Wednesday, 5 March 2014

artificial outer ear

The outer ear
Outer ear (pinna) loss can result from cancer or trauma.  Researchers believe that in addition to improving a person’s appearance, artificial (prosthetic) ears can help improve hearing and speech recognition in noisy environments.

The function of the outer ear is to collect sounds for the middle and inner ear to process.  People with outer ear loss may have difficulty hearing and understanding speech.  Researchers at Northwestern University Feinberg School of Medicine in Chicago used models to discover that artificial outer ears improved hearing and speech recognition in the presence of background noise.  The next step for investigators is to conduct similar tests on actual patients with artificial ears.
 
Growing new outer ears

Up to a thousand troops might need an ear, and prosthetics are not a great solution. A rod or other fastener is required to attach them to the head. They don't look or feel natural and they wear out every couple of years. A matching ear grown from a patient's own cells would be a huge improvement.

Using a computer model of a patient's remaining ear, a 3D digital model was created and designed with help from a facial plastic surgeon to make sure the shape and proportions were correct.The resulting model was printed and cast in polydimethylsiloxane, a special silicone compound, to create a mould which was then split along the outer contour, resulting in two pieces.

They take a snip of cartilage from inside the nose or between the ribs and seed the scaffold with these cells. This is incubated for about two weeks in a lab dish to grow more cartilage. When it's ready to implant, a skin graft is taken from the patient to cover the cartilage and the ear is stitched into place.
Scientists  have maintained lab-grown sheep ears on those animals for 20 weeks, proving it can be done successfully and last long-term. They also have grown anatomically correct human ears from cells. These have been implanted on the backs of lab rats to kee
p them nourished and allow further research. But that wouldn't happen with ears destined for patients -- they would just be grown in a lab dish until they're ready to implant.
The researchers from Massachusetts worked with a plastic surgeon to create the 3D mould.
the above diagram shows the implants wire that keeps them in shape to give them a natural look.
limitations
 A novel way of producing a biological ear scaffold has been hatched the problem will come when it needs to be inserted into the tight skin of the head. The skin on the back of the rat was baggy and so the skin covering was easy.
If the scaffold is not strong enough it would collapse when inserted.
graft rejection might also still be an achillies foot in this discovery and the plethora of drugs that ride along it.
However this issues remain tentaive as we wait for human implants to be approved.

Tuesday, 4 March 2014

bionics

the word bionic was coined by Jack E. Steele in 1958, possibly originating from the technical term bion (pronounced bee-on) (from Ancient Greek: βίος), meaning 'unit of life' and the suffix -ic, meaning 'like' or 'in the manner of', hence 'like life'
Some dictionaries, however, explain the word as being formed as a portmanteau from biology + electronics.
Bionics, the study of the functions of living organisms for the purpose of building mechanical or electronic devices to copy or imitate these functions. Much of the work done in bionics has been experimental, but bionics has led to a number of practical medical and industrial devices. Medical devices developed through bionics include kidney-dialysis machines and computer-controlled artificial limbs. ( Artificial Limb; Kidney, subtitle Kidney Disorders: Kidney Failure.) Industrial devices developed through bionics include robots used to perform repetitive tasks, such as assembling automobile parts. Much research in bionics concerns the development of computers that can perform functions ordinarily associated with human intelligence.

In medicine

Bionics is a term which refers to the flow of concepts from biology to engineering and vice versa. Hence, there are two slightly different points of view regarding the meaning of the word.
In medicine, bionics means the replacement or enhancement of organs or other body parts by mechanical versions. Bionic implants differ from mere prostheses by mimicking the original function very closely, or even surpassing it.
Bionics' German equivalent, Bionik, always adheres to the broader meaning, in that it tries to develop engineering solutions from biological models. This approach is motivated by the fact that biological solutions will usually be optimized by evolutionary forces.