Electroconvulsive therapy apparatus and method for monitoring patient seizures

• US 5,269,302 A
• Filed: 05/06/1992
• Issued: 12/14/1993
• Est. Priority Date: 05/10/1991
• Status: Expired due to Term

• Current Assignee: Somatics Incorporated
• Original Assignee: Somatics Incorporated
• Inventors: Swartz, Conrad M., Abrams, Richard S.
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): Getzow, Scott M.
• Application Number:
  US07/876,710
• Time in Patent Office: 587 Days
• Field of Search: 128/419 S, 128/731, 128/732, 128/733
• US Class Current: 607/45
• CPC Class Codes: A61N 1/38 for producing shock effects

Abstract

In electroconvulsive therapy (ECT) the duration of the generated skeletal muscle, heart and brain wave activity during the administration of the electrically induced therapeutic seizures is automatically monitored. The ECT device includes a special purpose electromyograph (EMG) to detect isolated muscle activity and, in one embodiment, an electrocardiograph (ECG) to detect heart-beat intervals, and in another embodiment also includes an electroencephalograph (EEG) system to detect an EEG parameter of the electrically induced EEG seizure. The detected voltage from the EMG, ECG and EEG are converted to digital data and compared to a set of threshold reference values previously obtained from the same patient. The operator is informed by a display, or auditory signal, if the selected parameters have crossed the predetermined threshold reference value and the time period, since termination of the ECT that each parameter has taken to reach the reference value.

Claims

1. A method in electroconvulsive therapy (ECT) to monitor the termination of an induced seizure in a patient, the method including the steps of:

(a) selecting a major muscle group of the patient and isolating the muscle group from effects of muscle relaxing pharmacological agents;

(b) detecting the muscle activity of the muscle group prior to the ECT by amplifying the electrical signals from the muscle group to detect EMG signals, converting the EMG signals into a first set of EMG digital data, setting an established EMG reference voltage for the EMG signals based upon the first set of EMG digital data, and storing in system digital computer memory the established EMG reference voltage;

(c) employing an ECT device, removably securing a plurality of electrodes of the ECT device on the head of the patient and applying electricity through the electrodes in an electroconvulsive therapy session to induce seizure;

(d) in the range of less than 30.0 seconds immediately following termination of the application of electricity to induce the seizure by the ECT device, commencing detecting the muscle activity of the major muscle group of the patient by amplification of the electrical signals from the patient'"'"'s muscle group using the EMG device and removable electrodes and converting the amplified EMG signals into a second set of digital EMG data in order to commence the monitoring of the termination of the seizure;

(e) automatically determining, by use of the digital computer system, the termination of seizure as indicated by the monitored EMG signals declining to the established EMG reference voltage by a comparison of the established EMG reference voltage with the second set of digital EMG data; and

(f) displaying the results of said comparison as indicating said termination of seizure.

2. A method in electroconvulsive therapy as in claim 1, including the step of measuring and displaying an elapsed time from the commencement of said monitoring until the termination of seizure.

3. A method in electroconvulsive therapy as in claim 1 including displaying the lack of a seizure by the monitored EMG signals not increasing to the established EMG reference voltage within a selected time period.

4. A method in electroconvulsive therapy as in claim 1 wherein the first and second sets of data are integrated voltages over a selected time period in the range of 0.5-3 seconds.

5. A method in electroconvulsive therapy as in claim 1 including the step of establishing the established EMG reference voltage prior to said ECT by measuring said muscle activity during at least two selected time periods, during which said periods the muscle activity is within a selected percentage of one period compared to another period, and averaging said muscle activity over said periods.

6. A method in electroconvulsive therapy as in claim 1 including the additional steps of:

(a) detecting the brain wave activity of the patient prior to the ECT by amplifying the electrical signals from the brain using an electroencephalographic (EEG) device having electrodes removably attached to the head of the patient to detect EEG signals, converting the EEG signals into a first set of EEG data and setting an established EEG reference voltage based on the first set of EEG data, and storing in system computer memory the established EEG reference voltage;

(b) in the range of less than 30 seconds immediately following termination of the application of electricity to induce the seizure by the ECT device, commencing detecting the brain wave activity of the patient by amplification of the electrical signals from the brain using the EEG device and removable electrodes and converting the amplified EEG signals into a second set of EEG data to commence the monitoring of the termination of the seizure;

(c) automatically analyzing the termination of seizure as indicated by the monitored EEG signals declining to the established EEG reference by a comparison, using the digital computer system, of the established EEG reference voltage with the second set of EEG data;

(d) combining the EEG comparison with the EMG comparison in the computer system to provide a combined EMG and EEG determination of the termination and generalization of seizure; and

(e) displaying the results of said combined determinations indicating said termination of seizure.

7. A method in electroconvulsive therapy as in claim 6 wherein EEG electrodes are applied to the head of the patient on opposite sides of the head and, by changes in EEG coherences, seizure onset and termination are thereby detected.

8. A method in electroconvulsive therapy as in claim 1 wherein the patient has a brain having portions susceptible to different cortical discharges, including the additional steps of:

(a) detecting the brain wave activity of the patient prior to the ECT by amplifying the electrical signals from the brain using an electroencephalographic (EEG) device having electrodes removably attached to the head of the patient to detect EEG signals, converting the EEG signals into a first set of data, setting an established EEG reference based on the first set of EEG data, storing in system computer memory the established EEG reference;

(b) in the range of less than 30 seconds immediately following termination of the application of electricity to induce the seizure by the ECT device, commencing detecting the brain wave activity of the patient by amplification of the electrical signals from the brain using the EEG device and removably electrodes and converting the amplified EEG signals into a second set of EEG data;

(c) automatically, in a digital computer system, analyzing the termination of seizure as indicated by the monitored EEG signals declining to the established EEG reference by a comparison of the established EEG references with the second set of EEG data;

(d) comparing the EEG termination of seizure comparison with the EMG termination of seizure comparison in the digital computer system to provide a seizure concordance index reflecting cortical discharges in different parts of the brain; and

(e) displaying the seizure concordance index.

9. A method in electroconvulsive therapy as in claim 1 including the steps of:

(a) detecting the brain wave activity of the patient prior to the ECT by amplifying the electrical signals from the brain using an electroencephalographic (EEG) device having electrodes removably attached to the head of the patient to detect EEG signals, converting the EEG signals into a first set of EEG data, setting an established EEG reference based on the first set of EEG data, storing in system computer memory the established EEG reference;

(b) in the range of less than 30 seconds immediately following termination of the application of electricity to induce the seizure by the ECT device, commencing detecting the brain wave activity of the patient by amplification of the electrical signals from the brain using the EEG device and removable electrodes and converting the amplified EEG signals into a second set of EEG data to commence the monitoring of the termination of the seizure;

(c) automatically in a digital computing system determining the termination of seizure as indicated by the monitored EEG signals declining to the established EEG reference by a comparison of the established EEG reference with the second set of EEG data;

(d) in the range of less than 30 seconds immediately following termination of the application of electricity to induce the seizure by the ECT device, measuring the power of the brain wave activity of the patient by amplification of the electrical signals from the brain using the EEG device and removable electrodes, and automatically in the digital computer system computing an energy index based upon the multiplication product of the EEG power and the total seizure duration; and

(e) displaying the energy index and the results of the determination of termination of seizure.

10. A method in electroconvulsive therapy as in claim 9 wherein the energy index is a delta energy index based upon absolute power measured in the delta band.

11. A method in electroconvulsive therapy as in claim 9 wherein the energy index is a total energy index based upon absolute power measured across the entire band of 2-25 Hz.

12. A method in electroconvulsive therapy as in claim 9 wherein a seizure suppression index is automatically computed and displayed, said seizure suppression index being based upon the percentage of reduction in the EEG power at the endpoint of the induced seizure.

13. A method in electroconvulsive therapy (ECT) to monitor the termination of an induced seizure in a patient, the method including the steps of:

(a) detecting the heartbeat rate of the patient prior to the ECT by amplifying the electrical signals from the heart using an electrocardiograph ECG device having electrodes removably attached to the skin of the patient to detect ECG signals, converting the ECG heartbeat rate signals into a first set of ECT heartbeat rate digital data, storing in system digital computer memory the first set of ECG digital data and setting an established ECG heartbeat rate reference based on said first set of ECG heartbeat rate digital data;

(b) employing an ECT device, removably securing a plurality of electrodes of the ECT device on the head of the patient and applying electricity through the electrodes in an electroconvulsive therapy session to induce seizure;

(c) in the range of less than 30 seconds immediately following termination of the application of electricity by the ECT device to induce the seizure, commencing monitoring the heartbeat rate of the patient by amplification of the electrical signals from the heart using the ECG device and removable electrodes and converting the amplified ECG signals into a second set of heartbeat rate digital data in order to commence the monitoring of the termination of the seizure;

(d) automatically determining the termination of seizure as indicated by the monitored ECG heartbeat rate signals declining to the established reference by a comparison, using the digital computer system, of the established ECG heartbeat rate reference with the second set of ECG digital data; and

(e) displaying the results of said comparison as indicating said termination of seizure.

14. A method in electroconvulsive therapy as in claim 13, including the step of measuring and displaying an elapsed time from the commencement of said monitoring until said termination of seizure.

15. A method in electroconvulsive therapy as in claim 13 including displaying the lack of a seizure by the monitored ECG signals not increasing to the established ECG reference within a selected time period.

16. A method in electroconvulsive therapy as in claim 13 wherein two paris of detecting EEG electrodes are applied to the head of the patient on opposite sides of the head and changes in EEG coherence seizure onset and termination are thereby detected.

17. A method of electroconvulsive therapy as in claim 13 including the step of establishing the established ECG reference prior to said ECT by measuring said heartbeat rate during at least two selected time periods, during which said periods the heart rate is within the selected percentage of one period compared to another period, and averaging said heart rate over said periods.

18. A method in electroconvulsive therapy (ECT) as in claim 13 including the additional steps of:

(a) detecting the brain wave activity of the patient prior to the ECT by amplifying the electrical signals from the brain using an electroencephalographic (EEG) device having electrodes removably attached to the head of the patient to detect EEG signals, converting the EEG signals into a first set of EEG data, setting an established EEG reference voltage based on the first set of EEG data;

storing in system computer memory the established EEG reference voltage;

(b) in the range of less than 30 second immediately following termination of the application of electricity to induce the seizure by the ECT device, commencing detecting the brain wave activity of the patient, by amplification of the electrical signals from the brain using the EEG device and removable electrodes and converting the amplified EEG signals into a second set of EEG data to commence the monitoring of the termination of the seizure;

(c) automatically analyzing the termination of seizure as determined by the monitored EEG signal declining to the established EEG reference by comparison using the computer system of the established EEG reference voltage with the second set of EEG data;

(d) combining the EEG analysis with the ECG determination in the computer system to provide a combined ECG and EEG determination of the termination and generalization of seizure; and

(e) displaying the results of said combined determination as indicating said termination of seizure.

19. A method in electroconvulsive therapy (ECT) to monitor the termination of an induced seizure in a patient, the method including the steps of:

(a) selecting a major muscle group of the patient and isolating the muscle group from the effects of muscle relaxing pharmacological agents;

(b) detecting muscle activity of the muscle group prior to the ECT by amplifying the electrical signals from the muscle group using an electromyograph (EMG) device having electrodes removably attached to the muscle group to detect EMG signals, converting the EMG signals into a first set of EMG digital data, setting an established EMG reference voltage based on the first set of EMG digital data, storing in system digital computer memory the established EMG reference voltage;

(c) detecting the heartbeat rate of the patient prior to the ECT by amplifying the electrical signals from the heart using an electrocardiograph (ECG) device having electrodes removably attached to the skin of the patient to detect ECG signals, converting the ECG signals into a first set of ECG heartbeat rate digital data, setting an established heartbeat rate ECG reference based on the first set of ECG heartbeat rate digital data; and

storing in system digital computer memory the established ECG heartbeat rate reference;

(d) detecting the brain wave activity of the patient prior to the ECT by amplifying the electrical signals from the brain using an electroencephalographic (EEG) device having electrodes removably attached to the head of the patient to detect EEG signals, converting the EEG signals into a first set of EEG digital data, and setting an established EEG reference voltage based on the first set of EEG digital data, and storing in system digital computer memory the established EEG reference voltage;

(e) employing an ECT device, removably securing a plurality of electrodes of the ECT device on the head of the patient and applying electricity through the electrodes in an electroconvulsive therapy session to induce seizure;

(f) commencing in the range of less than 30.0 seconds immediately following termination of the application of electricity to induce the seizure by the ECT device,

(i) detecting the muscle activity of the major muscle group of the patient by amplification of the electrical signals from the muscle group using the EMG device and removable electrodes and converting the amplified EMG signals into a second set of EMG digital data;

(ii) monitoring the heart beat rate of the patient by amplification of the electrical signals from the heart using the ECG device and removable electrodes and converting the amplified ECG signals into a second set of heart beat rate digital data;

(iii) detecting the brain wave activity of the patient using the EEG device and removable electrodes and converting the amplified EEG signals into a second set of EEG digital data;

(g) automatically analyzing the termination of seizure as determined by the monitored EEG, ECG and EMG signals approaching the established respective EEG, ECG and EMG references by comparisons using the digital computer system of the established EEG, ECG and EMG references with the second sets of respective EEG, ECG and EMG digital data;

(h) combining the EEG comparison, and the ECG heart beat comparison and the EMG comparison in the computer system to provide a combined EMG, ECG and EEG determination of the termination of seizure; and

(i) displaying the results of said combined determination as indicating said termination of seizure.

20. A system in electroconvulsive therapy (ECT) to induce seizure in a patient and monitor the termination of the induced seizure, the system including:

(a) EMG means for detecting muscle activity of a muscle group prior to the ECT by amplifying electrical signals from the muscle group, said EMG means including an electromyograph (EMG) device and electrodes adapted to be removably attached to the muscle group to produce EMG signals, A/D means for converting the EMG signals into a first set of EMG digital data, and computer means for established and storing in digital computer memory data of an established EMG reference voltage based on the first set of EMG digital data;

(b) ECT means for inducing the seizure including a plurality of electrodes adapted to be removably secured on the head of the patient and means for applying electricity through the electrodes to the patient in an electroconvulsive therapy session to induce seizure;

(c) means for storing a second set of EMG digital data obtained from the EMG means on commencement of the monitoring of the termination of the seizure in the range of less than 30 seconds after ceasing the said application to induce seizure;

(d) means for automatically determining the termination of seizure as determined by the monitored EMG signals declining to the established EMG reference by comparison, using the digital computer system, of the established EMG reference voltage with the second set of digital data; and

(e) means for displaying the results of said comparison as indicating said termination of seizure.

21. A system in electroconvulsive therapy as in claim 20, including means for measuring and displaying an elapsed time from the commencement of said monitoring until the said termination of seizure.

22. A system in electroconvulsive therapy as in claim 20 wherein the patient has a brain having portions susceptible to different cortical discharges, including:

(a) EEG means for detecting the brain wave activity of the patient prior to the ECT by amplifying the electrical signals from the brain, said EEG means including an electroencephalographic (EEG) device having electrodes removably attached to the head of the patient to detect EEG signals;

means for converting the EEG signals into a first set of data, and setting an established EEG reference based on the first set of EEG data and computer memory means for storing the established EEG reference;

(b) computer memory means for storing a second set of EEG data obtained from the EEG means in the range of less than 30 seconds immediately following termination of the application of electricity to induce the seizure by the ECT device;

(c) digital computer means for automatically analyzing the termination of seizure as indicated by the monitored EEG signals declining to the established EEG reference;

(d) digital computer means for comparing the EEG termination of seizure comparison with the EMG termination of seizure comparison to provide a seizure concordance index reflecting cortical discharges in different parts of the brain; and

(e) means for displaying the seizure concordance index.

23. A system in electroconvulsive therapy (ECT) as in claim 20, the system including:

(a) EEG means for detecting the brain wave activity of the patient prior to the ECT by amplifying the electrical signals from the brain, said EEG means including an electroencephalographic (EEG) device having electrodes removably attached to the head of the patient to detect EEG signals, means for converting the EEG signal into a first set of EEG data and for setting an established EEG reference based on the first set of EEG data, and computer memory means for storing the established EEG reference;

(b) computer memory means for storing a second set of EEG data obtained from the EEG means immediately following termination of the application of electricity to induce the seizure by the ECT device;

(c) digital computer means for automatically determining the termination of seizure as indicated by the monitored EEG signals declining to the established EEG reference;

(d) means for measuring the power of the brain wave activity of the patient, by amplification of the electrical signals from the brain using the EEG device and removable electrodes, in the range of less than 30 seconds immediately following termination of the application of electricity to induce the seizure by the ECT device;

means for automatically computing an energy index based upon the power measurement; and

(e) means for displaying the energy index and results of the determination of termination of seizure.

24. A system in electroconvulsive therapy as in claim 23 wherein the energy index is a delta energy index based upon absolute power measured in the delta band.

25. A system in electroconvulsive therapy as in claim 23 wherein the energy index is a total energy index based upon absolute power measured across the entire band of 2-25 Hz.

26. A system in electroconvulsive therapy as in claim 23 and including means for automatically computing and displaying a seizure suppression index based on the percentage of reduction in the EEG power at the end point of the induced seizure.

27. A system in electroconvulsive therapy (ECT) to induce seizure in a patient and monitor the termination of the induced seizure, the system including:

(a) ECG means for detecting the heart rate of the patient prior to the ECT by amplifying electrical signals from the heart, said ECG means including an electrocardiograph (ECG) device and electrodes adapted to be removably attached to the patient to produce ECG signals, A/D means for converting the ECG signals into a first set of ECG digital data, and computer means for storing in digital computer memory an EEG reference voltage based on the first set of ECG digital data;

(b) ECT means for inducing the seizure including a plurality of electrodes adapted to be removably secured on the head of the patient and means for applying electricity through the electrodes to the patient in an electroconvulsive therapy session to induce seizure;

(c) means for storing a second set of ECG heart beat rate digital data obtained from the ECG means on commencement of the monitoring of the termination of the seizure in the range of 1-30 seconds after ceasing the said application to induce seizure;

(d) means for automatically determining the termination of seizure as determined by the monitored ECG signal compared to the ECG heartbeat rate reference, using the digital computer system; and

(e) means for displaying the results of said comparison as indicating said termination of seizure.

28. A system in electroconvulsive therapy as in claim 27, including means for measuring and displaying an elapsed time from the commencement of said monitoring until the said termination of seizure.

29. A system in electroconvulsive therapy (ECT) to induce seizure in a patient by electrical stimulation and monitor the termination of the induced seizure, the system including:

(a) EMG means for detecting muscle activity of a muscle group prior to, during and immediately after the electrical stimulation by amplifying electrical signals from the muscle group, said EMG means including an electromyograph (EMG) device and electrodes adapted to be removably attached to the muscle group to produce EMG signals, A/D means for converting the EMG signals in respective first and second sets of EMG digital data, and computer means for storing in digital computer memory the sets of EMG digital data;

(b) EEG means for detecting the brain wave activity of the patient prior to, during and immediately after the electrical stimulation by amplifying electrical signals from the brain, said EEG means including an electroencephalograph (EEG) device and electrodes adapted to be removably attached to the head of the patient to produce EEG signals, A/D means for converting the EEG signals into respective first and second sets of EEG digital data, and computer means for storing in digital computer memory the sets of EEG digital data;

(c) ECG means for detecting the heart beat rate of the patient prior to, during and immediately after the electrical stimulation by amplifying electrical signals from the heart, said ECG means including an electrocardiograph (ECG) device and electrodes adapted to be removably attached to the skin of the patient to produce ECG signals, A/D means for converting the ECG signals into respective first and second sets of ECG digital data, and computer means for storing in digital computer memory the sets of ECG digital data;

(d) ECT means for inducing the seizure including a plurality of electrodes adapted to be removably secured on the head of the patient and means for applying electrical stimulation through the electrodes to the patient in an electroconvulsive therapy session to induce seizure;

(e) computer means for automatically analyzing the termination of seizure as determined by the monitored EEG, ECG and EMG signals approaching selected respective EEG, ECG and EMG references based on the first sets of respective EEG, ECG and EMG digital data to produce a combined indication of said termination; and

(f) display means to display the combined indication of said termination.

30. A system in electroconvulsive therapy as in claim 29, including means of measuring and displaying an elapsed time from the commencement of said monitoring until the said termination of seizure.