HOUGHTON — According to one study, more than 90 percent of U.S. medical expenses are spent on patients with chronic diseases. According the Center for Disease Control and Prevention, $190 billion are spent on cardiovascular disease that in many cases, patients are required to wear a heart monitor day and night. For those patients, heart monitoring will soon become easier, more comfortable, and more convenient, thanks to Michigan Technological University Researcher Ye (Sarah) Sun.

Sun, an assistant professor in the Department of Mechanical Engineering-Engineering Mechanics, and adjunct assistant professor of biomedical engineering, has designed a self-powered motion detector that obtains electrocardiogram (ECG) signals which, because it requires no battery, is lighter and captures a stronger signal than conventional ECG devices.

“It’s a motion-powered motion detector, so when we do walking and running, and also sometimes we climb up stairs and go down stairs, and sometimes we track people’s activities every day.”

The ECG is currently the main device used for diagnosis and treatment of heart disease. Compared to Sun’s motion detector, the ECG unit is large and bulky, and not as accurate. The ECG has a weak signal, which can make it less beneficial.

“So, for the things that we do for the project,” said Sun, “we designed a new sensor for the motion detector, and also we developed the associated algorithms to differentiate what that signal is for. For instance, we do running, and also we climb stairs, and the signals are different, and we need to track it automatically.”

In cases of rehabilitating patients, Sun said the patient’s behavior must be known, so the patient’s motions must be known.

“We can provide a platform technology,” she said. “We provide a sensor, and say the sensor can be used for different application scenarios.”

For patients in a hospital, the motion detector can be used in clinical studies. In addition, the device can be used instead of, or with, a Fitbit.

Sun’s device can also obtain ECG signals without electrodes contacting skin, which allows those using the device to avoid allergic reactions or skin irritations. It is also smaller and lighter than conventional ECG units.

“Everybody can have it, and for the sensor, its uniqueness is it’s self-powered,” Sun explained. “It’s powered by the motion itself, so it’s not necessary to have a large battery to give it power.”

Sun said she hopes the motion detector will be available to the public within two years.

“We hope that we can really make it as a mature device,” said Sun. “We need more subjects to test in different environmental settings, in the clinic, and other scenarios, and finally we can come up with a general device that can be modified for different purposes.”

The machine obtains raw data, which by itself tells very little. However, with the associated algorithms, the device itself can determine what the patient’s movements consist of.

“So the device itself can provide this type of information medically, because of the algorithms in the device,” Sun said.