Aug. 8, 2014

Recognizing a need for affordable bionics, GE Engineer & Technologist Lyman Connor was inspired to use his expertise and the tools at his disposal to reinvent the bionic hand.

Last October, Connor had a serious cycling accident and when he waked up he was in an intensive care unit in a local hospital. When he was leaving the hospital he met a young boy in the elevator who had obviously been upset for something. Connor tried to cheer him up by saying "hey, can't be that bad, look at my face, look at all that scars." And the young boy raised his hand, and said that "at least you were born with a whole hand."

Connor didn't have any words for the boy. But it inspired him to build an affordable bionic hand for those in need.

Connor is a single father of four children, three of which are young adults and his youngest is 11. He is originally from Indiana, Pa which is a quiet country town 50 miles from Pittsburgh, Pa. Connor has worked in multiple roles and industries throughout his career and is a firm believer that technology is portable in the sense that you can utilize your accumulated knowledge to work in any industry.

After the encounter in the hospital, Connor was eager to learn how everything works to build a bionic hand using 3D printing. "Once I started doing the research I became enthralled with the notion that I could do something similar at a fraction of the cost using my skills." Connor told us. "I have an extensive electronics foundation acquired via college and the United States Navy so I was able to piece together the hardware requirements quickly and write some initial code that provided me proof of concept."

Connor started out reading white papers published by Universities into their Bionic research projects and researching all that has been done in the RoboHand project in South Africa.

"You'll find all forms of actuation methods that have been perfected, string, pneumatic, hydraulic, solid moldable alloys (SMA),Servos, Stepper Motors and Rare earth DC motors." Connor explained. "I then researched what the leading providers are manufacturing and I settled on the same solution using a motor drive system. I selected my initial motor and gear drive assembly and pieced my prototype together. One moment that I'll never forget was applying some dc voltage to the motor and seeing the joint bend for the first time. I relied on Thingiverse and GrabCad to give me some templates from which I modified in RHINO5. All of the structural parts were printed on my FlashForge Creator 3D printer (MakerBot Clone FDM dual extruder). Formlabs was kind enough to print those parts that needed an immaculate finish on their new FormLabs 1 SLA printer."

Connor said that his RHINO5 experience was limited to their Level 1 tutorial and he had no experience writing smartphone apps or Smart Blue Tooth interface code. But difficulties can always be surmounted by patience and perseverance. "In the end the knowledge gained and increase in confidence are well worth the effort." Connor said.

All bionic hands use myo electric sensors built into the prosthesis to initiate pre-programmed gestures. In order to initiate any of these gestures one must flex certain muscle groups in a certain sequence. "This is not a very fluid way of moving a joint or hand as there is considerable hysteresis between the "initiate reaction" and "actual reaction"." Connor explained to "Some use Myoelectric sensors and a Smartphone app."

Connor's bionic hand "Mano-Matic", uses Force sensing resistors for discrete open-close functionality. Another 25 pre-programmed gestures can be activated via a smartphone app. His smartphone app is integrated to work with a myo bracelet that is worn on the good limb. The Myo bracelet is trained to recognize hand, wrist and arm movements and associate a specific action to each movement.

"In my application the Myo bracelet is integrated directly into the smartphone app such that moving your good limb causes the app to initiate sequences in the source code which in turn cause the prosthetic to articulate to the desire position. Each sequence is initiated via the user making an "Okay" sign with the good limb and then making a subsequent gesture that would cause the hand to move."

Stress testing:

Now Connor is looking for the young man he met in the hospital elevator in Roanoke, Virginia on October 3, 2013. He didn't get the name of the young boy but he wants to help him. If you might know who he is in the area, contact Connor at

Connor hopes that he can release a final version of this DIY bionic hand in October. When being asked about the rewarding part of his effort, Connor said, "The young boy inspired me, the technology captured my attention, the realization that I could build it sustained me, the fact that I can make it very cheap, affordable and help many is the reward."

Posted in 3D Printing Applications

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Lyman Connor wrote at 8/9/2014 9:33:41 PM:

This effort can be supported at Indiegogo

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