US Patent 11617543 Catheter for monitoring pressure

A catheter insertable into a cavity of a patient for monitoring pressure including a first lumen for drainage from the cavity and an expandable balloon. The balloon has a liquid containing chamber to monitor pressure within the cavity of the patient as pressure on the outer wall of the balloon deforms the balloon and compresses the liquid within the balloon. An exit port provides passage of air from an interior of the balloon to outside the catheter. A membrane has plurality of pores dimensioned to enable passage of air but prevent passage of the liquid therethrough. A pressure sensor communicates with the liquid containing chamber for measuring pressure based on compression of liquid caused by deformation of the expanded balloon.