Marc Fairman, who was in his late 30s when he was diagnosed with type 1 diabetes, developed diabetic peripheral neuropathy about 15 years ago. The condition, which affects between 60 and 70% of individuals who have diabetes, can cause pain, tingling, or numbness in the toes, ankles, and legs, and very occasionally in the fingers. On numerous occasions in the years that followed, the 72-year-old retired engineer got painful foot ulcers that kept him bedridden for weeks at a time.
“I have no sensation in my feet, so didn’t even realize when I stepped on a paper clip and it went through my toe,” Fairman says. “Another time, an infection spread in my foot and I had to have that foot opened up. It was a 16-month long recovery time.”
But since Fairman, who lives in Northern California, began wearing a pair of the new Siren Diabetic Socks a few months ago, his feet are healthy. Each sock, made of Siren’s NeurofabricTM is embedded with six sensors that enable continuous monitoring. Whenever an area of the bottom of his foot becomes warmer than it should be, Fairman gets an alert on his phone (the data is also sent to the Siren Hub which is included as part of the system so you can get the information if you don't have a smartphone.)
Fairman says the socks, which look and feel like ordinary socks have been “a lifesaver.” “I had one alert,” he says. “I stayed off my foot for a day and it was a normal temperature the next day.”
The Siren Diabetic Socks monitor foot temperature continually, and if a certain area of the foot becomes four degrees warmer than the same spot on the opposite foot, the alert is sent to the user. A rising temperature signals inflammation, which can be the precursor to diabetic foot ulcers.
The fact that someone’s foot becomes warmer during inflammation is not new knowledge and occurs when the body is fighting injury or disease, says Alexander Reyzelman, DPM, co-director of the UCSF Center for Limb Preservation, associate professor at the California School of Podiatric Medicine in the Bay Area and a Siren Sock advisor. “We have known this for awhile, but until now we have not had a wearable sock that could detect these temperature increases,” Dr. Reyzelman says.
The socks look like any other socks and come in various colors. “It feels like any other sock,” Fairman says. “When you run your fingers over the sock, you don’t feel any of the wiring in the fabric.” The sensors are embedded directly into the fabric, and the socks are machine-washable and dryable. The socks are seamless, non-binding, and moisture-wicking; it’s recommended that they be worn all day.
Monitoring the temperature of the bottom of your feet is up to 87.5% more effective at preventing foot ulcers than standard foot care, says Ran Ma, the biomedical engineer who developed the Siren sock technology. Since the average cost of treating a foot ulcer is $24,000 and an amputation costs more than $100,000, the socks make great economic sense, she says.
Ms. Ma formerly worked in the wound lab at Northwestern University as a biomedical engineer. While there, she saw a lot of diabetic foot ulcers. “This really stuck with me,” she says. “I found out that temperature monitoring could be effective in reducing diabetic foot ulcers, and I also knew that there were no tools that people could use at home to detect this.”
Three years ago, she founded Siren and recruited a team. “I was determined to come up with a device that you could use at home,” she says. “You can’t go to a podiatrist every single day but you could get an injury to your foot every single day.”
For individuals with peripheral neuropathy, the Siren socks are an amazing invention. Fairman, for instance, had struggled with the condition for some time. In 2013, he developed a small ulcer on his foot, for which he was prescribed antibiotics. When the foot was x-rayed, doctors saw a small fracture. Three weeks later, his foot was swollen and painful. He needed an operation in which a plate was inserted into the foot and he was bedridden for nearly six months. Then a subsequent surgery took 14 months to heal. “I was able to walk during part of that time because the foot wasn’t broken, it was healing from the incision,” Fairman says. “But all of this could have been prevented if I’d had this sock.”
Can these new Siren socks actually reverse diabetic neuropathy in patients? “This is a prevention mechanism,” Dr. Reyzelman says. “They don’t do anything to reverse the neuropathy. They are an alert system to the patient to detect a problem early and, if needed, have an intervention by their treating physician.” The physician may order special footwear or braces, or maybe just tell the person to stay off their feet, he says.
Frequent visits to the doctor are important for an individual with peripheral neuropathy, Dr. Reyzelman says. “We would like to see them before the tissue injury occurs, not after it develops,” he says. “It is much harder to treat a foot ulcer than to prevent it.”
The Siren Diabetic Sock and Foot Monitoring System are only available online. At a cost of $19.95 per month, Siren will ship five new pairs of socks to the user every six months. The user will also receive continuous monitoring, alerts, and reports as part of the system. For more information, visit siren care.