Implantable device for in-vivo intracranial and cerebrospinal fluid pressure monitoring

• US 6,533,733 B1
• Filed: 09/24/1999
• Issued: 03/18/2003
• Est. Priority Date: 09/24/1999
• Status: Expired due to Fees

• Current Assignee: UT-Battelle LLC
• Original Assignee: UT-Battelle LLC
• Inventors: Smith, Stephen F., McKnight, Timothy E., Ericson, Milton N., Hylton, James O.
• Primary Examiner(s): MARMOR II, CHARLES ALAN
• Application Number:
  US09/406,280
• Time in Patent Office: 1,271 Days
• Field of Search: 600/300, 600/485, 600/486, 600/561, 600/398, 600/488, 600/505, 600/587, 600/588, 600/591, 600/593, 600/438, 607/30, 607/31, 607/32, 607/33, 607/60, 737/00, 737/15, 737/08, 737/16, 128/900, 128/903, 128/904
• US Class Current: 600/561
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/031 Intracranial pressure
• CPC Class Codes: A61M 27/006 Cerebrospinal drainage; Accessories therefor, e.g. valves
• CPC Class Codes: Y10S 128/903 Radio telemetry

Abstract

The present invention relates to a completely implantable intracranial pressure monitor, which can couple to existing fluid shunting systems as well as other internal monitoring probes. The implant sensor produces an analog data signal which is then converted electronically to a digital pulse by generation of a spreading code signal and then transmitted to a location outside the patient by a radio-frequency transmitter to an external receiver. The implanted device can receive power from an internal source as well as an inductive external source. Remote control of the implant is also provided by a control receiver which passes commands from an external source to the implant system logic. Alarm parameters can be programmed into the device which are capable of producing an audible or visual alarm signal. The utility of the monitor can be greatly expanded by using multiple pressure sensors simultaneously or by combining sensors of various physiological types.

Claims

1. An apparatus comprising:

an implant for implanting within the body of a patient, said implant including;

means for sensing a physiological parameter of said patient within whose body the implant is implanted;

means for generating a signal corresponding to said sensed parameter;

means for processing said signal corresponding to said sensed parameter;

a transmitter for transmitting said processed signal;

a power source for powering said implant; and

a receiver external to said patient for receiving said transmitted processed signal from said transmitter, wherein said sensing means comprises a means for sensing cerebral spinal fluid flow, wherein said means for sensing cerebral spinal fluid flow measures cerebral spinal fluid flow by measuring thermal-mass flow.

2. An apparatus comprising;

an implant for implanting within the body of a patient, said implant including;

means for sensing a physiological parameter of said patient within whose body the implant is implanted;

means for generating a signal corresponding to said sensed parameter;

means for processing said signal corresponding to said sensed parameter;

a transmitter for transmitting said processed signal;

a power source for powering said implant; and

a receiver external to said patient for receiving said transmitted processed signal from said transmitter;

wherein said sensing means comprises a means for sensing cerebral spinal fluid flow, wherein said means for sensing cerebral spinal fluid flow measures cerebral spinal fluid flow by measuring inertial-drag flow.

3. An apparatus comprising:

an implant for implanting within the body of a patient, said implant including;

means for sensing a physiological parameter of said patient within whose body the implant is implanted;

means for generating a signal corresponding to said sensed parameter;

means for processing said signal corresponding to said sensed parameter;

a spread spectrum transmitter for transmitting said processed signal;

a power source for powering said implant; and

a receiver external to said patient for receiving said transmitted processed signal from said transmitter, wherein said sensing means comprises a pressure transducer including a deflectable membrane having one side of the membrane monitoring a reference pressure condition and another side of the membrane coupled to a chamber that has a pressure.