Automatic Measurement of the Carotid Blood Flow for Wearable Sensors: A Pilot Study.

Riccardo Matera,Stefano Ricci

doi:10.3390/s21175877

Abstract

The assessment of the velocity of blood flowing in the carotid, in modern clinical practice, represents an important exam performed both in emergency situations and as part of scheduled screenings. It is typically performed by an expert sonographer who operates a complex and costly clinical echograph. Unfortunately, in developing countries, in rural areas, and even in crowded modern cities, the access to this exam can be limited by the lack of suitable personnel and ultrasound equipment. The recent availability of low-cost, handheld devices has contributed to solving part of the problem, but a wide access to the exam is still hampered by the lack of expert sonographers. In this work, an automated procedure is presented with the hope that, in the near future, it can be integrated into a low-cost, handheld instrument that is also suitable for self-measurement, for example, as can be done today with the finger oximeter. The operator should only place the probe on the neck, transversally with respect to the common tract of the carotid. The system, in real-time, automatically locates the vessel lumen, places the sample volume, and performs an angle-corrected velocity measurement of the common carotid artery peak velocity. In this study, the method was implemented for testing on the ULA-OP 256 scanner. Experiments on flow phantoms and volunteers show a performance in sample volume placement similar to that achieved by expert operators, and an accuracy and repeatability of 3.2% and 4.5%, respectively.

Highlights

The echo-Doppler [1] investigation of the velocity of blood that flows in the carotid artery is one of the most practiced exams in current clinical activity
Echographic equipment is often not as available as it needs to be. This is apparent for developing countries and/or rural areas [4], but it applies to densely populated cities in developed countries where hospitals and health-care points are often insufficient and overutilized, and where governments are striving for a more efficient use of public resources [5]
The distance between the 2 arrays was calculated so that their axes cross at about 23 mm of depth, which is compatible with the typical depth of the carotid artery [22]

Summary

Introduction

The echo-Doppler [1] investigation of the velocity of blood that flows in the carotid artery is one of the most practiced exams in current clinical activity. It is employed, for example, to investigate general cardiovascular conditions, to inspect the presence of dangerous atherosclerotic plaques [2], to monitor the hemodynamics of patients who have undergone endarterectomy or stent insertion [3], etc. Echographic equipment is often not as available as it needs to be This is apparent for developing countries and/or rural areas [4], but it applies to densely populated cities in developed countries where hospitals and health-care points are often insufficient and overutilized, and where governments are striving for a more efficient use of public resources [5]. Telesonography, i.e., the use of ultrasound scanners from a remote site, could reduce the problem, but the current scanners are often not suitable for this employment [6]

Methods

Results

Discussion

Conclusion