Signal processing photoplethysmography from a wearable optic patch in relation to biomedical impact

Using hybrid printed electronics technology, Holst Centre has developed a wearable optic sensor by integrating silicon photodiodes with multiple light sources and readout electronics into a lightweight and flexible patch. By recording optical signals from the skin using light sources with different wavelengths, our patch simultaneously measures signals from different skin depths. This provides advantages to overcome significant challenges in the field.

Our current R&D is focused on photoplethysmography (PPG) by recording optical signals from the illumination of the human tissue. Morphological features from the PPG signal can be translated into multiple patho-physiologies, from cardiovascular disease to diabetes. Different optical wavelengths have differing efficiencies of absorption dependent on biomolecules. As such there is a growing interest to further investigate common PPG features and there prevalence with increased wavelength possibilities.

Your challenge

Working in an interdisciplinary team of engineers and scientist (electrical engineering, material science, biomedical photonics), you will measure and analyse PPG signals using Holst Centre’s wearable optical sensor patch and existing software platforms. The challenges reside in

  1. obtaining reliable PPG signals and extracting morphological features from the sensors

  2. linking the sensors to existing physical conditions of individuals, in particular with an interest in cardiovascular diseases (CVDs).

Project goal

  • Gain a basic understanding of biomedical optics and of propagation of light in human tissue

  • Provide a literature review on PPG signal analysis and biomedical biomarker extraction, with a focus on the dicrotic notch

  • Determine methodologies used within literature to assess alterations in signal

  • Develop protocols for evaluation of morphology with test optical devices

  • Acquire PPG signals with Holst Centre’s wearable optical patch

  • Conduct experiments and potential volunteer study

  • Communicate via presentations and report writing findings

Your tasks

As a team member your tasks will be:

  • Knowledge acquisition through literature survey, discussion with other team members, and internal seminars/colloquiums

  • Data acquisition through measurements

  • Analysis and presentation of experimental data

  • Documentation of results in a technical report or scientific publication

  • Presentation of results in internal seminars/colloquiums

Your Profile

  • A master degree in biomedical engineering, electrical engineering, physics, optics or related with both theoretical and experimental skills

  • Knowledge in signal processing, filtering, calibration, data analysis using MATLAB/Python or other platforms

  • Experience in signal processing and algorithms development

  • You have good communication skills in English

  • Independent but also a team player

  • Affinity for biomedical photonics

  • Analytical skills – ability to make analysis of complex situation and make a plan forward.

Have we sparked your interest? Then please send your application or any questions you may have to:

Ahmad Khatoun (