Les Baugh, from Colorado, becomes the “first bilateral
shoulder-level amputee” who can control both prosthetic limbs while wearing it (“Amputee
Makes History,” 2014). Les could control both limbs by merely thinking about
moving his limbs, in addition he was able to complete a range of tasks during a
brief exercise (“Amputee Makes History,” 2014). This was accomplished thanks to
Johns Hopkins University. He went through a surgery at the university’s
hospital called targeted muscle reinnervation. This procedure involves
reassigning nerves that used to control the arm and hand and with the use of algorithms,
information from the brain can be used to create movement in the prosthetic
arms. This is a huge breakthrough for individuals that have lost limbs due to
accidents or diseases. However, would it be ethical for this procedure to be performed
on a patient with healthy limbs who wants enhanced limbs? What ethical
principles would be violated in this situation, and what if this procedure is
available for everyone like plastic surgery or Botox? If this procedure is available
for everyone are the principles of justice or autonomy violated? In this theoretical
situation, we are respecting the decision of the patient and everyone has the opportunity
to obtain this procedure.
Amputee Makes
History with APL’s Modular Prosthetic Limb. (2014, December 16). Retrieved from
http://www.jhuapl.edu/newscenter/pressreleases/2014/141216.asp
Great questions Ajay! As with all amputees and paralysis patients, the perception of self and self image are profoundly altered and can have lasting effects on the mental state of patients and their perceived abilities. The article you reference discussed the reprogramming of nerves which you wonderfully explained. The patient, an amputee named Les Baugh, received a custom-fit prosthetic that was tailored to respond to his thought patterns and created a personalized system which afforded him new ranges of movement he had no access to for the last 40 years. That is certainly no small feat, and has certainly improved Baugh's quality of life. But his prosthetic system still requires conscious control, and as seen in the video it seems that the prosthetics are very much detachable from his whole person, which make me wonder whether he perceives the prosthetics as part of himself or as separate from his person.
ReplyDeleteLast week, I read an article published in Nature, wherein researchers implanted brain-machine interface (BMI) chips into rhesus monkeys that had been chronically amputated - that is, monkeys that were not amputated for the purpose of this study. Researchers placed these chips onto the contralateral (opposite side of body; generally the side that would control the amputated limb) or ipsilateral (same side of body) primary motor cortical neurons of the monkeys. With learning, both groups of monkeys demonstrated regained function of limbs that were otherwise amputated, though contralateral chips showed faster gain of function. The neural connections grew denser, but the ipsilateral group "pruned" their connections first before growing a new, dense neural cluster.
This BMI learning has been shown in paralysis patients, but this study was novel in demonstrating a similar rewiring in amputated patients. The increasing density of the connections with practice suggest that the movements may one day become more passively controlled and gives hope that full regain of function can be achieved with prosthetics. I wonder if this is the case for Les Baugh, as well, who was a double amputee. I am tempted to believe that it would be different for patients like Les Baugh whose apparatus can be removed and reattached as needed, versus for patients who have integrated limbs.
This brings us back to some of your final questions. Certainly with the encouraging prospect of autonomous control over prosthetic limbs, there may be a temptation for some to enhance their natural capabilities with artificial appendages. There is a significant entrepreneurial opportunity in this field. If one didn't quite want to replace their existing limbs with prosthetic limbs, BMI chips may be the key to promoting long-term potentiation in a short period of time - something elite athletes may be tempted to take advantage of. Again, there is a business opportunity in creating performance-focused BMI chips for enhancing motor movements, both for the elite market, and also for everyday individuals with loss-of-function due to age, neurodegenerative disorders, amputation, or birth defects. There is a tremendous capability for improving the quality of life for many patients and otherwise normal people. The discussion then shifts to asking whether anyone can control who gets to decide who is worthy of receiving such technology with so much potential for a better life. There is much research that needs to be done, but what an interesting can of worms this area of research has opened up.
Balasubramanian, K., Vaidya, M., Southerland, J., Badreldin, I., Eleryan, A., Takahashi, K., . . . & Hatsopoulos, N. G. (2017). Changes in cortical network connectivity with long-term brain-machine interface exposure after chronic amputation. Nature Communications, 8(1). doi: 10.1038/s41467-017-01909-2
Link to open article: https://www.nature.com/articles/s41467-017-01909-2