Ultra miniature pressure sensor

摘要

A guide wire having pressure sensing capabilities for measuring the pressure of liquid in a vessel comprising a flexible elongate member and having proximal and distal extremities and having an outside diameter of 0.018'' or less. The distal extremity of said flexible elongate member is adapted to be disposed in the liquid in said vessel. A housing is carried by the flexible elongate member and has a diameter substantially the same as the diameter of the flexible elongate member. The housing has a space therein with a pressure sensor mounted in the space in the housing. The pressure sensor has a diaphragm that is sensitive to changes of pressure in the liquid in the vessel. The diaphragm is rectangular in shape and is bordered by a rim surrounding the well. A backing plate is formed of an insulating material bonded to the crystal and serves to reinforce the rim of the crystal of semiconductor material. The backing plate has a cavity therein underlying the diaphragm and is in substantial registration with the diaphragm. The cavity serves to provide a pressure reference.