Dressed for medical success

When most people think of wearables, they often think of the obligatory smart watches, fitness monitors and heart rate monitors that are typically worn on the wrist. However, one emerging market is smart clothing for health care — the idea of weaving electronics into a shirt, a blanket, a bandage, a knitted cap or pants to perform specific patient care functions.

E-textiles are designed to feel comfortable on the skin but at the same time be functional. These smart fabrics consist of traditional fabric woven with conductive fibres as well as electronic elements such as biomedical sensors, microcontrollers, fibre optics and wearable antennas.

An example of a biomedical sensor that could be used in e-textile applications is Analog Devices’ AD8232/33 Heart Rate Monitor Front End. It is an integrated signal conditioning block for ECG and other biopotential measurement applications, designed to extract, amplify and filter small biopotential signals in the presence of noisy conditions.

E-textiles may be created, in part, on a typical tabletop sewing machine that embroiders thread into fabric in a pattern via a computer program. Instead of thread, however, metallic fibres from metals such as silver, nickel, carbon, copper, aluminium and stainless steel, like Adafruit’s wearable electronic platforms from Mouser, are used and feel the same as traditional thread to the touch.

Depending on how the conductive fibres are woven in and the electronics included in the smart clothing, the fabric is durable and able to be washed like regular clothing, although some durability issues need to be ironed out before mass commercialisation.

Challenges for smart clothing

With a continued rise in many parts of the world of chronic disease — such as diabetes, heart disease, cancer and respiratory disorders — ageing populations that are living longer and an increase in the number of surgeries performed, e-textile developments are on the rise. In some clinical trials, smart clothing has been shown to protect against infectious disease, help sense the state of the wearer’s health and help prevent, treat and manage health.

However, e-textiles face challenges that must be overcome, including further development in reliability, liability and certification. Regulatory approvals present a challenge for device manufacturers and researchers, as do approvals and certification from insurance companies. Many smart clothing projects will take between three to five years to come to fruition. Many experts see this inflection point happening in the 2020 time frame.

Solving current problems

One area gaining a lot of interest is bedsheet or mattress e-textiles that are integrated with pressure sensors to manage and prevent bed sores by ensuring the patient is moving around. Conditions such as bed sores and incontinence in the elderly cost hospitals and care facilities money and time. Moisture sensors integrated into smart clothes for mapping incontinence in patients could prove to be a very worthwhile investment in the long run.

Clothing+ is working with Jabil to mass produce textile-integrated sensors that meet the necessary FDA requirements for medical-grade solutions. One e-textile idea is a bioimpedance vest, which measures water accumulation in the lungs to indicate heart conditions, and can be worn at home for trend analysis before hospitalisation, saving time and money. Another idea is a chest belt to provide a lung’s performance through a topographic picture of the lungs, and a light therapy blanket for babies with jaundice allowing them to be removed from cradle light therapies and held by parents or loved ones instead.

Edema ApS is developing a washable stocking to measure and monitor changes in leg volume with patients suffering from edema (fluid accumulation or swelling) in the lower limbs. While not yet available for patients, the stocking is being prepped for clinical trials and validation. Future uses of the stocking could be to monitor congestive heart failure or pre-eclampsia, which happens during pregnancy and involves hypertension, edema and protein in the urine.

A wearable, washable stocking that can be worn at home for use in monitoring edema in patients’ legs is moving into the clinical trial and validation phase. Image credit: ©Edema ApS.

Academia leading the way

Among those developing e-textiles for the healthcare market, work being done at the university level offers much promise for the future of patient care technology.

One interesting project is being developed by VTT Technical Research Center of Finland, where researchers have created smart fabric that can be used as clothing or blankets that calculate whether a patient needs to be cooled or warmed based on the initial date measured from the person and the environment. These garments could also be used by surgeons that get too hot during an operation with the clothing adjusting to the temperature of the body during surgery.

Ohio State University’s ElectroScience Laboratory is working towards functional e-textiles that gather, store or transmit digital information by weaving antennas — such as the Intel Edison development platform — into something like a brain cap that senses activity in the brain to help treat conditions such as epilepsy or addiction. The researchers are also working on a smart bandage that tells a doctor how well the tissue beneath it is healing without removing the bandage.

Meanwhile, the University of Bristol is working on soft robotic clothing that could help vulnerable people avoid falls by supporting them while they walk and giving others bionic strength to move between sitting and standing positions or climb stairs.

The smart clothing involves nanoscience, 3D fabrication, electrical stimulation and full-body monitoring technologies. Researchers believe this technology could ultimately lead to potentially freeing wheelchair-bound people from having to use the devices.

Researchers at the University of Bristol are working to integrate soft robotics into clothing to support those vulnerable to falls or have trouble walking up stairs. Image credit: ©University of Bristol.

The future of smart clothing

While many of these academic endeavours are moving forward and are working towards commercialisation, innovations in high-tech fabrics and advances in microelectronics are opening even further possibilities for healthcare-related e-textiles. Some experts see smart clothing completely replacing bedside monitoring in hospitals with shirts that track heart rate, blood pressure, oxygen intake and more. It is clear that e-textiles have a big future in improving healthcare outcomes for patients and practitioners.

Chris Huang* is a reporter for Mouser Electronics. For more information, visit https://au.mouser.com.

Top image: Fibre optics integrated into a blanket or shirt in order to monitor skin circulation to prevent bed sores or monitor heart rates is what researchers at Empa are working on. Image credit: ©Empa.