Implantable medical device is designed to warn patients of impending heart attack

April 13, 2012

More than 30% of the one million heart attack victims in the United States each year die before seeking medical attention. Although widespread education campaigns describe the warning signs of a heart attack, the average time from the onset of symptoms to arrival at the hospital has remained at 3 hours for more than 10 years. In their upcoming Ergonomics in Design article, "'This is your heart speaking. Call 911,'" authors Mary Carol Day and Christopher Young study the benefits of the AngelMed Guardian®, an implantable medical device currently undergoing clinical trials that alerts users about a potential heart attack through a combination of vibrations, audible tones, and visual warnings.

What makes the device distinctive is this combination of alert modes. Although vibrotactile (vibrating) alarms are sometimes used to warn medical personnel in operating rooms or ICUs of an emergency, very little research has focused on their potential as a self-monitoring device for patients. Auditory alarms are provided with selected implantable heart defibrillators, but research indicates that some patients -- particularly the elderly -- are unable to hear the alarms.

"A vibrotactile alarm provided by the implanted device has two major advantages," says Day. "First, the implanted device can't be left behind like a portable device. Second, a vibrotactile alarm from the implanted device is more likely to be felt than an auditory alarm is to be heard because, for example, the patient may be wearing heavy clothing, has hearing loss, or is in a noisy environment."

The device offers two levels of alarm urgency: A high-priority alarm indicates that the patient may be having a and should call , and a low-priority alarms indicates that a condition has been detected that requires a doctor visit within 48 hours. The alarms are provided by an implanted , similar in size to a pacemaker, that is placed in the upper left chest, plus an external device, similar to a pager, that emits an auditory alarm and flashes a red or yellow warning light.

In a series of studies with older adults designed to test the device's design and user-friendliness, participants were able to tell the difference between the low-priority and high-priority vibration patterns and respond appropriately. They also reported that they liked the vibrating alarms and the redundancy of the auditory, visual, and vibrotactile warnings.

"If the Guardian is approved for sale by the FDA," continues Day, "it might be extended in ways that will change the way the patient interacts with the system as a whole. This would require more research and simulated-use studies to refine and validate the new interactions between the patient and the system."

Explore further: New patient guidelines for heart devices

Related Stories

New patient guidelines for heart devices

April 17, 2011

A series of new guidelines for cardiac specialists has been developed to determine when heart failure patients should receive a mechanical heart-pumping device.

A 'guardian angel' to watch over your heart

April 26, 2011

When a heart attack begins, a stopwatch starts. With each passing minute heart tissue is deprived of blood, causing it to deteriorate or die. In order to minimize damage to the heart, blood flow must be restored promptly, ...

Recommended for you

Artificial heart design features porous plastic foam

October 2, 2015

Artificial hearts with multiple moving parts increase the chance of failure; scientists have worked up a device which is a single piece. No less interesting is the material they used; the team is taking a page out of soft ...

What powers the pumping heart?

September 25, 2015

Researchers at the Ted Rogers Centre for Heart Research have uncovered a treasure trove of proteins, which hold answers about how our heart pumps—a phenomenon known as contractility.

Sticky gel helps stem cells heal rat hearts

September 24, 2015

A sticky, protein-rich gel created by Johns Hopkins researchers appears to help stem cells stay on or in rat hearts and restore their metabolism after transplantation, improving cardiac function after simulated heart attacks, ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.