Automated resuscitation device with ventilation sensing and prompting
A device for assisting a caregiver in delivering cardiac resuscitation to a patient, the device comprising a user interface configured to deliver prompts to a caregiver to assist the caregiver in delivering cardiac resuscitation to a patient; at least one sensor configured to detect the caregiver's progress in delivering the cardiac resuscitation, wherein the sensor is configured to provide a signal containing information indicative of ventilation; a memory in which a plurality of different prompts are stored, including at least one ventilation progress prompt to guide the rescuer's performance of ventilation; a processor configured to process the output of the sensor to determine a parameter descriptive of ventilation progress and to determine whether the ventilation progress prompt should be selected for delivery. Possible parameters descriptive of ventilation progress include ventilation rate, delivered tidal volume, and flow rate.
1. A device for assisting a caregiver in delivering cardiac resuscitation to a patient, the device comprising
a user interface configured to deliver prompts to a caregiver to assist the caregiver in delivering cardiac resuscitation to a patient;
a motion sensor positioned and configured to detect a movement of the chest wall of the patient;
a processor configured to determine an estimate of the delivered ventilation rate from an output of the motion sensor and to distinguish between ventilations and chest compressions based at least in part on the shape of the leading edge of detected movement for determining the estimate; and
a memory in which a plurality of different prompts are stored, including at least one ventilation progress prompt pertaining to the estimate of the delivered ventilation rate,
wherein the processor is further configured to select a ventilation progress prompt based at least in part on the estimate of the delivered ventilation rate.
2. The device of claim 1 wherein the processor determines the estimate of the ventilation rate without using information from an airway pressure sensor.
3. The device of claim 1 wherein the processor determines the estimate of the ventilation rate using information from both the motion sensor and an airway pressure sensor.
4. The device of claim 1 wherein the processor is further configured to estimate a chest compression rate from the output of the motion sensor.
5. The device of claim 1 wherein the processor is configured to examine a sharpness of the leading edge, wherein greater sharpness is suggesting a chest compression.
6. The device of claim 5 wherein the processor is further configured to examine a frequency content in the leading edge, with higher frequency content suggesting the chest movements result from chest compressions.
7. The device of claim 5 wherein the processor is configured so that generally the sharper the leading edge and the higher the frequency content the more likely that the processor determines that the waveform detected by the motion sensor is a chest compression and not a ventilation.
8. The device of claim 1 wherein the processor is further configured to consider a direction of the movement of the chest wall at the leading edge, with downward displacement increasing the likelihood that the movement is a chest compression.
9. The device of claim 1 wherein the processor is configured to apply a bandpass filter to the output of the motion sensor as part of making the determination of whether the movement is a ventilation or a chest compression.
10. The device of claim 1 wherein the motion sensor comprises an accelerometer.