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Concepts in Human Factors Engineering (Part 11 of 11)
Concepts in Human Factors Engineering (11): The Bionic Worker of the Future
By Dennis R Andrews PhD, PSP, CECD (ExpertPages member profile page)
The human body is a very complex mechanism. Engineers have been analyzing the human body as moderately comparable to machine functions. While this may be easier to understand it should not be considered exacting. The tendon or bone of the body is not a cable or moment arm when it relates to individual strength the comparison should only be made from a biomechanical standpoint.
|Concepts in Human Factors Engineering is a series containing eleven articles:|
Body part replacement has reached a level of technology where artificial joints and limbs are almost an everyday occurrence. Dental implants or false teeth have been around for quite some time but technology has allowed a better form of dental implants then in the past. It is said that George Washington was not only the founder of our country but one of the first artificial dental implants known as wooden teeth. Knees are a crucial and complex part and a quite fragile area of the lower limbs. The ACL, anterior cruciate ligament, is usually stretched and torn due to the heavy forces placed upon it in everyday life, especially for athletes. Without this ligament the knee can dislocate and severely injure other components of the knee. This ligament is usually replaced using a graft from the patient donor. This operation is not always successful for many reasons one of which is man cannot replace such a delicate part as well as nature does.
Artificial organs are more complicated to replace and repair then and ACL. Skin is replaced for serious burn victims by graphs from other parts of their bodies or artificial skin, which has recently been available and grown in the laboratory with the latest technology. The Lungs main function is to supply oxygen but other functions are performed such as filtration of the blood etc. At the present time no artificial lungs can mimic the real thing and the best the artificial lung can do is act as oxygenators. Kidneys are similar to lungs in that it exchanges mass, with the lungs its oxygen and carbon dioxide with the kidneys its waste in the blood. Kidneys have been successfully implanted but only the removal of wastes is back to 100 percent other functions are not so successful. A successful kidney transplant patient will be required to take anti-rejection medication as well as medication to perform the regulatory functions a transplanted kidney cannot. One of the most heralded and scientific breakthroughs have been with human heart transplants and minimal success with mechanical hearts. Even with today's technology the pumping mechanism of the human heart cannot be satisfactorily re-created. The heart is such a complicated organ the electronic pulses are difficult to mimic as well as the increase of heart rate when needed.
Artificial hearing aids have been around for many years and had been getting smaller and smaller which increases the demand for its use. Seeing artificially is still not within our technological capabilities at this point in time. There has been some moderate success with cornea transplants but medical technology has not advanced to what would be considered a very successful stage. Ironically our technology has advanced to a point where our motor vehicles are capable of seeing in the dark, taking action on its own and knowing exactly where we are using GPS but the human body has not progressed to this advanced state of artificial senses.
In summary engineers, and mainly biomechanics, view the human body as a mechanical structure of varying degrees of complexity. It is relatively simple to replace a bone with a metal rod or even understand the movements of the hand and fingers. Recent developments have allowed a few hand transplants but the jury is still out as to the degree of success. Sensation in the fingertips may come back but not at the level they once were. Biomechanics is a science attempting to analyze and treat the body as a machine, which i
References and End Notes
Alvin S. Hyde PhD MD, Crash Injuries: How & Why they Happen (HAI Key Biscayne Florida 1992), 50
Alan J. Watts PhD et. al., Low Speed Automobile Accidents-Biomechanics (Lawyers & Judges 1999), 195
John H. Dirckx MD editor, Stedmans Concise Medical Dictionary (Williams & Wilkins 1997), 471
Yoichi Watanabe et. al., Relationship Between Occupant Motion & Seat Characteristics in Low Speed Rear Impacts (SAE 1999-01-0635, 1999), 8