Pressure transducer

An apparatus for use in a direct pressure monitoring system in which a catheter is adapted to be inserted into a patient and is connected to pressure tubing filled with a sterile liquid, said apparatus comprising:

• a semiconductor pressure transducer element comprising a pressure diaphragm adapted to be deflected by blood pressure pulses communicated through said sterile liquid and further comprising means for transforming said deflections of said diaphragm into corresponding electrical signals;
• a housing comprising a chamber filled with a fluid for transmitting said blood pressure pulses through said chamber, and a cavity disposed adjacent to said chamber, said cavity containing said transducer element;
• and
• means removably connected to said chamber of said housing for isolating said chamber from the sterile liquid used to fill said pressure tubing and catheter, such that said apparatus is adapted for re-use by removing and discarding said means.

An apparatus for use in a direct blood pressure monitoring system which includes a catheter adapted to be inserted into a patient and connected to liquid-filled tubing for communicating blood pressure pulses through said liquid-filled catheter and tubing to a diaphragm of a pressure transducer, and a monitor for displaying data corresponding to said blood pressure pulses, said apparatus comprising:

• a housing comprising a chamber filled with a fluid for transmitting said blood pressure pulses through said chamber, and a cavity disposed adjacent to said chamber, said cavity containing said pressure transducer;
• means removably connected to said chamber of said housing for isolating said chamber from said liquid used to fill said pressure tubing and catheter, such that said pressure transducer is adapted for re-use by removing and discarding said isolating means;
• means for placing one side of said diaphragm in fluid communication with said blood pressure pulses transmitted through said liquid-filled pressure tubing and catheter;
• means for venting the other side of said diaphragm through said cavity to atmospheric pressure;
• and
• means for introducing a calibration pressure into said cavity on the side of said diaphragm that is vented to said atmospheric pressure.

In a direct blood pressure monitoring system including an indwelling catheter and pressure tubing filled with a fluid for communicating blood pressure pulses to a diaphragm of a pressure transducer, and a monitor for displaying data corresponding to said blood pressure pulses, a method of calibrating said monitor to said diaphragm of said pressure transducer comprising the steps of:

• placing one side of said diaphragm in communication with said blood pressure pulses in said pressure tubing and catheter;
• venting the other side of said diaphragm to atmospheric pressure;
• and
• introducing a calibration pressure on the side of said diaphragm that is vented.