Tremor Mouse: first Alpha release announcement

It is early days, but we have made progress on the Tremor Mouse adapter. We are using an Adafruit RP2040 USB Host device.   As you can see from the photograph, it has two USB connectors.  You plug your mouse into the USB ‘A’ connector and you plug a cable from your computer into the USB C connector.  Yes, it’s plug and play.  No software to install and it comes pre-configured.  

At present, the configuration needs to be set by a programmer before the software is compiled.  Later versions will have a web interface to allow you to customize the settings so it best suits your needs.

The first Alpha release of the software is ready. If you want to test it out, the pre-compiled software is available here.  The source code is also available for those of you who are a bit more adventurous. You can change the configuration settings and compile your own personal configuration using the Arduino IDE.

This first release only attenuates the speed of mouse movements.  The majority of the time, the mouse needs to move relatively quickly to get to some target destination and precision is not required.  During these faster movements, there is no attenuation of the mouse.  As you approach your target, you usually slow down.  At this slower speed, the mouse is attenuated by 2:1, filtering out some of you tremors.  When you get very close to the target you slow down even more and the attenuation is set at 4:1.  These values are fixed for now, but seem to be about right for someone with mild to moderate Essential Tremors of the hand/forearm.  Testing will refine these values.

This is just the first feature.  More will be released as the project develops.

Credit where credit is due.  This project wouldn’t be possible without Ha Thach and TinyUSB, Adafruit who built the hardware and provided s/w to build applications with the Arduino IDE.  And a big thank you goes to BillB of AtMakers.org who developed the original hardware, pushed it through a couple of generations of refinements and somehow persuaded LadyAda to build and source this board that we are using.

If you want to test drive the Tremor Mouse, please contact me here or over on Reddit  and I will be happy to walk you through the process of getting it working.  Your feedback will help us refine the configuration and perhaps suggest other modifications to make it easier to work with the Tremor Mouse.

If you are a ‘C’ programmer and interested in contributing to the development process, please chime in here in the comments, or the Discussions and/or Issues on github. 

Cala Trio: non-clinical test results

September 1, 2022. Cala Health published the results of long term use of the Cala Trio for the treatment of Essential Tremors of the hand/forearm.  The study included 321 individuals who used the Cala Trio for at least 90 days between August 2019 through June 2021.

This study compared the before and after measurement of tremor amplitude in a 20 second postural hold.  59% of the group had a 50% reduction in the measured tremor amplitude power.  This compares favorably with the best pharmacological treatment of Essential Tremors.

Patients with severe tremors experienced the greatest reduction in their tremors from this treatment.

No significant habituation was observed in patients who use the Cala Trio for more than one year.

In a voluntary survey, patients reported improvements in three areas of activities of daily living: eating 74%, drinking 65%, writing 64%.  65% of the survey preferred treatment with the Cala Trio over both medication and surgical intervention.

The full paper can be found here. 

Whoops! I made a math mistake: It works for me (revised)

In the Discrete Fourier Transform script I wrote to convert from time domain to frequency domain, the constant 2π is used.  I incorrectly entered  6.2318 instead of the correct value of  6.28318.  This not only changed the spectrum but significantly changed the peak amplitude as illustrated by the revised plots below. 

Before stimulus tremor spectrum with the correct constant

After stimulus tremor spectrum with the correct constant.

Instead of reducing my peak tremors by 2/3, it actually reduced the peak amplitude by 40% (3/5). I apologize for any distress that my error might have caused.

-----------------------------------------------revision ends----------------------------------------------------------------

 I can finally announce that my tremor stimulus device works for me.  15 minutes of stimulus reduced the peak amplitude of my forearm tremors by ⅔.

Here is the Discrete Fourier Transform (DFT) chart of my forearm tremor before I used my stimulus device.

And here is the DFT chart after 15 minutes of stimulation

Before the peak tremor amplitude was about 0.6.  After the stimulus was applied the peak amplitude is just a smidge over 0.2  Almost a ⅔ reduction in the peak amplitude!

I’m typing this about 3 hours after recording that data.   Usually I get a large number of double keystrokes.  So far the tremors are mostly not there.  Oh they will return, but I can get relief from my tremors within a few minutes.  A non-drug, non-invasive, inexpensive temporary solution to my tremors.  Maybe I’ll be able to draw again.

My tremor stimulus device is based on Commercial Off The Shelf hardware and some custom software.  It is entirely battery powered so there are no dangerous voltages. The software is Open Source, so you can copy it, and build your own tremor stimulus device. 

How much does it cost?  About $200USD.  Prices vary so much due to the shortages of chips and of course shipping costs are dependent on where you live.  If you change the stick on electrodes every week, the running cost will be less than $1USD/week.

Have tremors in both hands?  Just stick the electrodes onto the appropriate area on the other hand.

ama

(Please note: This information should not be used as a substitute for medical treatment and advice. Always consult a medical professional about any health-related questions or concerns.)

Video of EssentialTremorLab Electrical Neurostimulation device

This first video is me recording my forearm tremor before applying the electrical neurostimulation.  I’ll run a Discrete Fourier Transform over this data to provide a snapshot of the spectrum of my tremors. 

Here is a rather longer video of the device in action edited down to leave out  the long gaps between the minutes. 

Apologies but the video is too large for blogger to upload so here is a link to it on YouTube

Here is the DFT of before:

and here is the DFT after 15 minutes of electrical neurostimulation.

Technical details and how to build your own device can be found here.

 #EssentialTremorLab

Photograph and description of our prototype

This photograph shows the current stimulus device and all the wiring and components.  A link to most of these components can be found in the parts list.  #9, #12, #13, #14a, and #14b have recommendations but you have the option to locally source these components.

1. Adafruit PyGamer.  I think the name is derived from Python-GameBoy. You can actually play games on it (and write your own games) but not at  the same time as you are running the tremor software.  The full specification can be found from the link in the parts lists.  All the cables are on sockets so no soldering!  Apologies for not powering it up so the LCD screen was easily visible. It also contains a rechargeable battery, and a Micro-SD slot for recording tremor data.
2. Is  a USB cable.  The end that plugs into the PyGamer is a Micro USB port.  Choose a cable that  will plug into your PC/Mac/Linux computer and has a Micro USB connector on the other end.  You will need this cable to load the tremor software onto the PyGamer.
3. 3a provides power and control to the Solid State Relays (10).  Red for power, Black for ground, and 2 white cables are the controller wires.  One white cable is part of the port/connector cable that supplied power and ground.  The other white cable comes from the other port.  3b is the power and ground from the second port and are not used.
4. Is the JST PH to JST SH Cable - STEMMA to QT / Qwiic - 200mm long.  This cable supplies power, ground, contro, and data to the Inertial Measurement Unit (IMU), since it is quite short, we have extended it via #5 and #7 to make it easy to use.
5. Is a Qwiic Adapted to allow us to connect a longer cable (#7) between the PyGamer and the IMU.
6. I made a mistake when labeling the image.  There is no #6.  Sorry!  ;-(
7. Is a 500mm Qwiic cable.  Sockets both ends so again, no soldering!
8. Is the IMU.  There are two options for this component in the parts list. One includes a magnetometer that is not used by the tremor device.  The IMU in the image is the one with the magnetometer.  It was the only one available at the time due to the worldwide silicon chip shortages.  Either IMU will work.  The IMU contains a 3 axis accelerometer and a 3 axis gyroscope.  This is the component that actually measures your tremor.
9. This is a cinch strap.  The IMU is sewn to this strap. It all looks rather mundane but it is quite important. A firm mount is a must to get good repeatable measurements of your tremor.  You need to be able to easily position the IMU on the back of your hand in the same position every day.  The cinch strap, as illustrated, can be adjusted for larger or smaller hands.  There is very little ‘give’ in the strap providing a firm base for the IMU. An alternative would be to use a glove and attach the IMU to it.
10. Are the Solid State Relays.  There is a pair of them. Under software control, these SSRs switch the electrical stimulation provided by the TENS Unit (#15),  between the Median and Radial nerves delivered via the electrodes #14a and #14b
11. #11a adn ##11b is the two sets of leads that are compatible with your TENS unit.  You need  two sets of these leads.  #11a is used to deliver the TENS stimulus to the SSRs (#10) and provides the ‘return path’ via electrode #13.  #11b supplies the TENS signal from the SSRs to the Median and Radial nerves via electrodes #14a and #14b.
12. Is a short jumper wire to connect the TENS output to both center taps of the SSRs.
13. Is the ‘return path’ electrode which should be attached to the back of the wrist.
14. ‘a’ and ‘b’ are the two electrodes that deliver the stimulus to the Radial and Median nerve.  These should be attached to the underside of the wrist.
15. TENS unit. Transcutaneous Electrical Nerve Stimulation (TENS) therapy involves the use of low-voltage electric currents to treat pain.  Because the TENS unit can produce a safe stimulus, it is used by the tremor device to stimulate the Radial and Medial nerve. 

Please Note: This device is not an FDA-approved system or device. The FDA’s responsibility is to regulate products on the commercial market and help safeguard the public. It’s not manufactured or sold anywhere in the world. It’s an open-source designed system that you can choose to build yourself. The FDA doesn’t currently regulate self experimentation. Individuals who build this device are essentially doing an (N=1) experiment, which they have a right to do by themselves, on themselves. If you decide to build anything described herein, you do so at your own risk.

(Please note: This information should not be used as a substitute for medical treatment and advice. Always consult a medical professional about any health-related questions or concerns.)

March 1 should be International Essential Tremor day!!!!

 First a little history: The familial Essential Tremor was first described by the German physician Georg Friedrich Most in 1836, while the term essential tremor (originally from the Italian language ‘tremore semplice essenziale’) was used for the first time in 1874 by the professor of medicine Pietro Burresi, who described the case of an 18-year-old man suffering from severe hand tremor while moving, as well as head tremor. In 1817, James Parkinson was the first to point out that ET was a disorder separate from Parkinson’s disease (PD), but his report was not published until 1887. A classic description of the disease was presented in 1925 by the Russian neurologist Lazar Salomonowicz Minor, after which ET is often also called ‘Minor’s disease’ 

Historical underpinnings of the term essential tremor in the late 19th century

https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC3461999/ 

It took until 2013 for Essential Tremors to receive its own medical classification identifier!  

The International Classification of Diseases-10th Revision-Clinical Modification (ICD-10-CM) ushers in, for the first time, a specific diagnostic code for essential tremor (“G25.0, essential tremor”). This milestone should not pass without comment. --Elan D Louis

From: The Lancet Neurology MARCH 01, 2013

The full description reads:

 2021 ICD-10-CM Diagnosis Code is  G25.0  Essential tremor (benign) 

…and that in my opinion is incorrect.  Benign Essential Tremors is an old and now obsolete term. I even doubt the veracity of the term “Essential” but that is the term the medico people use.

Essential: In medicine, of unknown cause… 

There is nothing benign about Essential Tremors. Essential Tremors has the potential to significantly disrupt daily activities and/or social interactions.

Transcutaneous Electrical Nerve Stimulation (TENS) of the Median and Radial nerve using COTS hardware (draft #1)

 JM Elek et al. described the attenuation of human wrist tremors by electrical stimulation in a paper in 1989. Recently the FDA approved a home use electrical stimulation device for the treatment of Essential Tremors (CALA Trio).  The technology behind this type of stimulation is well described and easily accessible from a large number of papers published by various authors during the past 30 years.  Having been introduced to the current generation of microcontrollers by an old acquaintance, I decided to investigate the feasibility of building an electrical stimulus device using Commercial Off The Shelf (COTS) hardware. It wasn’t a straight line path from early 2021 to this juncture.  It was an adventure in learning: both from reading and experimentation but that is a story for another time. 

Here are two photographs of my proof of concept stimulus device that I got working today, February 19, 2022.

This proof of concept test rig consists of a TENS unit I purchased from Amazon for about $100.  It has the advantage of being battery powered so it is portable and there are no dangerous voltages or currents involved.  My hand/arm tremors inspired me to deep dive into the research papers on Essential Tremors. All the online, freely accessible information, led me through a convoluted path that was littered with many interesting ideas and more than a few disappointments; "The best of the best (treatment) only works for about half of us ET sufferers!".  

Aside from the learning curve and the technical challenges, I wanted to see if it was possible to build an affordable device that was free from the substantial recurring costs of the commercial offering mentioned above.  Recurring costs are: a small amount of electricity necessary to charge the TENS unit and three round TENS self adhesive electrodes: cost about $0.50 each and they last a week or so. This "proof of concept" device is only the first step.  I have already started sourcing parts for the next version.  The control unit will be battery powered, portable, and will have a much simplified design.

The output of the TENS unit is switched between the Median nerve and the Radial nerve by a pair of Solid State Relays (SSR) seen next to my thumb.  The switching is controlled by an Arduino Mega 2690 microcontroller just above and to the left of my forefinger.  The Mega 2690 also measured the frequency of my tremors via a 3-axis gyroscope/accelerometer combo IMU mounted on a Velcro strip on the back of my hand.  Total cost was about $175 excluding taxes and shipping.

From my research, something like 40% of the ET population could benefit from this type of stimulation.  So I don’t yet know if this will attenuate my tremors in my forearm.  Whether or not I’m in that group will be discovered over the next couple of weeks of testing and adjustment.

AMA!

(Please note: This information should not be used as a substitute for medical treatment and advice. Always consult a medical professional about any health-related questions or concerns.)