The sequel to my questions post
Mk3 nearly finished - but in use last night and now. Just the individual finger cables to be stitched in today. Many Thanks to all who have helped me. Especially Colin. Mk4 can wait till we get back from our 2 week holiday
The travelling kit
Answers - background
Kanwar Bhutani is probably the celebrity draw that gets us all interested in this. We want the gloves because of the change they made to his life, and the various videos demonstrating that
Kanwar visited the Tass clinic on 17 June 2018 (5 years ago)
After 4 hours treatment at the clinic he achieved a substantial improvement
Although it may have changed since, for that much broadcast first visit improvement, he was using the old glove, not the new "racing car" glove, and RCR with no jitter
Answers
1) I can measure to an accuracy of +-5 microns. Peter Tass reduced amplitude was 60 microns (0.06mm) to 100 microns (0.1mm). Aiming at 80 microns I would be in the range 75-85. Close enough for jazz
2) Official , Stanford trials are waiting for a patent filing. In the twitchy women presentation Dr Tass mentioned June. It looks like it will be "autumn". Initial trials will test the new racing glove features. Dr Tass expects to have news of a timeline to authorisation early in the new year (2024). That will involve trials of at least 4 months. Probably authorisation and general availability no sooner than end 2025, beginning 2026. There may be an opportunity for some US members to participate in trials before then
3) The trials for FDA approval will include a sham. If the sham is obvious - then its not much use as a sham. If it's not obvious, then it is possible DIY glove makers are delivering the placebo. Pat Riddle and Manypony seem to feel the sham is easily detected.
4) Peter Tass advised against DIY construction although he appreciates the impatience. He cautioned that devices using electrical stimuli might be dangerous. His published papers have stated that certain scenarios can increase and reinforce synchronisation. I remain grateful to friends with a proper understanding of the maths that Dr Tass uses for their advice and guidance. I think , if I am going to "have a go", I want to play as safe as possible by copying as many of the details of the existing Stanford glove and software as possible. Imitation, not innovation.
5) To the question "when will it be available"? - looking at the amount of time research has been ongoing, progress since 2018, Dr Tass' indication of their approach, and experience with PD treatments, the answer is "not for at least 2 years" - especially for those in Europe. People in the USA may be able to get on a trial before then. For a treatment which may slow progress, if with careful consideration and expert advice, it is possible to build a glove and use it now, rather than wait 2 years, I feel it is worth at least exploring
6) "How much"? Affordable. The component cost of the old system probably would have meant a retail of $5000 or more. The racing car version which Stanford plan to release instead? We'll have to wait and see, but not necessarily more expensive if they have a good engineering partner and are looking at huge global volumes.
New question - what are the secret enhancements and how important are they? My guess at an answer to follow
Very helpful summary of the specific points that matter for the DIY Glove Community!
Just a brief comment on pt. (4), i.e. features where it may be safe (or perhaps even beneficial?) to deviate from the current Stanford protocol.
In his recent NoSilverBullet presentation, Peter Tass indicated that the 4-finger-stimulation setup of the original glove was not due to fundamental considerations, but initial technical limitations (availability of amplifier channels, etc.), so setups that involve 5 fingers, or generally not just focus on stimulating digits 2-5 of a hand, may also be ok.
He also stated that it may be ok to stimulate just one hand (on the more affected side) for an effect.
In that context, it may be unlikely that the mirrored vs. non-mirrored setting of left- vs. right-hand stimulation really matters. Personally, I think that it may be more beneficial to use a non-mirrored setting here, for better desynchronization, but that remains to be more systematically tested.
How much does the concrete stimulation frequency of 250Hz matter? Tass and colleagues have indicated that they are specifically targeting the Pacinian corpuscles with the stimulation, so I like to think that other frequencies (such as 170Hz of the bHaptics gloves) are also ok as long as they also mainly excite the PC. (But that may be wishful thinking, as I am using the bHaptics at the moment.) I realise that this question is linked to point (1) of the stimulation amplitude or intensity.
Generally I agree: Imitation not Innovation - but some Variation may be allowed within reason.
Ah - good points. I was about to cover some of them in my answer to my own question about what the racing car version would include, and the day job got in the way. So
If you wear the gloves you realise why the thumb is left out. I think the 8 channel amp was a bit of a red herring. In his papers he emphasises that a minimum of 3 stimulation points are needed to produce desynchronisation. 4 is plenty
I think one "new feature", certainly something he will be testing is using one glove only
I think he may be looking at contact points away from the finger tip, to leave the finger tips free to do other tasks. Not the feet! But the middle finger section
I think he may be looking at frequency variation - ie not 250Hz. But f(burst) is related to f(CR) which in turn is the frequency for stimulation patterns, and I prefer to leave well alone for now - not least because of the background point. If it was good enough for Kanwar, it's good enough for me for now
I think he may be looking at initial skin indentation adjustment on the new gloves. Currently I achieve that by "shimming" under the exciter, but if he has the engineering resources I'm sure he can do that more elegantly. It's a complex area where customisation may be important - but it's not simple. I am working on the "light as possible" principle, rather than crunching the numbers. The skin tension, finger mass, exciter compliance, and exciter mass form a coupled oscillator - and I know enough from my HiFi learning that - ...they're best left to the mathematicians. I am pretty sure my current exciters are a wee bit more compliant than a C2 , never mind his custom variant. The Mk4 glove exciter is a bit more compliant than that. All of us will have different skin tensions. So the ability to adjust, enables a custom solution
Related to the previous point he may have an amplitude adjustment facility. Currently my amplifier has individual volume controls for each channel. It's limitation is that I can't adjust the left and right hands independently. If I increase the signal amplitude to the index finger, it is for both hands at the same time. This is an easy fix if I think it important. Add another amplifier, one per hand, and split the signal at the output from the HDMI splitter and inputs to the amplifiers. I would imagine the "racing car" will have that feature
His patent item I suspect is the combined amplitude and temporal jitter feature. But again - whilst I can implement this, it wasn't needed in June 2018 - and I'd take those results for now until Dr Tass is able to release his new glove
I agree, based on the one-glove option, it probably doesnt matter if you mirror or not. In my case, if I want to go 8 channel, I am either going to have to accept a bulky USB sound card, or go for Dolby 7.1 decoding (and the lf channel is not ideal there)
I missed your mention of bHaptics earlier (day job distractions!). I haven't seen them, but they are several steps away from "as close as possible to the original". Specifically , the vibrations are not "y axis" - you haven't got the skin being prodded with a narrow prod (like a blunt pencil tip). Instead, I think, the vibration is of a small plate, like a mobile phone vibrate. I think that probably is a fairly important difference. Combined with a frequency that is significantly different, and outside the 200-300Hz sensitivity range, there must be a higher risk of a disappointing outcome .
I accept that, although there may be a range of combinations of intensity x frequency x placement which achieve the necessary stimulation of the Pacinian corpuscles, at least subjectively.
I've had a chance to play with EAI's C-MF tactors and compare them to the LRAs in the bHaptics TactGloves. While indeed these two are quite different in design, I thought that some of the settings of the C-MFs at 250Hz and low intensity felt not quite unlike the LRAs at 170Hz and higher intensity, if the latter were placed carefully under the fingertips. Also, they seemed to cover similar receptive fields. That's not a proof that the two will do the same, of course.
On the other hand, the handling of the TactGloves is probably the best of all the DIY designs, they are neat (no exposed wiring), lightweight, mobile, easily recharged and you can handle objects while wearing them, even type on a keyboard (if clumsily).
So in an ideal world, I would like to see bHpatic gloves fitted with C tactors. Well, maybe that's what the new Tass 'racing car' gloves will look like..
Can't argue about the convenience and ergonomics. If they are delivering the results that makes them a great option. It would be good to get some sort of results feedback from all the different projects. I did my off-meds "before" video a few days ago. I don't think I'll get to do the "after" until we are back from holiday. Fortunately I had my first appointment with my new local neurologist yesterday and he's very supportive
I've been using the TactGloves for >6 weeks now, about 2-3 hrs per day, and felt that they'd given me some benefit (although more of the mild Pat Riddle kind than the dramatic Kanwar Bhutani kind): mainly improved smell/taste, reduced tremor -- but unfortunately, all objective testing is off for the moment, because of (a) a recent bout of late COVID, which completely took away my smell, so I am starting again from zero on that measure, and (b) some necessary dose experimentation with my levodopa medication to get a troublesome leg dystonia under control (actually would be wonderful if the gloves had some effect here). The new level of medication will be fixed at the start of July when I will see my neurologist again, so I should establish a new baseline for the subsequent 'gloving' then.
Hope you get your distonia fixed soon.
Thank you.
what are the Tact gloves please?
The TactGloves, produced by bHaptics ( bhaptics.com/shop/tactglove ) are gloves designed to provide vibrotactile feedback on the fingertips, mainly for virtual-reality or gaming applications. They share some features with the Tass gloves but not others, as discussed in detail on this forum. It is currently not clear at all if they can provide any relief in PD symptoms as suggested for the Tass gloves. Nonetheless, some stimulation scripts exist to try and use them for this purpose.
I have no expertise. My friends with relevant expertise are in the fields of computer programming, maths, physics and acoustic engineering. They are not neurologists. But, based on Dr Google and my exposure to medical stuff I think that your hopes for the bhaptics are unlikely to be met. Good old wiki has this to offer."These corpuscles are especially sensitive to vibrations, which they can sense even centimeters away.[4] Their optimal sensitivity is 250 Hz, and this is the frequency range generated upon fingertips by textures made of features smaller than 1 µm.[6][7] Pacinian corpuscles respond when the skin is rapidly indented but not when the pressure is steady, due to the layers of connective tissue that cover the nerve ending"
It's not just the frequency. You could probably make a case for 200-300hz. But 170hz is comfortably outside that range. And 250hz would appear to be optimal and not merely the mid-point in a range.
Moreover, Peter Tass focuses in his specifications on vibration by rapid indentation ("y" axis vibration) and wiki suggests that is because pacinian corpuscles only respond to that sort of stimulus. Looks like Dr Tass knew his stuff, and the bhaptics, whilst smart and convenient are not of any use for this purpose
The classical reference for the response curve of the PCs appears to be this paper by Verrillo: link.springer.com/content/p... -- which indeed shows that the optimal response = minimal threshold of the PCs is at 250-300Hz sinusiodal vibration (note that this was for a 'large contactor' of 2.9cm2).
The optimal response is not a singularity, but part of a gradual curve, so vibration at 170Hz should also be able to drive the PCs if applied at a greater intensity (about 5dB higher than for the optimal response point according to these curves, which means roughly doubling the amplitude).
Nonetheless, I am with you that it would be best to stick with the original = optimal stimulation frequency, as this whole complex of stimulation frequency x intensity x focus is likely quite essential for the vCR to work. (I also think that this is where the fitting to individual sensitivity thresholds comes into play.)
Ah well, so I guess I should figure out how to program the C-MFs (but until I manage that, I'll keep using the TactGloves, just in case 😀).
250hz seems optimal for stimulating these receptors. But the bigger issue is that they are only triggered by skin compression. And I don't think the bhaptics vibrate that way
Time to put my hand up and admit my crystal ball is not as good as I thought. Looks like I got some features of the racing car glove. But not the main one. Looks like it will have a feedback feature. It will monitor brain activity and adapt the vcr to respond to the results. That's a huge leap, and not so easy for DIY to copy. But I come back to my first point that my DIY ford fiesta was good enough for kanwar bhutani. Indeed, my ford fiesta has quite a few worthwhile mods compared with the bhutani original
I think I've just won the prize for the most unusual request at our holiday camp site reception?"can I borrow a soldering iron to repair my tass-wannabe parkinson's gloves please?"
"A horse, a horse, my kingdom for a soldering iron"The site failed to locate the company soldering iron. At first Sophie was named. She shopped Guillaum, and interpol were informed, but in the end it became another holiday duplicate purchase. (to be fair, I wouldn't plan to take a soldering iron on holiday normally)
Normal glove service was resumed last night, thankfully. I definitely missed it when it wasn't available
OK. Partly to answer CBailey11's question about ideas for tactor design, I will describe where I am up to with the Mk4 glove. First - I have switched to one of the new exciters produced by Dayton specifically to meet demand for vibrotactile applications. The DAEX-13-4SM is half the width of the previous device, which should make for MUCH more comfortable gloves to wear. The Mk3 stretched your fingers wide uncomfortably, and often the ring finger & pinkie would cross, and tug each other around. Dayton have produced a similar looking exciter, half the size of this one, which would have been wonderful - but it was too weedy (too compliant).
The previous mounting arrangement involved punching a hole in foam mouse mat the size of the rear magnet, and interference fitting that in the ABS box. Height adjustment was by shimming under the mouse mat with cut up business cards. This didn't work in the new compact case, where the corners were lost to mounting bolt platforms. Anyway, I wanted a less klutzy height adjustment. The metal washer is an interference fit on the base, but I also use a dab of hot-melt glue. This is then covered with some double sided foam tape, with the backing paper left on. This acts to damp the case, and somewhat acoustically isolate the case from the magnet vibrations. The exciter is held in place by its magnet and the washer.
However, it could move around inside the case which was not good for locating the contact peg. So it is now held still laterally by the corner sections, with some cut-out channels. The cables now exit at either end, through slots which allow a bit of room for heavy-handed soldering. The lid is held in place by locator pegs at one end and M3 bolts at the other end. The plastic boxes are fairly "dead" acoustically anyway, and they are wrapped in elastic in the glove which provides further absorbtion of stray energy
After the backing paper has been removed from the exciter ring, a jig is used to ensure the centre of the vibration tip is directly central in the hole in the finger cut-out. The plastic disc is 3D printed with a threaded hole, that a printed screw fits into. With the screw fully inserted, the 8mm diameter tip is just below the top of the box wall (which is the base of the lid, which is the surface of the fingertip). It needs to be adjusted to be just level, and then a further half turn plus 5 minutes gives 0.5mm resting indentation of the fingertip.
Each finger can be individually adjusted to suit different skin elasticity. The amplitude of the vibration can be adjusted for each finger individually using the volume controls on the amplifier
The lid is fixed by 2 locator pegs and 2 M3 bolts. It is shaped to hold the finger comfortably in a fixed position relative to the vibration point, and to help isolate the rest of the finger from the vibration generated in a fixed location.
The boxes will be mounted in elastic "pods" which allow the housing to be firmly, but not too tightly held against the finger tip at the end of the glove fingers. Velcro is used to adjust the tightness of the elastic.
I am happy these are final, so will start a production run, and hope Mrs WTP can finish the seamstress bit this weekend.
As a result of trying to cross check a couple of things I am reminded what a muddled and frustrating topic the DIY gloves has become. And I have contributed to that lack of cohesion by responding on someone else's thread with the final version of my gloves adventure. When really, for cohesion it should have been here. So apologies for repeating myself but here is the finished project{this was a picture taken by my wife last night when I had nodded off wearing them}
Parkinson's Recovery Project
Tass glove on voice 
DIY Parkinson's Glove Users - How are you adjusting?
Mobility Aid Design Project
