The present invention is an apparatus for treating a selected patient tissue or organ region, at the surface of such region. The apparatus has an accessing tool for accessing the patient region, the tool having a distal end, and a proximal end at which the tool can be manipulated to place the distal end adjacent to the patient region. The apparatus also has a probe carried on the distal end and defining a contact surface that may be urged against the patient region thereby creating contact pressure. A pressure transducer is operatively coupled to the probe and is capable of producing a measurable response to the contact pressure. A monitoring device is operatively connected to the pressure transducer, for determining the contact pressure. An effector is operatively disposed on the probe for producing a given effect on the patient region when the effector is activated, and an activator operatively connected to the effector, by which the effector can be activated.