0011 Schaub 6:00
L18
RECENT ADVANCES IN UPPER-LIMB PROSTHESES AND THE
SHORTCOMINGS OF PROPRIOCEPTIVE FEEDBACK TECHNOLOGY
Emily Brindley (ecb44@pitt.edu)
INTRODUCTION: CURRENT
PROSTHESIS TECHNOLOGY AND THE
PROGRESS STILL TO BE MADE
In the past decade, the technology of prosthetic limbs has
made great advancements. The U.S. Defense Advanced
Research Projects Agency (DARPA) has been focusing
funding on projects designed to advance prostheses
technology [1], a worthwhile endeavor as it aims not for
empty advancements, but for positive changes in the lives of
amputees.
This funding is targeted specifically toward upper limb
prosthetics research and development as upper limb
prostheses remain woefully short of the capabilities of flesh
and blood limbs [1]. Because of the devastation that can and
typically does accompany upper limb loss, the continuing
development of prosthesis technology is an absolutely
necessary and worthy endeavor. Recent advancements in
prosthesis
technology
include
myoelectric,
or
electromyogram, control as well as the specialization of
terminal devices.
Despite these advances, prosthetic
technology remains largely incapable of providing
proprioceptive feedback [3], a shortcoming that must be
accounted for if prostheses are to undergo continued
advancement.
BACKGROUND INFORMATION ON
PROPRIOCEPTIVE FEEDBACK
TECHNOLOGY IN CURRENT
PROSTHESES
The most prominent drawback of modern prosthetic
limbs is their lack of proprioceptive feedback, which limits
the movement and capability of the artificial limb.
Currently, the only reliable sensory feedback is visual,
which necessitates increased and unnatural attention to the
artificial limb and considerably restricts the capability to
execute precise motions.
One possible solution to the proprioception problem is
“directly interfacing…afferent peripheral nerves using
signals derived from the prosthesis” [6]. This method,
though, has not yet left the hypothetical stages of
development, as researchers are still attempting to
understand how the brain processes sensory input and adapts
to new stimuli [6].
The development of proprioceptive feedback technology
has the potential to entirely alter the lives of amputees,
allowing them to participate in physically stringent activities
University of Pittsburgh, Swanson School of Engineering 1
Submission Date 2013/10/01
and to be self-sufficient in their daily lives. Continued
research and development is necessary if prostheses will
ever be able to truly replace native limbs.
ETHICAL DILEMMA
As stated above, current proprioceptive feedback
technology has not left the hypothetical stages. However,
imagine that a company has recently made a significant
breakthrough and has developed a method of interfacing the
nerve system with the mechanical prosthesis. Only shortterm testing has been conducted on this interfacing method,
and it is suspected that the materials that must be used in this
new technology will cause neural and brain damage during
long-term use. Despite this, the company wishes to send the
technology on to mass testing and, as soon as possible, to
place the technology on the market for public use. The
potential dangers of the interfacing technology would be
hidden from the public and, by the time problems begin to
manifest themselves, the company hopes to have a solution
prepared. As a key member of the technology development
team, I have the power to announce the dangers of the
interfacing method; though doing so would almost certainly
cost me my job. My other option is to allow the technology
onto the market while working on a solution to the future
problem, knowing that in the mean time many amputees
would find happiness in the regained use of their lost limb.
CONSULTATION OF ENGINEERING
CODES OF ETHICS
In order to decide how to proceed in this situation,
consultation of the engineering ethics codes is essential.
First, consider the overarching engineering code which
applies to all engineering fields; the National Society of
Professional Engineers (NSPE) provides several guidelines
on matters of deception and public endangerment. In
scenarios where the safety of others hangs in the balance, the
NSPE states that this safety should be held “paramount” to
all other concerns, and that the proper authorities should be
notified if an individual is unable to control the situation on
his own [7]. Following these guidelines, it is clear that the
new proprioceptive feedback technology should not be
permitted on the market, as it risks the safety of anyone who
uses it. However, the potential benefits of the technology
must also be considered. Allowing the interfacing method to
be put into use would greatly improve the quality of life of
many amputees, with no guarantee that problems will arise
Emily Brindley
in the future. The safety of patients must be weighed with
their happiness in order to properly evaluate this issue.
In addition to safety guidelines, the NSPE discusses
the presentation of information and research. Engineers
should “issue public statements only in an objective and
truthful manner,” and should include “all relevant and
pertinent information” within the report [7]. This code of
ethics specifically denounces deception in engineering,
which would be necessarily included in allowing the public
to have access to the new interfacing method. Because the
potential dangers of the technology are known (or at least
highly suspected), withholding this information conflicts
directly with the engineering code of ethics. Again,
however, such omission could be justified by reasoning that
these dangers are a long way off, and a solution to any issue
could be found before the repercussions become irreversible.
Such reasoning is not entirely sound, as the exact nature of
the potential dangers is not known, and therefore there is no
guarantee that they can be reversed or even prevented.
As this scenario is entirely within the field of
bioengineering, consulting the Bioengineering Code of
Ethics is also advised. The Biomedical Engineering Society
addresses the ethical responsibilities of bioengineers; their
code states that bioengineers have a responsibility not only
to public safety, but also that “responsibility
to...patients…[is] their primary concern” [8]. In addition,
bioengineers are responsible for “accurately and clearly”
presenting all research information [8], which would include
addressing all potential dangers with newly developed
technologies.
Supreme to all of these specific
responsibilities, bioengineers should be committed to
“increasing the prestige and honor of the biomedical
engineering profession” [8], which necessitates honesty in
reports and candor where health risks are concerned. These
guidelines leave little room for misleading the public about
the new interfacing method.
It is possible, however, to justify breaking these
ethical guidelines for the greater good of the patients, who
would receive the technology more quickly. The code of
ethics does state that bioengineers must “consider the larger
consequences of their work” [8], which could be interpreted
as a permission to blur the other guidelines for the greater
good. Specific to this scenario, it may be reasoned that the
greater good would be served by allowing access to this
technology now with the intent to solve any problems
retroactively, as these problems are not of immediate
concern. Though the bioengineering code of ethics decries
deception and endangerment of the public, it also encourages
a commitment to the big picture, which may at times permit
the previously denounced behavior.
Though the ethics codes point toward legalistic, rigidly
correct behavior, some scholars have been calling for a shift
in the way engineers approach ethics. The rule-based ethics
of the past, called preventive ethics, focuses on the
avoidance of “professional misconduct and harm to the
public” [9]. However, many are calling for the adoption of
aspirational ethics, which concerns itself much more with
the “promotion of human well-being” [9]. Applying this
perspective change to this situation, it may be reasonable to
allow the new interfacing method onto the market, as this
would enhance the wellbeing of amputees in the short-term.
The underlying assumption is that there would be sufficient
time to find a solution to any future problems, though this
assumption may be incorrect. If a worst-case scenario is
considered instead of assuming that a solution will be found,
the opposite conclusion is reached. That is, if a solution to
the potential damage cannot be found, then patients using
the new technology in the long-term will ultimately suffer
more from the use of the technology than they would have
suffered without it. Assessing this situation with regard to
the wellbeing of the public results in opposite conclusions
depending on whether or not a solution to potential issues
can be found.
If I were to subscribe to the concept that deception
is permissible where it may serve the greater good (an “ends
justify the means” perspective), I must then establish
whether or not deception is permissible in this specific
situation. This situation certainly does involve deception,
even though it includes the deliberate omission of a truth
instead of the assertion of a falsehood. Deception is the
“intentional attempt” to lead someone to false conclusions,
which can be done “with or without asserting something”
[10].
I must now determine if this deception is a morally
allowable act. A consequentialist view of lying and deceit
asserts that “an action is right if it has the best
consequences” [10]. Using this definition, I might argue that
the best consequences would include keeping my job and
allowing my company to become successful. However,
looking at the big picture, it is clear that the potential longterm consequences of patient harm and even death are larger
detriments than the positive outcomes are beneficial.
Though neither outcome is ideal, the best consequences
occur when patients are kept out of `harm’s way. For this
reason, even the consequentialist, non-legalistic perspective
struggles to justify putting a dangerous product on the
market for public access.
CONSULTATION OF ADDITIONAL
ETHICS RESOURCES
At this point of reasoning through the scenario, multiple
ethical resources have been consulted and the situation has
been viewed from the perspective of its consequences on
others. Though all of the possible impacts on the “greater
ADDITIONAL RESOURCES AND
ADDITIONAL CONSIDERATIONS
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Emily Brindley
good” have been considered, there is one relatively undiscussed effect of taking or not taking action. As much as I
would like to imagine that I would only be concerned with
what is morally right, the reality is that if I were placed in
this situation, I would also be concerned with what would
happen to me if I were to denounce the actions of my
company. More than likely, taking action in this way would
cost me my job. Depending on my own situation and the
state of the economy, this may be a considerable concern.
Though at this point I have fairly well reasoned that the only
moral behavior is to notify the public of my company’s
intentions, fear for my own welfare would likely lessen my
resolve on the matter.
“Retaliation against the
whistleblower” is a reasonable and expected outcome in
these types of situations [11]. However, after considering
the magnitude of the harm that could be done to many
people by this new interfacing method, the tendency towards
self-preservation must be weighed with moral obligation and
the wellbeing of others.
Once I have made my decision, a course of action
or non-action must be established. If the decision is for nonaction, then I must evaluate whether or not I can live with
this choice. Erma Bombeck once declared that guilt is “the
gift that keeps on giving.” If allowing the unsafe technology
onto the market causes me any initial discomfort, that guilt is
only going to multiply with time. From a purely self-serving
standpoint, I must consider the effects upon myself that this
ongoing guilt will have. Will I be able to forgive myself if
people come to harm from this technology? Will I regret
this decision in the future, when I have my job but not my
good conscience? The answers to these questions may be
enough to spur me to action.
In the case of taking action against my company, I
must remember to go about it carefully and deliberately.
Nothing will be achieved if I call out my company correctly,
but with inadequate proof to back up my claims. With
appropriate documentation and evidence, it is possible even
that I may retain my job while simultaneously preventing my
company’s dishonest conduct [11]. Though this end result is
less likely, in any case I must approach the whistleblowing
delicately, calmly, and with great attention to detail.
think that staying silent would be morally wrong, I would
consult several codes of ethics to determine what was
expected of me in such a context. These ethics codes would
undoubtedly confirm my previous suspicion that silence
would be immoral, and at this point I would have arrived at
my conclusion nearly unshakably. However, in order to
entirely confirm this conclusion, and also to provide me with
sufficient courage to follow through with my intentions, I
would read through several articles on deception and truth
telling, as well as consider some common adages about lying
and guilt. At this point, I would have chosen definitely to
take action against my dishonest company, and, with the
additional confidence from my research, I would proceed to
document the misconduct to the best of my ability and to
report it to the appropriate authorities.
CONCLUSION: THE RESOLUTION OF
THE ETHICAL DILEMMA
It is undeniable that prosthetic technology would be
greatly improved with the advent of proprioceptive
feedback. However, such improvements to the field do not
justify unsafe shortcuts or the endangerment of patients.
Though it is possible that solutions and damage reversal
methods may be found before any problems begin to
manifest themselves, the risk is too great to be justified. Not
even the threat of job loss could prevent me from becoming
a whistleblower in this scenario, as the possibility of lost or
harmed lives is simply unacceptable. As a result, I would
certainly take action against my company, hoping also that
careful documentation of the misconduct would result in the
respect of my employers, perhaps allowing for a win-win
situation in which I also retain my job. Whether or not this
win-win situation is achieved, my moral responsibility to my
fellow men would prevent me from doing anything but
announcing the dangers of this technology to the public.
REFERENCES
[1] Kroeker, Kirk L. "Engineering Sensation in Artificial
Limbs." Communications of the ACM Apr. 2011: 16-18.
ACM Digital Library. Web. 28 Sept. 2013.
<http://dl.acm.org/citation.cfm?id=1924428&bnc=1>.
[3] Rouse, Elliott J., D. C. Nahlik, Michael A. Peshkin,
and Todd A. Kuiken. "Development of a Model OsseoMagnetic Link for Intuitive Rotational Control of UpperLimb Prostheses." IEEE Transactions on Neural Systems
and Rehabilitation Engineering 19.2 (2011): 213-20. Print.
[6] Gillespie, R. Brent, Jose Luis Contreras-Vidal,
Patricia A. Shewokis, et al. "Toward Improved Sensorimotor
Integration and Learning Using Upper-limb Prosthetic
Devices." Engineering in Medicine and Biology Society
(2010): 5077-080. IEEEXplore Digital Library. Web. 28
Sept.
2013.
ETHICAL DILEMMA THOUGHT
PROCESS
My thought process in order to come to a
conclusion in this situation would begin with consideration
of the danger to those who use the interfacing method.
Simply knowing that lives may be lost in the future would
likely be enough for me to take action, though I would also
wish to first consider the situation from all angles. Firstly, I
would consider the outcomes of both options:
whistleblowing and remaining silent. I would weigh the
pros and cons of each scenario, attempting to be as objective
and unbiased as possible. Secondly, having already begun to
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Emily Brindley
<http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=56262
06&tag=1>.
[7] "NSPE Code of Ethics for Engineers." NSPE Code of
Ethics for Engineers. N.p., n.d. Web. 27 Oct. 2013.
[8] "Biomedical Engineering Society Code of Ethics
(2004)." Welcome. N.p., n.d. Web. 27 Oct. 2013.
[9] Crawford, Mark. "Engineers Must Embrace
Aspirational Ethics." www.ASME.org. N.p., Sept. 2012.
Web. 28 Oct. 2013.
[10] Bivins, Thomas H. "THE ETHICS OF
STRATEGIC COMMUNICATION."
Www.journalism.uoregon.edu. University of Oregon, 2008.
Web. 28 Oct. 2013.
[11] "Inspiring Others to Ethical Action: When to Blow
the Whistle." Inspiring Others to Ethical Action When to
Blow the Whistle. N.p., n.d. Web. 28 Oct. 2013.
ADDITIONAL SOURCES
Hochberg, Leigh R., and Dawn M. Taylor. "Intuitive
Prosthetic Limb Control." The Lancet 369.9559 (2007): 34546. Print.
Williams, T. Walley, III. "Progress on Stabilizing and
Controlling Powered Upper-limb Prostheses." Journal of
Rehabilition Research & Development 48.6 (2011): ix. Print.
Hammert, Warren C. "Update on Advances in Upper
Extremity Prosthetics." The Journal of Hand Surgery 36.10
(2011): 1711-717. Sciencedirect.com. Web. 28 Sept. 2013.
<http://www.sciencedirect.com/science/article/pii/S0363502
311009890>.
Corbett, Elaine A., Todd A. Kuiken, and Eric J.
Perreault. "Comparison of Electromyography and Force as
Interfaces for Prosthetic Control." Journal of Rehabilition
Research & Development 48.6 (2011): 629. Academic
OneFile.
Web.
28
Sept.
2013.
<http://go.galegroup.com/ps/i.do?action=interpret&id=GAL
E%7CA263880122&v=2.1&u=upitt_main&it=r&p=AONE
&sw=w&authCount=1>.
Gould, Joe. "New Prosthetic Arm Born from ‘Star
Wars'" Marine Corps Times. N.p., 10 Mar. 2012. Web. 29
Sept. 2013.
ACKNOWLEDGEMENTS
I would like to thank my father for sparking my interest
in this field of engineering. His enthusiasm for innovative
technology such as prostheses captured my attention and
was my first introduction into this integrated field of
engineering and medicine.
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