Fingertip Impedance Plethysmography: A New Window Into Peripheral Blood Flow

Seamus D. Thomson, Seobin Jung

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Keywords: Impedance Plethysmography, Fingertip, Hemodynamics, Blood Flow, Wearables, Health Sensing

TL;DR: This paper introduces the first reported successful and repeatable acquisition of impedance plethysmography signals directly from the human fingertip, demonstrating its feasibility as a new non-invasive method for assessing peripheral hemodynamics.

Abstract: This paper presents the first reported measurements of impedance plethysmography (IPG) signals directly from the human fingertip for the purpose of evaluating peripheral hemodynamics. The human fingertip serves as a vital non-invasive access point for cardiovascular monitoring, with photoplethysmography (PPG) widely adopted for its assessment of superficial blood flow. However, the optical sensing depth of PPG limits its capability to fully characterize deeper peripheral hemodynamics. Here, we developed a novel four-electrode fingertip IPG prototype and measurement protocol, enabling the consistent capture of pulsatile impedance waveforms reflecting blood volume changes within the digit. Preliminary data from two participants illustrates clear signal reproducibility and enables the derivation of key pulse wave metrics, including pulse arrival time (PAT). Given IPG’s electrical sensing principle, distinct from PPG’s optical approach, our findings suggest that fingertip IPG offers a complementary “new window” into peripheral circulation. This work establishes fingertip IPG as a significant advancement for non-invasive physiological monitoring, holding promise for both clinical applications and wearable health sensing.

Track: 2. Sensors and systems for digital health, wellness, and athletics

NominateReviewer:

Seamus D. Thomson, [e-mail]
Seobin Jung, [e-mail]

Submission Number: 75