CPR chest compression monitor

• US 7,108,665 B2
• Filed: 03/22/2002
• Issued: 09/19/2006
• Est. Priority Date: 11/09/1998
• Status: Expired due to Term

• Current Assignee: Zoll Circulation Incorporated (Asahi Kasei Corporation)
• Original Assignee: Zoll Circulation Incorporated (Asahi Kasei Corporation)
• Inventors: Berger, Ronald D., Halperin, Henry R.
• Primary Examiner(s): Thanh, Quang D.
• Application Number:
  US10/104,674
• Publication Number:
  US 20020193711A1
• Time in Patent Office: 1,642 Days
• Field of Search: 601 41- 44, 601/107, 733/790.1, 738/625.42, 733/790.3, 733/790.8, 600/587, 600/594, 600/595, 434/262, 434/265, 128/897, 128/898, 128/202.16, 128/204.19
• US Class Current: 601/41
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/1135 by monitoring thoracic expansion
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/6825 Hand
• CPC Class Codes: A61B 5/6831 Straps, bands or harnesses
• CPC Class Codes: A61B 5/721 using a separate sensor to detect motion or using motion information derived from signals other than the physiological signal to be measured
• CPC Class Codes: A61B 5/725 using specific filters therefor, e.g. Kalman or adaptive filters A61B5/316 take precedence
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61H 2201/5007 computer controlled
• CPC Class Codes: A61H 2201/5048 Audio interfaces, e.g. voice or music controlled
• CPC Class Codes: A61H 2201/5058 Sensors or detectors
• CPC Class Codes: A61H 2201/5064 Position sensors
• CPC Class Codes: A61H 2201/5071 Pressure sensors
• CPC Class Codes: A61H 2201/5084 Acceleration sensors
• CPC Class Codes: A61H 2230/04 Heartbeat characteristics, e.g. E.G.C., blood pressure modulation
• CPC Class Codes: A61H 2230/06 : Heartbeat rate
• CPC Class Codes: A61H 2230/855 : used as a control parameter for the apparatus
• CPC Class Codes: A61H 31/00 : Artificial respiration or heart stimulation, e.g. heart massage artificial respiration by treatment with gas or air, e.g. mouth-to-mouth respiration A61M16/00; applying electric currents by contact electrodes for stimulation, e.g. heart pace-makers A61N1/36 ; teaching or training models, demonstration models for medical purposes G09B23/288
• CPC Class Codes: A61H 31/005 : with feedback for the user
• CPC Class Codes: A61H 31/006 : Power driven
• CPC Class Codes: A61H 31/007 : Manual driven
• CPC Class Codes: A61M 16/00 : Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes stimulating the respiratory movement by mechanical, pneumatic or electrical means, iron lungs combined with gas breathing means A61H31/00
• CPC Class Codes: A61M 16/10 : Preparation of respiratory gases or vapours
• CPC Class Codes: A61M 2230/06 : Heartbeat rate only
• CPC Class Codes: A61N 1/39044 : in combination with cardiopulmonary resuscitation [CPR] therapy
• CPC Class Codes: G06F 2218/04 : Denoising
• CPC Class Codes: G09B 23/288 : for artificial respiration or heart massage

Abstract

Chest compressions are measured and prompted to facilitate the effective administration of CPR. A displacement detector produces a displacement indicative signal indicative of the displacement of the CPR recipient'"'"'s chest toward the recipient'"'"'s spine. A signaling mechanism provides chest compression indication signals directing a chest compression force being applied to the chest and a frequency of such compressions. An automated controller and an automated constricting device may be provided for applying CPR to the recipient in an automated fashion. The automated controller receives the chest compression indication signals from the signaling mechanism, and, in accordance with the chest compression indication signals, controls the force and frequency of constrictions. The system may be provided with a tilt compensator comprising a tilt sensor mechanism outputting a tilt compensation signal indicative of the extent of tilt of the device, and may be further provided with an adjuster for adjusting the distance value in accordance with the tilt compensation signal. An ECG signal processor may be provided which removes the CPR-induced artifact from a measured ECG signal_obtained during the administration of CPR.

Claims

1. A method for monitoring the compression of the chest of a patient, said method comprising:

providing a chest compression monitor adapted to follow the movement of the chest of a patient undergoing compression, said chest compression monitor comprising an accelerometer adapted to sense upward and downward acceleration of the chest compression monitor, said compression monitor further adapted to output an acceleration signal indicative of the upward and downward acceleration of the chest; and

a computer adapted to process the acceleration signal to determine the depth of chest compression and produce a compression signal indicative of the depth of compression of the patient'"'"'s chest;

placing the chest compression monitor in fixed relationship with the chest so that it follows the movement of the chest;

causing at least one compression of chest of the patient;

processing the acceleration signal with the computer, and determining the start of a compression without reference to an external reference, and thereafter calculating downward displacement of the chest using the acceleration signal; and

producing the compression signal.

2. The method of claim 1 further comprising the step of:

determining the end of compression, and thereafter calculating upward displacement of the chest using the acceleration signal.

3. The method of claim 1 wherein the step of:

determining the start of a compression is based on the acceleration signal, a zero-point of acceleration and changes in the direction of velocity calculated by the computer.

4. The method of claim 2 wherein the step of:

determining the end of a compression is based on the acceleration signal, a zero-point of acceleration and changes in the direction of velocity calculated by the computer.

5. The method of claim 1 further comprising:

repeatedly compressing the chest, causing a plurality of chest compressions, and determining the start of each compression based on the acceleration signal, a zero point of acceleration and changes in the direction of velocity calculated by the computer.

6. The method of claim 2 further comprising:

repeatedly compressing the chest, causing a plurality of chest compressions, and determining the end of a each compression based on the acceleration signal, a zero point of acceleration and changes in the direction of velocity calculated by the computer.

7. A method for determining a displacement of a chest of a patient, the method comprising the steps of:

providing a compression monitor comprising an accelerometer capable of measuring the acceleration of a Cardio Pulmonary Resuscitation (CPR) recipient'"'"'s chest during CPR;

placing the compression monitor on the CPR recipient'"'"'s chest and performing CPR by performing compressions on the patient'"'"'s chest;

measuring the acceleration with the accelerometer without reference to an external reference; and

determining the zero points of acceleration; and

calculating the displacement of the chest of the patient using the measured acceleration and the zero points of acceleration.