Afferent is well positioned to take advantage of an untapped market. “There are five and a half million stroke survivors in the U.S.; 700,000 new strokes per year,” he says, and “there are no [rehabilitation] devices out there that really work.”But what Hable, Harry, and Collins all stressed to me (again and again and again…) is that the technology has legs beyond stroke rehab. In fact, that application was only barely on the radar screen when the company got off the ground. The first iteration of the technology the team toyed around with was a pair of crazy-looking vibrating insoles, designed to help the elderly balance better and to improve life for people with diabetic peripheral neuropathy.Peripheral neuropathy is a deadening of the nervous system in the extremities, and people who suffer from it are prone to health problems such as infections from cuts on their feet that they can’t feel. By heightening sensation in the feet, the insoles could help prevent that, as well help improve balance by allowing wearers to better detect—and compensate for—the sort of changes in foot pressure that occur when you sway from side to side.The insoles are still around, but Hable says for the moment, they are priority two. (If everything works out, the plan is to get the stroke treatment device to market early next year). However, he thinks that the balance application in particular would have a big market. “Talk to any senior citizen, and you can hear how nervous they are about their balance,” he says. Rather than an insole, though, Hable envisions a pacemaker-like implantable device that would “deliver a constant sensory boost” and reduce the likelihood of falls. And the Afferent website lists still more potential applications, from sports medicine to treatments for incontinence. These guys are casting a wide net.Whatever the application, Afferent has been getting attention. The National Institutes of Health has ponied up grants totaling about $2.5 million through the Small Business Innovation Research program since the company was founded. Afferent’s October 2004 Series A financing round netted $4 million, from sources including New England-based Judith Point Capital, Long River Ventures, and Village Ventures (and, to keep it interesting, the huge Japanese device maker Nitta). In December of 2006, the orthopedic device maker Stryker made an investment, though how much of one Afferent wouldn’t tell me.Presumably, each of these organizations has its own favorite from Afferent’s menu of possible applications. Personally, I’m intrigued by the sports medicine idea—Collins imagines building the technology right into sports equipment to help prevent injuries. I can see the ads now: “Air Jordans—now with stochastic resonance!”