A pressure monitoring device is provided for use with a tool such as a medical endoscope. The device includes a housing which is fluidically coupled with an internal volume of the endoscope. A pump is used to change the pressure inside the device housing and endoscope, thereby establishing a pressure differential from the ambient environment. During an endoscopy procedure, the pressure inside the device housing is monitored, and a change in pressure exceeding a predefined limit causes an alarm signal indicating a leak has occurred in the endoscope. The device housing may be directly mounted to the endoscope, located remotely and connected with a coupling tube, or integrated with an accessory device connected to the endoscope. The pump may be integrated internally to the device housing, or it may be a separate external pump which is connected to the housing. The pressure differential may be positive or negative relative to ambient.
