Monte Carlo Analysis of Optical Interactions in Reflectance and Transmittance Finger Photoplethysmography

Chatterjee, Subhasri; Kyriacou, Panayiotis A.

doi:10.3390/s19040789

Cited by 60 publications

(72 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Work done with fibre optics [17,18] shows optimum separation at 3 to 6 mm. Additionally there are also simulated computer models confirming that for the wavelengths of 660 nm and 940 nm in a finger model, an ideal separation distance <1 cm yields optimal depth of light penetration for SaO 2 values >90% [19]. Components available at the time of the design of the sensor meant that a compromise had to be made in the placement and geometrical arrangement.…”

Section: Discussionmentioning

confidence: 98%

A Novel Photoplethysmography Sensor for Vital Signs Monitoring from the Human Trachea

et al. 2019

View full text Add to dashboard Cite

Current pulse oximeter sensors can be challenged in working accurately and continuously in situations of reduced periphery perfusion, especially among anaesthetised patients. A novel tracheal photoplethysmography (PPG) sensor has been developed in an effort to address the limitations of current pulse oximeters. The sensor has been designed to estimate oxygen saturation (SpO2) and pulse rate, and has been manufactured on a flexible printed circuit board (PCB) that can adhere to a standard endotracheal (ET) tube. A pilot clinical trial was carried out as a feasibility study on 10 anaesthetised patients. Good quality PPGs from the trachea were acquired at red and infrared wavelengths in all patients. The mean SpO2 reading for the ET tube was 97.1% (SD 1.0%) vs. the clinical monitor at 98.7% (SD 0.7%). The mean pulse rate for the ET sensor was 65.4 bpm (SD 10.0 bpm) vs. the clinical monitor at 64.7 bpm (SD 9.9 bpm). This study supports the hypothesis that the human trachea could be a suitable monitoring site of SpO2 and other physiological parameters, at times where the periphery circulation might be compromised.

show abstract

Section: Discussionmentioning

confidence: 98%

A Novel Photoplethysmography Sensor for Vital Signs Monitoring from the Human Trachea

et al. 2019

View full text Add to dashboard Cite

show abstract

“…In this section, the working principle of a wrist-worn photoplethysmography (PPG) sensor is outlined. PPG is a key technique that uses optical sensors for non-invasive monitoring of the volume changes in the arterial blood [7]. Conventionally, an optical biosensor is used to measure the arterial oxygen saturation (SpO 2 ) level.…”

Section: Working Principle Of the Ppg Sensormentioning

confidence: 99%

“…Photoplethysmography (PPG) is a technology that uses optical sensors for non-invasive monitoring of the volume changes in arterial blood [7,8]. PPG is widely used in pulse oximetry for the measurement Figure 1.…”

Section: Introductionmentioning

confidence: 99%

A Wristwatch-Based Wireless Sensor Platform for IoT Health Monitoring Applications

Kumar

Buckley

Barton

et al. 2020

Sensors

View full text Add to dashboard Cite

A wristwatch-based wireless sensor platform for IoT wearable health monitoring applications is presented. The paper describes the platform in detail, with a particular focus given to the design of a novel and compact wireless sub-system for 868 MHz wristwatch applications. An example application using the developed platform is discussed for arterial oxygen saturation (SpO2) and heart rate measurement using optical photoplethysmography (PPG). A comparison of the wireless performance in the 868 MHz and the 2.45 GHz bands is performed. Another contribution of this work is the development of a highly integrated 868 MHz antenna. The antenna structure is printed on the surface of a wristwatch enclosure using laser direct structuring (LDS) technology. At 868 MHz, a low specific absorption rate (SAR) of less than 0.1% of the maximum permissible limit in the simulation is demonstrated. The measured on-body prototype antenna exhibits a −10 dB impedance bandwidth of 36 MHz, a peak realized gain of −4.86 dBi and a radiation efficiency of 14.53% at 868 MHz. To evaluate the performance of the developed 868 MHz sensor platform, the wireless communication range measurements are performed in an indoor environment and compared with a commercial Bluetooth wristwatch device.

show abstract

“…25 The calculation of the arterial and venous blood absorption coefficients has been discussed in detail in our previous publication. 18 The details of the parameters used in the simulation are illustrated in Table 1: volume fraction of total blood in each tissue-layer (V) and the optical properties (i.e., absorption coefficient, scattering coefficient, anisotropy factor, and refractive Table 1 The parameters of the buccal tissue model: optical properties at red (660 nm) and infrared (880 nm) wavelengths and blood volume. The optical properties include the coefficients for absorption (μ a ) and scattering (μ s ), the scattering anisotropy (g), and the refractive index (R.I.).…”

Section: Tissue Descriptionmentioning

confidence: 99%

“…The Monte Carlo method is the most convenient approach to model the optical quantities in a certain sensor-tissue configuration. 18 In this paper, a rigorous analysis is presented to evaluate the efficacy of the sensor using a robust Monte Carlo model that has been evaluated against a set of in vivo investigations. The combined knowledge obtained through the simulations and experiments presented in this paper will inform the design and application-protocols of the proposed sensor, leading to the future development of a sensing technology for the continuous and dynamic intestinal viability monitoring.…”

Section: Introductionmentioning

confidence: 99%

In silico and in vivo investigations using an endocavitary photoplethysmography sensor for tissue viability monitoring

et al. 2020

Self Cite

View full text Add to dashboard Cite

In silico and in vivo investigations using an endocavitary photoplethysmography sensor for tissue viability monitoring," J. AbstractSignificance: Colorectal cancer is one of the major causes of cancer-related deaths worldwide. Surgical removal of the cancerous growth is the primary treatment for this disease. A colorectal cancer surgery, however, is often unsuccessful due to the anastomotic failure that may occur following the surgical incision. Prevention of an anastomotic failure requires continuous monitoring of intestinal tissue viability during and after colorectal surgery. To date, no clinical technology exists for the dynamic and continuous monitoring of the intestinal perfusion.Aim: A dual-wavelength indwelling bowel photoplethysmography (PPG) sensor for the continuous monitoring of intestinal viability was proposed and characterized through a set of in silico and in vivo investigations.Approach: The in silico investigation was based on a Monte Carlo model that was executed to quantify the variables such as penetration depth and detected intensity with respect to the sensortissue separations and tissue perfusion. Utilizing the simulated information, an indwelling reflectance PPG sensor was designed and tested on 20 healthy volunteers. Two sets of in vivo studies were performed using the driving current intensities 20 and 40 mA for a comparative analysis, using buccal tissue as a proxy tissue-site.Results: Both simulated and experimental results showed the efficacy of the sensor to acquire good signals through the "contact" to a "noncontact" separation of 5 mm. A very slow wavelength-dependent variation was shown in the detected intensity at the normal and hypoxic states of the tissue, whereas a decay in the intensity was found with the increasing submucosal-blood volume. The simulated detected-to-incident-photon-ratio and the experimental signal-to-noise ratio exhibited strong positive correlations, with the Pearson product-moment correlation coefficient R ranging between 0.65 and 0.87. Conclusions:The detailed feasibility analysis presented will lead to clinical trials utilizing the proposed sensor.

show abstract

Monte Carlo Analysis of Optical Interactions in Reflectance and Transmittance Finger Photoplethysmography

Cited by 60 publications

References 59 publications

A Novel Photoplethysmography Sensor for Vital Signs Monitoring from the Human Trachea

A Novel Photoplethysmography Sensor for Vital Signs Monitoring from the Human Trachea

A Wristwatch-Based Wireless Sensor Platform for IoT Health Monitoring Applications

In silico and in vivo investigations using an endocavitary photoplethysmography sensor for tissue viability monitoring

Contact Info

Product

Resources

About