"We improve the ability to move by reinforcing the mistakes," says the engineer. This would sound strange. However, if a stroke patient, for example, wants to grab something, but does not make it precise, the rehab robot reinforces this inaccuracy by creating a slight resistance. In this way, the patient has to work harder. The learning algorithm developed by Marchal-Crespo independently decides which patient complicates the task and which one makes it easier.
During training, the robot decides whether to help or resist. Photo: Adrian Moser
In addition to Armin, there is also a horizontal running machine in the Bern open-plan office. Marchal-Crespo can then examine a patient even during the exercise in a magnetic resonance tomograph. Lying, he either actively or passively moves his legs there using a knee-jack robot. The researcher wants to find out which areas of the brain are stimulated by such specific exercises and how the neurons re-connect after a stroke. She is currently trying to simulate the feeling of walking as real as possible, so that the pressure on the soles is felt.
Originally she came from the suburbs of Barcelona, she laughs. She was very fortunate that she received a scholarship for the USA at the time. Because her parents were not academics, and her father earned money as a taxi driver. Her mother has always supported her and her two sisters in every way, she adds. One is now a mechanical engineer in Australia, the other a chemist in Barcelona.
Because Marchal-Crespo's man comes from the capital of Catalonia, he speaks with the three children together, aged three to seven Catalan, while she speaks Spanish with them. Everyday life with family and work is a challenge, but it is also exciting and a privilege, she finds. Her husband works as an engineer at ABB in Zurich. As the family lives there, she commutes to Bern four days a week. "If it's possible, we'll all do outdoor activities together on the weekend and either go hiking or cycling."
Therapy with Virtual Reality
Marchal-Crespo is fascinated in her work above all by the sheer inexhaustible possibilities of the virtual world. So one of her doctoral students now brings out a VR glasses. If you open it, you are in a virtual room where suddenly an apple, then a pear or another apple is hanging in the air. With a controller you now have to control a ball exactly to these fruits and at the same time count the fruits.