CENTRUM FÖR MEDICINSK TEKNIK OCH FYSIK

Smart clothes for the heart

Heart frequency is usually measured using electrocardiogram (ECG) where electrodes are taped to the body. But arrhythmia, or disorders in the heart rhythm, often occurs very irregularly which makes it hard to measure. In Umeå, an ongoing project is developing so called “smart clothes” to facilitate the measurements. The clothes have interactive sensors and are able to measure for example heart frequency and body temperature.

The project is directed mainly to patients who are in their homes but still need to be under medical surveillance. Urban Wiklund conducts scientific research at Umeå University and is in charge of the project. He talks about the difficulties with the methods used for heart monitoring today.
“Walking around with several electrodes taped to your body and also control the device they are connected to is very impractical, especially for children, who sometimes also are allergic to the glue” he says.
“Also, these ECG-equipments are sensitive and the measurements can be affected by things like signals from electrical appliances, other muscles in the body getting tense or the electrodes not being connected right.”

The solution that Wiklund and his crew are working on, is clothing where the electrodes are imbedded in the fabric. And it is no regular t-shirt, but advanced technology.
“The clothes must be tight in order for it to work” he says, “and it will take several electrodes, in form of bulgy points, integrated in the clothes to increase the precision of the measurements.”
That is another part of the project, to further develop the advanced method for analysis needed to interpret the large numbers of measured values received from the different electrodes. Urban Wiklund shows the mathematical filter, a so called multi channel ECG, that interprets information from several points of measurement to be able to screen out disturbing signals and identify the heart beats.

The idea is for the clothes to primarily work as monitors and collect data which is then analyzed by a doctor. Next step would be to develop a web based system for surveillance via the internet or a mobile phone. In theory, the technique could also, in the future, be used to warn patients before problems occur, but Wiklund is restrictively positive to such a development.
“Of course it would be ideal to be able to detect the warning signals before they become serious problems” he says, “but at the same time there is a danger in automatic alarm systems since they can react on the wrong things and get people all worried for no reason.”
In the first stage of the product, the smart clothes will therefore be ordained by a doctor who will also do all the analysing of the measured values.  

As the project is cooperating with different actors, like the Swedish School of Textiles in Borås, it is hard to say when the smart clothes will be available on the market. Today, there are prototypes used to test the technique, but there are still practical details like how to wash the clothes and more studies of the technology used, that need to be taken care of. However, the interest from the market is big and many companies are interested in the smart clothes.  

The project, which is partially financed by the EU’s structural fond, is also working on methods to integrate the measurements of heart frequency, blood pressure and respiration to be able to give more accurate diagnoses to people with problems concerning the autonomous nervous system.
“The respiration, for example, affects many other things in the body” Wiklund explains, “and sometimes it is hard to know exactly where the problem is, but by looking at more factors we increase the chances of finding the real reason.”
This part of the project has also received additional funding from the Swedish Research Council and Wiklund therefore has every reason to be positive about the future.