A Method to Adjust for Finger Arterial Pulse Temporal Variations: A Pilot Study
College
College of Allopathic Medicine
Format
Poster
Start Date
6-11-2020 11:15 AM
End Date
6-11-2020 11:30 AM
Abstract
Objective. To determine if temporal variability of the maximum rate of change of peripheral pulses, assessed via photoplethysmography (PPG), is reduced by normalization to peak PPG. Background. PPG derived data is useful to assess arterial stiffness, heart-rate-variability, blood pressure parameters and other conditions. But, temporal variability in PPG signals complicates interpretation. The proposed normalization method targets this issue. Methods. A convenience sample of seven medical students participated after signing an approved consent. While supine, a PPG sensor was placed around an index finger and pulses recorded for 45-minutes. At four time points after recording start (60-840-1740-2640 sec), 30 sequential pulses were analysed. Parameters analysed were the peak of the PPG pulse (PPGmax) and its maximum rate of change (dPPG/dt)max. Temporal variability of these and their ratio was determined based on the coefficient of variation among these time points. Results: Coefficients of variance averaged over time for PPGmax, (dPPG/dt)max, and the normalized ratio (dPPG/dt)max/PPGmax was 13.8%, 27.2% and 14.1% respectively. Conclusion: These pilot results indicate that temporal variance in the maximum rate of change of PPG pulses (dPPG/dt)max is reduced almost in half (27.2% vs. 14.1%) when its value is normalized to the peak PPG value. This adjustment may reduce variations in assessment parameters derived from PPG-signals such as blood pressure and pulse wave velocity. These pilot study findings provide a rationale for future studies with increased number of subjects to verify the present findings for healthy subjects with subsequent extensions to clinical applications and in persons with cardiovascular dysfunction.
A Method to Adjust for Finger Arterial Pulse Temporal Variations: A Pilot Study
Objective. To determine if temporal variability of the maximum rate of change of peripheral pulses, assessed via photoplethysmography (PPG), is reduced by normalization to peak PPG. Background. PPG derived data is useful to assess arterial stiffness, heart-rate-variability, blood pressure parameters and other conditions. But, temporal variability in PPG signals complicates interpretation. The proposed normalization method targets this issue. Methods. A convenience sample of seven medical students participated after signing an approved consent. While supine, a PPG sensor was placed around an index finger and pulses recorded for 45-minutes. At four time points after recording start (60-840-1740-2640 sec), 30 sequential pulses were analysed. Parameters analysed were the peak of the PPG pulse (PPGmax) and its maximum rate of change (dPPG/dt)max. Temporal variability of these and their ratio was determined based on the coefficient of variation among these time points. Results: Coefficients of variance averaged over time for PPGmax, (dPPG/dt)max, and the normalized ratio (dPPG/dt)max/PPGmax was 13.8%, 27.2% and 14.1% respectively. Conclusion: These pilot results indicate that temporal variance in the maximum rate of change of PPG pulses (dPPG/dt)max is reduced almost in half (27.2% vs. 14.1%) when its value is normalized to the peak PPG value. This adjustment may reduce variations in assessment parameters derived from PPG-signals such as blood pressure and pulse wave velocity. These pilot study findings provide a rationale for future studies with increased number of subjects to verify the present findings for healthy subjects with subsequent extensions to clinical applications and in persons with cardiovascular dysfunction.