Biomedical Engineering Reference
In-Depth Information
from birth (congenital) or to supplement defective body parts. Inside the body,
artificial heart valve are in common use but artificial heart and lungs are under
active technology development. Other prosthetics include hearing aids, artificial
eyes, dentures, and gastric bands.
Prostheses are the medical devices that are completely finished and are tech-
nically connected to the body. One such example is the artificial limb that is
made up of the C-leg, the socket, and the attachment hardware parts including
the foot. New plastics and nanomaterials, such as carbon fiber, have allowed
artificial limbs to be stronger and lighter, limiting the amount of energy neces-
sary to operate the limb especially in transfemoral amputees. New materials
have allowed artificial limbs to look realistic making transradial and trans-
humeral amputees more likely to have the artificial limb exposed.
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Existing body-powered arms contain sockets made of hard epoxy or carbon
fiber while the wrist units are either screw-on connectors featuring the UNF
1/2-20 thread (USA) or quick release connector.
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At the end of these arms are
hooks, hands, or other devices. Hands rare usually uncomfortable because they
require a large activation force unlike hooks that require a much lower force.
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Tang et al. studied whether the design of a transmetatarsal amputation pros-
thesis with a carbon-fiber plate would improve gait pattern in patients with
transmetatarsal amputations.
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In this study at a tertiary medical center, eight
male patients with transmetatarsal amputations were recruited. Nine healthy
male volunteers were recruited as the control group. A full-length standard
shoe and a transmetatarsal amputation prosthesis with a carbon-fiber plate
with a custom-molded insole, a mounted toe filler, and a thin, lightweight,
carbon-fiber plate was used. The results of the kinetic and kinematic studies
showed that the transmetatarsal amputation prosthesis with a carbon-fiber plate
improved gait pattern significantly in patients with transmetatarsal amputa-
tions. In addition, drastic shoe modifications were not necessary to have the
prosthesis inserted. The transmetatarsal amputation prosthesis with a carbon-
fiber plate indicated that it was a good alternative footwear in patients with
transmetatarsal amputations.
Nanomaterial-based prostheses have also been used for spine prostheses.
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In this study, a group of 42 patients were submitted to excision of one or more
vertebral bodies for the treatment of neoplastic pathology, with reconstruction
by prosthetic carbon fiber modular implant to obtain immediate stability, and to
stimulate solid intervertebral fusion by bone grafts introduced inside the prosthe-
sis. At the end of 26 months after the surgery, a clinical and instrumental follow-
up for all the patients showed that the use of a carbon prosthesis did not cause
short- or long-term mechanical complications. The results showed that carbon
fiber modular implant may have filled loss of bone substance of the vertebral col-
umn, allowed for immediate weight bearing, and favored bone fusion. Features of
the carbon prosthesis favorably adapted to the surgical method of vertebrectomy,
wherein (1) various components of the prosthesis adapted to bone resection of
the vertebral body even in unexpected situations and (2) connection to posterior
