Ligature detection

A controller for detecting a ligature on a door mounted within a door frame on a mount, comprising:

• a communication module configured to receive, from a load sensor, load sensing data indicative of a detected load applied by the door to the mount, and receive, from an angle sensor, angle data indicative of a measured angle of the door relative to the door frame;
• one or more processors;
• and
• a memory storing computer executable instructions therein which, when executed by the one or more processors, cause the one or more processors to:
• obtain baseline load data indicative of an expected load applied by the door to the mount as a function of the angle of the door, wherein the baseline load data indicates a relationship between expected load applied by the door to the mount and the angle of the door, the baseline load data indicating a different expected load at a first angle of the door than at a second angle of the door;
• determine a threshold load value indicative of a ligature on the door for the measured angle in dependence on the baseline load data and the angle data;
• determine whether the load indicated by the load sensing data exceeds the threshold load value for the measured angle;
• and
• output an indication of a detected ligature event if the load exceeds the threshold load value.