Developing medical devices takes time because large parts of the control systems can be designed and tested only once the hardware is ready.
Beat by beat, the heart pumps blood through the arteries. In some people, however, the heart is too weak to supply the body with enough oxygen and nutrients, a condition often referred to as myocardial insufficiency or heart failure. A heart pump implanted in the body can help, although the control system that gives the pump the relevant commands must work precisely. When developing medical devices such as heart pumps, engineers usually proceed one step after the next (serial development). The developers first develop the hardware: in this case, the heart pump. Only much later can they complete development of the control software, combine it with the hardware, and test it manually.
Researchers from the Project Group for Automation in Medicine and Biotechnology at the Fraunhofer Institute for Manufacturing Engineering and Automation IPA are speeding up this drawn-out process. “Using the hardware-in-the-loop method, we reduce both development times and development costs by up to 50 percent,” explained Jonathan Schächtele, who is a scientist in the project group.
Hardware-in-the-loop (HiL) techniques were pioneered in the automotive industry. The previous method had been to develop many components in sequence, whereas HiL allowed engineers to develop parts in parallel processes and shorten integration times. Instead of testing electronic control units (ECUs) on the hardware, which runs the risk of damaging them, engineers create a computer model of the car that includes all details relevant for testing. They use this model to test the ECUs before the vehicle is even built. Special interfaces connect the ECU to the virtual car. The ECU receives information from the vehicle and also sends back commands for the simulated car to execute. Because the process is automated, developers can analyze a large number of test cases while also investigating critical system states in a reproducible,