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Zoll Medical Case Study

Zoll Pocket CPR deviceZOLL Medical's Palm Sized CPR Device Leverages Analog Device's iMEMS® Motion Sensor Technology to Assist Rescuers of Sudden Cardiac Arrest Victims —

PocketCPR® provides real-time instruction and audio/visual feedback to first responders.

The statistics are sobering. An individual experiencing sudden cardiac arrest has only minutes to survive unless high quality CPR (cardiopulmonary resuscitation) is administered. And according to the American Heart Association, more than 95 percent of sudden cardiac arrest victims die before reaching the hospital.

ZOLL Medical Corporation developed the PocketCPR device to assist a rescuer in the delivery of high-quality CPR chest compressions. The PocketCPR device uses Analog Devices' iMEMS (integrated micro-electromechanical systems) technology to provide rescuers with real-time, step-by-step guidance and performance-specific feedback while performing manual CPR on individuals experiencing sudden cardiac arrest.

Life Saving Response Time is Minutes

Defined as the abrupt and unexpected cessation of heart function, sudden cardiac arrest is an acute event requiring immediate attention by a rescuer. According to the American Heart Association guidelines, CPR must be performed accurately within four to six minutes of sudden cardiac arrest, and each minute that passes without effective CPR increases the rate of death by 10 percent. Coupled with this urgency is the fact that the first responder is often an untrained family member or bystander. One of the biggest challenges associated with sudden cardiac arrest is that bystanders are often untrained, unwilling or lack the confidence to initiate CPR in an emergency.

Pocket CPR coaches the rescuer with audio and visual instructions to initiate the critical rescue steps needed for sudden cardiac arrest, such as checking responsiveness and calling for help, before it provides real-time feedback on the depth and rate of compressions. All steps follow the recommended American Heart Association Guidelines.

iMEMS Inertial Sensor Enables Real-Time CPR Compression Monitoring

Analog Devices' ADXL322 ± 2 g iMEMS accelerometer enables ZOLL Medical to deliver a real-time CPR monitoring device by providing precise sensing and motion monitoring of chest compression activity. Using the AHA and International Liaison Committee on Resuscitation (ILCOR) guidelines for recommended chest compression of just 1.5 inches to 2 inches (3.8 cm to 5.1 cm) depth, the ADXL322 iMEMS accelerometer provides a real-time, precise measurement of the depth of each individual chest compression during CPR, while a metronome beeps to help the rescuer maintain the recommended 100 beats per minute heart rate. It is the ADXL322 accelerometer's motion sensitivity that enables an exact determination of the rescuer’s subtle changes in chest pressure that result in different amounts of chest movement. If there is insufficient compression for effective blood flow, the PocketCPR will audibly and visually prompt the CPR giver to push "harder" to keep blood flowing effectively throughout the body. The device audibly states "good compression" when the pressure is correctly generating at least 1.5" of movement and has a corresponding LED for a visual cue. Four LEDs illuminate when "good compression" is applied and one LED lights to give a visual indication that the displacement is below the medically recommended 1.5 inches. PocketCPR's audible and visual reinforcement features give the rescuer the confidence and support needed for this demanding critical situation.

Compact, Low-Power Device Design

Tightly integrated on a single monolithic IC, the ADXL322 is a complete dual-axis accelerometer with signal conditioned voltage outputs. With 2-mg resolution (at 60 Hz), the small and thin (4 mm × 4 mm × 1.45 mm LFCSP) accelerometer is optimized for critical point-of-care medical devices that need high resolution in an energy-efficient, handheld form factor. For the PocketCPR device, the ADXL322 performs the crucial sensor function to measure the depth and rate of chest wall movement during each compression. The PocketCPR device’s 12-hour, battery-powered operation is supported by the ADXL322 accelerometer's low power consumption of 340 µA at Vs = 2.4 V. The versatile ADXL322 accelerometer is designed to measure both dynamic acceleration (vibration) and static acceleration (gravity), optimizing it for a wide range of applications.

With the ADXL322, accelerometer functionality continues to increase the depth and breadth of a full range of applications. Because of its small footprint, low power consumption and high resolution, the ADXL322 fuels high performance and full-feature designs in a multitude of portable device designs. With continuing improvements in sensitivity, low power and small size in multi-axis devices, iMEMS inertial sensing from Analog Devices is helping system designers implement next generation designs with new capabilities in data entry, menu and display control, power management, situational awareness, and navigation.

Designed with the reliability to assist rescuers in an actual sudden cardiac event, the PocketCPR is also used as a training tool to assist CPR trainers by enabling first-hand practice in a classroom setting. By incorporating Analog Devices' iMEMS technology into their state-of-the art design, ZOLL Medical ensures that trained and untrained CPR technicians have the guidance and confidence they need to save lives at a moment's notice.

iMEMS is a registered trademark of Analog Devices. PocketCPR is a registered trademark of ZOLL Medical Corporation.