Photoplethysmography for the assessment of peripheral vascular disease

Allen, John

doi:10.1016/b978-0-12-823374-0.00005-0

Cited by 7 publications

(12 citation statements)

References 116 publications

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“…Studies have shown (see inter alia: [ 30 , 38 , 39 ]) that for the algorithm to operate without noticeable distortions of the useful rheographic signal, the frequency resolution must be at least 0.1 [Hz], which corresponds to a segment length of 2500 samples. For example, for the signal shown in Figure 2 , the cut-off frequency of the zero line is

[Hz], and the maximum frequency of the useful rheogram is

[Hz].…”

Section: Resultsmentioning

confidence: 99%

Advanced Computing Methods for Impedance Plethysmography Data Processing

Khoma

Kenyo

Kawala-Sterniuk

2022

Sensors

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In this paper we are introducing innovative solutions applied in impedance plethysmography concerning improvement of the rheagraph characteristics and the efficiency increase of the developing rheograms using computer methods. The described methods have been developed in order to ensure the stability of parameters and to extend the functionality of the rheographic system based on digital signal processing, which applies to the compensation of the base resistance with a digital potentiometer, digital synthesis of quadrature excitation signals and the performance of digital synchronous detection. The emphasis was put on methods for determination of hemodynamic parameters by computer processing of the rheograms. As a result–three methods for respiratory artifacts elimination have been proposed: based on the discrete cosine transform, the discrete wavelet transform and the approximation of the zero line with spline functions. Additionally, computer methods for physiological indicators determination, including those based on wavelet decomposition, were also proposed and described in this paper. The efficiency of various rheogram compression algorithms was tested, evaluated and presented in this work.

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[Hz], and the maximum frequency of the useful rheogram is

[Hz].…”

Section: Resultsmentioning

confidence: 99%

Advanced Computing Methods for Impedance Plethysmography Data Processing

Khoma

Kenyo

Kawala-Sterniuk

2022

Sensors

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“…Photoplethysmography (PPG) is a vascular optics technique that can provide composite information about the micro- and macro-circulation (Allen 2007 ). PPG has many clinical applications, but one important area is the detection of peripheral arterial disease (PAD) due to atherosclerosis (Allen 2021 ). PAD of increasing severity progressively leads to exercise-induced leg pain (intermittent claudication), and if more severe, potentially to rest pain, gangrene and amputation.…”

Section: Assessment Of Peripheral Arterial Diseasementioning

confidence: 99%

“…The prevalence of PAD increases with age and is also associated with an increased risk of coronary disease and stroke. It is critical to establish a PAD diagnosis in middle aged and older subjects, since other conditions, such as musculoskeletal disease, can mimic the symptoms of PAD (Allen 2021 ). Screening for PAD with PPG could help ensure the early diagnosis of PAD as well as for follow up and evaluating the efficiency of therapy.…”

Section: Assessment Of Peripheral Arterial Diseasementioning

confidence: 99%

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The 2023 wearable photoplethysmography roadmap

Charlton¹,

Allen²,

Bailón³

et al. 2023

Physiol. Meas.

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Photoplethysmography is a key sensing technology which is used in wearable devices such as smartwatches and fitness trackers. Currently, photoplethysmography sensors are used to monitor physiological parameters including heart rate and heart rhythm, and to track activities like sleep and exercise. Yet, wearable photoplethysmography has potential to provide much more information on health and wellbeing, which could inform clinical decision making. This Roadmap outlines directions for research and development to realise the full potential of wearable photoplethysmography. Experts discuss key topics within the areas of sensor design, signal processing, clinical applications, and research directions. Their perspectives provide valuable guidance to researchers developing wearable photoplethysmography technology.

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“…Previous studies have shown that PPG can detect compensatory changes in local blood flow as well as predict changes in systemic hemodynamic variables during a variety of physiological and pathological conditions ( Ovadia et al, 1995 ; Allen, 2007 ; Ovadia-Blechman et al, 2015a ; Ovadia-Blechman et al, 2015b ; Ovadia-Blechman et al, 2017 ; Ovadia-Blechman et al, 2018 ; Ahmed et al, 2022 ). Moreover, using PPG monitoring, changes in peripheral blood supply following a unilateral clinical intervention can exert significant contralateral effects, the characterization of which may be further elucidated by advanced post-acquisitional analysis of the PPG signals ( Ahmed et al, 2022 ; Allen, 2022 ; Mejia-Mejia et al, 2022 ).…”

Section: Introductionmentioning

confidence: 99%

Morphological features of the photoplethysmographic signal: a new approach to characterize the microcirculatory response to photobiomodulation

Ovadia-Blechman,

Hauptman,

Rabin

et al. 2023

Front. Physiol.

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Introduction and Objectives: Advanced analysis of the morphological features of the photoplethysmographic (PPG) waveform may provide greater understanding of mechanisms of action of photobiomodulation (PBM). Photobiomodulation is a non-ionizing, red to near-infrared irradiation shown to induce peripheral vasodilatation, promote wound healing, and reduce pain. Using laser Doppler flowmetry combined with thermal imaging we found previously in a clinical study that PBM stimulates microcirculatory blood flow and that baseline palm skin temperature determines, at least in part, why some individuals respond favorably to PBM while others do not. “Responders” (n = 12) had a skin temperature range of 33°C–37.5°C, while “non-responders” (n = 8) had “cold” or “hot” skin temperature (<33°C or >37.5°C respectively). The continuous PPG signals recorded from the index fingers of both hands in the original clinical study were subjected to advanced post-acquisitional analysis in the current study, aiming to identify morphological features that may improve the accuracy of discrimination between potential responders and non-responders to PBM.Methods: The PPG signals were detrended by subtracting the lower envelope from the raw signal. The Root Mean Square (RMS) and Entropy features were extracted as were two additional morphological features -- Smoothness and number of local extrema per PPG beat (#Extrema). These describe the signal jaggedness and were developed specifically for this study. The Wilcoxon test was used for paired comparisons. Correlations were determined by the Spearman correlation test (rs).Results: The PPG waveforms of responders to PBM had increased amplitude and decreased jaggedness (Baseline vs. 10’ post-irradiation: Entropy, 5.0 ± 1.3 vs. 3.9 ± 1.1, p = 0.012; #Extrema, 4.0 ± 1.1 vs. 3.0 ± 1.6, p = 0.009; RMS, 1.6 ± 0.9 vs. 2.3 ± 1.2, p = 0.004; Smoothness, 0.10 ± 0.05 vs. 0.19 ± 0.16, p = 0.016). In addition, unilateral irradiation resulted in a bilateral response, although the response of the contralateral, non-irradiated hand was shorter in duration and lower in magnitude. Although subjects with ‘cold,’ or ‘hot,’ baseline skin temperature appeared to have morphologically distinct PPG waveforms, representing vasoconstriction and vasodilatation, these were not affected by PBM irradiation.Conclusion: This pilot study indicates that post-acquisitional analysis of morphological features of the PPG waveform provides new measures for the exploration of microcirculation responsiveness to PBM.

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Photoplethysmography for the assessment of peripheral vascular disease

Cited by 7 publications

References 116 publications

Advanced Computing Methods for Impedance Plethysmography Data Processing

Advanced Computing Methods for Impedance Plethysmography Data Processing

The 2023 wearable photoplethysmography roadmap

Morphological features of the photoplethysmographic signal: a new approach to characterize the microcirculatory response to photobiomodulation

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