Medical Devices & Technology Archive

Atrial fibrillation can be dangerous from a fast heart rate and a higher stroke risk

Is atrial fibrillation serious? People who are old enough to remember the sound of wind-up clocks often refer to their hearts as their "tickers." It's an affectionate term that pays tribute to the regular, rhythmic beat of the healthy heart. In fact, though, the healthy heart is much more sophisticated than the most precise Swiss timepiece.

Instead of maintaining a single, monotonous beat, the heart can speed up in response to exercise, strong emotions, and fever. Common chemicals can also jack up the heart rate; examples include caffeine, nicotine, and decongestants. And the healthy heart can also slow down when you rest, relax, or sleep.

Studies of drugs, diets, and devices all come with their own unique set of challenges.

The best way to know if a new medical treatment truly works is with a randomized controlled trial — the "gold standard" of research studies, also known simply as a clinical trial. Volunteers are randomly assigned to receive either the new treatment or the comparison, which may be a placebo (an inactive therapy) or a treatment that's already available.

As the nation's top cause of death, cardiovascular disease has been at the leading edge of evidence generation, says Dr. Robert Yeh, director of the Smith Center for Outcomes Research in Cardiology at Harvard-affiliated Beth Israel Deaconess Medical Center. "We probably have more evidence for cardiovascular treatments than for any other field of medicine," he says. Among the studies with the greatest impact were the clinical trials that heralded new therapies to treat heart attacks. These include clot-dissolving drugs in the 1980s, followed in the 1990s by artery-opening angioplasty procedures, which remain the standard of care today. Stents, the tiny mesh tubes used in these procedures, have also been extensively studied in clinical trials (see "Testing devices: Different dilemmas").

On call

Q. Exercise guidelines recommend a certain number of hours per week, depending on whether it's moderate or vigorous intensity. So how do I measure exercise intensity?

A. Outside of a physiology laboratory, there really is no standard agreement on how people should gauge their level of exercise intensity.

Research we're watching

Most home blood pressure monitors sold in Australia are not carefully tested for accuracy, according to a study published online April 10, 2020, by the journal Hypertension.

Because more than 90% of the devices the researchers studied were purchased from international online platforms such as Amazon and eBay, that means many devices purchased in the United States and elsewhere might give inaccurate readings, the authors say.

Learn about a device's pros and cons so you're not stranded.

John was in trouble: The 84-year-old wound up on the floor after sliding out of a chair. While unhurt, John couldn't get up. He lived alone and couldn't reach his cellphone, house phone, or alert button; all were on a table next to his chair. After three long hours trying to inch across the floor, John remembered that his "smart" speaker (activated by voice commands) was connected to his smartphone. John called out for the speaker to dial his daughter, who sent help right away.

Electronic gadgets like smart speakers can be a great addition to the home.  But a smart speaker won't save the day in every emergency. Before investing in a gadget for security, learn about its potential limitations.

Research we're watching

Smart watches and wrist-worn fitness trackers that estimate your heart rate appear to be reliable in people with a range of different skin tones. But their accuracy may vary during different types of everyday activities, a new study finds.

Researchers recruited 53 people with different skin tones to test six different devices, which work by measuring changes in blood flow through the skin using a special sensor. The volunteers also wore electrocardiogram patches (which provide a gold-standard heart rate measurement) while they did different activities: sitting still, breathing deeply, walking, and typing.

Here's what a heart rate monitor might do for you.

All kinds of high-tech exercise gadgets are available nowadays, from activity trackers to Apple Watches. However, one of the oldest technologies is still quite valuable: the simple heart rate monitor.

"For some people, a heart rate monitor is the ideal fitness tool to help them stay in tune with their body, so they can exercise better, smarter, and safer," says Dr. Meagan Wasfy, a cardiologist with Harvard-affiliated Massachusetts General Hospital.

Do a thorough assessment to make sure equipment is safe.

Your doctor or an occupational therapist may recommend that you use some kind of medical equipment, such as a walker, electric scooter, cane, lift chair, or shower chair. Such equipment can help you maintain your independence or continue living at home. But what if your insurance won't pay for an item or if you need a spare? For many people, the solution is gently used equipment.

Bargain hunting

You'll find used medical equipment in consignment shops and thrift stores, and through online classified ad sites (such as Craigslist). The deals are substantial: you may find a used electric wheelchair (that retails for $2,500 new) for a few hundred dollars, or a used power lift chair ($500 new) for just $75.

News briefs

A research team from Harvard reports that it has harnessed the powerful gene editing tool called CRISPR to recognize and kill viruses. The findings were published online Oct. 2, 2019, by Molecular Cell. CRISPR can alter strands of both DNA and RNA (a molecule related to DNA), which are built like strings of beads. Each bead consists of one of four chemicals called bases. CRISPR can recognize a specific sequence of bases (such as one that is characteristic of a particular virus), latch on to that sequence and cut it, and change the sequence to a different one. This can scramble the genetic sequence of a virus in such a way that the virus no longer can make copies of itself. The Harvard team used this technique to kill several viruses that are made of RNA — including influenza virus — in a laboratory dish. The next step will be to see if the CRISPR technique can also be used to kill viruses in a living animal. That will be much harder. However, if it works, the technique might someday help humans fight viral infections.

Image: © Bill Oxford/Getty Images

If you’re like most people with hearing loss, you’ll probably find that it takes time to accept the idea that you need a hearing aid, and you may be unhappy when your audiologist recommends that you get not one, but two. Chances are that your first question will be, “Is it normal to get two hearing aids?” And then, “Do I really need two?”

If you have hearing loss in only one ear and normal or nearly normal hearing in the other, then one hearing aid is all you need. But most people have hearing loss in both ears, especially if the loss is age-related. (You may have one ear that’s better than the other, but chances are both will be in the same ballpark.) In that case, research and experience suggest that you’ll ultimately be more satis­fied with two hearing aids.