Design and Implementation an Infrared Control-sensing System to Detect Air Bubbles in the Tubes of the Peritoneal Dialysis Machine

Due to the damage that air can cause to the intestines and diaphragm, it is essential to prevent air from entering peritoneal dialysis fluid. Bubble detection systems and air infiltration control systems are mandatory components of peritoneal dialysis machines. An infrared sensor is one of the most efficient ways to detect bubbles in the catheter tube. As the dialysis fluid passes through the infrared sensors, an output of approximately 1200 millivolts is produced. The voltage produced by infrared sensors is independent of the device's speed. Approximately 1200 millivolts can be obtained when the motor of the dialysis machine operates at speeds of 50, 40, and 30 RPM. Continuous measurement of this voltage is performed, and the processor checks the correctness of bubble detection by limiting the threshold level of output voltage. This threshold control to detect bubbles in the dialysis machine tubes is 1000 millivolts. If the output voltage drops below this value, the operation of the dialysis machine is prevented to prevent possible injuries to the patient.