External ear canal interface for the treatment of neurological disorders

#This invention is in the field of external medical devices for the treatment of neurological disorders such as epilepsy, febrile seizures, dizziness, tinnitus and sleep disturbances.

#Today most neurological disorders are treated with drugs that can have significant side effects. There are few existing devices for the treatment of neurological disorders that are not fully implanted. There are existing devices that use eye movement to indicate the onset of drowsiness and sound an auditory alerting signal. Current external devices do not include EEG, auditory, vestibular or caloric recording capability nor do they have electrical or caloric stimulation capability. Furthermore most external EEG or ECG monitoring devices are not capable of responsive interventions. Fischell and Upton in U.S. Pat. No. 6,016,449 (which is hereby incorporated by reference as though set forth in full herein) describe numerous embodiments of a responsive neurostimulator that can use responsive electrical and sensory (acoustic, vibratory and visual) stimulation applied externally to treat neurological disorders. Fischell and Upton, also describe an embodiment of their invention that could be completely external using “a control module located external to the patient's body connected to electrodes (either) external (or internal) to the patient's scalp. Such an externally located control module might be positioned behind the patient's ear like a hearing aid.” External scalp electrodes, however are not well suited for accurate detection of the onset of neurological states due to significant noise from artifacts such as muscle contraction, eye movement or sweating. As a result, most of the embodiments of the U.S. Pat. No. 6,016,449 utilize brain electrodes implanted under the scalp. Vestibular and caloric stimulation therapies were not mentioned at all as a potential responsive treatment for a neurological disorder.

#The two major problems associated with sleep are inability to get to sleep and difficulty in staying awake. Sleep apnea is currently treated with surgery to the throat or airways, air flow devices that often do not work and are uncomfortable and poorly tolerated by many patients and by ear clip oxygen sensors with acoustic feedback that will wake the patient contributing to interrupted sleep. In the second category, disorders relating to difficulty in staying awake such as narcolepsy can cause inadvertent drowsiness or sleep that is extremely dangerous when driving or operating heavy equipment. Currently stimulants are used to help keep such people awake during the day but are often either ineffective or cause additional problems of affecting normal night time sleep. In addition, there are no current non-drug treatments for sleep disorders associated with changes in time zone associated with travel nor are there any device solutions for control of sleep stages.

#FIG. 1 is a block diagram of the present invention system.

#FIG. 2 is a sketch of an integrated single ear canal sensor/stimulator unit.

#FIG. 3 is a sketch of an alternate embodiment of the present invention having a secondary control module that can be placed behind the ear like a hearing aid.

#FIG. 1 is a block diagram of the ear canal sensor/stimulator system 10 and the external equipment 11. The wires 17A through 17C from the electrodes 15A through 15C, and the wires 18A and 18B from the caloric transducer 16, are shown connected to both the event detection sub-system 30 and the stimulation sub-system 40. 15C is designated as the common electrode although any of the electrodes could be so designated. It is also envisioned to use the case of the control module 20 of FIG. 2 as the common (or indifferent) electrode 15C. The wires 17A and 17B carry EEG signals 21A and 21B from the electrodes 15A and 15B to the event detection sub-system 30. The electrodes 15A and 15B can be energized by the stimulation sub-system 40 via the wires 17A through 17C to electrically stimulate the patient's vestibular nerve using the stimulation signals 412A through 412N respectively. Although the electrodes 15A through 15C shown here are connected to both the event detection sub-system 30 and the stimulation sub-system 40, it is obvious that a separate set of electrodes and associated wires could be used with each sub-system.

#One envisioned embodiment of the caloric transducer is a bimetallic strip that can operate as a thermocouple to measure temperature or as a caloric stimulator to heat tissue in the vicinity of the patient's ear. It is contemplated that a bimetallic or resistive element can be used to heat the tissue, and a Peltier device or heat pump or exchanger can be used to either heat or cool the tissue. Other approaches are possible and will be recognized by a practitioner of ordinary skill in the art.

#The event detection sub-system 30 receives the EEG signals 21A and 21B (referenced to system ground 19 connected to the wire 17C from the common electrode 15C and processes them to identify neurological events such as sleep state or an epileptic seizure or its precursor. A central processing system 50 with central processor 51 and memory 55 acts to control and coordinate all functions of the system 10. The interconnection 52 is used to transmit programming parameters and instructions to the event detection sub-system 30 from the central processing system 50. The interconnection 53 is used to transmit signals to the central processing system 50 identifying the detection of a neurological event by the event detection sub-system 30. The interconnection 53 is also used to transmit EEG and other related data for storage in the memory 55.