30 results about "Csf shunt" patented technology

The disclosure is directed to an implantable device for sensing CSF flow through an implantable ventricular shunt. The sensing device is implanted with the CSF shunt, and includes a flow sensor to sense flow rate or shunt blockage. The sensing device is either placed within or adjacent to the fluid path through the shunt. The sensing device transmits the sensed flow rate to an external monitoring device by wireless telemetry. The sensing device may be integrally formed as part of the shunt, or clamped onto a portion of the shunt, in which case the sensing device may be resusable. An external monitor receives the transmitted flow signal and presents information based on the flow signal. The sensing device may be inductively powered or include its own power supply.

The present invention relates to an improved cerebrospinal fluid shunt system comprising a coating covering at least part of the system and a flow restricting component exerting a passive and essentially constant resistance to flow. The present invention also relates to methods for implanting different catheters of a cerebrospinal fluid shunt system into a brain ventricle and the sinus system, respectively, of an individual. The present invention further relates to methods for shunting cerebrospinal fluid from a brain ventricle to the sinus system of an individual.

Devices and methods for removing cerebrospinal fluid (CSF) from a CSF space of a patient at relatively constant flow rates for patients having normal intracranial pressures, e.g. patients not suffering from hydrocephalus. The devices and methods provide drainage paths which permit the removal of CSF at relatively low flow rates, usually below 0.2 ml/day, at normal intracranial pressures, e.g. an intracranial pressure between -170 mm of H2O in upright patients and 200 mm of H2O in reclining patients. The removal of CSF at relatively low, constant rates is particularly suitable for treating Alzheimer's disease and other conditions related to the presence of toxic and/or pathogenic substances in the CSF.

A novel ventricular catheter designed to reduce CSF shunt obstruction is disclosed comprising a tip using a membrane without any opening and capable of filtering the CSF. When the CSF flows through the membrane, neither tissue (choroid plexus, blood cells, tumor cells, suctioned ependymal tissue) nor proteins can break through the membrane, making this ventricular catheter capable of preventing obstruction from tissue invasion but also preventing clogging from protein precipitation, coagulation or flocculation along the downstream shunt system.

Methods and devices for testing for the presence, absence and/or rate of flow in a shunt tubing implanted under the skin by using a measurement pad having a plurality of temperature sensor configurations, or by using other temperature sensor arrangements, or by using a temperature sensitive material, which are positioned over, or in the vicinity of, the CSF shunt in substantially an upstream and downstream orientation. A temperature source, e.g., a cooling agent, is then applied at a predetermined location with respect to the measurement pad that is insulated from the temperature sensors, or to the temperature sensitive material. The movement of this temperature “pulse” is detected by the temperature sensors, or temperature sensitive material, via the shunt tubing as the CSF carries the temperature pulse while a control sensor detects the pulse via convection through the skin. The temperature data from these sensors are provided to a CSF analyzer that subtracts the control sensor data from each of the other sensors for determining a CSF shunt flow status or flow rate. A reader is used to optically or electrically detect the changes in the temperature sensitive material for determining a CSF shunt flow status or flow rate.

A method for evaluating cerebrospinal fluid (CSF) flow rate in a CSF shunt applied to a patient for transmitting the CSF between first and second locations of the patient includes applying temperature sensors to the CSF shunt for determining a flow rate of the CSF through the shunt to provide a determined CSF flow rate and applying an error correction sensor to the patient for providing an error correction signal. The determined CSF flow rate is adjusted in accordance with the error correction signal to provide a corrected CSF flow rate. The sensor can be a temperature sensor such as a thermistor. The CSF is cooled and a temperature value of the CSF is measured in accordance with the cooling. A time value is determined in accordance with the temperature value and the CSF flow rate is determined in accordance with the time value.

Cerebrospinal fluid shunts (implantable devices for diversion of excess fluid from the brain to other body cavities) used to treat hydrocephalus often malfunction. A common etiology of shunt malfunction is obstruction of the distal catheter tip by accumulating particulate matter such as fat or proteinaceous debris. The proposed implantable device maintains the patency of the cerebrospinal fluid shunt with mechanical energy which serves to “scrub” the catheter lumen of particulate debris. The proposed device accomplishes this by housing a source of mechanical energy which is coupled to the external aspect of the catheter, itself traversing through a bore in the device. The energy source secondarily induces a waveform in the cerebrospinal fluid flowing through the catheter. The fluid waveform exerts shearing forces on the catheter wall and serves to disrupt the formation and accumulation of debris that potentially could occlude the shunt catheter, thereby maintaining patency of the shunt.

An apparatus capable of generating flow in cerebrospinal fluid (CSF) shunt systems by vibrating the shunt, tubing or shunt valve dome, or applying cyclical pressure to the various parts of the shunt system. A method of generating flow and method of using the apparatus in shunt patency assessment, for example, hydraulic resistance assessment, is also disclosed. The apparatus allows, in conjunction with a thermal dilution method or radionuclide method, a quick CSF shunt patency assessment based upon CSF shunt resistance and not upon CSF flow or intracranial pressure (ICP) separately. This provides a more objective measure of shunt obstruction compared to other methods. Furthermore, the apparatus can be used to enhance flow in shunts, identify partial occlusion before symptoms occur, differentiate between patent, partially-occluded and occluded shunts. The apparatus can be used to generate flow in shunts if there is a need to lower ICP or move drugs administered via an injection chamber or a shunt dome.

A method and device for testing for the presence, absence and/or rate of flow in a shunt tubing implanted under the skin by using a measurement pad having a plurality of temperature sensors, one of which is aligned with the shunt and the other sensors being symmetrically displaced on either side of the first temperature sensor in a direction transverse to the shunt tubing. These “outer” temperature sensors act as control temperature sensors. A temperature source, e.g., a cooling agent, positioned within an insulated enclosure, is then applied at a predetermined location on the measurement pad that is insulated from the temperature sensors. The movement of this temperature “pulse” is detected by the shunt-aligned temperature sensor via the shunt tubing as the CSF carries the temperature pulse while the control sensors detect the pulse via convection through the skin. The temperature data from these sensors are provided to a CSF analyzer that determines a CSF shunt flow status or flow rate.

The CSF shunt valve includes an elongate, hollow housing and a valve unit disposed within the housing. A plurality of exit ports are formed along the wall of the housing, and a plurality of bleeder ports are formed on the bottom of the housing. The valve unit includes at least one regulating mechanism disposed within the housing. Each regulating mechanism includes an obstructing member operatively attached to a spring. The spring is compressible within a predefined range of fluid pressure. The obstructing member compresses the attached spring in response to fluid pressure acting thereon, opening the exit ports for fluid being drained. The spring-biased obstructing members facilitate self-adjustment for drainage flow. Although arranged in series, the range limits are not continuous with subsequent springs, which safeguards against transient spikes in fluid pressure and ensures independent compression of subsequent springs in response to the predefined limits of pressure for that spring.

An apparatus and method for determining a continuous CSF flow rate in an implanted CSF shunt in real-time. The system/method utilize a Peltier sensor formed on a flexible pad that is placed against the patient's skin. The Peltier sensor includes a Peltier device coupled to a thermal resistor that is contact with the patient's skin over the CSF shunt location. The Peltier device is operated continuously, controlled by the Peltier temperature sensor to a predetermined temperature that is below the patient's core temperature to form a temperature differential that causes any heat generated by the skin/CSF flow to be detected by a skin temperature sensor and the Peltier temperature sensor. Upstream and downstream temperature sensors, as well as control temperature sensors, are utilized to form a zero flow rate baseline that is used to calibrate a Peltier signal that corresponds to a real-time CSF flow rate. A sensor processing device processes all sensor data for generating the zero flow rate baseline and the Peltier signal.

An apparatus and method that utilizes thermal dilution to detect a wide range of flow rates and/or flow status in cerebrospinal fluid (CSF) shunt systems. The use of a large cold source in combination with thermosensor pad of a particular construction provide a fluid flow analyzer with the ability to detect very low levels of CSF flow. In addition, a method for adjusting thermal dilution readings to compensate for varying shunt catheter depth is shown and for determining a steady state of the thermal dilution readings. The thermosensor pad is conformable to a patient's skin contour thereby making the apparatus and method less sensitive to ambient temperature errors and, as a result, more accurate in assessing CSF flow. Furthermore, a software error check is provided for identifying poor sensor-to-skin contact for alerting an operator to re-apply the thermosensor pad to correct, as well as a post-test check to determine if temperature data is reasonable before determining flow status or flow rate.

The invention provides a self-powered and adjustable electromechanical system pressure difference valve. The valve belongs to a cerebrospinal fluid diversion device for treating neurosurgical hydrocephalus, syringomyelia and other diseases and is mainly used for setting different pressure gear positions according to treatment needs and characterized by having the functions that the pressure is adjustable, self-energy utilization and conversion are achieved, and electronic pressure recognition and setting are achieved.

A cerebral spinal fluid shunt plug includes a shunt plug housing having a shunt valve recess formed therein and an intracranial monitoring device recess with an access hole. A shunt valve is positioned within the shunt valve recess of the shunt plug housing and an intracranial monitoring device is passed through the central access hole of the shunt plug housing.