March 11, 2011      

Touch Bionics Inc. outfitted the first patient with its evolutionary i-LIMB Pulse, a remarkably advanced, lifelike, and ergonomic bionic upper-limb prosthetic device, in June 2010. The new i-LIMB Pulse is a vastly improved and more ergonomic version of the company’s flagship i-LIMB Hand, which debuted in 2007.

Both the i-LIMB Hand and the latest i-LIMB Pulse are nonsurgical devices that fit over what remains of the person’s arm. Both devices contain onboard microprocessors that allow amputees to open and close their plastic bionic hands and grip objects. The i-LIMB Pulse, however, incorporates more advanced, miniaturized internal components and more varied sensors.

A pioneer in the field of fully articulating myoelectric prosthetic upper limbs, Touch Bionics is a five-year-old privately held firm headquartered in Livingston, Scotland, with an office in Hilliard, Ohio. The i-LIMB Hand was the first commercially available device in its class.

Touch Bionics’ ability to utilize the smaller computer chips and sensors is tangible proof of the accelerated pace of development in the bionic upper-limb product arena. Such technology advances within a relatively short three-year span bodes well for the growth, commoditization, and ultimately, the affordability of all robotic limbs, but specifically arms.

A Superior Solution
The i-LIMB Hand was the gold standard for upper-limb bionic prosthetic devices. Compared with the latest i-LIMB Pulse, though, the i-LIMB Hand’s abilities and movements are now rudimentary and primitive. The i-LIMB Hand could, for example, grip objects, but it could not control the intensity of the grip, so clasping more delicate objects was difficult if not impossible. Additionally, the digits or fingers on the i-LIMB Hand were incapable of separate, independent movement. Patients who have used both the i-LIMB Hand and the i-LIMB Pulse describe the latter as a much superior solution.

In that regard, and in several other crucial respects, the i-LIMB Pulse incorporates several key bionics/robotics technological advances that will greatly improve the everyday life of amputees and also solidify Touch Bionics’ leadership position as the premier supplier in this market segment. The i-LIMB Pulse enhancements include:

  • Pulsing grip strength
  • Eight different software-enabled grip patterns (e.g., to enable the fingers to point and pinch)
  • Robust aluminum features and construction for increased durability and user flexibility
  • The ability to move digits/fingers separately and independently of one another
  • The addition of Bluetooth wireless connectivity and BioSim software to send out signals to enable prosthetists and end users to have a greater measure of control over both the speed and movement of the bionic hand and digits
  • Improved ergonomics; the i-LIMB Pulse has a more anatomically correct appearance-there are several different sizes and 10 different skin tones and it is able to assume a more natural position while in repose.

Pricey Technology
The i-LIMB Pulse joins Touch Bionics’ existing product portfolio of bionic hands that have served more than 1,200 patients worldwide. To date, approximately two dozen amputees have been outfitted with the new device. Touch Bionics does not quote specific pricing on any of its i-LIMB products. According to the company, insurance generally covers the cost of the device. Prices vary according to the individual user’s prosthetic, his or her geographic location, and the amount the insurance will pay. However, at this point in time they are still very expensive, retailing for tens of thousands of dollars. As the underlying robotics and microprocessor technology gains more widespread adoption, pricing will follow the normal product maturation curve and decline-most likely by 30 to 50 percent over the next three to five years.

Software Key
Key to the i-LIMB Pulse is BioSim, Touch Bionics’ new Bluetooth-enabled software. The addition of the software is also a boon for clinicians, therapists, and end-user patients. BioSim allows prosthetists, and for the first time ever, users, to select the features and control strategies that work best. Prior to this, prosthetists would fit a prosthetic device to a patient and then ensure that the person had training and therapy. But with the addition of digital pulsing software technology, prosthetists can work with patients on a much deeper and more personal level to find the best settings and movements for them, shortening the adjustment period.

Durable, Functional, and Easy to Use
With an aluminum chassis, knuckles, and dislocators, the i-LIMB Pulse is robust, durable, and capable of supporting a load of up to 90 kg. This is roughly four times the capacity of the i-LIMB Hand, according to Touch Bionics officials. Candidates for the original i-LIMB Hand are also candidates for the new i-LIMB Pulse, but the aluminum features expand the product line’s potential user base to include those individuals who can accommodate increased activity levels.

The i-LIMB Pulse is expected to have a four-year life span, a year longer than its predecessor the i-LIMB Hand. Users have the option to replace individual fingers (which typically wear out first) on both the i-LIMB Hand and i-LIMB Pulse, which also extends the bionic arm’s life span.

The name “i-LIMB Pulse” comes from the bionic hand’s ability to send a pulsing signal to the microelectronics in the device to allow the fingers and thumb to apply 30 percent greater grip force than the i-LIMB Hand when needed for tasks like pulling a light cord, tying shoelaces, or tightening a belt.

The articulating digit is another crucial enhancement. The i-LIMB Pulse incorporates a small motor and an onboard microprocessor chip housed in the base of each finger that controls and enables the speed of the hand movements, the ability to articulate independent movement, and a wider range of grip strengths. This effect is generated by sending rapid, high-frequency electronic pulses to the finger motors; this causes them to close more securely around objects. The BioSim software senses when the bionic hand is closed around an object and it can send a signal telling the limb when to stop applying pressure. This is an innovation that far exceeds the classic pincer grip of the earlier i-LIMB Hand model. The Bluetooth wireless connectivity and BioSim software allow clinicians, prosthetists, or the end users to connect to it and activate certain features and make adjustments. The i-LIMB Pulse now has the ability to automate different grip patterns and features; e.g., pointing with an index finger or making a pinch movement, such as a three-fingered pinch.

The i-LIMB Pulse is also a much slimmer and more like a human hand in appearance-in much the same way as the robots in The Terminator movie looked human. There are now off-the-shelf male and female model bionic hands that are available in 10 different skin tones; people also have the ability to customize their prosthesis with hair and even freckles.

Premier Supplier
Today, Touch Bionics has about 90 employees. The founders provided the majority of the seed money, though the company recently received an undisclosed sum from outside investors. Touch Bionics is currently the only vendor with a commercially available product. Although other firms are actively developing similar devices, Touch Bionics is the clear market leader by virtue of its experience and the accelerated pace of its research and development efforts.

The i-LIMB Pulse cements and solidifies Touch Bionics’ position as the premier supplier of bionic upper limbs, which have robotics at the core of their technology. It marks a significant step in the evolution of upper-limb bionic prosthetic devices. The BioSim software enables Touch Bionics to add new features via software updates, which is extremely beneficial for the company, clinicians, and the users. It also obviates the need to build an entirely new robotic hand. This, in turn, reduces the amount of money spent on R&D and accelerates the time it takes Touch Bionics to bring the next generation of the i-LIMB to market. Company executives are predictably mum about when or what new features the next-generation i-LIMB device will incorporate, but they acknowledge that it probably will be in less than three years.

Next Steps
Touch Bionics should now launch an aggressive marketing campaign to raise awareness of its bionic upper-limb technology in order to attract the attention of additional doctors and clinicians who can, in turn, promote more widespread use. Once the device is commoditized, the list pricing will decline commensurately, making it more acceptable to insurance companies and more affordable for persons who may lack insurance or have only limited coverage. Meanwhile, though, the i-LIMB Pulse bionic hand is a significant milestone in prosthetic robotic limb technology.

The Bottom Line

  • Touch Bionics has released i-LIMB Pulse, an advanced, fully articulating myoelectric prosthetic upper limb that builds on the success of its precursor, the i-LIMB Hand.
  • The i-LIMB Pulse incorporates a number of new hardware and software technologies that will enhance the lives of its users, solidifying Touch Bionics’ leadership position as the premier supplier of upper-limb prosthetic devices.
  • Touch Bionics is currently the only vendor offering commercially available upper-limb bionic technologies, although a number of companies are developing similar products.