Developing a Wireless Heart-Rate Monitor with MAX30100 and nRF51822

The purpose of this project was to develop a wireless heart rate monitor based on the principle of photoplethysmography and using the Bluetooth Low Energy (BLE) technology for wireless transfer. The emphasis here was not on the hardware prototype but mainly on the software that drives the sensor and a compatible client mobile application. The mobile client application is an Android application developed for smart phones powered by Android version 4.4.3 or higher. It enables the Android device to communicate with the sensor to recieve PPG data, process, store and display results. In this project, the mobile device used during the development and testing was an LG Nexus 5 smart phone. The heart rate monitor developed in this project has two main units, the sensor unit,and the mobile client application. The sensor unit consists of two main components: a heart rate sensor integrated circuit (IC), max30100, which is a complete pulse oximeter and heart-rate sensor solution from Maxim Integrated, and a BLE chip, nRF51822, which is a multiprotocol system on chip for Bluetooth smart and 2.4 GHz ultra low-power wireless applications from Nordic Semiconductors. Both components work as a unit to collect photoplethysmograph (PPG) samples and stream them through an emulated UART/Serial port over BLE to a connected mobile device. The result of this project includes a laboratory setup for a finger-based heart rate sensor, a firmware for the sensor, and an Android mobile application that works with the sensor. The sensor setup could be further developed into a finger wearable heart rate monitor prototype that can run the same firmware using MAX30100 and nRF51822. With some modifications in the firmware and the client application, the result of this project could also be further developed into a prototype of an oximeter that would also measure blood oxygen saturation

Printed, skin-mounted hybrid system for ECG measurements

In this paper we report a design and fabrication process for a screen printed, skin-mounted hybrid system for electrocardiogram (ECG) measurements. The system consists of printed electrodes on a stretchable bandage substrate designed to be attached to the chest, an electronics module, and a data receiving device. The electronics unit is reversibly attached to the single-use electrode bandage to measure the ECG data. The ECG data is then transmitted to a mobile device via Bluetooth Low Energy and the mobile device then displays the data graphically and sends it further a cloud for storing and further analysis. The attained quality of the measured ECG signals is fully satisfactory to compute important cardiac parameters and after preprocessing the signal could be used for more profound analysis of ECG wave shapes.acceptedVersionPeer reviewe