Development and Clinical Validation of a Miniaturized Finger Probe for Bedside Hemodynamic Monitoring

Abstract

Background: Hypertension, or elevated blood pressure (BP), is a marker for many cardiovascular diseases and can lead to life-threatening conditions such as heart failure, coronary artery disease, and stroke. BP monitoring using a traditional arm cuff device is often inconvenient and possibly painful in long-term use, i.e. during sleep. Methods: We present a miniature cuffless tonometric finger probe system, that uses the oscillometric method to measure blood pressure (BP). Our approach uses a motorized press that is used to apply pressure to the finger tip to measure BP. Results: We verified the functionality of the device in a clinical trial (n=43) resulting in systolic (SBP) and diastolic (DBP) pressures ((mean±SD) mmHg) of (-3.5±8.4) mmHg and (-4.0±4.4) mmHg, respectively. Comparison was made with manual auscultation (n=26) and automated cuff oscillometry (n=18). In addition to BP, we demonstrated the ability of the device to assess arterial stiffness (n=18) and detect atrial fibrillation (n=6). Conclusions: We were able to introduce a sufficiently small device that could be used for convenient ambulatory measurements and worn during sleep with minimal discomfort. Lastly, we evaluate methods to further develop the concept and discuss future directions.

Continuous Blood Pressure Monitoring Using Nonpulsatile Photoplethysmographic Components for Low-Frequency Vascular Unloading

“…However, the accuracy of the continuous BP measurement in any VUT method depends heavily on the accuracy of the oscillometric calibrations performed at certain intervals. This is usually done with a brachial cuff, but in our previous study we have shown that it can be done robustly with the finger tonometry method [27], [35].…”

Hemodynamic Bedside Monitoring Instrument with Pressure and Optical Sensors: Validation and Modality Comparison

“…The developed instrument consists of a pressure sensor, optionally a PPG unit, and a motor that applies external compression force to the fingertip, as shown in Figure 1b. [13,17] To measure BP, the user places their fingertip on top of the sensor, and the compression force is then gradually increased. The recorded pressure and PPG signal is processed to extract the oscillometric envelope, from which the BP values can be estimated.…”

“…An oscillometric response can be recorded with a pressure cuff, with an optical photoplethysmography (PPG) sensor [14] or via a finger pressing method. [13,[15][16][17] In this study, we present results from compact instrument for measuring hemodynamics at the bedside designed to have similar form factor as in commonly used pulse oximeters (Figure 1a). The developed technology is presented and analyzed in three different embodiments, all sharing the same fundamental technology.…”