Design of Low-Cost Optical Flow-Rate Sensor Using LED-Photodiode Pair for Portable Peritoneal Dialysis Module

Peritoneal dialysis is a regular treatment for a patient who is at 'Stage Five” of chronic kidney disease (CKD)., which is also known as 'end-stage” renal failure. Similar to the hemodialysis procedure., a peritoneal dialysis patient needs to undergo a 4-hour treatment., 3 times a week., which limits the daily movement or personal activities. Quite recently., the Institute of Microengineering and Nanoelectronics (IMEN) has develop a prototype of a portable peritoneal dialysis module., which requires a flow-rate sensor as the most important component to monitor the peritoneal dialysis fluid-flow. However., this sensor., which is using sonar - an ultrasound technology - is expensive. This limitation has been a bottleneck in producing a low-cost., reliable., and affordable solution. Therefore., this paper presents a design concept and preliminary research work of using a light-emitting diode (LED) and photodiode (PD) pair as an alternative flow-rate sensor for the developed portable peritoneal dialysis module. With a unique arrangement of the LED-PD pair., an optical flow-rate sensing mechanism can be achieved by considering the intensity., incident angle., and separation distance between the LED and the PD. The LED-PD pair offers the advantages of being a low-cost., non-invasive approach and has the potential for use in many emerging applications.