Implant for in-vivo parameter monitoring, processing and transmitting

• US 20030216666A1
• Filed: 02/24/2003
• Published: 11/20/2003
• Est. Priority Date: 09/24/1999
• Status: Active Grant

• Current Assignee: James O. Hylton, Milton N. Ericson, Stephen F. Smith, Timothy E. Mcknight
• Original Assignee: James O. Hylton, Milton N. Ericson, Stephen F. Smith, Timothy E. Mcknight
• Inventors: Smith, Stephen F., McKnight, Timothy E., Ericson, Milton N., Hylton, James O.
• Granted Patent: US 7,621,878 B2
• Time in Patent Office: Days
• 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 by electronic means to a digital pulse by generation of a spreading code signal and then transmitted to a location outside the patient by means of 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 for monitoring intra-cranial cerebral spinal fluid pressure in a subject, said apparatus comprising

a sensor for sensing intracranial pressure;

control means for collecting data from said sensor corresponding to sensed intracranial pressure;

a spread-spectrum transmitter;

means for communicating said data from said control means to said transmitter;

a power source for powering said sensor and said control means.

2. The apparatus of claim 1 wherein said sensor is a pressure transducer comprising a deflectable membrane having one side of the membrane monitoring a reference pressure condition and the opposite side of the membrane coupled to a chamber of a fluid-handling system.

3. The apparatus of claim 1 wherein said sensor comprises one or more pressure tranducers in combination.

4. The apparatus of claim 1 wherein said spread-spectrum transmitter is a radio-frequency transmitter that operates in one or more frequency ranges of 902-928 MH, 2450-2483.5 MHz, 5150-5250 MHz, 5250-5350 MHz, and 5725-5825 MHz.

5. The apparatus of claim 1 wherein said spread-spectrum transmitter is a radio-frequency transmitter that operates at frequency of 915 MHz.

6. The apparatus of claim 1 wherein said spread-spectrum transmitter is an ultrasonic transmitter.

7. The apparatus of claim 1 wherein said power source is one or more batteries of the type selected from the group consisting of lithium, nickel-cadmium, and a self-contained radioactive material.

8. The apparatus of claim 1 wherein said power source is a capacitive element.

9. The apparatus of claim 1 wherein said power source receives inductive power from an inductive power source which operates at a frequency less than 100 kHz.

10. The apparatus of claim 1 wherein said power source receives inductive power from an inductive power source which operates at a frequency greater than 1 MHz.

11. The apparatus of claim 1 wherein said power source receives inductive power from an inductive power source which operates at a frequency range of 100 kHz to 1 MHz.

12. The apparatus of claim 1 wherein said data is transmitted to an external receiver by generation of a spreading-code signal through spread-spectrum modulation wherein said spread-spectrium modulation comprises, alone or in combination, direct-sequence modulation, frequency-hopping modulation, and time-hopping modulation.

13. The apparatus of claim 2 wherein said fluid-handling system is controlled by a signal received from an external source.

14. The apparatus of claim 1 further comprising means for producing an audible or visual alarm signal.

15. The apparatus of claim 1 further comprising a receiving means for receiving control commands from an external source.

16. A monitoring apparatus in a subject, said apparatus comprising:

a sensor for sensing a physiological parameter;

control means for collecting data from said sensor corresponding to a sensed physiological parameter;

a spread-spectrum transmitter;

means for communicating said data from said control means to said transmitter;

a power source for powering said sensor and said control means.

17. The apparatus of claim 16 wherein said sensor monitors cerebral spinal fluid flow through thermal-mass flow means.

18. The apparatus of claim 16 wherein said sensor monitors cerebral spinal fluid flow through inertial-drag flow means.

19. The apparatus of claim 16 wherein said sensor is selected from the group consisting of:

acoustic, piezoresistive, biochemical, electrochemical, electrical and conductive.

20. The apparatus of claim 16 wherein said spread-spectrum transmitter is a radio frequency transmitter that operates in one or more frequency ranges of 902-928 MHz, 2450-2483.5 MHz, 5150-5250 MHz, 5250-5350 MHz, and 5725-5825 MHz.

21. The apparatus of claim 16 wherein said spread-spectrum transmitter is a radio frequency transmitter that operates at a frequency of 915 MHz.

22. The apparatus of claim 16 wherein said spread-spectrum transmitter is an ultrasonic transmitter.

23. The apparatus of claim 16 wherein said power source is one or more batteries of the type selected from the group consisting of lithium, nickel-cadmium, and a self-contained radioactive material.

24. The apparatus of claim 16 wherein said power source is a capacitive element.

25. The apparatus of claim 16 wherein said power source receives inductive power from an inductive power source which operates at a frequency less than 100 kHz.

26. The apparatus of claim 16 wherein said power source receives inductive power from an inductive power source which operates at a frequency greater than 1 MHz.

27. The apparatus of claim 16 wherein said power source receives inductive power from an inductive power source which operates at a frequency range of 100 kHz to 1 MHz

28. The apparatus of claim 16 wherein said data is transmitted to an external receiver by generation of a spreading-code signal through spread-spectrum modulation wherein said spread-spectrium modulation comprises, alone or in combination, direct-sequence modulation, frequency-hopping modulation, and time-hopping modulation.

29. The apparatus of claim 16 capable of producing an audible or visual alarm signal.

30. The apparatus of claim 16 used in combination, in one or more subjects, said combination transmitting data through multiple-access spread-spectrum means comprising code-division, frequency-division, and time-division modulation.

31. The apparatus of claims 16 further comprising receiving means for receiving control commands from an external source.