Features

ToughWare Prosthetics, an engineering and design group dedicated to developing innovative new assistive technologies, helps satisfy the global need for prosthetic devices that are inexpensive, designed to enable intense physical activity, labor, self-reliance, and are easy to maintain. The company, inspired by the many personal stories of hope, strength, determination, and endurance shared by amputees around the world, became aware of the great need for inexpensive assistive devices that are robust and highly functional.

Fig. 1 – The V2P device shown open, at left, and closed, at right.
Part of ToughWare’s commitment to drive innovation and create conceptually radical technologies is focused on matching and enhancing the needs and capabilities of each individual prosthetics user, the company began working with independent prosthetics manufacturers crafting assistive appliances for amputees who have lost hands and portions of their arms.

As the company’s devices gained popularity, military hospitals such as Brooke Army Medical Center and Walter Reed National Military Medical Center began requesting units fabricated from stainless steel for use by veterans. Through these collaborations, ToughWare successfully created a new prosthetic terminal device made out of stainless steel that allows strong military veterans to maintain their active lifestyles, while remaining affordable to the end user. The prosthetic devices for the project were unique in that they required additional strength and robustness not often required for other uses.

ToughWare used its Variable Pinchforce Prehensor™ (V2P) technology as the basic design platform, offering voluntary opening, six quick and easy pinch force settings, in-line elastics to provide shock absorption and additional stability, and ergonomic contours for enhanced gripping. Since users required the additional strengthening capabilities of stainless steel, ToughWare had to determine the ideal casting solution that would not only increase the prosthetic’s strength but also remain light enough to wear for every day usage.

Price quotes for the production of the prosthetic hand components through investment casting and conventional machining ranged from $5,000 to $10,000 for a one-part order with a two to eight week delivery time. Believing the cost and time constraints for using traditional methods were prohibitive, ToughWare actively explored alternative technologies in hopes of finding a more inexpensive solution.

Solution

Through its exploratory process, ToughWare discovered ExOne, a leading additive manufacturing company with 3D metal printing technology, capable of creating complex stainless steel/bronze matrix parts. For the precise parts ToughWare requested, ExOne was able to offer pricing between $100 and $150 for each piece, a drastic cost reduction from the multiple thousand dollar quotes ToughWare had been receiving previously, and could be delivered within a few days, instead of a few weeks.

ExOne’s digital part materialization uses 3D printing technology to create fullform parts directly from CAD data for a variety of industrial, commercial, and art applications. The additive manufacturing process is capable of geometric complexity, unmatched by conventional manufacturing methods. Components produced by ExOne — both large and microscale — can reduce weight, integrate multipiece assemblies, enhance product functionality, and significantly reduce lead times for prototype and short-run productions.

The company worked directly with ToughWare to develop each unique V2P device — in batch sizes ranging from eight to 20 pieces, with individuals parts sized about 3½ inches long and having complex contours. Both companies partnered for the entire process, from the initial concept and R&D stages, through the testing of grip strength, pressure, durability, and weight, among other key attributes, all the way to the final printing of each unique part. Utilizing additive manufacturing to build each individual piece layer-by-layer from a digital CAD design, the pieces were eventually condensed from multi-part assemblies to single piece parts, vastly reducing ToughWare’s back-end assembly time for the completed device from a few hours to less than 15 minutes. (See Figure 1)

“ExOne’s additive manufacturing process afforded us not only faster production time, but also provided us with a significant reduction in costs,” explained Bradley Veatch, founder and CEO of ToughWare. “For the first time, ToughWare was able to configure complex part designs while creating more elegant designs not possible with traditional casting.”

Additive manufacturing’s layer-by-layer creation method afforded the unique ability to incorporate hollow parts with interior strengthening structures that cannot be cast or conventionally machined and reduce the weight of the components without sacrificing necessary strength. Customers enjoy devices having visually appealing, complex contours for increased utility and comfort, with all of the benefits and strength of steel.

“I’m not sure if any other process besides additive manufacturing would be able to make the exact products our customers need to perform their specific daily functions at a high level,” Veatch added. “The future has arrived and the possibilities are endless — we’re already creating next-generation products that leverage even more of the advantages of additive manufacturing.”

As a result of the success that ToughWare experienced using ExOne’s additive manufacturing process for the development of the initial order of V2P devices, the company has asked for additional orders of similar prosthetic devices as well as help in creating necessary tooling and the development of additional prosthetics, including the Retro Classic Hook, an updated device similar to one that enjoyed wide popularity in the American Midwest that still retains its desirable features, combining them with new age benefits and improvements.

This article was written by Nick Studley, Sales Manager, ExOne The Americas, North Huntingdon, PA. For more information, visit http://info.hotims.com/40440-166. For more information on ToughWare Prosthetics, visit http://www.toughwareprx.com.