The number of people who suffer from renal disease is growing year-by-year, so it is important to develop good dialysis devices. The control software of a dialysis machine is quite complex because it is responsible for the correct operation of the pumps, actuators, and sensors. The machine must fulfill safety critical standards because a patient’s life depends on its harmless operation.
The problem is that a chronic hemodialysis machine, which is widespread around the world market, has a microcontroller that has become obsolete, so the porting of the control software that runs on it is a high priority task. The first step is to find the successor, but it is an important aspect in choosing the new microcontroller, that the change does not require major modifications in the software and hardware architecture.
A Power PC architecture base microcontroller has become the chosen one, which is similar to its predecessor. It is also suitable for medical usage and it contains the so-called eTPU coprocessor unit, that is responsible for the control of the various mechanical parts of the machine. According to this, my task is to port the low-level controller software. First I got to know the new microprocessor, by implementing test applications. In the second step, I modified the source of the MQX v4.2 operating system in order to run on the new target, then I implemented the required drivers. Finally, I suited the application layer to work with the new version of the operating system. The development was based on an evaluation board, so the final hardware was not available for me, which is the reason why I could not implement all the required functionality, but I have created a boost for further development.
The development process could go on after the printed circuit board is ready. Finally, the verification and validation processes, that are required by the standards, must be done.