Prosthetics

Replacing our body partsProsthetics

When a lizard loses his tailSome lizards can grow them back, like this green anole lizard below. But as you can see, the regenerated tail is not quite the same as the original tail.

Regrown tailThis is the Mexican axolotl

It can regrow all different parts of its body. Even its brain. This is a favorite animal to study by developmental biologists.We only have one part of our body that we can regrow. Can you guess what it is?Hint: people can donate part of theirs to someone who needs a transplant.

Its the liver!

Once you lose a part of your body Its gone. Its not going to grow back.

Arms! I have no arms to bear! What can I do?What do people do when they are missing a body part? Hide in the cellar and never come out?Hire people to do all the things that they cant do?Get a prosthetic to live a more normal life?

I recommend getting a prosthetic to live a more normal life. What is a prosthetic?A prosthetic is an artificial extension that replaces a missing part. It is used to replace body parts lost by injury, missing from birth, or to give more support to a defective body part.

The purpose and benefit of a prosthetic body part isTo restore function of lost limbsTo help with movement in daily activitiesProsthetics are made for animals as well as humans

The oldest prosthetic was foundOn an Egyptian female mummy. Scientists believe she could walk both in sandals and barefoot. This prosthetic big toe dates back to 750-910 BC.

In the past, People made do, or did without, depending on what they could afford.Prior to 1840, most people did not survive an amputation. As medicine improved, more people with amputations survived. They wanted better prosthetics, especially the injured soldiers after WWI and WWII .

Prosthetics can be very expensive.Jeff Powell came up with a way to make inexpensive prosthetics for children. Watch the video:Jeff Powell and 3D printing

What do you have to think about when designing a prosthetic?Where is it located? Are joints necessary?How strong does it have to be? How much will it weigh?How will the prosthetic be attached to the body?What is available to make the prosthetic?How much will it cost? Can people afford it?

Bioengineers have to think about all these things when they design prosthetics for people and animals.

What does the prosthetic have to do?Look like the real body part it is replacing: a cosmetic prosthetic

Mimic normal body movements: a functional prosthetic

Perform a specific activity, for example running: a specialty prosthetic

Basic parts of a prosthetic footSocket (Interface) is where the prosthesis meets the body. Pylon (Component) is the working part of the prosthesisFoot (or hand)Cover is the outside material used to make the prosthesis look more lifelike.

Types of Artificial LimbsTransradial: Replaces the arm below the wrist, includes wrist, hand and fingers. Transhumeral: Replaces the arm from above the elbow to the fingersTranstibilial: Replaces the leg below the knee to the foot.Transfemoral: Replaces the leg from above the knee to the foot.

What are prosthetics made of?Today prosthetics are made of modern materials such as:Specialty plasticsCarbon fiber compositesElectronic components to help for better control of movement

This allows the prosthetic to be stronger, light, and more realistic, both in looks and function. No more heavy and clunky peg legs and hooks!Now you get to be an bioengineer!Goal: design and build a low-cost, artificial hand for a child.The hand needs to be able to pick up simple objects that could be at a lunch table, such as a dixie cup, paper plate, plastic utensils, napkin, plastic water bottle, and a bottle cap.

Hand RequirementsMade of simple materialsAble to pick up and hold an object

Testing and EvaluatingYour hand will be evaluated by your team and your peersYes, you will have the opportunity to redesign and retest your hand. Thats what engineers do all the time!

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