Patent attributes
A pressure detector having a pipe inner pressure receiving opening section comprising a fluid passage for transporting fluid and a diaphragm hermetically sealing an opening made in one side face of the fluid passage, and a pressure detecting section coupled with the pipe inner pressure receiving opening section through the diaphragm and detecting physical variation of the diaphragm, characterized in that the diaphragm is provided loosely at the opening, and the pressure detecting section comprises at least a pressure detector, a load transmitting means having one end connected with the diaphragm and the other end touching the pressure detector, and means for loading the pressure detector. Since a fluid being measured is not exposed directly to air, possibility of clogging the circuit with a blood clot can be reduced; and since a stress load on the diaphragm is reduced, irreversible creep deformation of the diaphragm can be prevented; thereby allowing the pressure detector to perform continuous measurement stably with high accuracy for a long time.