Interventional medical device

An interventional medical device, comprising:

• an interventional sheath, wherein a proximal end of the interventional sheath is located outside a body of a subject and a distal end of the interventional sheath is operably inserted into the body of the subject;
• a catheter, wherein a distal end of the catheter is operably inserted into the body of the subject via an interior of the interventional sheath, and a gap is present between the catheter and the interventional sheath;
• a pressure measurement assembly, comprising:
• an operation portion, connected with a proximal end of the catheter and located outside the body of the subject, wherein a first chamber inside the operation portion that is in fluid communication with the gap;
• a first tubing assembly, in fluid communication with the first chamber, and configured to deliver a first flushing liquid to the first chamber;
• and
• a first pressure sensor, which is provided in the operation portion, is in fluid communication with the first chamber, and is configured to sense liquid pressure in the first chamber.