Measurement of water transfer changes during hemodialysis cycle

摘要

During the hemodialysis cycle which can be few hours, the actual apparatus of the dialysis does not display the water transfer ratio and since this cycle is around four hours, it is necessary to have the hydratation state of the patient and to avoid the over hydration or the dehydratation states. In this paper, we have investigated the concept of the bioimpedance and the biological body constitutions and its different compartments such as Total Body Water (TBW), Intra-Cellular Water (ICW), Extra-Cellular Water (ECW), Fat Free Mass (FFM), and Fat Mass (FM). During the treatment cycle, there is a variation of the quantity of water and this change of water is slowly varying function leading to small variation of the bioimpedance; therefore we developed a system to detect a small variation of the bioimpedance (order of few milliohms) and to extract and display the different biological compartments. This developed system with an STM 32discovery board displays in the real time the value of the bioimpedance and the calculated body water compositions taking into account the physical data of the patient such as age, sex, weight, length. Finally, the proposed embedded solution can be integrated in the hemodialysis apparatus in the purpose to help the nephrology doctor by giving an information on the over hydratation or the dehydratation states of the patients.