V-CHEK Clinical Trial

Comprehensive Evaluation of Cuffless Blood Pressure Monitoring

A large-scale Indian clinical study validating V-CHEK against mercury sphygmomanometer — 250 patients at Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bengaluru.

Introduction

Blood pressure monitoring is undergoing a paradigm shift from traditional cuff-based methods to cuffless wearable technology.

In the era of advanced digital health technology, the approach to blood pressure (BP) monitoring is shifting from in-office and home BP monitoring toward cuffless and wearable technology. Traditional cuff-based methods — introduced by Scipione Riva-Rocci almost 125 years ago — can be cumbersome, inconvenient, and potentially inaccurate, especially for frequent measurements.

Advancements in sensor technology, signal processing, and machine learning have opened opportunities for cuffless methods that establish precise relationships between biomedical signals like photoplethysmography (PPG) and changes in BP.

Background & Objective

Background

Conventional BP devices using inflatable cuffs offer limited snapshots. Cuffless technologies enable continuous monitoring, potentially revolutionizing hypertension management.

Objective

Compare accuracy of V-CHEK cuffless BP monitor against mercury sphygmomanometer and pulse oximeter for BP, heart rate, and SpO₂ in resting conditions.

Study Design

Cross-sectional study with 250 patients. Statistical analysis included Bland-Altman agreement assessment with 95% confidence intervals.

Key Results

Strong agreement across all vital parameters measured

−0.38

SBP Bias (mmHg)

95% CI: −0.76 to 0.004

0.77

DBP Bias (mmHg)

95% CI: 0.52 to 1.03

−0.08

Heart Rate Bias (bpm)

95% CI: −0.25 to 0.09

0.96

SBP Agreement

Pearson correlation coefficient

Metric	Result
SBP Bias	−0.38 mmHg (95% CI: −0.76 to 0.004) — 3.6% outside limits
DBP Bias	0.77 mmHg (95% CI: 0.52 to 1.03) — 4.6% outside limits
Pulse Rate Bias	−0.08 bpm (95% CI: −0.25 to 0.09) — 5.4% outside limits
SpO₂ Bias	−0.17% (95% CI: −0.24 to −0.10) — 4.3% outside limits
SBP Correlation	0.959 (95% CI: 0.953–0.965)
DBP Correlation	0.949 (95% CI: 0.941–0.955)
PR Correlation	0.982 (95% CI: 0.979–0.985)
SpO₂ Correlation	0.808 (95% CI: 0.782–0.832)

How V-CHEK Works

Non-invasive, cuffless BP monitor measuring BP, heart rate, and oxygen saturation

Optical sensors embedded in integrated hardware capture physiological signals at the fingertip
Waveforms analyzed by V-CHEK algorithms determine SBP and DBP relative to calibration point
Measured data displayed on device and smartphone app via Bluetooth
Requires no patient interaction — comfortable for daily home BP measurements
Calibration using sphygmomanometer reference before first use

Calibration Protocol

Step 1: Rest

Patient rested 5 min seated, hand open and relaxed, legs uncrossed.

Step 2: Reference BP

Three reference measurements (Ref1, Ref2, Ref3) using mercury sphygmomanometer. Average SBP and DBP entered in app.

Step 3: V-CHEK Measurement

Within 60s of reference, place finger on sensor. All four vital signs displayed in 40–60 seconds.

Conclusions & Key Messages

V-CHEK provides daytime BP measurements comparable to traditional sphygmomanometer
Negligible bias for BP (−0.377 mmHg), heart rate (−0.078 bpm), and SpO₂ (0.173%)
No statistically significant differences in resting SBP and DBP
Easy to learn and use across all age groups without assistance
Promising tool for cuffless BP monitoring in clinical and home settings

Published in: Journal of Indian College of Cardiology, Volume 14, Issue 3, July–September 2024

Authors: Rahul S. Patil, C. N. Manjunath, K. R. Nishanth

Institution: Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bengaluru

DOI: 10.4103/jicc.jicc_46_23