# US 2015/0148856 A1 · Rescuer protection from electrical shock during defibrillation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2015/0148856 A1 - Document ID: US20150148856A1 - Status: Published application - Kind: A1 - Application number: 14/091,455 - Filed: 2013-11-27 - Published: 2015-05-28 - Earliest claimed: 2013-11-27 - Assignees: ZOLL Medical Corporation - Applicants: ZOLL Medical Corporation - Inventors: Gary A. Freeman; Weilun Quan - Web page: https://patentgrep.com/patent/US20150148856A1 ## CPC - A61N 1/3931: {Protecting, e.g. back-up systems} - A61B 5/355: Detecting T-waves - A61B 5/4836: {Diagnosis combined with treatment in closed-loop systems or methods (A61B5/0036 takes precedence)} - A61N 1/3987: {characterised by the timing or triggering of the shock} - A61H 31/005: {with feedback for the user} - A61H 2201/5058: Sensors or detectors - A61H 2230/045: used as a control parameter for the apparatus - 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) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - A61H: PHYSICAL THERAPY APPARATUS, e.g. DEVICES FOR LOCATING OR STIMULATING REFLEX POINTS IN THE BODY; ARTIFICIAL RESPIRATION; MASSAGE; BATHING DEVICES FOR SPECIAL THERAPEUTIC OR HYGIENIC PURPOSES OR SPECIFIC PARTS OF THE BODY (electrotherapy, magnetotherapy, radiation therapy or ultrasound therapy A61N) ## Abstract This document relates to cardiac resuscitation, and in particular to systems and techniques for protecting rescuers from electrical shock during defibrillation of a patient. ## Claims ### Claim 1 A system comprising: a first set of ECG leads configured to be placed in contact with the skin of a rescuer; a second set of ECG leads configured to be placed in contact with the skin of a patient; and a computing device connected to the first and second set of ECG leads and configured to: determine whether a defibrillating shock to the patient's heart is suitable therapy based on one or more electrocardiogram signals of the patient received from the second set of ECG leads; and determine a gating signal configured to prohibit administration of the defibrillating shock to the patient's heart during one or more portions of the cardiac cycle of the rescuer, the gating signal determined based on one or more electrocardiogram signals of the rescuer received from the first set of ECG leads. ### Claim 2 (depends on 1) The system of claim 1, wherein the configurations to determine the gating signal comprise configurations to determine the gating signal such that the gating signal prohibits administration of the defibrillating shock to the patient's heart during a time period surrounding a T wave in the ECG of the rescuer. ### Claim 3 (depends on 1) The system of claim 1, wherein the configurations to determine the gating signal comprise configurations to determine the gating signal such that the gating signal prohibits administration of the defibrillating shock to the patient's heart during one or more vulnerable periods of the cardiac cycle of the rescuer. ### Claim 4 (depends on 1) The system of claim 1, wherein the configurations to determine the gating signal comprise configurations to: receive the electrocardiogram signal of the rescuer from the first set of ECG leads; determine a location of an R wave in the ECG signal of the rescuer; determine a location of a T wave in the ECG signal of the rescuer; and determine a time period measured from the R wave during which administration of the defibrillating shock to the patient's heart is prohibited, the time period including at least a portion of the T wave. ### Claim 5 (depends on 1) The system of claim 1, wherein the configurations to determine the gating signal comprise configurations to: receive the electrocardiogram signal of the rescuer from the first set of ECG leads; determine a location of the T wave in the ECG signal of the rescuer; and determine a time period that includes at least a portion of the T wave during which administration of the defibrillating shock to the patient's heart is prohibited. ### Claim 6 (depends on 1) The system of claim 1, wherein the one or more portions of the cardiac cycle of the rescuer include at least an interval from about 20% of the peak T wave voltage on the rising edge of the T wave to about 20% of the peak T wave voltage on the falling edge of the T wave. ### Claim 7 (depends on 1) The system of claim 1, wherein the one or more portions of the cardiac cycle of the rescuer include the entire duration of the T wave. ### Claim 8 (depends on 1) The system of claim 1, wherein the one or more portions of the cardiac cycle include the relative refractory period. ### Claim 9 (depends on 1) The system of claim 1, further comprising: a third set of ECG leads configured to be placed in contact with the skin of a second rescuer, wherein the configurations to determine the gating signal comprise configurations to determine the gating signal based on electrocardiogram signals from the first and third ECG leads to prohibit administration of the defibrillating shock to the patient's heart during one or more vulnerable periods. ### Claim 10 A medical system, comprising: a device configured to be placed in contact with the skin of a rescuer; an ECG lead configured to be placed in contact with the skin of the patient; and a safety mechanism configured to: detect electrical contact between the patient and the rescuer by applying a signal to the ECG lead and measuring a signal responsive to the applied signal at the device in contact with the skin of the rescuer; and prohibit delivery of a defibrillation shock upon detection of electrical contact between the rescuer and patient. ### Claim 11 (depends on 10) The system of claim 10, wherein the safety mechanism is further configured to enable delivery of the defibrillating shock to the patient upon detection of the absence of contact between the patient and the rescuer. ### Claim 12 (depends on 10) The system of claim 10, wherein measuring the signal responsive to the applied signal comprises measuring a signal transmitted between the ECG lead and the device in contact with the skin of the rescuer using the patient's body and the rescuer's body as conductive mediums. ### Claim 13 (depends on 10) The system of claim 10, wherein the device configured to be placed in contact with the skin of the rescuer comprises a wrist strap. ### Claim 14 A method comprising: receiving a first ECG signal from a first set of ECG leads in contact with the skin of a rescuer; receiving a second ECG signal from a second set of ECG leads in contact with the skin of a patient; and determining whether a defibrillating shock to the patient's heart is suitable therapy based on one or more electrocardiogram signals of the patient received from the second set of ECG leads; and determining a gating signal configured to prohibit administration of the defibrillating shock to the patient's heart during one or more portions of the cardiac cycle of the rescuer, the gating signal determined based on one or more electrocardiogram signals of the rescuer received from the first set of ECG leads. ### Claim 15 (depends on 14) The method of claim 14, wherein determining the gating signal comprises determining the gating signal such that the gating signal prohibits administration of the defibrillating shock to the patient's heart during a time period surrounding a T wave in the ECG of the rescuer. ### Claim 16 (depends on 14) The method of claim 14, wherein determining the gating signal comprises determining the gating signal such that the gating signal prohibits administration of the defibrillating shock to the patient's heart during one or more vulnerable periods of the cardiac cycle of the rescuer. ### Claim 17 (depends on 14) The method of claim 14, wherein determining the gating signal comprises: receiving the electrocardiogram signal of the rescuer from the first set of ECG leads; determining a location of an R wave in the ECG signal of the rescuer; determining a location of a T wave in the ECG signal of the rescuer; and determining a time period measured from the R wave during which administration of the defibrillating shock to the patient's heart is prohibited, the time period including at least a portion of the T wave. ### Claim 18 (depends on 14) The method of claim 14, wherein determining the gating signal comprises: receiving the electrocardiogram signal of the rescuer from the first set of ECG leads; determining a location of the T wave in the ECG signal of the rescuer; and determining a time period that includes at least a portion of the T wave during which administration of the defibrillating shock to the patient's heart is prohibited. ### Claim 19 (depends on 14) The method of claim 14, wherein the one or more portions of the cardiac cycle of the rescuer include at least an interval from about 20% of the peak T wave voltage on the rising edge of the T wave to about 20% of the peak T wave voltage on the falling edge of the T wave. ### Claim 20 (depends on 14) The method of claim 14, wherein the one or more portions of the cardiac cycle of the rescuer include the entire duration of the T wave. ### Claim 21 (depends on 14) The method of claim 14, wherein the one or more portions of the cardiac cycle include the relative refractory period. ### Claim 22 A method comprising: applying a signal to an ECG lead in contact with the skin of the patient; measuring a signal at a device in contact with the skin of a rescuer, the signal being responsive to the applied signal; detecting electrical contact between the patient and the rescuer based on the detected signal; and prohibiting delivery of a defibrillation shock upon detection of electrical contact between the rescuer and patient. ### Claim 23 (depends on 22) The method of claim 22, further comprising enabling delivery of the defibrillating shock to the patient upon detection of the absence of contact between the patient and the rescuer. ### Claim 24 (depends on 22) The method of claim 22, wherein measuring the signal responsive to the applied signal comprises measuring a signal transmitted between the ECG lead and the device in contact with the skin of the rescuer using the patient's body and the rescuer's body as conductive mediums. ### Claim 25 A system comprising: a sensor placed in contact with the skin of a rescuer; a set of ECG leads configured to be placed in contact with the skin of a patient; and a computing device connected to the sensor and the ECG leads and configured to: determine whether a defibrillating shock to the patient's heart is suitable therapy based on one or more electrocardiogram signals of the patient received from the set of ECG leads; and determine a gating signal configured to prohibit administration of the defibrillating shock to the patient's heart during one or more portions of a cardiac cycle of the rescuer, the gating signal determined based on one or more physiologic signals of the rescuer received from the sensor. ### Claim 26 (depends on 25) The system of claim 25, wherein the sensor comprises an SpO2 sensor. ### Claim 27 (depends on 26) The system of claim 26, wherein the configurations to determine the gating signal comprise configurations to determine the gating signal such that the gating signal prohibits administration of the defibrillating shock to the patient's heart during a time period surrounding a T wave in the patient's cardiac cycle based on the SpO2 signal of the rescuer. ### Claim 28 (depends on 25) The system of claim 25, wherein the configurations to determine the gating signal comprise configurations to determine the gating signal such that the gating signal prohibits administration of the defibrillating shock to the patient's heart during one or more vulnerable periods of the cardiac cycle of the rescuer. ### Claim 29 (depends on 25) The system of claim 25, wherein the configurations to determine the gating signal comprise configurations to: receive an SpO2 signal from the sensor; determine a location of a peak in the SpO2 signal of the rescuer; determine a location in the SpO2 signal of the rescuer corresponding to a location of a T wave in the patient's cardiac cycle; determine a time period measured from the peak in the SpO2 signal during which administration of the defibrillating shock to the patient's heart is prohibited, the time period including at least a portion of the T wave.