Device and method for detecting an epileptic event

• US 8,109,891 B2
• Filed: 09/19/2006
• Issued: 02/07/2012
• Est. Priority Date: 09/19/2005
• Status: Active Grant

• Current Assignee: Biolert Limited
• Original Assignee: Biolert Limited
• Inventors: Kramer, Uri, Shaham, Amos, Shpitalnik, Shai, Weissman, Noam, Goren, Yael, Kartoun, Uri
• Primary Examiner(s): SZMAL, BRIAN SCOTT
• Application Number:
  US12/067,174
• Publication Number:
  US 20090137921A1
• Time in Patent Office: 1,967 Days
• Field of Search: 600/300, 600/587, 600/595, 600/534, 600/529, 600/586, 340/573.4, 340/566, 340/693, 340/573.7, 340/573.1, 340/573.6, 200/61.45 R, 702/190, 702/14, 702/15, 702/17, 702/18, 128/903, 128/905, 285/12, 285/13, 356/28.5, 356/477
• US Class Current: 600/595
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/002 Monitoring the patient using a local or closed circuit, e.g. in a room or building A61B5/0017 takes precedence
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/1123 Discriminating type of movement, e.g. walking or running A61B5/1116, A61B5/112 take precedence
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: G16H 40/67 for remote operation

Abstract

The invention discloses an epileptic event alert system, capable of detecting and analyzing whether motions sensed by at least one motion sensor of the system, are related to an epileptic seizure event. The system may be utilized for detection of additional motion-related pathologies. A detection method is similarly disclosed, as is computer-readable media adapted to perform the detection method of the invention.

Claims

1. A detection and analysis unit of an epileptic event alert system, the detection and analysis unit comprising:

a) one or more motion sensors adapted to produce an electrical signal corresponding with mechanical movement of the detection and analysis unit;

b) a microcontroller comprising;

i. non-volatile memory adapted to store at least one set of motion signal parameters associated with epileptic motion and at least another set of parameters associated with non-epileptic motion;

ii. computer readable software and dedicated hardware adapted to compare at least one signal parameter of the signal produced by said one or more sensors against at least one of said stored sets of motion signal parameters;

c) a communication unit adapted to transmit an alert signal to a remote location.

2. The system according to claim 1, wherein each motion sensor produces a separate signal, and wherein the separate signal produced by each given sensor includes information relating to motion of said sensor in a direction corresponding with an orientation of the given sensor.

3. The system according to claim 2, wherein any one or more of the separate signals reaching the threshold level causes a power management circuit in said control circuit to induce a power-saving mode in said system when the signals have not reached the threshold level for a predefined duration time.

4. The system according to claim 2, wherein the signal produced by said one or more motion sensors is an analog signal and system further comprises an analog to digital converter.

5. The system according to claim 1, wherein said software (ii) is adapted to output a seizure probability value based on a comparison of parameters of the signal produced by said one or more sensors and the stored set of motion signal parameters associated with epileptic motion.

6. The system according to claim 5, wherein the seizure probability value is additionally based on a comparison of parameters of the signal produced by said one or more sensors and the stored set of motion signal parameters associated with non-epileptic motion, and wherein the seizure probability value is positively related to a correlation between the sensor signal parameter with one or more parameters in the parameter set associated with epileptic movement and inversely related to a correlation between the sensor signal parameter with one or more parameters in the parameter set associate with non-epileptic movement.

7. The system according to claim 5, further comprising an alert decision unit adapted to produce a local alert signal based on the seizure probability value and based on a predefined duration of signal.

8. The system according to claim 7, wherein the local alert signal produced by said decision unit is adapted to trigger said communication unit to transmit a remote alert signal.

9. The system according to claim 7, further comprising a switch operable by the user, for deactivating a local alert signal prior to a remote alert signal being triggered.

10. The system according to claim 1, wherein said communication unit utilizes wireless communication to transmit said alert signal to a remote location.

11. The system according to claim 1, further comprising an output signal for instructing an epileptic treatment unit to administer an epileptic treatment in response to an alert signal.

12. The system according to claim 11, wherein said epileptic treatment unit applies a treatment substantially automatically in response to either a local or remote alert signal.

13. The system according to claim 11, wherein said epileptic treatment unit is adapted to be triggered by a treatment signal initiated remotely and received through said communication unit.

14. The system according to claim 1, further comprising a visual display activated by said control circuit;

and wherein the microcontroller is adapted to initiate a self-test.

15. The system according to claim 1, further comprising a microphone for detecting sounds originating in the vicinity of the user, and said communication unit is adapted to transmit said sounds detected by said microphone.

16. the system according to claim 1, wherein said control circuit is adapted to trigger an alert when no motion signals are detected during a predefined period of time.

17. The system according to claim 1, wherein said signal parameters produced by said motion sensor and said stored epileptic motion signal parameters, are selected from at least one of the following group:

the frequency of the motion, frequency variation over time, the amplitude of the signal, amplitude variations over time, the relative direction of the motion, the direction variation over time, and the duration of the motion.

18. The system according to claim 1, wherein said system is adapted to be worn upon the limb of a user.

19. The system according to claim 18, wherein said system has the general appearance of a wristwatch.

20. The system according to claim 1, further comprising a recorder, adapted to store and allow retrieval of at least one of the following:

motion signal parameters of a user, processed motion signal parameters, and alert signal transmission data.

21. A method of detecting an epileptic seizure comprising:

a. fastening at least one motion sensor to the limb of a user, said sensor adapted to produce electrical signals corresponding with mechanical movement of the sensor, the sensor being operative to output a separate electrical signal for movement in each of the X,Y,Z axes;

b. measuring said electrical signals produced by said at least one motion sensor and performing computerized processing of said signals to obtain signal motion parameters, the signal motion parameters including frequency of motion;

c. comparing said parameters of said measured electrical signals, against at least one stored set of epileptic motion signal parameters and/or against at least one set of non-epileptic epileptic motion signal parameters, wherein said comparison is performed using computerized processing means;

d. outputting a seizure probability value based on said comparison;

e. transmitting an alert signal to a remote location, using a communication unit, if said seizure probability value is within a predetermined range of values.

22. The method according to claim 21, wherein said signal parameters measured by said motion sensor and said stored motion signal parameters, are further comprised of at least one of the following:

frequency variation over time, the amplitude of the signal, amplitude variations over time, the relative direction of the motion, the direction variation over time, and the duration of the motion.

23. The method according to claim 21, further comprising a step of autocorrelation, performed during said step (b), wherein said autocorrelation is performed upon the signal measured by each sensor, or performed upon signals measured by different sensors of said system.

24. The method according to claim 21, further comprising a step of removal of DC bias, performed during said step (b).

25. Computer-readable media storing a computer program that when executed performs steps (b), (c) and (d) of claim 21, wherein the computer-readable media is a disk, read-only memory (ROM), random access memory (RAM), electrically programmable read-only memory (EPROM), electrically erasable and programmable read only memory (EEPROM), magnetic card, or optical card.

26. The computer-readable media according to claim 25, the computer program being further adapted to initiate transmission of the alert signal to the remote location, using the communication unit, if said seizure probability value is within the predetermined range of values.

27. A detection and analysis unit of an alert system for detection and identification of pathological motion events, the detection and analysis unit comprising:

a) one or more motion sensors adapted to produce an electrical signal corresponding with mechanical movement of the detection and analysis unit;

b) a microcontroller comprising;

i. non-volatile memory adapted to store at least one set of motion signal parameters associated with pathological motion and at least another set of parameters associated with normal non-pathological motion;

ii. computer readable software and dedicated hardware adapted to compare at least one signal parameter of the signal produced by said one or more sensors against at least one of said stored sets of motion signal parameters;

c) a communication unit adapted to transmit an alert signal to a remote location.