Examining and monitoring heart activity in little patients is a difficult task. So far, there have been no devices on the medical market addressed to the youngest users. This project of a Holter monitor for children improves their comfort during tests and eliminates basic inconveniences, such as the excess of cables, which get tangled and are hard to hide. MALU consists of a waistcoat that helps in fixing the device to the chest and a monitor which is adapted to the child’s body. Parents can choose the way their child will carry the monitor. The adjustable straps can be adapted to the patient’s height, the cables can be covered, and the simple, rounded shape of the monitor does not distract children. The project was consulted with paediatric cardiologists, parents of children with heart conditions, and specialists in medical technologies.