Reflectance Photoplethysmography as Noninvasive Monitoring of Tissue Blood Perfusion

“…Equation (9) is used to calculate the average depth of probing (Z r,λ ) for particular optical properties(μ a , μ s ') and source to detector separation (r). Equation (10) describes the probability distribution (P z,r ) of the depths reached by photons. …”

Section: Customization Of the Ppg Sensor Boardsmentioning

confidence: 99%

“…By analyzing the pulsatile and non-pulsatile components of the PPG signal, information about the perfusion and oxygenation of the tissue probed can be extracted [9,10]. Note that the pulsatile components stem from the arterial pulsations and the non-pulsatile components stem from the optical properties of the tissue, venous blood, and non-pulsatile arterial blood [9].…”

Section: Introductionmentioning

confidence: 99%

In-silico and in-vitro investigation of a photonic monitor for intestinal perfusion and oxygenation

Robinson

Butcher

Wilson

et al. 2017

Biomed. Opt. Express

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Abstract:The quantification of visceral organ oxygenation after trauma-related systemic hypovolemia and shock is critical to enable effective resuscitation. In this work, a photoplethysmography-based (PPG) sensor was specifically designed for probing the perfusion and oxygenation condition of intestinal tissue with the ultimate goal to monitor patients post trauma to guide resuscitation. Through Monte Carlo modeling, suitable optofluidic phantoms were determined, the wavelength and separation distance for the sensor was optimized, and sensor performance for the quantification of tissue perfusion and oxygenation was tested on the in-vitro phantom. In particular, the Monte Carlo simulated both a standard block three-layer model and a more realistic model including villi. Measurements were collected on the designed three layer optofluidic phantom and the results taken with the small form factor PPG device showed a marked improvement when using shorter visible wavelengths over the more conventional longer visible wavelengths. Overall, in this work a Monte Carlo model was developed, an optofluidic phantom was built, and a small form factor PPG sensor was developed and characterized using the phantom for perfusion and oxygenation over the visible wavelength range. The results show promise that this small form factor PPG sensor could be used as a future guide to shock-related resuscitation.

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“…Measurement locations are usually extremities such as finger and earlobe, but several different locations such as the esophagus, splanchnic organs, and flaps have been investigated as well (Kyriacou 2006(Kyriacou , 2013. While the ac component of the signal is predominantly used to assess local arterial blood inflow, the dc component has been proved to provide information on venous blood, respiration, vasodilation/constriction, blood pressure, and perfusion (Shelley 2007, Reisner et al 2008, Walton et al 2010, Abay and Kyriacou 2015. However, the main application of PPG signals is the noninvasive estimation of arterial oxygen saturation (SpO 2 ).…”

Section: Introductionmentioning

confidence: 99%

Comparison of NIRS, laser Doppler flowmetry, photoplethysmography, and pulse oximetry during vascular occlusion challenges

Abay

Kyriacou

2016

Physiol. Meas.

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Monitoring changes in blood volume, blood flow, and oxygenation in tissues is of vital importance in fields such as reconstructive surgery and trauma medicine. Near infrared spectroscopy (NIRS), laser Doppler (LDF) flowmetry, photoplethysmography (PPG), and pulse oximetry (PO) contribute to such fields due to their safe and noninvasive nature. However, the techniques have been rarely investigated simultaneously or altogether. The aim of this study was to investigate all the techniques simultaneously on healthy subjects during vascular occlusion challenges. Sensors were attached on the forearm (NIRS and LDF) and fingers (PPG and PO) of 19 healthy volunteers. Different degrees of vascular occlusion were induced by inflating a pressure cuff on the upper arm. The responses of tissue oxygenation index (NIRS), tissue haemoglobin index (NIRS), flux (LDF), perfusion index (PPG), and arterial oxygen saturation (PO) have been recorded and analyzed. Moreover, the optical densities were calculated from slow varying dc PPG, in order to distinguish changes in venous blood volumes. The indexes showed significant changes ( p < 0.05) in almost all occlusions, either venous or over-systolic occlusions. However, differentiation between venous and arterial occlusion by LDF may be challenging and the perfusion index (PI) may not be adequate to indicate venous occlusions. Optical densities may be an additional tool to detect venous occlusions by PPG.

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Reflectance Photoplethysmography as Noninvasive Monitoring of Tissue Blood Perfusion

Abstract: This is the accepted version of the paper.This version of the publication may differ from the final published version. Permanent repository link

Cited by 87 publications

References 46 publications

Investigation of photoplethysmography, laser doppler flowmetry and near infrared spectroscopy during induced thermal stress

Investigation of photoplethysmography, laser doppler flowmetry and near infrared spectroscopy during induced thermal stress

In-silico and in-vitro investigation of a photonic monitor for intestinal perfusion and oxygenation

Comparison of NIRS, laser Doppler flowmetry, photoplethysmography, and pulse oximetry during vascular occlusion challenges

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