Many of us will have seen the various active assistive devices which have appeared over the last few years to help people with a hand tremor. Probably the best known was a fork with a set of servos and an accelerometer, that kept the end of the utensil steady despite the owner’s hand movements. It’s a field which has the potential to help many people, but it’s undeniable that such technology comes with a cost.
What if the same effect could be achieved passively, without all those electronics? It’s something [Jacob] is investigating with his mechanical anti-tremor cup handle. It’s a university project completed as part of his studies so it’s very much a work-in-progress which if we’re being fair isn’t quite there yet, but we think the potential in this idea of bringing a useful assistive device at least bears further attention.
The write-up is available as a Norwegian PDF file so takes a little bit of Google Translate cut and pasting for an Anglophone. Sadly due to what must be report format requirements set by the university it’s long on procedure and shorter on engineering calculations than we’d like, but there’s an attempt to calculate the properties of the helical springs in each of the joints to match the likely forces. Our intuition is that the design as shown would require significantly more mass on the end of it than that of the mug and beverage alone to achieve some form of stability, but despite that as we said it’s an interesting enough idea that it deserves more thought.
Hand tremor assistive devices have appeared more than once on these pages before, here’s one for soldering that enlists the aid of a camera gimbal.
I once read about a design study in which a concept for a drinking cup for Parkinson’s patients was presented. Small breakwaters were integrated into the cup, like on the coast. When the patient had a tremor, the water in the cup was calmed by the breakwaters. I think the science is called gerontology. Gerontology will be the new big market in an aging society.
Nice a gimbal with springs! I will try this with a Gopro, maybe with my smartphone too.
Maybe as a Soldering Iron holder aid for really really small parts.
Or placing Dominos…
Soldering iron, bomb defusing, and brain surgery too!
If someone wants to read the original PDF I can recommend ‘deepl.com’ for translation.
Or learning Norwegian :p (sorry)
Norwegian is notoriously hard to learn. Not because it’s complicated, but good luck finding a Norwegian who doesn’t want to practice their English.
Or a Swede who doesn’t like fish.
I can agree to that, took me quite some time even living here and the daily practice is still low
This is Finnish, but not the End!
:-D
I have fairly shaky hands, though fortunately not to the point where I’d need something on this level for everyday tasks. But there are cases (drawing, soldering) where I’d consider a mechanical aid if it was super-easy to deploy. I’d be interested to know if anyone had experimented with using resistance to control tremors – like, so you have to pull against a bungie cord while holding a pen.
Single-purpose devices like the OP are obviously good for people with disabling severe tremor, but you’re talking about a whole house set up with such devices. There’s also a place for simpler, more versatile devices you can carry in a pocket; even if they don’t help as much, they could help in a lot more situations.
Maybe this palm rest will help you when you want to draw.
https://en.wikipedia.org/wiki/Maulstick
‘The painter could then rest his brush-guiding hand on the stick if he wanted to paint particularly fine contours and needed a particularly steady hand for this.’
Back in product design class we had learned drawing exercises to adjust our hand eye coordination. Something like drawing gymnastic before we sketch. And after the sketch, the fine drawing.
I started with a square and kept drawing small squares inside the square. The same goes with circles. it’s just to warm up, but it helps.
When I paint on the easel, I use an exercise from bodybuilding. If you are new to weight training it is important 6 months only on machine, just to learn the clean execution of the exercise and so avoid injury later. The movement sequence and the nerves in the brain must first be formed. And a trick to accelerate this is to lift a very heavy weight once at the beginning and then back to the normal weights. It stimulates the nerve like a beacon. On the canvas i take a small weight plate and hold it like a piece of calk and draw the lines in my mind. Remenber the weight or resistance is just to wake up your nerves and adjust your hand and eye. And than i start painting with a brush.
But something really interesting is the Adeli suit, it is a custom made resistance band suit. The resistance forces you to concentrate only on the motion. maybe its time for a diy version. :-)
https://en.wikipedia.org/wiki/Adeli_suit
hope this little inside helps.
Rather than adding one or more spring resistances, viscous damping would probably be better. I’m thinking a pantograph with a rod suspended in a container of something viscous as the “follower”. Either the size of the rod, the viscosity of the liquid, or the ratio of the pantograph can be used to tune the damping.
Instead of the maulstick, hang a rubber band from left to right like a hamok so your hand can rest on and it is not stiff. An easy way to dampen motion.
I personally use very old, but well made beanbag (these for cameras) as a handrest when i use my tablet on the desk. I write my notes and my stylus/writing hand goes back on the beanbag. Also i like to draw with it, when my hand is little higher than the tablet. And when my hand, rest on the beanbag can draw much finer details.
One issue that will probably rear its head with this will be the need to vary the damping (and potentially spring force) as the weight changes. You have to tune a system like this to a specific weight and if that weight changes, it will no longer be critically damped which introduces oscillations or reacts too slowly.
Looking forward to see where the project goes.
I’ve been trying to make some similar stuff for my mom. A big problem with passive systems relying on mass and damping is that it’s heavy and elderly people struggle to hold heavy things up for any length of time, which is why I think active systems have a lot of advantages.
I tried a variety of different ideas. What seemed to help me most was pushing my elbows tight to my side.
My essential tremor was well controlled with medication until about a year ago. Last Fall, I chose to pursue DBS. It has been amazing! My tremor is gone and I don’t need to take any medications.