Cardiovascular diseases are a leading cause of mortality globally, with ischaemic heart disease being a significant contributor. This study focuses on the development and validation of a novel integrated wearable system designed for continuous cardiorespiratory monitoring. The system aims to support heart-attack detection algorithms and consists of two main components: a wristband and a chest band.
The wristband is equipped with a MAX30105 photoplethysmography sensor, which is used for cardiac pulse-wave and SpO2 acquisition. The chest band features innovative optical respiratory detection and an MPU6050 inertial measurement unit, which monitors respiratory rate and movement. Both devices utilize ESP32-C3 microcontrollers and connect via Bluetooth Low Energy to a custom mobile application, allowing for real-time data visualization and cloud-based storage.
Validation of the wearable system was conducted against clinical-grade reference equipment, specifically the ADInstruments physiograph and the EDAN iM8 monitor. The study involved 43 healthy volunteers, yielding a total of 50 acquisitions—30 at rest and 20 post-physical activity. The results indicated that heart rate measurements showed the closest agreement with the reference equipment, with a percentage error of ±1.94% post-activity and limits of agreement to 4.21 BPM. The respiratory rate also demonstrated a reasonable accuracy with an error of ±3.47%.
However, the SpO2 measurements showed a tolerance error of 1.64% at rest and 2.98% post-activity, but the correlation with the reference was weak due to range restriction in the healthy cohort. As a result, the SpO2 readings are not yet suitable for applications that require absolute saturation values.
This study establishes the technical feasibility of a low-cost, multi-sensor wearable system, achieving accuracy that meets the pre-specified feasibility criterion of less than 5% error in a healthy young cohort. This is an important step toward future validation in clinical populations where the system is intended to be used.
What this study does not show
This study does not demonstrate the effectiveness of the wearable system in clinical populations or its ability to detect heart attacks in real-world settings. Further validation in diverse patient groups is necessary to establish its clinical utility.
Evidence scorecard
- Analytic validity: Established
- Clinical validity: Not established
- Clinical utility: Not established
The evidence is based on a technical feasibility study in healthy volunteers.