Method and apparatus for the measurement of intracranial pressure

• US 5,117,835 A
• Filed: 08/30/1991
• Issued: 06/02/1992
• Est. Priority Date: 07/31/1990
• Status: Expired due to Term

• Current Assignee: Medys, Inc.
• Original Assignee: Edwin C. Mick
• Inventors: Mick, Edwin C.
• Primary Examiner(s): Jaworski, Francis
• Assistant Examiner(s): Akers, Scott R.
• Application Number:
  US07/752,870
• Time in Patent Office: 277 Days
• Field of Search: 128/748, 128/774, 128/782
• US Class Current: 600/561
• CPC Class Codes: A61B 5/0051 by applying vibrations
• CPC Class Codes: A61B 5/031 Intracranial pressure

Abstract

A method and apparatus for non-invasively measuring changes in intracranial pressure (ICP) in a patient'"'"'s skull which allow trends in such pressure to diagnosed over time. A method performed, or an apparatus made in accordance with the instant invention comprises a generation of a predetermined vibration signal which is applied to a first location on a skull, detecting an output vibration from another location on the skull, storing data characteristic of the two signals, repeating the above-mentioned steps over time, and analyzing the data to diagnose changes in ICP over time.

Claims

1. A method of non-invasively measuring changes in a patient'"'"'s intracranial pressure in said patient'"'"'s skull from said patient'"'"'s normal intracranial pressure, comprising the steps of:

(a) measuring the thickness and radius of a patient'"'"'s skull non-invasively by using non-invasive thickness measuring means;

(b) generating a predetermined input vibration signal and applying said input signal at a first location on a patient'"'"'s skull;

(c) detecting an output vibration signal from a second location on said patient'"'"'s skull, said output signal being a modification of said input signal, said input signal having been changed as a function of said patient'"'"'s intracranial pressure as it travels from said first location to said second location;

(d) storing data characteristic of said thickness and radius, and said input and output signals into a data base; and

(e) estimating said patient'"'"'s normal intracranial pressure vibration signal from said data by using estimation means.

2. A method according to claim 1, wherein said data stored into said data base comprises natural frequency data.

3. A method according to claim 1, wherein said data stored into said data base comprises frequency response data.

4. A method according to claim 1, wherein said first location and said second location are located at substantially the same place on said patient'"'"'s skull.

5. A method according to claim 1, wherein the estimation of frequency response at step e comprises the use of a microprocessor.

6. A method according to claim 1, wherein said input signal comprises a shock signal.

7. A system for non-invasively measuring changes in a patient'"'"'s intracranial pressure from said patient'"'"'s normal intracranial pressure, comprising:

(a) means for non-invasively measuring the thickness and radius of a patient'"'"'s skull;

(b) means for generating a predetermined input vibration signal and applying said input signal at a first location on a patient'"'"'s skull;

(c) means for detecting an output vibration signal from a second location on said patient'"'"'s skull, said output signal being a modification of said input signal, said input signal having been changed as a function of said patient'"'"'s intracranial pressure as it travels from said first location to said second location;

(d) means for storing data characteristic of said thickness and radius on said input and output signals into a first data base; and

(e) means for estimating said patient'"'"'s normal intracranial pressure vibration signal from said data by using estimation means.

8. A system according to claim 7, wherein the data stored by said data storing means comprise natural frequency data.

9. A system according to claim 7, wherein the data stored by said data storing means comprise frequency response data.

10. A system according to claim 7, wherein the means for generating and applying said input signal comprises an impact hammer.

11. A system according to claim 7, wherein the means for detecting said output signal comprises an accelerometer.

12. A system according to claim 7, wherein, the estimation means at step e, the calculating means at step f, and the comparison means at step h comprise a microprocessor.

13. A system according to claim 7, wherein the input signal comprises a shock.

14. A system according to claim 7, wherein the means for generating and applying said input signal, and the means for detecting said output signal comprise a vibration exciter transducer.

15. A system according to claim 7, wherein the means for detecting said output signal comprises a velocity sensor.

16. A system according to claim 7, wherein the means for detecting said output signal comprises a displacement sensor.

17. A system according to claim 7, wherein the means for measuring said skull'"'"'s thickness comprises computer aided tomography means.

18. A system according to claim 7, wherein the data stored by said data storing means at step d comprises dynamic vibration behavior characteristics.