Description
Tinkertron EMG Switch for AAC Clients
A nerve impulse, electromygography device. We created the EMG Switch (Electromyography Device) that will give you independence!
Our uniquely designed, easy to use EMG switch device can be used as a caregiver alert, as a mouse click for computer access, as a switch input for speech generating devices, and as a control switch for power wheelchairs. It’s small but has rapid response rates at 10ms! Our EMG Switch senses muscle activations and provides switch closure, threshold adjustment and comes with a standard 3.5mm connector to control switch activated devices. It also has a built-in digital signal processor that extracts intentional activations from weak muscles.
WHAT can the EMG Switch do? Our versatile and easy to use switch interface can be used as a caregiver alert, as a mouse click for computer access, as a switch input for speech generating devices, and as a control switch for power wheelchairs. Small 3.2”W x 1.3”H x 4.8”L enclosure --- with rapid response rate 10ms! Senses muscle activations and provides switch closure Simple threshold adjustment Provides standard 3.5mm connector to control switch activated devices Built in digital signal processing extracts intentional activations from weak muscles Safe battery powered operation using AA NiMH rechargeable batteries Our versatile and easy to use switch interface can be used as a caregiver alert, as a mouse click for computer access, as a switch input for speech generating devices, and as a control switch for power wheelchairs.
If you haven’t been able to control switches because of ALS, spinal muscular atrophy, or spinal cord injury, our products can help you achieve independence. Unlike other switches, the Tinkertron switch senses the tiny signals which activate muscle. Use of the muscle control signals from your nervous system to your muscle makes the switch very easy to activate. The sensor is connected directly on the muscle site which makes attachment simple. The sensor does not depend on motion so it remains in the proper position even as you move around. Small 3.2”W x 1.3”H x 4.8”L enclosure — with rapid response rate 10ms!
Senses muscle activations and provides switch closure
Simple threshold adjustment
Provides standard 3.5mm connector to control switch activated devices
Built in digital signal processing extracts intentional activations from weak muscles
Safe battery powered operation using AA NiMH rechargeable batteries
Built in battery and charger
Compatible with readily available Ag/AgCl EMG patch electrodes
Any device or program that accepts switch input can be controlled by the EMG Switch
- power wheelchairs
- mobility devices
- environmental control devices
- email programs
- other computer programs
- scanning software (ie: EZ Keys)
- communication devices
- and many more…
HOW does the EMG Switch work?
By using tiny electrical impulses from muscle contractions, the EMG Switch is designed to detect and convert electromyographic (EMG) signals which are present on the skin through muscle activity in your body into electrical information that is processed and input into a special switch closure used to output/activate your assistive technology/device such as a wheelchair, keyboard, etc. The input to the EMG switch comes from cloth electrodes, which provides contact to the tiny signals on the surface of the skin. The EMG switch continuously monitors the signal under the electrodes, and when the signal level exceeds a user adjustable threshold, a relay is energized providing an isolated switch closure output.
Which muscles can control the EMG switch?
Almost any controllable single muscle on the body can be used to control the Tinkertron EMG Switch, such as pectoral muscles, brow muscles, jaw muscles, cheek muscles, and others.
How much muscle strength is needed to move the switch?
Minimal. Because the EMG Switch is very sensitive, even tiny muscle twitches provide enough electrical signal to be detected and used by the EMG Switch.
Will this work with my power wheelchair?
The EMG Switch can control most power wheelchairs that accept switch input.
What software do I need to install this switch scanner?
Your existing software and computer programs are all that is required, as long as they accept switch input.
DIRECTIONS to start using your EMG Switch
The EMG switch is designed to convert tiny electromyographic (EMG) signals which are present on the skin near muscle activity into a standard switch closure that can be used to activate assistive technology equipment. The input to the EMG switch comes from an active electrode, which provides amplification of the tiny signals on the surface of the skin. The EMG switch continuously monitors the signal from the active EMG electrode, and when the signal level exceeds a user adjustable threshold, a relay is energized providing an isolated switch closure output. The unit is fully battery powered, and can operate for up to 60 hours on a charge. The internal batteries can be recharged using a wall mounted transformer provided with the unit.
DIRECTIONS to start using your EMG Switch
The EMG switch is designed to convert tiny electromyographic (EMG) signals which are present on the skin near muscle activity into a standard switch closure that can be used to activate assistive technology equipment. The input to the EMG switch comes from an active electrode, which provides amplification of the tiny signals on the surface of the skin. The EMG switch continuously monitors the signal from the active EMG electrode, and when the signal level exceeds a user adjustable threshold, a relay is energized providing an isolated switch closure output. The unit is fully battery powered, and can operate for up to 60 hours on a charge. The internal batteries can be recharged using a wall mounted transformer provided with the unit.
Step ONE
Connect the green reference electrode lead to the rear panel jack labeled REFERENCE.
Connect the grey active electrode leads the to the jacks labeled + and -.
Connect the SWITCH #1 through a standard 3.5mm cable and plug to the primary assistive technology device to be controlled.
If desired connect SWITCH #2 to the secondary assistive technology device to be controlled.
Step TWO
Snap the cloth electrodes onto the other end of the electrode leads.
Place the reference electrode at some convenient location on the body away from the activation site.
Place the active electrodes over the muscle site to be monitored. For very weak muscle activity electrode placement is critical.
Observe the muscle twitch and place the electrode near the movement site, orienting the two electrodes in line with the muscle movement.
Step THREE
Press the POWER switch to turn the power on.
Turn the THRESHOLD knob fully counter clockwise and verify that the SWITCH lamp comes on.
Fully counter clockwise corresponds to the lowest threshold setting, and at this setting the switch is closed all the time.
Turn the THRESHOLD knob fully clockwise. Clockwise rotation corresponds to the highest threshold setting. At a fully clockwise setting it takes a very large muscle contraction to activate the switch. With the muscle site inactive, gradually turn the knob counter clockwise until the SWITCH light is illuminated. Illumination of the light indicates that the switch is active. With the muscle site inactive turn the THRESHOLD knob slightly clockwise to increase the threshold above noise. Ask the user to activate the muscle site, and verify that the light comes on when the site is activated and that the light goes out when muscle site is at rest. It may take some experimentation to optimize the placement of the electrodes, and to optimize the setting of the THRESHOLD knob. The lower the threshold setting the more sensitive the device is to surface signals. A higher threshold takes a stronger signal to activate the switch and also minimizes the false triggers.
Downloadable our Operations Manual
Operating Manual Tinkertron Dual EMG Switch Box Shielded Electrodes — PDF file, 80 kb
Rehabilitation Engineering & Assistive Technology Society of North America 28th Annual Conference (2005, Atlanta, GA) “EMG Single Switch Activation Algorithms and Methods”
Rehabilitation Engineering & Assistive Technology Society of -North America 29th Annual Conference (2006)
“Electromyographic Switch Navigation of Power Wheelchairs” — PDF file, 160 kb
Poster
White Paper (2009)
“Single_EMG_Sensor_Control_of_Multifunction_Technologies” — PDF file, 1.9 megs
Who is the EMG Switch for?
The EMG Switch was first developed for those with severely impaired mobility. Then, we realized that anyone with affected limited muscle control can benefit greatly from using our Tinkertron EMG.Today our EMG Switch is specially useful to Amyotrophic Lateral Sclerosis (ALS) and Spinal Muscular Atrophy (SMA) patients, stroke victims, quadriplegics, those who suffer from various dystrophies, and anybody with limited muscle control who uses single- or dual-switch devices for scanning technology.With the EMG Switch, a user can control his or her power wheelchair with ease and comfort, enjoy any modern software on a personal computer that can accept scanning software, and even control his or her environment from one’s chair or bed using the power of the EMG Switch paired with environmental control software.
User Testimonials!
“I can truthfully say that this technology intervention has given me the most independence I have enjoyed for over 15 years.”
“With the EMG probe placed on my left pectoral muscle, I have full functionality from the twitch of my shoulder.”
From power wheelchair user and SMA patient Darren Gabbert:
The EMG switch was the key for me to make single-switch scanning an effective option for controlling my power wheelchair. Due to having an advanced form of spinal muscular atrophy, I have used and modified numerous driving mechanisms to accommodate the progression of the disease. It wasn’t until July 2004 that I had no alternative but to consider single-switch scanning navigation, or what rehabilitation professionals call the “option of last resort.” While by itself it may be worthy of this title, using the Tinkertron EMG Switch* with an EMG probe as the “single-switch” introduced significant benefits that has changed the “option of last resort” to an “option of great report!”
I have been using a Permobil power wheelchair, PG Technologies’ Omni+ single-switch scanning interface, and Tinkertron’s EMG switch for since 2005. With the EMG probe placed on my left pectoral muscle, I have full functionality from the twitch of my shoulder. After a slight learning curve with regard to avoiding inadvertent triggers from muscle movement, using the switch quickly became second nature. The response rate of the EMG switch allows me to press, hold, and release at the necessary split-second intervals to effectively navigate the wheelchair. No fatigue. Very impressive! And being freed from the necessity of having my arm or head precisely positioned to operate a more traditional driving mechanism, I can independently use the full range of seating functions without losing my ability to return to a driving position.
With the EMG probe, a vast scope of possibilities exists for finding an efficient, minimal-fatiguing way for anyone to engage the system. Furthermore, once an effective placement site has been determined for the EMG probe, all seating and positioning considerations can focus on stability and comfort. This is in stark contrast to solutions where comfort must take a back seat to finding and maintaining a range of movement necessary to operate the control mechanism.
While single-switch scanning is clearly not as fluid and “natural” as proportional control, I think I would have given up the proportional control earlier than I did had I known the overall benefits to be gained. With the EMG driven single-switch scanning system, I have experienced increased independence and functionality while having lost physical ability.
Am I able to confidently navigate indoors and outdoors without anyone else present? YES!Am I able to change position using the full range of backrest, tilt in space, footrests and seat elevator functions? YES!
Am I able to travel long distances without fatigue? YES!
When I measure according to these terms, I can truthfully say that this technology intervention has given me the most independence I have enjoyed for over 15 years.
It is all too common for people with progressive neuromuscular diseases to have a net loss of independence and functionality while trying to maintain and modify proportional technology that they have became accustomed to. For those who are hobbling along trying to make proportional driving mechanisms work beyond your ability to use them, take a second look at the “option of last resort.” With the right Omni+ parameter settings, single-switch scanning can be very effective using different profiles for different environments and functions (e.g. indoor proximity navigation, outdoor distance navigation, tedious precision navigation). Combine this with the benefits of using the EMG switch, and the scales of overall independence begin to tip.
The first use of my chair outside of my home environment came on September 25 at my daughter’s wedding. With the Permobil seat elevator raised, I enjoyed conversation at eye level and easily mingled within a crowded room without being a risk to myself or others. I have also independently (at my wife’s consternation) drove all over our acreage. Having my wife leave the front door cracked, I have mastered opening, entering, and closing (yes, closing) the front door. Pretty fluid-like behavior from a single-switch system. I certainly don’t think anyone has gotten this much mileage out of their left pectoral.
An important key issue making this really work is the ability the EMG switch gave me to use another (slightly more functioning) muscle to engage a “cutoff” switch. The cutoff switch is definitely necessary to make single-switch navigation safe and practical.
Videos are posted by our Tinkertron EMG Switch usersSpecial Order: This is not a stock item and is ordered specifically. Unfortunately, no returns, no cancellation, so please call our trained staff with any questions you may have prior to ordering to ensure you make a well informed, educated purchase.