DESIGN AND DEVELOPMENT OF A LOW COST BLOOD LEAK DETECTOR FOR DIALYSIS MACHINE APPLICATION

Abstract

Blood leak detector is an important safety components in the dialysis machine. It is intended to protect patients from loss of too much blood and infusion of non-sterile dialysate, through a rupture in the dialyzer membrane. Immediate corrective action was needed for preventing the blood leak developing in the membrane. Such a detector together with the alarm system were usually mounted in the machine and triggered when the amount of blood leaks in the dialysate line. This research was focused on the development of an optical detection instrument for blood leak detection in the dialysate line of the dialysis machine. The specially developed instrument consists of LEDs, photodetectors, signal conditioning system, and digital signal processing system. An important design criteria for the detector is that it must be sensitive to the blood concentration. The optical detector used in this experiment matches the spectral properties of blood, in order to achieve a maximum sensitivity while minimizing false alarms. An algorithm was developed to detect the amount of blood concentration of the sample from a set of optical transmission parameters recorded from the sample. The results shows that the detection limit of the sensor is 0.2 ml/cm3