25-08-2017, 09:32 PM
Bio Instrumentation For several decades considerable amount of research activity has been directed towards advances and developments of biomedical instrumentation. These researches lead to new concepts for measurements such as breath monitoring by thermal film, heart beat monitoring by electro mechanical film, bio impedance measurement using spot electrode array, and electrophysiological measurement using dry electrodes currently available breath monitoring system operates by inserting a thermistor into patient™s nostril. A new method that is less intrusive and more useful is being introduced based on a versi colour thermal film in conjunction with image processing techniques. Ex-inhalation is displayed as 2D colour pattern on the film placed under the nose. Conventional method of heart beat monitoring is by using microphones as in phonocardiogram (PCG). By using electro mechanical film type transducer, composed of thin, elastic, three layered polypropylene films, PCG can be recorded more easily. Like an ECG electrode this film transducer can be directly attached to the chest to detect vibrations from heart. Applications of bio impedance measurement include evaluation of cardiac output, stroke volume as well as cardiac function. In earlier days, for clinical purpose, we made use of tetra polar band electrode system. This method could not be used for continuous monitoring purpose. Thus we go for another method called spot “electrode array. The impedance changes measured with this electrode array showed a good correlation with those using 3D finite element methods (FEM). Electro physiological signals such as ECG, EEG and EMG are monitored by attaching electrodes to the skin through gel which may cause skin reddening and irritation. Why not monitor it with high stability, high signal to noise ratio and without any skin irritation using capacitive type electrodes, flexible dry surface electrode or carbon nano tube array based dry electrode? All these dry electrodes are under development. Monitoring of health at home is very important. Researches in the field of biomedical instrumentation have lead to the development of a system called fully automated network system for long term health care monitoring. This system provides continuous monitoring of a bedridden patient without needles or sensor attachments, let the patient be in bath tub or bed