Future Work

In the future, the developed laboratory practice should be performed by Biomedical Engineering students. In order to determine how useful the educational tool is and what other improvements can be considered (e.g. to check if the interface layout is the most appropriate), they should provide feedback after the laboratory session.

Two main improvements regarding the functioning of the physical device could be implemented in the future.

Firstly, the accuracy of the software timing mode could be enhanced. At this moment, the user can successfully induce the heart to pump at different rates and with different duty cycles. However, if the timing switch is set to software mode while the code is not executing, there will be a constant voltage value at the DTR terminal, so in order to avoid the membrane to move while a recording is not being performed, pressure and vacuum regulators must be set to zero. Once the reading code starts executing, pressure can be increased but the first

69 samples recorded will not have any meaning. Once the code stops executing, the regulators need to be set to zero again. In the future, it should be allowed to the user to control timing from the computer without concerning about the pressure regulator.

Secondly, it would be useful to allow the user reading real-time pressure and flow at the same time. In this way pressure-volume loops could be obtained and compared with the simulated ones. There are two main problems regarding this issue.

 In the first place, the differences between the transducers, the different communication velocities and data format, make very difficult to program a code with the needed timing requirements. The callback function of the timers would need to execute not one but two different decoding routines and finish in time so that they do not interrupt the next timer. This might be achieved if executing routines in parallel was possible and with a tight control of the acquired raw data.

 In the second place, if this wanted to be achieved, a different way of controlling timing through software should be considered, as at the moment the port which is not being used for the recording is being used to send the pulses.

The fact that the electronic modifications have been designed in a modular way will make easier any future work. Each module of the system may be replaced using components that offer characteristics that fit better with the nature of the research being carried out at each moment. This does not only apply to the physical modifications but also to all the codes developed, which are structured in functions so that new pieces of code can be easily integrated.

70

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ANNEXES