As it is known, Hemodialysis is currently the most efficient way to treat patient of acute or chronic Kidney failure. The machine works as human kidney to take blood out of the body, exchange substances in the dialyzer through extracorporeal circulation, remove metabolic waste and excess water, and then return to the body through the vein.
The treating process cannot be interrupted and it must be ensured that the indicators in the dialysis operation are in normal stage in order to guarantee the clinical treatment. Various sensors, including pressure sensors, temperature sensors, etc., play an important role in the entire system.
Pressure sensor monitoring blood flow pressure
Accurate measurement of dialysate and venous pressure is critical to patient safety during dialysis treatment. At present, some miniature pressure sensors, especially MEMS pressure sensors, are used in various fine liquid monitoring devices such as dialysis machine.
In such machine, the main function of the pressure sensor is to accurately detect the fluid and blood flow pressure to ensure that the pressure is maintained within the suitable range, in prevention of overpressure or under-pressure, both of which will cause rupture of blood vessels or air bubbles, threatening the safety of patients.
Practically, to achieve higher precision and faster response time, the sensing part must be as close as possible to the flow of liquid. In this consideration, liquid compatible sensor can solve the problem of design complexity and extra cost.
Heating Control by Temperature Sensor
In Hemodialysis treatment, dialysate has to be maintain on the temperature of 36.5 to 37.5 ℃. Normally it is set 37 ℃. If the temperature falls out of this range, it will caused discomfort on the patient or even death. Therefore, monitoring on the temperature of the dialysate is critical. Usually, the dialysate has a temperature indicator and a thermistor in the dialysate loop. It is used to monitor the temperature of the dialysate to keep it within a constant range.
In practical use, in order to achieve the same temperature of the fluid and the patient’s body, temperature management solutions will be used in the dialysis machine. By applying temperature sensing part like flexible heater, blood and dialysate can be heated to body temperature before injected into human body. In this process, heating controller can control the temperature of the dialysate on a high precision.