High-DR PPG demonstrator

Wearable electronics are becoming popular, making personal health care devices like chest patches, wristbands, and smartwatches a reality. These devices can measure signal modalities like ECG, BioZ, EEG, and PPG, which monitor different health parameters, such as heart rate (HR), heart rate variability (HRV), blood pressure, and much more. It plays a vital role in fitness monitoring nowadays and even in clinical diagnosing and monitoring. Wearable PPG is one of the most important modalities. Besides HR and HRV, from the dual-wavelength PPG measurement, the oxygen saturation levels (SpO2) can be derived as well. 

The wearable chest PPG monitoring is rather more interesting because it not only measures the HR, HRV as a standard chest ECG patch does, but it also provides SpO2, and respiration at the same time. SpO2 usually gets measured by a dedicated PPG finger clip. All these biomedical parameters can be extracted with a single setup on the chest, aiming to diagnose or monitor lung diseases. For example, we are suffering the covid-19 pandemic, and chest PPG is a promising application for covid-19 patients. Currently, we developed and characterized our 1st chest PPG chip. However, the chest PPG patch still needed to be designed to enable the in-vivo, ambulatory chest PPG measurement. Further signal processing and analysis are also required to validate the chest PPG chip fully.

This internship project aims to design a suitable, small form factor chest patch (demonstrator) with real-time signal processing. The student will be involved in the hardware design, in-vivo, real-time chest PPG recording, and the relevant signal processing. 

Specific  objectives:

• Study and understand the theory behind PPG recording and the architecture of the chest PPG IC.
• Investigate and build a small form-factor chest PPG patch by using off-the-shelf components and the chest PPG chip. For this, the design and layout of custom printed circuit boards (PCB's) will be required.
• Code the micro-controller to realize the communication between the chip and the PC.
• Measure the real-time chest PPG signals in-vivo.
• Analyze or process the measured signal.

Requirements:

• Interest and enthusiasm in analog microelectronics and circuits.
• Knowledge of analog IC design principles
• Knowledge of PCB design tools (Altium)
• Basic knowledge of PCB layout implementation
• Knowledge of Matlab or python
• Knowledge of microcontroller (e.g., Arduino, Teensy, etc.) or FPGA is a plus.