Cordis Corporation

Siemens-Pacesetter, Inc.

Michael D Hooven

Christian Sainte-Rose

Donald M Cohen

Stanley H Saulson

James E Barcel

William S Tremulis

Joel Cummings

An implantable medical sensor (42) determines the oxygen content of blood. The sensor includes a miniaturized hybrid circuit (130) that includes light-emitting diode means (32), phototransistor means (34, 36), and a substrate (110) to which the light-emitting diode means and phototransistor means are bonded in a desired circuit configuration. The hybrid circuit is hermetically sealed within a cylindrical body (140) made from a material that is substantially transparent to light, such as glass. Feedthrough terminals (132, 134) provide means for making an electrical connection with the hybrid circuit. The light-emitting diode means is driven with a stair-stepped current pulse. In one embodiment, the sensor is embedded within a bilumen pacemaker lead (60) and positioned near the distal electrode (66) of the lead so that the sensor resides within the heart when the lead is implanted within a patient, thereby allowing the sensed oxygen content (MVO.sub.2 concentration) of the blood within the heart to be a physiological parameter that can be used to control the pacing interval of a rate-responsive pacemaker (56).

Implantable blood oxygen sensor and method of use

An implantable valve for controlling the passage of cerebrospinal fluid (CSF) from a ventricle of the brain to a suitable drainage location in the body includes a movable diaphragm responsive to pressure differentials between the ventricle and the drainage location. When the pressure differential is below a minimum threshold level, the valve is closed and CSF flow is prevented. When the pressure differential increases beyond the minimum threshold, the valve operates in a constant pressure mode to maintain a first predetermined CSF pressure differential across the valve. When the differential pressure increases beyond an intermediate threshold level, the valve operates in a flow control mode to maintain a desired CSF flow rate through the valve. When the pressure differential increases beyond a maximum threshold level, the valve operates in a constant pressure mode to maintain a second predetermined CSF pressure differential across the valve. To provide for the various valve operating modes, the valve includes a valve stem and a valve closure member, which coact with a valve seat carried on the diaphragm. The valve closure member defines an annular valving surface which coacts with the diaphragm to provide improved fluid control at low differential pressures.

Three stage implantable flow control valve with improved valve closure

An implantable valve for allowing the passage of cerebrospinal fluid (CSF) from a ventricle of the brain to a suitable drainage location in the body includes a movable diaphragm, one side of which is in pressure communication with the drainage location of the body and the other side of which is in pressure communication with the ventricular spaces of the brain. A valve assembly, actuable by displacement of the diaphragm in response to a pressure differential applied thereto, regulates passage of CSF from the ventricular spaces to the drainage location. When differential pressure is relatively small, the valve is actuated to a constant pressure mode in which a predetermined differential pressure across the valve is maintained. In response to a sudden increase in differentail pressure, the valve mechanism is actuated to a constant flow mode in which a desired relatively constant rate of fluid flow is maintained. Above a predetermined pressure differential, the valve is actuated once again to a constant pressure mode in which differential pressure above a predetermined maximum is prevented.

Three stage valve

An intercranial pressure regulator valve adapted particularly for the treatment of hydrocephalus and the draining of cerebrospinal fluid (CSF) from a ventricle in the brain to another location in the patient's body includes a movable, flexible diaphragm having first and second surfaces of substantial area which are contacted by the fluid which is being drained and the fluid in the area to which the CSF is to be drained, respectively. A valve seat on the diaphragm is movable therewith and the valve seat includes a passage for the flow of the fluid which is being drained through the diaphragm. A ball closure valve is positioned on the cephalad side of the diaphragm. When the pressure differential on both surfaces of the diaphragm is low, the valve seat flexes into engagement with the ball closure valve to close the passage. When the pressure differential between these two surfaces increases, the diaphragm flexes in response to the increase such that the valve seat moves away from the ball closure valve to open the passage and drain the CSF from the ventricle to the other location in the body.

Intercranial pressure regulator valve

The infusion pump delivers liquid to a body at an adjustably controlled rate of delivery. The pump comprises a syringe section including a syringe barrel having a nozzle at one end. A syringe piston has an inner end situated in the syringe barrel and an outer end extending out of the other end of the syringe barrel. A drive mechanism comprising a generally cylindrical housing has one end mounted to the other end of the syringe barrel. The outer end of the piston extends into the one end of the housing. A gas spring is situated at the other end of the housing and a dampening/timing mechanism is positioned between the gas spring and the outer end of the syringe piston. The dampening/timing mechanism includes a viscous fluid which is movable through a passageway in the housing from a space adjacent the gas spring to a space above the piston. A control mechanism is provided for altering the flow rate of the viscous fluid through the passageway and between the spaces.

Infusion pump

An implantable valve for controlling the passage of cerebrospinal fluid (CSF) from a ventricle of the brain to a suitable drainage location in the body includes a movable diaphragm which positions a valve seat in response to the pressure differential between the inlet and outlet of the valve. The valve seat defines a fluid orifice. An improved valve stem, preferably of one-piece construction, and provided with a series of cooperating diverging and converging frusto-conical portions, extends through the orifice to provide four stages or conditions of fluid flow and pressure control in response to relative movement between the valve seat and stem. In a first stage or condition of operation of the valve, wherein the fluid pressure differential falls below a threshold level, fluid flow is prevented. In a second stage, sufficient fluid flow is permitted to maintain a first substantially constant predetermined differential pressure. In a third stage, fluid flow through the valve is maintained at a substantially constant rate, and in a fourth stage sufficient fluid flow is permitted to maintain a second substantially constant predetermined differential pressure.

Three stage intracranial pressure control valve

An implantable valve for controlling the passage of cerebrospinal fluid (CSF) from a ventricle of the brain to a suitable drainage location in the body includes a movable diaphragm, one side of which is in pressure communication with the drainage location of the body and the other side of which is in pressure communication with the ventricular spaces of the brain. The diaphragm includes a flexible valve seat which moves relative to a valve closure means and a fluid flow control means in response to applied pressure differentials, thus regulating passage of CSF from the ventricular spaces to the drainage location. When the pressure differential is relatively small, the valve operates in a constant pressure mode to maintain a predetermined pressure differential across the valve. In response to a sudden increase in differential pressure, the valve operates in a constant flow mode to maintain a desired relatively constant CSF flow rate through the valve. Above a predetermined pressure differential, the valve operates n a constant pressure mode to maintain a predetermined maximum pressure differential across the valve.

Three stage valve with flexible valve seat

An implantable valve for allowing the passage of cerebrospinal fluid (CSF) from a ventricle of the brain of a patient to a suitable drainage location in the body of the patient includes a movable diaphragm having one of its sides in contact with dura mater and its other side in pressure communication with the drainage location. A valve assembly, actuated by movement of the diaphragm in response to increased epidural pressure, controls passage of CSF from the ventricle to the drainage location.

Implantable servo valve having integral pressure sensor

An implantable valve for allowing the passage of cerebrospinal fluid (CSF) form a ventricle of the brain to a suitable drainage location in the body includes a plurality of fluid flow pressure differential responsive valves arranged in parallel relationship and having common inlet and outlet means, a portion of said inlet and outlet means imparting fluid flow restriction to the system in conjunction with the operation of at least one of said valves, the system being in pressure communication with the drainage location of the body and the ventricular spaces of the brain. When the pressure differential is relatively small, the system operates in a constant pressure mode to maintain a first predetermined pressure differential across the system. In response to a sudden increase in differential pressure, the system operates in a constant flow mode to maintain a desired relatively constant CSF flow rate through the system. Above a predetermined pressure differential, the system operates in a constant pressure mode to maintain a second predetermined maximum pressure differential across the system.

Plural valve three stage pressure relief system

A non-invasively adjustable cerebrospinal fluid pressure relief valve includes a magnetized element which is positionable, through application of an external magnetic field, to permit post-implantation adjustment of the valve's opening threshold pressure setting. An indicator for non-invasively ascertaining the relative adjustment setting of the valve following implantation includes a magnetic pointer which rotates to a position in alignment with the magnetic field produced by the magnetized element. To provide a reference against which the relative valve setting can be measured, the indicator includes an alignment structure which repeatably orients the indicator relative to the implanted valve.

Adjustable implantable valve having non-invasive position indicator

An implantable valve for allowing the passage of cerebrospinal fluid (CSF) from a ventricle of the brain to a suitable drainage location in the body includes a housing having an inlet and outlet with valving means in the housing to control fluid flow from the inlet to the outlet. The valving means includes various parts which are coaxially aligned between the inlet and outlet, the valving means having a valve seat, a valve closure means, a fluid flow restrictor means and a positioning means to control variable positioning of the valve closure means relative to the parts of the valving means. The valving means is actuable in response to applied pressure differentials, and regulates passage of CSF from the ventricular spaces to the drainage location. When the pressure differential is relatively small, the valve operates in a constant pressure mode to maintain a predetermined pressure differential across the valve. In response to a sudden increase in differential pressure, the valve operates in a constant flow mode to maintain a desired relatively constant CSF flow rate through the valve. Above a predetermined pressure differential, the valve operates in a constant pressure mode to maintain a predetermined maximum pressure differential across the valve.

Three stage pressure regulator valve

An implantable valve for allowing the passage of cerebrospinal fluid (CSF) from a ventricle of the brain to a suitable drainage location in the body includes a movable diaphragm, one side of which is in pressure communication with the drainage location of the body and the other side of which is in pressure communication with the ventricular spaces of the brain. A valve assembly, actuable by displacement of the diaphragm in response to applied pressure differentials, regulates passage of CSF from the ventricular spaces to the drainage location. When the pressure differential is relatively small, the valve operates in a constant pressure mode to maintain a predetermined pressure differential across the valve. In response to a sudden increase in differential pressure, the valve mechanism operates in a constant flow mode to maintain a desired relatively constant CSF flow rate through the valve. Above a predetermined pressure differential, the valve operates in a constant pressure mode to maintain a predetermined maximum pressure differential across the valve. To simplify construction, the valve includes a single-piece valve stem having a ramp surface at one end and a fluid restrictor surface at the other end which cooperate with the valve diaphragm to provide the three operating modes.

Three stage intracranial pressure relief valve having single-piece valve

A tubing assembly is provided which includes a length of elastomeric tubing over which is positioned and affixed a substantially shorter length of tubing having micro orifices ion sputtered therethrough. The tubing assembly is manufactured by a method that includes stretching the elastomeric tubing in association with the application of medical adhesive at an interface between the elastomeric tubing and the ion sputtered tubing, and relaxing the elastomeric tubing to provide an effective seal along the ends of the ion sputtered tubing. These tubing assemblies are particularly suitable for use as ventricular catheters within intracranial pressure relief systems.

Manufacture of tubing assembly for drainage catheter

A portable instrument system is provided for the testing of pressure and flow characteristics of implantable ventricular shunt valves using a gaseous testing fluid that may be drawn from the testing environment. The system includes a rate pump having a control mechanism that provides a variety of selective constant flow rates so that the valve characteristics can be determined under various operating conditions. Fluid communication is provided between the pump, the valve and a pressure sensing device such that the pressure sensing device receives the same pressure and flow rate that the valve does. Typically, the pressure sensing device is a gauge transducer that utilizes atmospheric pressure as a reference point and senses the changes in the gas pressure in the valve, relaying the pressure readings to a digital display or chart recorder.

Portable instrument to test pressure/flow of ventricular shunt valves

A self calibrating differential pressure sensor having a pair of pressure transducers connected in fluid series with two on/off valves. The system can be calibrated to eliminate base line or zero shift and can also be used to measure other variable conditions, such as differential voltage between two voltage points or differential chemical concentrations between two concentration points.

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Miami, FL, United States of America

Michael D Hooven