Methods and apparatuses for detection and classification of seizures using EMG sensors
A system for monitoring a patient for seizure activity may include one or more detection units. The detection units may include one or more electromyography sensors configured to evaluate a patient for seizure activity. The detection units may further include one or more sensors configured to detect an orientation of the patient and/or when a sensor is bearing a portion of the patient's weight or otherwise pressed against the patient. In some embodiments, methods of detection may include adjusting an algorithm for seizure detection based on a recognition of whether a muscle is constrained or whether the muscle is free to move.
1. A method of monitoring a patient for seizure activity comprising:
placing a detection unit over a muscle located on said patient's body, said detection unit including at least one EMG sensor, at least one orientation sensor, and at least one pressure sensor;
wherein said at least one orientation sensor is configured to determine how said muscle is oriented with respect to the ground;
wherein said at least one pressure sensor is configured to indicate if a weight of said patient is pressed against said at least one pressure sensor;
collecting EMG signals from said at least one EMG sensor;
collecting orientation data from said at least one orientation sensor;
collecting pressure data from said at least one pressure sensor; and
analyzing the EMG signal, said orientation data, and said pressure data to determine if a seizure is detected and whether to initiate a response;
wherein the detection of said seizure is calibrated based on whether the patient is lying substantially horizontally, lying substantially horizontally with the patient's weight on said one or more pressure sensor, or oriented substantially vertically.
2. The method of claim 1 wherein said response includes an emergency alarm response.
3. The method of claim 1 wherein said response includes sending a warning signal to a caregiver.
4. The method of claim 1 wherein the analyzing the EMG signals includes comparing a value for at least one seizure characteristic to a threshold value; and
wherein said threshold value is dependent upon the orientation of said muscle during monitoring.
5. The method of claim 1 wherein the response is based on whether said patient was determined to be prone or engaged in a non-prone activity at a start of said seizure.
6. The method of claim 1 wherein the response is based on whether orientation data indicates that said muscle was approximately vertically oriented with respect to the ground at a start of said seizure and approximately horizontally oriented after completion of said seizure.
7. A detection unit configured for monitoring a patient for a presence of seizure activity, said detection unit comprising:
one or more EMG sensors configured for measurement of muscle electrical activity; and
one or more pressure sensors configured for determining if a weight of a patient is being pressed against at least one of said one or more pressure sensors.
8. The detection unit of claim 7 further comprising a position sensor.
9. The detection unit of claim 7 further comprising an oxygen saturation sensor.
10. The detection unit of claim 7 wherein the detection unit is configured for placement over one of a patient's biceps, triceps, hamstrings, or quadriceps.
11. The detection unit of claim 7 wherein the detection unit is configured for placement over a muscle suitable for collecting muscle electrical activity indicative of a patient seizure.
12. The detection unit of claim 7 wherein the detection unit is configured to detect when the patient may be side sleeping, and to allow the patient to side sleep without sending an alarm in the absence of a detected seizure.
13. The detection unit of claim 7 wherein the detection unit is configured to detect when the patient may be side sleeping, and to adjust one or more EMG thresholds for detection of a seizure based on whether the patient may be side sleeping.
14. A method of monitoring a patient for seizure activity comprising:
placing a detection unit including an EMG sensor over a muscle located on one side of said patient's body, said detection unit including a pressure sensor;
collecting and analyzing an EMG signal from said EMG sensor;
collecting pressure sensor data using said pressure sensor;
determining whether said pressure sensor data indicates that a weight of said patient is pressed against said pressure sensor; and
determining whether said EMG signal meets one or more threshold values in order to detect a seizure;
wherein said one or more threshold values are dependent upon whether a portion of said patient's body is resting on said pressure sensor; and
initiating a response if a seizure is detected.
15. The method of claim 14 wherein said response includes an emergency alarm response.
16. The method of claim 14 wherein said response includes sending a warning signal to a caregiver.
17. The method of claim 14 wherein said detection unit includes a microelectromechanical element configured to determine an orientation of said detection unit.
18. The method of claim 17 wherein said orientation indicates whether the patient is lying in a substantially prone orientation or standing in a vertical orientation.
19. The method of claim 17 wherein said detection unit includes a position sensor.