Different Prosthetic Body Parts

In medicine prosthetic body parts, also called prostheses, are artificial extensions that replace a missing or defective body part due to accident, traumatic injury or congenital disease (where the parts are missing from birth). Prosthetic body parts belong to the field of biomechatronics, which is the science of combining mechanical devices with the skeleton, muscles and nervous systems to enhance or support motor control loss due to defect, disease or trauma.

Lower Extremity

• Lower extremity prosthetics are the replaced limbs located at hip level or lower. They can be subcategorized as transtibial (or below the knee prosthesis, "BK" for short) and transfemural (or above the knee prosthesis, "AK" for short). BK is any amputation transecting the tibia bone and AK is any amputation transecting the femur bone. Other less common lower extremity cases include hip disarticulations, knee disarticulations, and symes (ankle disarticulation).

Arms

• Prostheses are also available for replacing below-elbow and above-elbow body parts. The most common types of arm prostheses typically make use of metal, plastic shells, hooks and mechanical devices. More advanced prosthetic arms use robotics or lifelike replacements using silicone or polyvinyl chloride.

Robotics

• In recent years robotics has been widely integrated into creating prosthetic limbs. Most of these devices use biosensors that detect signals from the nervous or muscular systems and process feedback from the limb and actuator, mimicking muscle action in producing movement and force. The signals are processed and relayed to a controller inside the device. Some examples of biosensors include needle electrodes implanted in the muscle, wires that detect electrical activity on the skin and solid-state electrode arrays where nerves can grow through them.

Cosmesis

• Cosmesis is an advancement which involves the creation of lifelike limbs, typically made from silicone or polyvinyl chloride. One example is an artificial hand that mimics the appearance and movement of real hands complete with veins, freckles, fingerprints and hair. Ready-made cosmeses come in various sizes while custom-made ones are generally more expensive, costing thousands of dollars. Depending on the design cosmeses can be attached to the body using suction, adhesive, skin sleeve or form fitting.

Neuroprosthetics

• Neuroprosthetics can be either neuromotor or neurocognitive. Neuromotor involves nerves and muscles while neurocognitive modulates and detects neural function to augment or reconstitute cognitive processes such as language, memory, attention and executive function. This technology is still largely under development. It aims to help patients with cerebral palsy, autism, traumatic brain injury, stroke and Alzheimer's disease among others.

Organs

• While most prostheses are external, there are also internal prostheses such as artificial heart valves which are becoming more common.along with artificial lungs. Artificial hearts are less common but are still under active development. Some medical aids and devices that can be considered prosthetics include gastric bands, artificial eyes, palatal obturators and dentures.