One of the challenges faced by people with Parkinson's disease is the possibility of "freezing" during normal movement, causing falls and lack of mobility. Surprisingly, small external cues can help them escape freezes or avoid them altogether — and De Oro has raised $2.8 million to commercialize its NexStride portable gadget, which provides those cues on demand.

The simplest way to understand freezing is that the normal pathway in the brain for your body turning the impulse "walk forward" into actual movement doesn't activate correctly. This can lead to slow or stopped movement despite willing one's limbs to move the way they normally do.

Studies have found a surprisingly effective technique for preventing this: cueing. When a person sees or hears an external cue associated with moving forwards, it activates a different pathway for walking forward, breaking the person out of the frozen state.

De Oro's device provides two such cues. One is a little metronome-like ding that makes the brain think about moving in time with it rather than going step by step. The second is a laser-projected line just ahead of the user's feet that seems to activate the idea of stepping over or past something rather than just "forward."

The NexStride attaches to a walker or cane using a little stretchy loop like a bike headlight, with a corded controller that can be put somewhere convenient for the user. Hardware dials on the main unit let them control the volume and tempo of the metronome, and the position of the laser line.

There's plenty of studies about the efficacy of this approach in the lab, and the company has polled its customers, finding a large majority were able to get around more confidently and with less fear. Clinicians they've worked with recommend the device to clients as well as a convenient catch-all way to improve mobility.

Walter and Richard both found the device very useful in getting around on their own terms. Image Credits: De Oro