Using the CPR Function

The CPR-D padz include a sensor that detects the rate and depth of CPR chest compressions. This sensor is placed (as part of the electrodes application) on the patient's chest so that it is located between the rescuer's hands and the patient's lower sternum during chest compressions. When the rescuer performs CPR compressions, the sensor detects their rate and depth and sends the information to the ZOLL AED PLUS unit.

When used with ZOLL CPR-D padz, the ZOLL AED PLUS monitors the depth and rate of CPR chest compressions. It provides a CPR metronome function designed to encourage rescuers to perform chest compressions at the AHA/ERC recommended rate of 100 compressions per minute (CPM) as well as voice and visual prompts to encourage a compression depth of 1� - 2 inches for adult patients.

The metronome function is disabled during periods when CPR should not be performed (for example, during ECG analyses and defibrillation shock sequences). During periods when CPR may be indicated, the metronome begins issuing audible beeps following detection of the rescuer's first few compressions. The beeps continue automatically (at rates described below) until a few seconds after chest compressions are halted by the rescuer or until the recommended "CPR period" ends (1 minute for AHA and ERC protocols). If the rescuer ceases chest compressions during the CPR period, metronome beeps will stop within a few seconds after compressions are halted. Audible beeps will resume during the CPR period following any re-initiation of CPR compressions. If no CPR compressions are detected during "CPR periods", the ZOLL AED PLUS will periodically re-issue IF NO CIRCULATION, CONTINUE CPR prompts.

The rate of beeps issued by the ZOLL AED PLUS metronome function adapts to the rescuer's actual chest compression rate. The metronome will beep at 100 CPM when chest compressions are delivered at greater than 80 compressions per minute (CPM). Should the rescuer fail to deliver compressions at 80 CPM or greater, the metronome will beep at a rate that is approximately 15 CPM higher than the rescuer's actual rate. This increased metronome rate is intended to encourage the rescuer to increase his/her chest compression rate until the recommended 100 CPM rate is achieved. The metronome beeps at a minimum rate of 60 CPM in cases where the rescuer's compression rate is substantially below 60 CPM.

During CPR, the ZOLL AED PLUS may issue one or more audible prompts based on the depth of chest compressions detected. When the CPR monitoring system determines that compression depth is consistently less than 1� inches, a PUSH HARDER prompt will be issued. A GOOD COMPRESSION prompt will be issued if the rescuer responds by increasing compression depth to 1� inches or more.

Measuring CPR Chest Compression

Failure to adequately compress a victim's chest is a common error during CPR. The force required to properly compress a victim's chest 1� -2 inches varies depending on the patient's build and anatomy. Until now, only force and pressure sensors have been available. New technology in ZOLL's CPR-D padz includes a hand placement locator, an accelerometer, electronics, and a sophisticated processing algorithm. This system accurately measures CPR compression and converts the motion of the accelerometer over time into distance moved. The infrequent rescuer now has help providing CPR support for the victim.

One Electrode Size Fits All

A one-piece electrode design must account for anatomical variation in the patient population. The design of ZOLL's CPR-D padz is based on extensive human anthropometric data and studies designed to accommodate the wide range of patient sizes and shapes and to ensure that a one-piece electrode meets the needs of emergency AED use. The design developed for the CPR-D padz meets the anthropometric characteristics of 99% of human chest anatomy. A special feature lets the rescuer separate the apex electrode to cover the other 1% of the population and other anatomical variations that require special adaptation.

Simplified Electrode Placement

Simplifying electrode placement is critical to widespread use of AED's. Labeling helps but is often overlooked or discarded in an emergency that is sudden and unanticipated. The infrequent rescuer is easily confused when looking at a victim as to "left," "right," "up," and "down." Two separate electrodes cause concern over incorrect placement and technical complications if electrodes stick together before being placed correctly on the patient. The unique one-piece design of ZOLL's CPR-D padz addresses these problems by orienting the simple design to the head while using the easily remembered CPR landmark (the sternum) as the key placement cue. Packaging is then removed by a simple pull after positioning. Because this is the same placement taught for CPR hand position, AED users benefit from having to remember only one easy landmark for both interventions.

Four-Year Shelf Life Sacrificial Element Technology

Infrequently used AED's need electrodes that do not require frequent replacement. Most AED electrodes will expire before they are used. Corrosion of the electrode element due to long-term contact with ionic gel is the main limitation of electrode shelf life.

ZOLL's new CPR-D padz protect the electrode elements with a novel design that sacrifices a non-critical element in the electrode to control the corrosion process and allow an unmatched four-year AED electrode life. ZOLL's CPR-D padz reduce electrode replacement costs, facilitate AED readiness and maintenance, and decrease the probability of an AED's failure due to electrode expiration.