AutoPulse

AutoPulse

The AutoPulse is an automated, portable, battery-powered cardiopulmonary resuscitation (CPR) device developed by Revivant and subsequently acquired and presently manufactured by ZOLL Medical Corporation. It comprises a constricting band and a half backboard, serving as an adjunct to CPR during advanced cardiac life support administered by professional healthcare providers. Known in literature as LDB-CPR (Load Distributing Band-CPR), the AutoPulse utilizes a distributing band to administer chest compressions.

Before delivering its unique combination of thoracic and cardiac chest compressions, the AutoPulse measures chest size and resistance. Compression depth and force vary depending on the patient, with chest displacement resulting in a 20% reduction in anterior-posterior chest depth. Operating with a physiological duty cycle of 50%, it offers a choice between a 30:2 or continuous compression mode, selectable by the user.

During operation, the patient's head, shoulders, and upper back are positioned on the base unit, with the AutoPulse controls located beside the patient's left ear. The device can be adapted to provide cervical spinal support if needed. Housing the control computer, rechargeable battery, and motors operating the LifeBand, the unit employs an adjustable strap called the LifeBand, covering the entire rib cage. Upon activation, the LifeBand tightens around the chest, gauging chest size and resistance before rhythmically constricting the rib cage, achieving a heart-pumping rate of 80 compressions per minute. Although the LifeBand can be placed over defibrillation pads, it must be briefly loosened for standard paddle defibrillation, then repositioned post-shock delivery. Disposable by design, the LifeBand is intended for single-patient use for hygiene purposes.

The load-distributing band system, incorporating thoracic compressions, generates higher blood flow compared to CPR employing sternal compressions alone. The potential to restore blood flow for a sudden cardiac arrest victim hinges largely on the peak power of the compression, influenced by compression force, depth, and duration at maximum depth.

While automated CPR machines have demonstrated superiority over manual CPR in animal studies, translating this success to human research has been less promising. While some studies observed improved coronary perfusion pressure and more spontaneous return of circulation with the AutoPulse, a large, multicentered, randomized clinical trial was halted prematurely by the Institutional Review Board (IRB). The decision was based on the finding that patients receiving manual CPR were more likely to leave the hospital walking, indicating that further investigation is warranted to determine factors beyond the device's mechanical capabilities that influence its effectiveness.