My Two Cents on Prosthetic Hands

Three-dimensional printed hand is a product which revolutionary narrows the gap between a person's need and an affordable solution. In our world today, a prosthetic hand which can substitute a real hand, will usually cost around 30K$ to the end customer. In a time when many people with disabilities can't even afford basic products such as medicine, a pricy prosthetic hand is an unreachable and frustrating dream.

Right picture: Me and Prof. Matan Ninio with Haifa3D's prosthetic hand, developing low cost and improved prosthetic hand (left picture), with HandOn team in TOM:TLV 2015.

Is a Prosthetic Hand a Basic Need? For my readers who don't know how it feels like to use only one hand, I recommend try starting your day doing everyday life activities while using only one hand. To make the experience even closer to reality try not using the dominant one. Try it for an hour: getting dressed, taking care of you hair, brushing your teeth, washing your face, using the toilet, preparing coffee and food, eating breakfast and more. Than please answer the question: is a prosthetic hand a basic need? My answer will be: Hell, Yes.

Revolution in Our Time Accordingly, many people and businesses have tried and succeeded in creating 3D printed hands, that operate without electricity and cost up to 100$ to print. It is important to notice, that this revolution is relevant to many other products for people with disabilities. The inadequacy between the person's financial abilities to the product's cost, is clearly not only a moral problem, but also a huge business challenge. The claim that a product's cost is outrageously high because the target audience of people with disabilities is small, became ridiculous once the audience was exposed to online prices. I could argue that the sizes of the target audiences of people with or without disabilities are similar enough to make a product's price the same, but it is for another discussion. Nothing is stronger than viewing two products that are almost the same, one is for disabled and the other is not, when the first product is highly-priced while the other one is priced at a mere fraction of that. For example:

This is a deliberate and embarrassing exploitation of a captive market, and the time has come for a change. Companies who gained to understand that, are now redesigning their products or inventing new ones which are more financially suitable for their markets. Open Bionics who participated in Intel's "Make It Wearable" competition at the end of 2014, and won the 2015 James Dyson prize, developed a 3D prints custom-made lightweight prosthetics that can be cheaply and quickly fitted to those with missing limbs. They also teamed with Disney and created 3D printed superhero prosthetic arms for children, that will be available, they say, at the end of 2016. The low-cost robotics company believes they will be able to price them at $500 -$1,000 USD. To help keep the cost as low as possible, Disney has waived all royalties.

Hand Motor Skills To examine the 3D prosthetics quality we will need to understand the basic functionality required first, so I went and did my small research. I talked with occupational therapists, specialists in hands rehabilitation, prosthetics professionals, and of course "my right hand" Suzanna, which is Cassit's occupational therapist, and asked them about it.

The first issue I had to pay attention to was that unlike lower body prosthetics, who function with gross motor skills, the hands use both gross and fine motor skills. It is far more complex to compensate for the lack in fine motor skills than for gross motor skills. With fine motor skills we need to regulate the power and accuracy control, from very low to very high levels. Take the example of getting dressed: you have to pull up your pants or pull down your shirt or dress: an activity that uses both gross and fine motor skills. By moving your hands above your head you use gross motor skills, by holding the fabric between your fingers and pulling it you use fine motor skills. In the range of many fine motor skills, one major challenge is: the pinch grasp.

The Pinch Grasp

The pinch grasp is, in my eyes, the main matter that needs to be taken care of in low-cost hand prosthetics today. The most common 3D printed hand of the leading company in this field, eNABLE, allows gross motor skills. In the developed world, it is relatively easy to find and download three dimensional hand files from open-source platforms, and print them in various shops today. It is not yet easy to assemble and if you will use a simple home printer you might face challenges with the sizes, plastic supports and other technical issues, but the progress of 3D printers is amazing. It is safe to assume that soon enough we will have an easy-to-use home 3D printers. While participating as a mentor in TOM:TLV – a 72 hours marathon to create solutions for people with disabilities, I joined a group that was assembled on the spot. Our goals were to take the simple eNABLE prosthetic hand and to add to it two elements: the first one is the pinch grasp, demonstrated in our video below. The second one was to add a feedback that is not visual.

Non-Visual Feedback A person shouldn't continuously look at his hand to get the feedback that he is touching something, but the feedback from a mechanical prosthetic hand is only visual. In cases such as driving, one has to have another feedback, other than visual, to know he/she is holding the wheel. The feedback can be taken by sound, touch, muscles etc.

Imaginary World Let's take a short look at the far end of prosthetic hands: probably the wet dream of every person with amputated arm. Darpa (left picture below) created a prosthetic hand that connects directly to the brain, and allows to "feel" physical sensations. Its cost: 100,000$. In the United States alone, which is one of the superpowers with the highest purchasing power in the world, there are 1.6 Million upper limb amputees. How many amputees in the world can actually pay for that? Another prosthetic hand, the bebionic3 (right picture below) was developed by Leeds-based assistive living company RSLSteeper and can form multiple grips. Its cost: 25,000-35,000$. In an imaginary world, we would supply the best prosthetic hand to everyone who needs it. In real life, according to the WorldBank/ 2012, only 25% of the world low income population has access to electricity, to begin with. Those 4.5 Billion people, who can't pay the 30K$ because they earn 2$ a day, will probably never hear about those prosthetics due to the lack of access to information.

Doing Good and Doing Well

Haifa3D's prosthetic hand with HandOn team in TOM:TLV 2015

30,000$ for a hand. Its parts, I assume, cost at most 1000$. What if many customers would have been able to purchase this hand for an affordable price. What a dream. We can think not only about how much more purchases there would be, but how much joy it would have bring to this world. We have become accustomed to live in a society that is pricing its products by status rather than by need, a society that enriches the rich and abandons the poor. Don't we all live in this world? It all comes down to how we experience our lives. Are we in prolonged chase after the economic well-being, or whether relationships between people is what matters to us, love thy neighbor, mutual responsibility? I believe that money is just a tool and love is the main motive, and businesses are now starting to understand that doing good and doing well not only can live side by side, but also meant to exist together.