There is described a medical apparatus, which may comprise a fluid collection vessel and a sensor. The sensor is arranged to sense when the fluid collection vessel is substantially full even when the fluid collection vessel is tilted by up to a predetermined angle from its preferred orientation. The fluid collection vessel may comprise a main chamber and a sensor chamber in fluid communication with one another. The sensor is located in the sensor chamber. The fluid inlet, the main chamber and the sensor chamber are arranged such that fluid entering the fluid collection vessel via the fluid inlet flows into the main chamber even when the fluid collection vessel is tilted by up to the predetermined angle from its preferred orientation, and, once the main chamber is full, any further collected fluid flows from the main chamber into the sensor chamber.
