Systems and methods for flow detection and measurement in CSF shunts
First Claim
1. A method for monitoring cerebrospinal fluid (CSF) flow in a normal pressure patient having an implanted CSF drainage shunt, said method comprising:
- externally receiving an output signal from a flow sensor in a flow lumen of the implanted CSF drainage shunt, said signal being representative of CSF flow through the flow lumen.
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Accused Products
Abstract
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.
106 Citations
28 Claims
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1. A method for monitoring cerebrospinal fluid (CSF) flow in a normal pressure patient having an implanted CSF drainage shunt, said method comprising:
externally receiving an output signal from a flow sensor in a flow lumen of the implanted CSF drainage shunt, said signal being representative of CSF flow through the flow lumen. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for monitoring cerebrospinal fluid (CSF) flow in a patient having an implanted CSF drainage shunt, said shunt assembly having a heat source and a temperature sensor proximate the heat source, said method comprising;
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directing energy to heat the heat source, wherein an increase in the CSF flow rate reduces the temperature detected by the temperature sensor;
externally receiving an output signal from the temperature sensor; and
determining based on the output signal whether the shunt is draining CSF. - View Dependent Claims (14, 15)
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16. An implantable apparatus for draining cerebrospinal fluid (CSF), said apparatus comprising:
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an implantable drainage catheter having one end adapted for implantation in a subarachnoid space (SAS), a drainage end adapted for implantation in a drainage space, and a flow lumen therebetween; and
a flow sensor which is coupled to sense flow through the flow lumen of the drainage catheter and which transmits a signal representative of flow through the flow lumen, wherein the sensor is capable of detecting flows at least as low as 12 ml/day. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A system for draining cerebrospinal fluid (CSF) and monitoring such drainage, said system comprising;
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an implantable drainage catheter having a flow sensor adapted to detect a flow corresponding to a flow rate at least as low as 12 ml/day;
a power supply having an antenna adapted to externally deliver energy to the flow sensor when the flow sensor is implanted; and
an external receiver adapted to receive signals from the flow sensor when the flow sensor is implanted.
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Specification