Method and apparatus for enhancement of chest compressions during CPR

Apparatus for assisting a rescuer in performing chest compressions during CPR on a victim, the apparatus comprising:

• a pad or other structure configured to be applied to the chest near or at the location at which the rescuer applies force to produce the chest compressions;
• at least one motion sensor connected to the pad, the motion sensor being configured to sense movement of the chest;
• processing circuitry for processing the output of the motion sensor to estimate the maximum velocity of compression of the chest;
• and
• at least one prompting device connected to the processing circuitry for providing the rescuer with information representative of the maximum velocity of compression.

A method of determining chest compression during CPR, the method comprising

• applying a motion sensor to the chest of a patient at a location near or at the location at which a rescuer applies force to produce chest compressions;
• determining chest displacement from analysis of features of the motion waveform produced by the motion sensor,
• wherein the motion sensor is an accelerometer, and
• further comprising processing the output of the accelerometer to provide velocity and acceleration waveforms, and
• further comprising prompting a rescuer based as to whether compressions are within desired limits on compression depth and compression release,
• wherein the prompts to the rescuer are based on multi-cycle trends, so that they are not immediately influenced by the rescuer taking a brief break in the application of CPR.

A method of determining chest compression during CPR, the method comprising

• applying a motion sensor to the chest of a patient at a location near or at the location at which a rescuer applies force to produce chest compressions;
• determining chest displacement from analysis of features of the motion waveform produced by the motion sensor,
• wherein the motion sensor is an accelerometer, and
• further comprising processing the output of the accelerometer to provide velocity and acceleration waveforms, and
• further comprising prompting a rescuer based as to whether compressions are within desired limits on compression depth and compression release, and
• further comprising determining chest compliance, and using the determined chest compliance to adjust the level of pressure/force that the rescuer is permitted to apply at the end of a compression stroke without being prompted as to insufficiently releasing the chest.

A method of determining chest compression during CPR, the method comprising

• applying a motion sensor to the chest of a patient at a location near or at the location at which a rescuer applies force to produce chest compressions;
• determining chest displacement from analysis of features of the motion waveform produced by the motion sensor,
• wherein the motion sensor is an accelerometer, and
• further comprising processing the output of the accelerometer to provide velocity and acceleration waveforms, and
• wherein the features determined from the waveforms include one or more of the following:
• width, amplitude, area, center of mass, skewness, height/width ratio, TAR, TAMPR and TWR.

A method of analyzing ECG signals during application of CPR, the method comprising:

• detecting ECG signals during application of chest compressions;
• detecting the output of a sensor from which information on the velocity of chest compressions can be determined;
• and
• using the information on the velocity to reduce at least one signal artifact in the ECG signal resulting from the chest compressions.

Apparatus for assisting a rescuer in performing chest compressions during CPR on a victim, the apparatus comprising:

• a pad or other structure configured to be applied to the chest near or at the location at which the rescuer applies force to produce the chest compressions;
• at least one motion sensor connected to the pad, the motion sensor being configured to sense movement of the chest;
• at least one force sensor connected to the pad, the force sensor being configured to sense force applied to the chest;
• and
• processing circuitry for processing the output of the motion sensor and force sensor to estimate the compliance of the chest.