Pulse detection apparatus, software, and methods using patient physiological signals

• US 7,917,209 B2
• Filed: 06/27/2005
• Issued: 03/29/2011
• Est. Priority Date: 09/30/1999
• Status: Expired due to Fees

• Current Assignee: Physio-Control Incorporated (Stryker Corporation)
• Original Assignee: Physio-Control Incorporated (Stryker Corporation)
• Inventors: O'Hearn, Patricia, Jayne, Cynthia P., Stickney, Ronald E., Joo, Tae H., Yerkovich, Daniel, Hampton, David R., Lank, Paula, Crone, William E., Taylor, James W.
• Primary Examiner(s): EVANISKO, GEORGE ROBERT
• Application Number:
  US11/167,247
• Publication Number:
  US 20050240234A1
• Time in Patent Office: 2,101 Days
• Field of Search: 607 6- 8
• US Class Current: 607/6
• CPC Class Codes: A61B 5/0535 Impedance plethysmography for measuring blood flow A61B5/0295
• CPC Class Codes: A61B 5/0538 invasively, e.g. using a catheter
• CPC Class Codes: A61B 5/363 Detecting tachycardia or bradycardia
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61B 7/00 Instruments for auscultation
• CPC Class Codes: A61B 7/04 Electric stethoscopes microphones, acoustic transducers therefor H04R
• CPC Class Codes: A61N 1/365 controlled by a physiological parameter, e.g. heart potential evoked response A61N1/371
• CPC Class Codes: A61N 1/39044 in combination with cardiopulmonary resuscitation [CPR] therapy
• CPC Class Codes: A61N 1/3925 Monitoring; Protecting
• CPC Class Codes: A61N 1/3987 characterised by the timing or triggering of the shock
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

The presence of a cardiac pulse in a patient is determined by evaluating physiological signals in the patient. In one embodiment, a medical device evaluates two or more different physiological signals, such as phonocardiogram (PCG) signals, electrocardiogram (ECG) signals, patient impedance signals, piezoelectric signals, and accelerometer signals for features indicative of the presence of a cardiac pulse. Using these features, the medical device determines whether a cardiac pulse is present in the patient. The medical device may also be configured to report whether the patient is in a VF, VT, asystole, or PEA condition, in addition to being in a pulseless condition, and prompt different therapies, such as chest compressions, rescue breathing, defibrillation, and PEA-specific electrotherapy, depending on the analysis of the physiological signals. Auto-capture of a cardiac pulse using pacing stimuli is further provided.

Claims

1. A device for providing treatment to a patient, comprising:

a sensor to sense a physiological condition of the patient;

a patient impedance measuring device to measure a patient impedance;

a processor to determine that cardiopulmonary resuscitation (CPR) should be administered based on the sensed physiological condition; and

an output device to prompt a caregiver to commence CPR when the controller determines that CPR should be administered,

in which the controller is further configured to determine, during a CPR period after the prompt to commence CPR, that CPR has not been administered based on the patient impedance, and

the output device is further configured to prompt the caregiver to provide CPR, during the CPR period after the prompt to commence CPR, when it is determined that CPR has not been administered.

2. The device of claim 1, wherein the physiological condition comprises a pulse of the patient, and wherein the processor is configured to determine that CPR should be delivered when the sensor senses absence of the pulse.

3. The device of claim 1, wherein the physiological condition comprises a pulse of the patient and a cardiac rhythm, and wherein the processor is configured to determine that CPR should be delivered when the sensor senses absence of the pulse and a non-shockable cardiac rhythm.

4. The device of claim 1, wherein the physiological condition comprises a pulse of the patient and a cardiac rhythm, and wherein the processor is configured to determine that CPR should be delivered when:

the sensor senses absence of the pulse and a shockable cardiac rhythm, and

the processor determines that one or more defibrillation pulses have been delivered to the patient.

5. A method for providing treatment to a patient, comprising:

sensing a physiological condition of the patient via a sensor;

measuring a patient impedance via a patient impedance measuring device;

determining whether cardiopulmonary resuscitation (CPR) should be administered based on the sensed physiological condition;

prompting a caregiver to commence CPR when it is determined that CPR should be administered;

determining, during a CPR period after the prompting to commence CPR, that CPR has not been administered based on the patient impedance; and

prompting the caregiver to provide CPR, during the CPR period after the prompting to commence CPR, when it is determined that CPR has not been administered.

6. The method of claim 5, wherein sensing the physiological condition comprises sensing a pulse, and wherein determining that CPR should be delivered comprises determining that the patient is pulseless.

7. The method of claim 5, wherein sensing the physiological condition comprises sensing a pulse and a cardiac rhythm, and wherein determining that CPR should be delivered comprises determining that the patient is pulseless and the cardiac rhythm is non-shockable.

8. The method of claim 5, wherein the sensing the physiological condition comprises sensing a pulse and a cardiac rhythm, and wherein determining that CPR should be delivered comprises:

determining that the patient is pulseless and the cardiac rhythm is shockable; and

determining that one or more defibrillation pulses have been delivered to the patient.