. Fundamental considerations aside, the sensitivity, reproducibility and technical simplicity of the technique recommend its use for in-flight assessments of muscles during orbital or interplanetary missions.
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Affiliation(s)
- C A Shiffman
- Physics Department, Northeastern University, Boston, MA, USA.
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41
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Sanchez B, Louarroudi E, Jorge E, Cinca J, Bragos R, Pintelon R. A new measuring and identification approach for time-varying bioimpedance using multisine electrical impedance spectroscopy. Physiol Meas 2013; 34:339-57. [PMID: 23442821 DOI: 10.1088/0967-3334/34/3/339] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The bioimpedance measurement/identification of time-varying biological systems Z(ω, t) by means of electrical impedance spectroscopy (EIS) is still a challenge today. This paper presents a novel measurement and identification approach, the so-called parametric-in-time approach, valid for time-varying (bio-)impedance systems with a (quasi) periodic character. The technique is based on multisine EIS. Contrary to the widely used nonparametric-in-time strategy, the (bio-)impedance Z(ω, t) is assumed to be time-variant during the measurement interval. Therefore, time-varying spectral analysis tools are required. This new parametric-in-time measuring/identification technique has experimentally been validated through three independent sets of in situ measurements of in vivo myocardial impedance. We show that the time-varying myocardial impedance Z(ω, t) is dominantly periodically time varying (PTV), denoted as ZPTV(ω, t). From the temporal analysis of ZPTV(ω, t), we demonstrate that it is possible to decompose ZPTV(ω, t) into a(n) (in)finite sum of fundamental (bio-)impedance spectra, the so-called harmonic impedance spectra (HIS) Zk(ω)s with [Formula: see text]. This is similar to the well-known Fourier series of a periodic signal, but now understood at the level of a periodic system's frequency response. The HIS Zk(ω)s for [Formula: see text] actually summarize in the bi-frequency (ω, k) domain all the temporal in-cycle information about the periodic changes of Z(ω, t). For the particular case k = 0 (i.e. on the ω-axis), Z0(ω) reflects the mean in-cycle behavior of the time-varying bioimpedance. Finally, the HIS Zk(ω)s are directly identified from noisy current and voltage myocardium measurements at the multisine measurement frequencies (i.e. nonparametric-in-frequency).
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Affiliation(s)
- B Sanchez
- Electronic and Biomedical Instrumentation Group, Department of Electrical Engineering, Universitat Politecnica de Catalunya (UPC), E-08034 Barcelona, Spain.
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42
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Bharati S, Rishi P, Tripathi SK, Koul A. Changes in the electrical properties at an early stage of mouse liver carcinogenesis. Bioelectromagnetics 2013; 34:429-36. [DOI: 10.1002/bem.21783] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Accepted: 01/11/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Sanjay Bharati
- Department of Biophysics; Panjab University; Chandigarh; India
| | - Praveen Rishi
- Department of Microbiology; Panjab University; Chandigarh; India
| | | | - Ashwani Koul
- Department of Biophysics; Panjab University; Chandigarh; India
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43
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Marzec E, Sosnowski P, Olszewski J, Krauss H, Piątek J, Samborski W, Micker M, Zawadziński J. Dielectric properties of hypothermic rat artery. Colloids Surf B Biointerfaces 2013; 101:1-5. [PMID: 22789782 DOI: 10.1016/j.colsurfb.2012.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 06/05/2012] [Accepted: 06/06/2012] [Indexed: 11/16/2022]
Abstract
The temperature and frequency dependencies of the dielectric parameters for the rat artery are used to analyse effects of hypothermia on this tissue. Measurements were performed over the frequency range 500 Hz to 100 kHz and at temperatures from 19 to 60°C. The artery samples contained about 12% water by mass at room temperature at a relative humidity of 70%. The frequency dependencies of the loss tangent for the control, mild hypothermic and moderate hypothermic artery exhibit two peaks at 2 kHz and 35 kHz in the α-dispersion region. The results were discussed in terms of the distribution of relaxation frequencies and the activation energy for the conduction and polarization mechanisms particularly in the elastin-water and collagen-water systems. The knowledge about dielectric behavior of the hypothermic rat artery in vitro is important due to clinical application of local and systemic hypothermia.
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Affiliation(s)
- E Marzec
- Department of Bionics and Bioimpedance, University of Medical Sciences, Poznań, Poland.
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44
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Dobiszewski KF, Deek MP, Ghaly A, Prodan C, Hill AA. Extracellular fluid conductivity analysis by dielectric spectroscopy for in vitro determination of cortical tissue vitality. Physiol Meas 2012; 33:1249-60. [PMID: 22735505 DOI: 10.1088/0967-3334/33/7/1249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Brain tissue is extremely metabolically active in part due to its need to constantly maintain a precise extracellular ionic environment. Under pathological conditions, unhealthy cortical tissue loses its ability to maintain this precise environment and there is a net efflux of charged particles from the cells. Typically, this ionic efflux is measured using ion-selective microelectrodes, which measure a single ionic species at a time. In this paper, we have used a bio-sensing method, dielectric spectroscopy (DS), which allows for the simultaneous measurement of the net efflux of all charged particles from cells by measuring extracellular conductivity. We exposed cortical brain slices from the mouse to different solutions that mimic various pathological states such as hypokalemia, hyperkalemia and ischemia (via oxygen-glucose deprivation). We have found that the changes in conductivity of the extracellular solutions were proportional to the severity of the pathological insult experienced by the brain tissue. Thus, DS allows for the measurement of changes in extracellular conductivity with enough sensitivity to monitor the health of brain tissue in vitro.
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Affiliation(s)
- K F Dobiszewski
- Federated Department of Biological Sciences, New Jersey Institute of Technology and Rutgers University, Newark, NJ, USA
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45
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Beltran NE, Ceron U, Sanchez-Miranda G, Remolina M, Godinez MM, Peralta IY, Sacristan E. Incidence of gastric mucosal injury as measured by reactance in critically ill patients. J Intensive Care Med 2012; 28:230-6. [PMID: 22733726 DOI: 10.1177/0885066612450415] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Gastric reactance has been proposed as a measure of mucosal ischemic injury in the critically ill. The purpose of this study was to evaluate the incidence of gastric mucosal injury as measured by gastric reactance in different subgroups of critical patients. We studied 100 adult patients admitted to 7 different hospital intensive care units, requiring a nasogastric tube. Gastric impedance measurements were continuously obtained from each patient for 24 hours. Patients were managed based on conventional protocols by hospital staff, blinded to the changes in gastric impedance parameters. The low-frequency central reactance (X L) reflects tissue edema caused by prolonged ischemia. The previously reported threshold of X L ≥ 13 - jΩ was used to classify injured mucosa; 80% of all patients had mean X L above this threshold. No significant differences were found in the incidence of mucosal ischemia between medical versus surgical, hemodynamic versus respiratory or neurological patients. Significant lower urine output was found in patients with X L above threshold (P < .01); also, there was a significant effect of fluid balance in those patients (P < .05). More complicated patients had higher average reactance. This study shows that gastric ischemia as estimated by gastric reactance has a very high incidence in the critically ill, independently of the reason for admission. High reactance is related with higher morbidity in agreement with other reports using different methods of assessing splanchnic hypoperfusion in this patient population.
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Affiliation(s)
- Nohra E Beltran
- Department of Process and Technology, Universidad Autonoma Metropolitana - Cuajimalpa, Mexico City, Mexico.
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46
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Mao S, Dong X, Fu F, Seese RR, Wang Z. Estimation of postmortem interval using an electric impedance spectroscopy technique: A preliminary study. Sci Justice 2011; 51:135-8. [DOI: 10.1016/j.scijus.2010.11.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 09/01/2010] [Accepted: 11/11/2010] [Indexed: 11/28/2022]
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Sanchez B, Schoukens J, Bragos R, Vandersteen G. Novel estimation of the electrical bioimpedance using the local polynomial method. Application to in vivo real-time myocardium tissue impedance characterization during the cardiac cycle. IEEE Trans Biomed Eng 2011; 58:3376-85. [PMID: 21878408 DOI: 10.1109/tbme.2011.2166116] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Classical measurements of myocardium tissue electrical impedance for characterizing the morphology of myocardium cells, as well as cell membranes integrity and intra/extra cellular spaces, are based on the frequency-sweep electrical impedance spectroscopy (EIS) technique. In contrast to the frequency-sweep EIS approach, measuring with broadband signals, i.e., multisine excitations, enables to collect, simultaneously, multiple myocardium tissue impedance data in a short measuring time. However, reducing the measuring time makes the measurements to be prone to the influence of the transients introduced by noise and the dynamic time-varying properties of tissue. This paper presents a novel approach for the impedance-frequency-response estimation based on the local polynomial method (LPM). The fast LPM version presented rejects the leakage error's influence on the impedance frequency response when measuring electrical bioimpedance in a short time. The theory is supported by a set of validation measurements. Novel preliminary experimental results obtained from real-time in vivo healthy myocardium tissue impedance characterization within the cardiac cycle using multisine excitation are reported.
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Affiliation(s)
- Benjamin Sanchez
- Department of Electronic Engineering, Technical University of Catalonia, Barcelona 08034, Spain.
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Mellert F, Winkler K, Schneider C, Dudykevych T, Welz A, Osypka M, Gersing E, Preusse CJ. Detection of (Reversible) Myocardial Ischemic Injury by Means of Electrical Bioimpedance. IEEE Trans Biomed Eng 2011; 58:1511-8. [DOI: 10.1109/tbme.2010.2054090] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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49
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Mao S, Fu F, Dong X, Wang Z. Supplementary Pathway for Vitality of Wounds and Wound Age Estimation in Bruises Using the Electric Impedance Spectroscopy Technique. J Forensic Sci 2011; 56:925-9. [DOI: 10.1111/j.1556-4029.2011.01756.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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50
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Mahmood F, Gehl J. Optimizing clinical performance and geometrical robustness of a new electrode device for intracranial tumor electroporation. Bioelectrochemistry 2011; 81:10-6. [PMID: 21256816 DOI: 10.1016/j.bioelechem.2010.12.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Revised: 12/08/2010] [Accepted: 12/17/2010] [Indexed: 11/29/2022]
Abstract
Current technology has limited applicability for electroporation based treatment of deep-seated tumors, and is in general, not optimized in terms of compliance with clinically relevant parameters. Here we present a novel electrode device developed for electrotransfer of antineoplastic drugs and genes to intracranial tumors in humans, and demonstrate a method to optimize the design (i.e. geometry) of the electrode device prototype to improve both clinical performance and geometrical tolerance (robustness). We have employed a semiempirical objective function based on constraints similar to those used in radiation oncology. The results show that small geometrical changes may yield a significant improvement. For example, a 2 mm displacement of 6 electrodes yields 14% better compliance with the clinical parameters, compared to the prototype, and additionally makes the electrode device less sensitive to random geometrical deviations. The method is readily applicable to other electrode configurations.
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Affiliation(s)
- Faisal Mahmood
- Copenhagen University Hospital Herlev, Center for Experimental Drug and Gene Electrotransfer, Department of Oncology, Herlev Ringvej 75, 2730 Herlev, Denmark.
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