The Opti Arm
An Optical Interface Prosthetic Device

 Current Technology

       Today's prosthetics, while complex, cannot mimic the movements of a human hand. None are able to give amputees the freedom and range of movement that they once had.

  • No types of current prosthetic limbs can communicate directly with the brain.

  • There is significant lag time between the thought of movement and the actual movement.

  • Prosthetic limbs today are heavy and hard to control.

  • They are not able to replicate the complex, fluid movements of the human arm.

  • The movements today's prosthetics make are very simple, so amputees have to develop complex strategies to try to accomplish a task.

  • Prosthetics are not able to relay sensory data back to the brain.

Robotic

Body Powered

Brain-Controlled

Myoelectric

     

Robotic or motor-powered prosthetic limbs make use of microprocessors to carry out the movements intended. They are pre-programmed with commands that allow the movements of some digits and the elbow.

This type of prosthetic is powered solely by body movements made by the wearer. Mr. David Moyer, who wears a body-powered prosthetic, says they are very durable and versatile. The opposite arm of the amputee is attached to the prosthetic by a strap. When the opposite arm moves, the strap moves, and this causes the prosthetic to move.  

Brain-controlled prosthetics attempt to sense electrical signals sent from the brain to the microprocessor in the prosthetic arm.  These prosthetics are not actually connected to the brain. This technology is very inaccurate.

Myoelectric prosthetics utilize electrical signals from muscle contraction to determine the movement the amputee desires to make. Contracting a certain muscle or muscle group will trigger a certain movement. This type of  prosthetic requires much thought to execute even the simplest of movements.

Disadvantages:

Disadvantages:

Disadvantages:

Disadvantages:

  • The amputee has to activate each command manually.

  • Water and electricity don't mix.

  • The prosthetic is very heavy because the power source adds extra weight to the arm.

  • The arm has to be charged to work.

  • The arm only moves accurately when the wearer is standing upright.

  • Abnormal body movements are required to make the prosthetic move.

  • Weaker amputees may not be able to make the arm move.
  • It is hard for the prosthetic to sense the signals.

  • They are not very accurate.

  • These prosthetics require a heavy power source to operate.

  • These are very expensive.

  • The amputee has to learn the trigger movements.

  • The arm requires different attachments for different jobs.

  • Myoelectric arms are heavy.

  • Water and electricity don't mix.