A medical device such as an external cardiopulmonary resuscitation (CPR) device delivers chest compressions to a patient. The patient may shift and/or slide within the CPR chest compression structure if the CPR chest compression structure is tilted from the horizontal, however. A tilt module is used to sense a tilt event, report it to a user of the CPR chest compression machine, and cause the CPR chest compression machine, user, or tilt module to respond to the tilt event. Response can be pausing the CPR chest compression machine, having the user reposition the CPR chest compression machine, or the like.
