Which Myoelectric Pattern Recognition System is Right for You?

Which Myoelectric Pattern Recognition System Feature Image

We are entering a period of bionic arm & hand development that is both exciting and potentially confusing. This article is meant to clarify the most recent options for pattern recognition systems.

A Slowly Unfolding Revolution

It is no secret that dual-site, direct-control myoelectric systems have struggled to deliver adequate user control of bionic hands.

Even though they may deliver a satisfactory solution to a segment of the limb-different community, we have yet to meet anyone who thinks that they are the ultimate solution.

Over the past decade, it has become increasingly clear that myoelectric pattern recognition systems offer far more potential for intuitive use. Systems like Coapt Engineering’s Gen2, Infinite Biomedical Technologies’ Sense, and Ottobock’s Myo Plus have all matured into very capable systems.

Most impressively, these systems have made huge strides in addressing the issues that have been so problematic for direct-control devices, such as signal degradation in different arm positions and the ever-changing conditions of residual limbs (hot, cold, sweaty, tired, etc.).

These systems are expensive but they’re also ready to use now, as shown in this Myo Plus video:

The problem for consumers is that just as these solid, reliable pattern recognition systems have begun to enter mainstream use, more revolutionary solutions have appeared on the horizon.

The Promise of a More Transformative Revolution

The BrainRobotics Prosthetic Hand Story

In November of 2018, a video appeared on YouTube of a girl playing the piano with a bionic hand:

The hand in question shares its roots with a company called BrainCo. In early 2020, BrainCo won a couple of awards at the 2020 Consumer Electronics Show (CES) for its Dexus Prosthetic Hand, which again featured an impressive level of user control over individual fingers.

At that time, the company told us that they hoped to win FDA approval of the hand by the end of 2020.

After this, BrainCo spun off its bionic hand into a company called BrainRobotics. This new company plans to release two bionic hands: a 2-channel hand in late 2021, and a more advanced 8-channel hand sometime after that. Only the 8-channel hand will deliver the kind of control needed to play a piano.

BrainRobotics has recently made a lot of progress in sorting all this out, focusing mainly on getting FDA approval for their 2-Channel hand, as well as organizing their website and other media assets to support its commercial launch. These are not small tasks and may not be complete until the start of 2022.

There is a reason that we are telling you this story. There is a big difference between building breathtaking prototypes versus bringing a product to market. We are optimistic about the future of BrainRobotics, and still very much excited about a bionic hand that will eventually allow users to play the piano. However, from a consumer standpoint, caution is in order. Until you can actually buy a hand and take it home, it isn’t a viable option.

The Atom Touch Story

In 2006, the Defense Advanced Research Projects Agency (DARPA) launched its Revolutionizing Prosthetics program. The goal of this program was to develop a bionic arm that could mimic natural arm and hand movements for any level of amputation.

In 2015, DARPA pushed the envelope a bit further by launching its Hand Proprioception and Touch Interfaces (HAPTIX) program. The goal of this program was to enable precision control of a bionic hand and sensory feedback via bi-directional nerve implants.

The Modular Prosthetic Limb (MPL), developed by Johns Hopkins University (JHU), became the lead project for this second initiative. Here is a look at the MPL during its first take-home trial in 2018, again with a focus on playing the piano:

Roll forward three years. The MPL has now entered a new phase where its technology is being commercialized as the Atom Touch from Atom Limbs.

The claims of advanced functionality for the Atom Touch, scheduled to launch in 2024, include:

  • user control over the hand that mirrors control of a natural hand, including control over individual fingers;
  • wrist and elbow components that mirror the abilities of a natural wrist and elbow;
  • advanced sensory feedback including the ability to sense contact, force, position, and velocity (it may also eventually include temperature).
Atom Touch Original Image

We’re not talking about an incremental improvement over existing bionic arms/hands here; we’re talking about a quantum leap.

According to the company, even the artificial intelligence (AI) component goes well beyond that of existing pattern recognition systems. While we can debate the terminology, what we cannot deny is that any system built on data from 200 sensors has the potential to be a lot more sophisticated than one built on 8 or 16.

The question is: will they deliver?

A Possible Middle Ground

In recent months, we’ve begun to encounter new bionic hands that may offer alternatives to the current dichotomy of a) reliable but expensive 3rd-party pattern recognition systems, versus b) ultra-advanced devices that may give you even more capability but are so far unproven.

One of these hands is called Adam’s Hand from BionIT Labs. It automatically adapts to the shape of whatever object it is trying to grasp, which eliminates the need for users to select different grips for different tasks. This, in turn, reduces the need for advanced pattern recognition to determine user intent.

Here is a bit of an outdated demonstration (i.e. outdated because a new video of updated capabilities is pending):

Adam’s Hand doesn’t completely eliminate pattern recognition. Instead, it uses a simplified version of the technology to distinguish between open and close commands, one that requires only a 2-channel sensor system, i.e. the same type of sensor system used for direct control.

We were skeptical of this version of pattern recognition at first but it has now been adopted by several bionic-hand startups, so it appears to have merit.

Note, we don’t have any data on whether this system works — Adam’s Hand won’t be launched commercially until early 2022 — but we certainly can’t argue with its strategy. We should also note that BionIT Labs is not a basement startup. It has serious support from various organizations in the European Union.

Another middle-ground contender may be the MeHand from Russia’s MaxBionic. The following video is in Russian with no English translations, but check out the impressive demonstrations of user control for some tasks:

The company claims that it supports the same level of user control as a Myo Plus system but with only 2-channel sensor input. This is a big claim but the company is already selling its hand in Russia, Germany, and the Commonwealth of Independent (CIS) countries. It’s also going through clinical trials in the U.K., with a similar process to follow in the U.S.

So, why do we refer to these two examples as a possible middle ground? First, because their current focus is on the completion of daily tasks, not more advanced capabilities. Second, because the complete cost of these devices, including the hand, socket, prosthetist fees, and their 2-channel pattern recognition systems is likely to be between $30,000 to $40,000 U.S. That is roughly half the cost of a middle-of-the-pack bionic hand like the bebionic when paired with one of the mainstream pattern recognition systems.

What’s a User to Do?

Here’s a statement that we feel comfortable making about the existing mainstream pattern recognition companies like Coapt, IBT, and Ottobock (i.e. it’s Myo Plus product): if you purchase one of these systems and you put the required effort into proper training, you will get what they promise. It won’t be the Atom Touch or the ability to play the piano, but it will be a notable and reliable upgrade over direct-control systems.

If you wait for the Atom Touch, the more advanced version of the BrainRobotics hand, and other advanced devices to reach the market, it will be several years before those hands are a) available, and b) prove themselves in the marketplace.

Alternatively, if you have access to new hands like Adam’s Hand or the MeHand, we suggest that you take them on a trial run to see if their claims are true.

We don’t have a horse in this race. Our job is to make you, our readers, aware of their options. We hope we have done that.

Clinical Insights

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The following comments are from clinicians with extensive experience with pattern recognition systems:

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Related Information

For a look at pattern recognition systems in general, see Myoelectric Pattern Recognition for Bionic Arms & Hands.

For a good overview of control systems in general, see bionic arm/hand control systems.

For a complete description of all current upper-limb technologies, devices, and research, see our comprehensive guide.

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