1
|
Katan M, Pearl O, Tzroya A, Duadi H, Fixler D. A Self-Calibrated Single Wavelength Biosensor for Measuring Oxygen Saturation. Biosensors (Basel) 2024; 14:132. [PMID: 38534239 DOI: 10.3390/bios14030132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 02/24/2024] [Accepted: 03/01/2024] [Indexed: 03/28/2024]
Abstract
Traditional methods for measuring blood oxygen use multiple wavelengths, which produce an intrinsic error due to ratiometric measurements. These methods assume that the absorption changes with the wavelength, but in fact the scattering changes as well and cannot be neglected. We found that if one measures in a specific angle around a cylindrical tissue, called the iso-pathlength (IPL) point, the reemitted light intensity is unaffected by the tissue's scattering. Therefore, the absorption can be isolated from the scattering, which allows the extraction of the subject's oxygen saturation. In this work, we designed an optical biosensor for reading the light intensity reemitted from the tissue, using a single light source and multiple photodetectors (PDs), with one of them in the IPL point's location. Using this bio-device, we developed a methodology to extract the arterial oxygen saturation using a single wavelength light source. We proved this method is not dependent on the light source and is applicable to different measurement locations on the body, with an error of 0.5%. Moreover, we tested thirty-eight males and females with the biosensor under normal conditions. Finally, we show the results of measuring subjects in a hypoxic chamber that simulates extreme conditions with low oxygen.
Collapse
Affiliation(s)
- Michal Katan
- Faculty of Engineering, Bar Ilan University, Ramat Gan 5290002, Israel
- The Institute of Nanotechnology and Advanced Materials, Bar Ilan University, Ramat Gan 5290002, Israel
| | - Ori Pearl
- Faculty of Engineering, Bar Ilan University, Ramat Gan 5290002, Israel
- The Institute of Nanotechnology and Advanced Materials, Bar Ilan University, Ramat Gan 5290002, Israel
| | - Alon Tzroya
- Faculty of Engineering, Bar Ilan University, Ramat Gan 5290002, Israel
- The Institute of Nanotechnology and Advanced Materials, Bar Ilan University, Ramat Gan 5290002, Israel
| | - Hamootal Duadi
- Faculty of Engineering, Bar Ilan University, Ramat Gan 5290002, Israel
- The Institute of Nanotechnology and Advanced Materials, Bar Ilan University, Ramat Gan 5290002, Israel
| | - Dror Fixler
- Faculty of Engineering, Bar Ilan University, Ramat Gan 5290002, Israel
- The Institute of Nanotechnology and Advanced Materials, Bar Ilan University, Ramat Gan 5290002, Israel
| |
Collapse
|
2
|
Kotturi D, Paterson S, McShane M. Surface-Enhanced Spatially Offset Raman Spectroscopy in Tissue. Biosensors (Basel) 2024; 14:81. [PMID: 38392000 PMCID: PMC10886963 DOI: 10.3390/bios14020081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/22/2024] [Accepted: 01/24/2024] [Indexed: 02/24/2024]
Abstract
One aim of personalized medicine is to use continuous or on-demand monitoring of metabolites to adjust prescription dosages in real time. Surface-enhanced spatially offset Raman spectroscopy (SESORS) is an optical technique capable of detecting surface-enhanced Raman spectroscopy (SERS)-active targets under a barrier, which may enable frequent metabolite monitoring. Here we investigate how the intensity of the signal from SERS-active material varies spatially through tissue, both experimentally and in a computational model. Implant-sized, SERS-active hydrogel was placed under different thicknesses of contiguous tissue. Emission spectra were collected at the air-tissue boundary over a range of offsets from the excitation site. New features were added to the Monte Carlo light-tissue interaction model to modify the optical properties after inelastic scattering and to calculate the distribution of photons as they exit the model. The Raman signals were detectable through all barrier thicknesses, with strongest emission for the case of 0 mm offset between the excitation and detector. A steep decline in the signal intensities occurred for offsets greater than 2 mm. These results did not match published SORS work (where targets were much larger than an implant). However, the model and experimental results agree in showing the greatest intensities at 0 mm offset and a steep gradient in the intensities with increasing offset. Also, the model showed an increase in the number of photons when the new, longer wavelengths were used following the Stokes shift for scattering and the graphical display of the exiting photons was helpful in the determination and confirmation of the optimal offset.
Collapse
Affiliation(s)
- Dayle Kotturi
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA (S.P.)
| | - Sureyya Paterson
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA (S.P.)
| | - Mike McShane
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA (S.P.)
- Department of Materials Science and Engineering, Texas A&M University, College Station, TX 77843, USA
| |
Collapse
|
3
|
Chaki C, De Taboada L, Tse KM. Three-dimensional irradiance and temperature distributions resulting from transdermal application of laser light to human knee-A numerical approach. J Biophotonics 2023; 16:e202200283. [PMID: 37261434 DOI: 10.1002/jbio.202200283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 05/02/2023] [Accepted: 05/02/2023] [Indexed: 06/02/2023]
Abstract
The use of light for therapeutic applications requires light-absorption by cellular chromophores at the target tissues and the subsequent photobiomodulation (PBM) of cellular biochemical processes. For transdermal deep tissue light therapy (tDTLT) to be clinically effective, a sufficiently large number of photons must reach and be absorbed at the targeted deep tissue sites. Thus, delivering safe and effective tDTLT requires understanding the physics of light propagation in tissue. This study simulates laser light propagation in an anatomically accurate human knee model to assess the light transmittance and light absorption-driven thermal changes for eight commonly used laser therapy wavelengths (600-1200 nm) at multiple skin-applied irradiances (W cm-2 ) with continuous wave (CW) exposures. It shows that of the simulated parameters, 2.38 W cm-2 (30 W, 20 mm beam radius) of 1064 nm light generated the least tissue heating -4°C at skin surface, after 30 s of CW irradiation, and the highest overall transmission-approximately 3%, to the innermost muscle tissue.
Collapse
Affiliation(s)
- Chironjeet Chaki
- Department of Mechanical and Product Design Engineering, Swinburne University of Technology, Melbourne, Australia
| | | | - Kwong Ming Tse
- Department of Mechanical and Product Design Engineering, Swinburne University of Technology, Melbourne, Australia
| |
Collapse
|
4
|
Singh S, Escobar A, Wang Z, Zhang Z, Ramful C, Xu CQ. Numerical Modeling and Simulation of Non-Invasive Acupuncture Therapy Utilizing Near-Infrared Light-Emitting Diode. Bioengineering (Basel) 2023; 10:837. [PMID: 37508864 PMCID: PMC10376585 DOI: 10.3390/bioengineering10070837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 07/10/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023] Open
Abstract
Acupuncture is one of the most extensively used complementary and alternative medicine therapies worldwide. In this study, we explore the use of near-infrared light-emitting diodes (LEDs) to provide acupuncture-like physical stimulus to the skin tissue, but in a completely non-invasive way. A computational modeling framework has been developed to investigate the light-tissue interaction within a three-dimensional multi-layer model of skin tissue. Finite element-based analysis has been conducted, to obtain the spatiotemporal temperature distribution within the skin tissue, by solving Pennes' bioheat transfer equation, coupled with the Beer-Lambert law. The irradiation profile of the LED has been experimentally characterized and imposed in the numerical model. The experimental validation of the developed model has been conducted through comparing the numerical model predictions with those obtained experimentally on the agar phantom. The effects of the LED power, treatment duration, LED distance from the skin surface, and usage of multiple LEDs on the temperature distribution attained within the skin tissue have been systematically investigated, highlighting the safe operating power of the selected LEDs. The presented information about the spatiotemporal temperature distribution, and critical factors affecting it, would assist in better optimizing the desired thermal dosage, thereby enabling a safe and effective LED-based photothermal therapy.
Collapse
Affiliation(s)
- Sundeep Singh
- Faculty of Sustainable Design Engineering, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada
| | - Andres Escobar
- Department of Biomedical Engineering, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Zexi Wang
- Department of Engineering Physics, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Zhiyi Zhang
- Advanced Electronics and Photonics Research Center, National Research Council Canada, Ottawa, ON K1A 0R6, Canada
| | - Chundra Ramful
- Advanced Electronics and Photonics Research Center, National Research Council Canada, Ottawa, ON K1A 0R6, Canada
| | - Chang-Qing Xu
- Department of Biomedical Engineering, McMaster University, Hamilton, ON L8S 4L8, Canada
- Department of Engineering Physics, McMaster University, Hamilton, ON L8S 4L8, Canada
| |
Collapse
|
5
|
Bürmen M, Pernuš F, Naglič P. MCDataset: a public reference dataset of Monte Carlo simulated quantities for multilayered and voxelated tissues computed by massively parallel PyXOpto Python package. J Biomed Opt 2022; 27:JBO-210365SSRRR. [PMID: 35437973 PMCID: PMC9016074 DOI: 10.1117/1.jbo.27.8.083012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 03/18/2022] [Indexed: 05/16/2023]
Abstract
SIGNIFICANCE Current open-source Monte Carlo (MC) method implementations for light propagation modeling are many times tedious to build and require third-party licensed software that can often discourage prospective researchers in the biomedical optics community from fully utilizing the light propagation tools. Furthermore, the same drawback also limits rigorous cross-validation of physical quantities estimated by various MC codes. AIM Proposal of an open-source tool for light propagation modeling and an easily accessible dataset to encourage fruitful communications amongst researchers and pave the way to a more consistent comparison between the available implementations of the MC method. APPROACH The PyXOpto implementation of the MC method for multilayered and voxelated tissues based on the Python programming language and PyOpenCL extension enables massively parallel computation on numerous OpenCL-enabled devices. The proposed implementation is used to compute a large dataset of reflectance, transmittance, energy deposition, and sampling volume for various source, detector, and tissue configurations. RESULTS The proposed PyXOpto agrees well with the original MC implementation. However, further validation reveals a noticeable bias introduced by the random number generator used in the original MC implementation. CONCLUSIONS Establishing a common dataset is highly important for the validation of existing and development of MC codes for light propagation in turbid media.
Collapse
Affiliation(s)
- Miran Bürmen
- University of Ljubljana, Faculty of Electrical Engineering, Ljubljana, Slovenia
| | - Franjo Pernuš
- University of Ljubljana, Faculty of Electrical Engineering, Ljubljana, Slovenia
- Sensum d.o.o., Ljubljana, Slovenia
| | - Peter Naglič
- University of Ljubljana, Faculty of Electrical Engineering, Ljubljana, Slovenia
- Address all correspondence to Peter Naglič,
| |
Collapse
|
6
|
Piao D, Borron H, Hawxby A, Wright H, Rubin EM. Effects of capsule on surface diffuse reflectance spectroscopy of the subcapsular parenchyma of a solid organ. J Biomed Opt 2018; 23:1-23. [PMID: 30054997 DOI: 10.1117/1.jbo.23.12.121602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 04/16/2018] [Indexed: 06/08/2023]
Abstract
We hypothesize that the capsular optical properties and thickness combined affect how accurate the diffuse reflectance on the surface of a capsular solid organ represents that on the subcapsular parenchyma. Monte Carlo simulations on two-layer geometries evaluated how a thin superficial layer with the thickness from 10 to 1000 μm affected the surface diffuse reflectance over a source-detector separation spanning 0.01 to 10 mm. The simulations represented the superficial layer presenting various contrasts concerning refractive index, anisotropy factor, absorption coefficient, and reduced scattering coefficient, versus those of the subsurface main medium. An analytical approach modeled the effects of the superficial layer of various thicknesses and optical properties on diffuse reflectance. Diffuse reflectance spectroscopy was performed ex vivo on 10 fresh human livers and 9 fresh human kidneys using a surface probe with a 3-mm source-detector separation. The difference of the device-specific diffuse reflectance on the organ between with the capsule and without the capsule has significantly greater spectral variation in the kidney than in the liver. The significantly greater spectral deviation of surface diffuse reflectance between with and without the capsule in the kidney than in the liver was analytically accountable by considering the much thicker capsule of the kidney than of the liver.
Collapse
Affiliation(s)
- Daqing Piao
- Oklahoma State University, School of Electrical and Computer Engineering, Stillwater, Oklahoma, United States
- Oklahoma State University, Department of Veterinary Clinical Sciences, Center for Veterinary Health, United States
| | - Halen Borron
- University of Oklahoma Health Sciences Center, College of Medicine, Oklahoma City, Oklahoma, United States
| | - Alan Hawxby
- University of Oklahoma Health Sciences Center, Oklahoma Transplant Center, Oklahoma City, Oklahoma, United States
| | - Harlan Wright
- University of Oklahoma Health Sciences Center, Oklahoma Transplant Center, Oklahoma City, Oklahoma, United States
| | - Erin M Rubin
- University of Oklahoma Health Sciences Center, Department of Pathology, Oklahoma City, Oklahoma, United States
| |
Collapse
|
7
|
Duadi H, Feder I, Fixler D. Near-infrared human finger measurements based on self-calibration point: Simulation and in vivo experiments. J Biophotonics 2018; 11:e201700208. [PMID: 29131520 DOI: 10.1002/jbio.201700208] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 11/09/2017] [Indexed: 05/26/2023]
Abstract
Near-infrared light allows measuring tissue oxygenation. These measurements relay on oxygenation-dependent absorption spectral changes. However, the tissue scattering, which is also spectral dependent, introduces an intrinsic error. Most methods focus on the volume reflectance from a semi-infinite sample. We have proposed examining the full scattering profile (FSP), which is the angular intensity distribution. A point was found, that is, the iso-path length (IPL) point, which is not dependent on the tissue scattering, and can serve for self-calibration. This point is geometric dependent, hence in cylindrical tissues depends solely on the diameter. In this work, we examine an elliptic tissue cross section via Monte Carlo simulation. We have found that the IPL point of an elliptic tissue cross section is indifferent to the input illumination orientation. Furthermore, the IPL point is the same as in a circular cross section with a radius equal to the effective ellipse radius. This is despite the fact that the FSPs of the circular and elliptical cross sections are different. Hence, changing the orientation of the input illumination reveals the IPL point. In order to demonstrate this experimentally, the FSPs of a few female fingers were measured at 2 perpendicular orientations. The crossing point between these FSPs was found equivalent to the IPL point of a cylindrical phantom with a radius similar to the effective radius. The findings of this work will allow accurate pulse oximetry assessment of blood saturation.
Collapse
Affiliation(s)
- Hamootal Duadi
- Faculty of Engineering, Institute of Nanotechnology and Advanced Materials, Bar Ilan University, Ramat Gan, Israel
| | - Idit Feder
- Faculty of Engineering, Institute of Nanotechnology and Advanced Materials, Bar Ilan University, Ramat Gan, Israel
| | - Dror Fixler
- Faculty of Engineering, Institute of Nanotechnology and Advanced Materials, Bar Ilan University, Ramat Gan, Israel
| |
Collapse
|