Intracranial pressure transducer
First Claim
1. An intracranial pressure transducer which comprises:
- a casing comprising an annular member having a threaded part on a radially outer wall thereof for fitting and securing to a skull of a body,a pressure-electric transducing portion comprising a supporting member which is inserted within a radially inner wall of said casing and is tightly fixed to a predetermined first portion of said casing at a first portion of said supporting member, and which has a hole of predetermined diameter, a thin strain sensing member 21 having a first surface bonded to a second surface of said supporting member 22 having said hole in order to close said hole, at least one strain sensitive element having two ends for converting the strain of said strain sensing member into an electrical signal provided at a strain sensing region, which region corresponds to said hole of said supporting member, on said thin strain sensing member, lead wires connected to said strain sensitive element through electrodes provided at both ends of said strain sensitive element and a receiving connector provided at an upper portion of said casing, and a pressure receiving layer adapted to be in contact with a dura under the skull and comprising resiliently compressible material for receiving an intracranial pressure under the dura as an internal pressure thereof which fills up a concave portion formed by a radially inner wall of a second portion of said casing, a portion of said second surface of said supporting member, and said second surface of said thin strain sensing member, andan indicating circuit, for indicating the intracranial pressure, in response to an output of said strain sensitive element, comprising an amplifier circuit connected to said lead wires within said pressure-electric transducing portion through connector means for engaging with said receiving connector, and indicating means connected thereto,whereby the intracranial pressure of a cerebrospinal fluid is converted to the internal pressure of the pressure receiving layer with the intracranial pressure transducer by means of a Coplanar method which maintains the dura to be coplanar by the depression of the pressure receiving layer of the transducer against the dura;
the internal pressure of the pressure receiving layer being applied to the strain sensing member;
the electrical signal being supplied by the strain sensitive element in response to the internal pressure of the pressure receiving layer; and
the intracranial pressure being indicated on the indicating means.
1 Assignment
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Accused Products
Abstract
An intracranial pressure transducer includes a casing comprising an annular member having a screwed part on an outer wall thereof for fitting and securing a skull of a body. A pressure-electric transducing portion including a supporting member which is inserted within an inner wall of the casing and is tightly fixed to the predetermined upper portion from a tip portion of the casing, an indicating circuit for indicating the intracranial pressure in response to an output of strain sensitive elements, and indicating means. The intracranial pressure transducer converts intracranial pressure of a cerebrospinal fluid to the internal pressure of a pressure receiving layer of the transducer by the copanar Coplanar method which maintains the dura to be coplanar by the depression of the pressure receiving layer of the transducer against the dura, applies internal pressure of the pressure receiving layer to a strain sensing member, supplies an electrical signal by a strain sensitive element in response to the internal pressure of the pressure receiving layer, and accurately and safely indicates the intracranial pressure on the indicating means.
74 Citations
20 Claims
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1. An intracranial pressure transducer which comprises:
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a casing comprising an annular member having a threaded part on a radially outer wall thereof for fitting and securing to a skull of a body, a pressure-electric transducing portion comprising a supporting member which is inserted within a radially inner wall of said casing and is tightly fixed to a predetermined first portion of said casing at a first portion of said supporting member, and which has a hole of predetermined diameter, a thin strain sensing member 21 having a first surface bonded to a second surface of said supporting member 22 having said hole in order to close said hole, at least one strain sensitive element having two ends for converting the strain of said strain sensing member into an electrical signal provided at a strain sensing region, which region corresponds to said hole of said supporting member, on said thin strain sensing member, lead wires connected to said strain sensitive element through electrodes provided at both ends of said strain sensitive element and a receiving connector provided at an upper portion of said casing, and a pressure receiving layer adapted to be in contact with a dura under the skull and comprising resiliently compressible material for receiving an intracranial pressure under the dura as an internal pressure thereof which fills up a concave portion formed by a radially inner wall of a second portion of said casing, a portion of said second surface of said supporting member, and said second surface of said thin strain sensing member, and an indicating circuit, for indicating the intracranial pressure, in response to an output of said strain sensitive element, comprising an amplifier circuit connected to said lead wires within said pressure-electric transducing portion through connector means for engaging with said receiving connector, and indicating means connected thereto, whereby the intracranial pressure of a cerebrospinal fluid is converted to the internal pressure of the pressure receiving layer with the intracranial pressure transducer by means of a Coplanar method which maintains the dura to be coplanar by the depression of the pressure receiving layer of the transducer against the dura;
the internal pressure of the pressure receiving layer being applied to the strain sensing member;
the electrical signal being supplied by the strain sensitive element in response to the internal pressure of the pressure receiving layer; and
the intracranial pressure being indicated on the indicating means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification