Design and development of a wireless medical device for blood leak detection during hemodialysis therapy

Hemodialysis therapy is a clinical intervention by inserting the needles on the arterial and venous blood vessel in the patient’s arm. The area where the needle is inserted can cause bleeding and it’s harmful for the patient. Previous method for detecting the blood vessel is by using a single point optical detection method. However, this method is not suitable for covering wide area. In this research, an electrochemical based multisensor is used for detecting the blood vessel around area of the inserted AV Fistula needles. This sensor is based on the impedance sensor. The main components of blood leak detection system are a multiplexer, an instrumentation amplifier, an impedance analyzer, microcontroller integrated Wi-Fi communication, and alarm system. An impedance analyzer is used to extract the signals into the real part and imaginary parts. The magnitude of the signals is computed from the real and imaginary parts of the signals. Such signals are computed using an artificial neural network (ANN) algorithm to classify the digitized signal output of the impedance analyzer whether the sample is human blood or not. The classification result in the form of messages is then sent to the alarm system to activate the visual and audio alarms. The messages were also transmitted to the nurse station through Wi-Fi communication system. Such message also consists of information about the location of the patient so the medical staf can go to the patient’s bed directly. Various testing activities such functional test, battery life test, transmision test have been performed in this work. The result shows that the system can detect the present of the blood leakage with the sensitivity greater than 90%.