Contactless operation of a medical device, such as a hemodialysis (HD) or peritoneal dialysis (PD) device, is provided via a mobile pointing apparatus and a receiving arrangement associated with the medical device. The mobile pointing apparatus includes a signal emitter for emitting an optical or electromagnetic signal, and the receiving arrangement associated with the medical device determines a pointing target of the mobile pointing apparatus relative to the medical device based on the signal emitted by the mobile pointing apparatus and triggers a function of the device based on the pointing target of the mobile pointing apparatus.