Wristwatch detector helps to predict heart attacks

An intriguing new mobile device, claiming to be able to identify incipient heart attacks, has hurtled a major development milestone, according to a study in the journal Heart Rhythm.

The device, called Wriskwatch, is strapped to a patient's wrist, and monitors arterial pulse swelling, John Rickard, co-author of the study, and a physician with the Cleveland Clinic, told MedPage Today. The device immediately detects a lack of pulse or defibrillation, and uses Bluetooth to wirelessly alert an emergency medical system, Rickard explained. Researchers just completed phase I testing on the device, and indicated that while it works, it will need some refining before phase II testing begins later this year.

The study found that the device could successfully detect a lack of pulse, although it did have a false-positive rate of 10 percent.

The unit has a motion sensor, so it should only activate the alert when the patient is sitting still. However, researchers said they're working to get the device to alert only when the patient is actually unconscious. They also plan to build in a live alarm that will beep at the patient, allowing him or her to turn the alarm off before the device calls emergency responders. It's a move they hope will ultimately bring that false positive percentage down.

The device's wristband may need some tweaking, too, according to the study's authors. The device must be strapped on "snugly," but in several cases didn't fit the patient well enough to read his or her pulse; in one case, it actually fell off a patient. The solution may be a simple re-sizable band, or multiple sizes for small, medium and large patients, according to a report by the Sudden Cardiac-Arrest Foundation.

Ultimately, the authors suggest that this type of device should shorten the time between onset of symptoms--which the patient may not even notice--and medical response.

"The primary determinant of survival following out-of-hospital cardiac arrest is time to defibrillation...[even] small delays can have a profound negative impact on outcomes," the authors wrote.

To learn more:
- take a look at the Heart Rhythm journal article
- check out MedPage Today's story
- read the Sudden Cardiac-Arrest Foundations analysis

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