# Highly Sensitive Pressure Transducer for Measuring Arterial Pulse Wave Velocity Based on Giant Magneto-Impedance Sensors

## TL;DR

A new non-contact pressure transducer using GMI sensors accurately measures arterial pulse wave velocity, offering a safer and more reliable alternative to traditional methods.

## Contribution

The paper introduces a contactless GMI sensor-based system for measuring arterial pulse wave velocity without mechanical amplification or optical interference.

## Key findings

- The GMI-based magnetometer successfully captures arterial pulse waveforms with high sensitivity and resolution.
- The contactless method enables simultaneous pulse wave acquisition at multiple arterial sites using magnetic markers and phase-sensitive GMI sensors.
- The system is unaffected by optical factors like ambient light or skin melanin density, improving usability in hard-to-reach areas.

## Abstract

A novel pressure transducer based on phase readings of GMI sensors enables non-contact, high-sensitivity measurement of arterial pulse waves.

The proposed system eliminates the need for mechanical amplification, improving spatial resolution and usability in hard-to-reach anatomical regions, thus providing a contactless method unaffected by optical factors such as ambient light intensity or skin melanin density.

What are the main findings?
The developed GMI-based magnetometer successfully captures arterial pulse waveforms and estimates pulse wave velocity (PWV) with high sensitivity and resolution.A contactless approach using magnetic markers and phase-sensitive GMI sensors was tested in a proof-of-concept setup for simultaneous pulse wave acquisition at multiple arterial sites.

The developed GMI-based magnetometer successfully captures arterial pulse waveforms and estimates pulse wave velocity (PWV) with high sensitivity and resolution.

A contactless approach using magnetic markers and phase-sensitive GMI sensors was tested in a proof-of-concept setup for simultaneous pulse wave acquisition at multiple arterial sites.

What is the implication of the main finding?

This innovation provides a safe, non-invasive, and cost-effective alternative to conventional pressure transducers for cardiovascular monitoring, unaffected by influences associated with conventional measuring approaches caused by factors such as the angle and amplitude of the incident force of contact between the probe and the skin, the probe’s dimension, and optical aspects.

The proposed system has the potential to enhance clinical diagnostics and expand access to cardiovascular assessment tools.

Pulse wave velocity (PWV) has been recognised as the gold standard for assessing arterial stiffness and a relevant indicator in diagnosing cardiovascular disease. Conventional approaches can be affected by factors such as the size of the probe, its positioning on the skin with the appropriate angle and magnitude of the incident force, or influenced by optical properties. Aiming at improving the assessment of PWV parameter, an important cardiovascular risk marker, the present study introduces a new arterial pulse wave measurement technique based on measurements of the impedance phase characteristics of giant magneto-impedance (GMI) sensors submitted to slight magnetic field variations caused by the displacement of a small magnetic marker placed on the patient’s skin, whose movement is coordinated by the local pressure wave. The proposed method eliminates the necessity of using probes with mechanical amplification, enhancing spatial resolution and usability in hard-to-reach anatomical regions through a contactless device unaffected by optical parameters. The obtained experimental results indicate the potential of the developed measurement system in measuring arterial pulse waveform and PWV.