The invention, which improves upon a bulkier wearable defibrillator system that is already in use, should help persuade heart patients at risk for sudden cardiac arrest to wear the shirt around the clock, Medical Xpress reports.

 

"In two studies, up to 20 percent of patients who received the defibrillator garment that's already available did not keep it on all the time because of comfort and appearance issues, problems sleeping in it, and frequent 'maintenance alarms,' which occur when the device does not get a good signal from sensors on the patient's skin," said Sandya Subramanian, a Johns Hopkins junior who led the team that built the new shirt.

Alert: The 2 Warning Signs of Sudden Cardiac Death
 

"For our class project, we set out to address these issues and design a device that heart patients would be more likely to wear for longer periods of time — because their lives may depend on it."
 

Wearable defibrillators, resting against the skin, can detect arrhythmia — an irregular heart rhythm that can cause death in minutes if it is not stopped by controlled jolts of electricity. People who have undergone open-heart surgery and those who have recently survived a heart attack face higher risks for arrhythmia.
 

The long-term treatment for such patients is to surgically implant a small defibrillator in the chest, similar to a pacemaker. But such operations cost roughly $150,000 and can take three months of testing and insurance review to get approval. During this waiting period, insurance providers usually pay for the rental of an external defibrillator garment and more than 100,000 of these devices have been prescribed in the United States during the last eight years.
 

The Johns Hopkins student team aimed to develop a shirt that would be easier to use and wear.
 

The new shirt replaces the chest harness-style garment now in use with a more comfortable vest-like design made of thin, breathable, and stretchable fabric, which also is waterproof for easy cleaning. It can be worn beneath a patient's clothing and its electrical components — encased in thin pockets on the sides of the garment — can deliver a shock to stop a deadly arrhythmia.
 

The students have completed preliminary testing of the shirt at the Johns Hopkins Hospital Simulation Center, and now plan to refine the prototype and confer with medical device makers about advancing the project.