Navigation Links
Stanford engineers monitor heart health using paper-thin flexible 'skin'
Date:5/16/2013

Most of us don't ponder our pulses outside of the gym. But doctors use the human pulse as a diagnostic tool to monitor heart health.

Zhenan Bao, a professor of chemical engineering at Stanford, has developed a heart monitor thinner than a dollar bill and no wider than a postage stamp. The flexible skin-like monitor, worn under an adhesive bandage on the wrist, is sensitive enough to help doctors detect stiff arteries and cardiovascular problems.

The devices could one day be used to continuously track heart health and provide doctors a safer method of measuring a key vital sign for newborn and other high-risk surgery patients.

"The pulse is related to the condition of the artery and the condition of the heart," said Bao, whose lab develops artificial skin-like materials. "The better the sensor, the better doctors can catch problems before they develop."

Your pulse

To find your pulse, press your index and middle finger into the underside of your opposite wrist. You should feel the steady rhythm of your heart as it pumps blood through your veins.

Each beat you feel is actually made up of two distinct peaks, even though you can't tell them apart with just your fingers. The first, larger peak is from your heart pumping out blood. Shortly after a heartbeat, your lower body sends a reflecting wave back to your artery system, creating a smaller second peak.

The relative sizes of these two peaks can be used by medical experts to measure your heart's health.

"You can use the ratio of the two peaks to determine the stiffness of the artery, for example," said Gregor Schwartz, a post-doctoral fellow and a physicist for the project. "If there is a change in the heart's condition, the wave pattern will change. Fortunately, when I tested this on myself, my heart looked fine."

Petite pyramids

To make the heart monitor both sensitive and small, Bao's team uses a thin middle layer of rubber covered with tiny pyramid bumps. Each mold-made pyramid is only a few microns across smaller than a human red blood cell.

When pressure is put on the device, the pyramids deform slightly, changing the size of the gap between the two halves of the device. This change in separation causes a measurable change in the electromagnetic field and the current flow in the device.

The more pressure placed on the monitor, the more the pyramids deform and the larger the change in the electromagnetic field. Using many of these sensors on a prosthetic limb could act like an electronic skin, creating an artificial sense of touch.

When the sensor is placed on someone's wrist using an adhesive bandage, the sensor can measure that person's pulse wave as it reverberates through the body.

The device is so sensitive that it can detect more than just the two peaks of a pulse wave. When engineers looked at the wave drawn by their device, they noticed small bumps in the tail of the pulse wave invisible to conventional sensors. Bao said she believes these fluctuations could potentially be used for more detailed diagnostics in the future.

Blood pressure and babies

Doctors already use similar, albeit much bulkier, sensors to keep track of a patient's heart health during surgery or when taking a new medication. But in the future Bao's device could help keep track of another vital sign.

"In theory, this kind of sensor can be used to measure blood pressure," said Schwartz. "Once you have it calibrated, you can use the signal of your pulse to calculate your blood pressure."

This non-invasive method of monitoring heart health could replace devices inserted directly into an artery, called intravascular catheters. These catheters create a high risk of infection, making them impractical for newborns and high-risk patients. Thus, an external monitor like Bao's could provide doctors a safer way to gather information about the heart, especially during infant surgeries.

Bao's team is working with other Stanford researchers to make the device completely wireless. Using wireless communication, doctors could receive a patient's minute-by-minute heart status via cell phone, all thanks to a device as thick as a human hair.

"For some patients with a potential heart disease, wearing a bandage would allow them to constantly measure their heart's condition," Bao said. "This could be done without interfering with their daily life at all, since it really just requires wearing a small bandage."


'/>"/>

Contact: Bjorn Carey
bccarey@stanford.edu
650-725-1944
Stanford University
Source:Eurekalert

Related biology news :

1. Stanford scientists develop gene therapy approach to grow blood vessels in ischemic limbs
2. Keck award enables Carnegie Mellon and Stanford to dramatically expand crowdsourced RNA design
3. Climate change may create price volatility in the corn market, say Stanford and Purdue researchers
4. Stanford and MIT scientists win Perl-UNC Neuroscience prize
5. Americas clean energy policies need a reality check, say Stanford researchers
6. Support for climate change action drops, Stanford poll finds
7. Stanford scientists document fragile land-sea ecological chain
8. Stanford researchers help predict the oceans of the future with a mini-lab
9. Stanford marine biologist Barbara Block wins Rolex Award for Enterprise
10. Stanford scientists find molecule to starve lung cancer and improve ventilator recovery
11. Stanford researchers calculate global health impacts of the Fukushima nuclear disaster
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/26/2016)... India and LONDON ... Infosys Finacle, part of EdgeVerve Systems, a product ... and Onegini today announced a partnership to integrate ... solutions.      (Logo: http://photos.prnewswire.com/prnh/20151104/283829LOGO ... to provide their customers enhanced security to access ...
(Date:4/15/2016)... , April 15, 2016  A new ... make more accurate underwriting decisions in a fraction ... timely, competitively priced and high-value life insurance policies ... screenings. With Force Diagnostics, rapid testing ... lifestyle data readings (blood pressure, weight, pulse, BMI, ...
(Date:4/13/2016)... CHICAGO , April 13, 2016  IMPOWER physicians ... are setting a new clinical standard in telehealth ... By leveraging the higi platform, IMPOWER patients can ... weight, pulse and body mass index, and, when they ... quick and convenient visit to a local retail location ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... , June 27, 2016 /PRNewswire/ - BIOREM Inc. (TSX-V: ... been advised by its major shareholders, Clean Technology Fund ... United States based venture capital funds ... of Biorem (on a fully diluted, as converted basis), ... disposition of their entire equity holdings in Biorem to ...
(Date:6/27/2016)... ... 27, 2016 , ... Cancer experts from Austria, Hungary, Switzerland, ... a new and helpful biomarker for malignant pleural mesothelioma. Surviving Mesothelioma has just ... now. , Biomarkers are components in the blood, tissue or body fluids ...
(Date:6/27/2016)... , ... June 27, 2016 , ... ... bring innovative medical technologies, services and solutions to the healthcare market. The company's ... of various distribution, manufacturing, sales and marketing strategies that are necessary to help ...
(Date:6/27/2016)... 2016  Liquid Biotech USA ... a Sponsored Research Agreement with The University of ... from cancer patients.  The funding will be used ... with clinical outcomes in cancer patients undergoing a ... be employed to support the design of a ...
Breaking Biology Technology: