# US 6,251,126 B1 · Method and apparatus for synchronized treatment of obstructive sleep apnea > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,251,126 B1 - Document ID: US6251126B1 - Status: Granted - Kind: B1 - Application number: 09/411,845 - Filed: 1999-10-04 - Granted: 2001-06-26 - Earliest claimed: 1998-04-23 - Assignees: Medtronic, Inc. - Inventors: Frans A. M. Ottenhoff; Koen J. Michels - Web page: https://patentgrep.com/patent/US6251126B1 ## CPC - A61N 1/36007: {of urogenital or gastrointestinal organs, e.g. for incontinence control} - A61N 1/3601: {of respiratory organs} - A61N 1/3611: {Respiration control (stimulating respiratory organs A61N1/3601)} - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) ## Abstract A method and apparatus for synchronized treatment of obstructive sleep apnea. In one embodiment such stimulation is provided by an implantable pulse generator, the implantable pulse generator having a stimulation stage to output stimulation pulses to a body structure, a sensing stage to sense the respiratory effort of a patient, and a controller, to coordinate, and preferably to synchronize, the output stimulation pulses with the sensed respiratory effort. The respiratory effort of a patient is sensed through the use of two electrodes disposed such that the diaphragm is positioned between, and the high frequency current is injected from one electrode to the other and the corresponding impedance is measured, the corresponding impedance thus being a function of the diaphragm position, itself indicating the respiratory effort of the patient. In such a manner the present invention permits the delivery of stimulation to be precisely controlled by the actual respiratory effort of the patient. ## Claims ### Claim 1 An implantable pulse generator for treating obstructive sleep apnea in a patient, comprising: means for determining when the patient has entered a sleep state; means for electrically stimulating a nerve in the upper airway tract of the patient to elicit a contraction by an innervated muscle, the means for electrically stimulating being operative for a pre-determined period of time after the sleep state determining means determines the patient has entered the sleep state; means for sensing the respiratory effort of a patient comprising first and second electrodes suitable for placement on opposite sides of the patient's diaphragm, the respiratory effort sensing means delivering high frequency current between the electrodes to thereby measure the impedance therebetween; and a controller to control the means for electrically stimulating in coordination with the sensed respiratory effort. ### Claim 2 (depends on 1) The implantable pulse generator according to claim 1 wherein the means for electrically stimulating a nerve in the upper airway tract comprises means for delivery electrical stimulation pulse trains. ### Claim 3 (depends on 2) The implantable pulse generator according to claim 2 means for delivery electrical stimulation pulse trains comprises means for delivery the electrical stimulation pulse trains to a nerve. ### Claim 4 (depends on 3) The implantable pulse generator according to claim 3 wherein the controller controls the means for electrically stimulating in synchrony with the sensed respiratory effort of a patient such that the means for electrically stimulating is activated only upon a sensed respiratory effort of a patient. ### Claim 5 (depends on 1) The implantable pulse generator according to claim 1 wherein the means for sensing the respiratory effort of a patient comprise a first electrode adapted to be positioned adjacent the diaphragm and a second electrode adapted to be positioned adjacent the diaphragm and opposite the first electrode, such that the diaphragm can be disposed between the first and second electrodes. ### Claim 6 (depends on 5) The implantable pulse generator according to claim 5 further comprising means for and sensing the impedance between the first electrode and the second electrode. ### Claim 7 (depends on 6) The implantable pulse generator according to claim 6 wherein the means for and sensing the impedance between the first electrode and the second electrode further comprises means for injecting a high frequency current between the first electrode and the second electrode. ### Claim 8 (depends on 7) The implantable pulse generator according to claim 7 wherein the means for injecting a high frequency current between the first electrode and the second electrode comprises means for injecting an alternating current having an amplitude of approximately 1 mAmp and a frequency between approximately 4 kHz-64 kHz. ### Claim 9 (depends on 1) The implantable pulse generator according to claim 1 wherein the controller controls the means for electrically stimulating in synchrony with the sensed respiratory effort of a patient. ### Claim 10 A method of treating obstructive sleep apnea in a patient, comprising the steps of: determining when the patient has entered a sleep state; sensing respiratory effort of the patient using first and second electrodes disposed on opposite sides of the patient's diaphragm, the first and second electrodes delivering high frequency current thereacross to permit measurement of the impedance therebetween as a measure of the sensed respiratory effort; and continuously stimulating a hypoglossal nerve of the patient for a pre-determined period of time after the sleep state has been entered, the stimulation being provided in coordination with the sensed respiratory effort. ### Claim 11 (depends on 10) The method of claim 10 wherein the step of sensing the respiratory effort further comprises injecting high frequency current across the diaphragm and sensing the resulting impedance. ### Claim 12 (depends on 11) The method of claim 11 wherein the step of injecting high frequency current across the diaphragm comprises injecting an alternating current having an amplitude of approximately 1 mAmp and a frequency between approximately 4 kHz-64 kHz. ### Claim 13 (depends on 10) The method of claim 10 wherein the step of stimulating the hypoglossal nerve comprises delivering electrical stimulation pulse train to the hypoglossal nerve. ### Claim 14 (depends on 13) The method of claim 13 wherein the step of delivering electrical stimulation pulse train to the hypoglossal nerve comprises delivering a series of at least two pulse to the hypoglossal nerve. ### Claim 15 (depends on 14) The method of claim 14 wherein the step of delivering electrical stimulation pulse train to the hypoglossal nerve comprises delivering a series of at least two pulse monophasic pulses to the hypoglossal nerve. ### Claim 16 (depends on 15) The method of claim 15 wherein the step of delivering electrical stimulation pulse train to the hypoglossal nerve comprises delivering a series of at least two pulse having an amplitude of between approximately 1-50 milliamps and pulse width between approximately 3-1000 microseconds.