Microcontrolled medical gas delivery device

During heart surgery there is a contact between blood and air that can generate air bubbles in the blood (Nitrogen has low solubility in blood). These bubbles can produce micro emboli able to damage the brain by blocking blood vessels. For this reason, a new medical device able to solve or at least mitigate this problem is needed. The main solution proposed concerns the use of CO2 as insulant from air. This gas works good for this purpose due to three main factors: it has a higher absorption rate in the blood compared with air (especially Nitrogen), it is relatively cheap and it does not react with anything in the operating room. At the moment the CO2 is delivered by a diffuser simply positioned near the thorax incision, so it a device is necessary able to control the flows, interface with operators and give information during the surgery. In the first part of this work, a thorax-heart model has been built. Also, an acquisition system has been prepared to measure the results on that model. In the second part a controller prototype consisting of some sensors, actuators and a microcontroller has been programmed. The aim of the code written during this part of the thesis project is to reduce and mitigate the risks related to the use of this device. For this purpose, the BS EN ISO 14971 norm (Risk management for medical devices) has been studied and the documentation related has been produced. In the last part, some results obtained during measurements on the thorax-heart model have been used to write a paper, currently under review. This new medical device is still a prototype and more time is needed before it becomes a full finished product, but the results and the code produced during this work will be the starting point for the final control code.