There seem to be a couple of problems inherent in the tech field of prosthetic design. First and foremost of them is that comparatively few people need artificial limbs, so not enough of them are manufactured at once to bring the cost down. A second problem is that because so few people tend to need them, designs don't seem to improve very rapidly. When enough of anything are not constructed, there isn't enough pressure for bugs to be ironed out rapidly, nor for designs to evolve in positive directions so relatively simple advances may not appear soon. Business and industry …