Abstract A blood flow and blood pressure transducer is provided including a core member having a fixed orifice lumen therethrough adapted to be coupled in line or about a blood vessel. Permanent magnets are coupled to the core forming a magnetic circuit, the force lines of which are perpendicular to the axis of the lumen. Two housings containing silver-silver chloride electrodes covered with permeable membranes are rigidly fastened to opposite sides of the core so that their electrodes extend into a gap in the magnetic circuit. The electrodes are aligned perpendicular to both the longitudinal axis of the lumen and the magnetic force lines. A third housing containing a silicon wafer strain gage is also coupled to the core member. A diaphragm formed of a very thin sheet of mica is provided at the interface of the housing and core lumen having one surface in contact with the strain gage and the other surface communicating with the core lumen.
The invention in accordance with claim 1 wherein said electrodes are set back within said housing from said housing-lumen interface and the walls of said core defining said lumen are lined with a thin membrane.
Claim 2
Dependent Claim
15 words
The invention in accordance with claim 1 wherein said magnetic circuit comprises permanent magnetic members.
Claim 3
Dependent Claim
54 words
The invention in accordance with claim 1 further comprising a metallic cup sealingly fitted within said third housing, said cup having an open end substantially in line with the housing lumen interface, and said diaphragm comprises a monocrystalline mica wafer extending across the open end of said metallic cup and is sealingly bonded thereto.
Claim 4
Dependent Claim
27 words
The invention in accordance with claim 1 wherein the ends of said core member include means thereon adapted for suturing said core member to a blood vessel.