Note: Descriptions are shown in the official language in which they were submitted.
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Patent application of
Chaz M. Holder
for
TITLE: ONE-PIECE SOCKETLESS MOUNTING
PLATFORM FOR A BELOW-THE-ELBOW
PROSTHETIC DEVICE
CROSS-REFERENCE TO RELATED APPLICATIONS
This invention employs the socketless prosthetic principles of my
co-pending patent application filed April 10, 2000" application number
2,304,743 for "Socketless Mounting Platform for an Upper Extremity
Terminal Device and Prosthetic Limb Suspension System".
BACKGROUND-FIELD OF INVENTION
This invention relates to the field of human limb prosthetic devices;
specifically, upper extremity, below-the-elbow.
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BACKGROUND-DESCRIPTION OF PRIOR ART
With the exception of my above noted invention, human upper
extremity below-the-elbow prosthetic systems typically employ either a
laminated resin or molded thermoplastic socket which act as a mounting
platform for a prosthetic terminal device and a limb suspension system.
These socket based mounting platforms suffer from a number of
disadvantages:
(a) These sockets are constructed in a multi-step process which
requires that a cast first be made of the residual limb of the
amputee.
(b) The socket type mounting platform thus created is a unique device
which will only fit an individual amputee, and any significant
change in the body of the amputee, as in weight gain or growth,
will render the socket thus created useless.
(c) A very limited amount of adjustment can be made to this system
by adding or removing prosthetic socks to the residual limb.
(d) Once the socket is fabricated it is nearly impossible to modify.
(e) This socket type design results in a heavy prosthesis.
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(f) Such a prosthesis cannot breathe and can trap moisture and
bacterial organisms leading to skin breakdown and infection.
(g) Because a socket is heavy and intimate fit of the limb in the socket
is difficult to maintain, significant loss of pronation and supination
often results.
(h) Decreased range of motion often results from socket bulk,
specifically elbow flexion or extension, which can cause loss of
function in such important tasks as eating and personal hygiene.
SUMMARY
In accordance with this invention a socketless mounting platform for
a prosthetic terminal device and suspension system comprises a one-piece
carbon fiber mounting platform incorporating a concave lifting pad, concave
counterforce pad; and a compression strap.
Objects and Advantages
Accordingly, several objects and advantages of the present invention
are:
(a) to provide a single step fitting process, eliminating hours of
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casting, construction, and fitting; because no socket is used
(b) to provide a mounting platform which may accommodate the
residual limb of almost any below-the-elbow amputee;
(c) to provide a mounting platform which can be adjusted for any
body changes in the amputee, as in weight gain or loss, or growth;
(d) to provide a mounting platform which may be easily adjusted
without adding or removing prosthetic socks;
(e) to provide a mounting platform that is extremely light;
(f) to provide an open mounting platform which will allow the skin to
breathe, and will not trap moisture or bacteria;
(g) to provide a mounting platform which will allow for natural range
of pronation and supination;
(h) to provide a mounting platform which will allow a full range of
motion when the elbow is in flexion or extension.
Further objects and advantages are to provide a mounting platform
which is inexpensive to manufacture, and can be supplied as an immediate
post-operative prosthesis. Further, the canted distal segment of the
mounting platform enhances the range of function of the prosthesis by
simulating the position of a slightly flexed human wrist. Still further
objects
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and advantages will be apparent from a consideration of the description and
drawings.
DRAWING FIGURES
In the drawings each figure has different numeric references.
Figure 1 shows the one-piece socketless the mounting platform in 3/4
view, left limb configuration.
Figure 2 shows the one-piece socketless mounting platform in left
limb configuration as incorporated in an upper extremity prosthetic system,
and its orientation to the residual limb.
Reference Numerals in Drawings
1 one-piece mounting platform 2 canted distal segment
3 medial segment 4 lateral segment
5 load lifting pad 6 counterforce pad
7 strap toggle 8 compression strap
9 suspension system 10 bowdin cable anchor
11 terminal device 12 residual limb
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DESCRIPTION - Figs. 1 and 2 - Preferred Embodiment
A preferred embodiment of the improved socketless mounting
platform for a below-the-elbow prosthetic device of the present invention is
illustrated in Figure 1 (3/4 view, left limb configuration) and Figure 2 (in
situ, left limb configuration). The invention consists of a one-piece carbon
fiber mounting platform fabricated with a canted distal segment (2), a medial
segment (3), and a lateral segment (4). A concave load lifting pad (5) is
integrally incorporated into the distal aspect of the lateral segment (4), and
a concave counterforce pad (6) is integrally incorporated into the proximal
aspect of the medial segment (3). A strap toggle (7) is affixed to the medial
segment (3) and a compression strap (8) of double-sided hook and loop
material is affixed to the dorsal aspect of the concave load lifting pad (5).
Alternative Embodiments-Figures 1 and 2
There are various possibilities with regards to the materials used in
the fabrication of the mounting platform and load lifting pad. The one-
piece mounting platform (1) may be constructed from plastic resin or
thermoplastic as well as carbon fiber. The compression strap (8) may be
synthetic belt or leather. The mounting platform may be fabricated in both
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right and left limb configuration, as well as in various sizes.
Advantages
From the description above, a number of advantages of the one-piece
socketless mounting platform become evident:
(a) An amputee can be fitted with a below-the-elbow prosthetic device
in a matter of minutes at one session, because the multiple step
casting, and fabrication process involved in socket making has
been eliminated.
(b) Almost any below-the-elbow amputee can be accommodated
because the mounting platform is fully adjustable for girth of the
residual limb.
(c) The strap which provides mechanical compression of the medial
and lateral arms can be adjusted to accommodate any changes in the
residual limb while maintaining intimate contact between the
mounting platform and the residual limb.
(d) The fit of the mounting platform is determined by the
compression strap, therefore no prosthetic socks are required to
maintain an intimate platform to residual limb interface.
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g
(e) The carbon fiber construction of the one-piece mounting platform
is lighter than a socket which uses much more material to completely
surround and enclose the residual limb.
(f) The open construction of the mounting platform allows air to
come in contact with the skin of the residual limb, and in so doing
helps to eliminate trapped moisture and bacterial growth.
(g) Pronation and supination are retained because of the positioning
of the mounting platform intimately against the residual limb in the
natural blade form created anatomically by the ulna and radius.
(h) Full range of flexion and extension of the elbow is preserved
since there is no sock or prosthetic bulk to impinge upon the elbow
joint.
Operation-Figures 1 and 2
There are two sets of operations involved in using the one-piece
mounting platform (1). The first set of operations are those involved in the
assembly of the below-the-elbow prosthetic system. The terminal device
(11) which replaces the hand lost to amputation can be attached to the distal
canted segment (2) by means of a drilled hole or by means of a prosthetic
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wrist which can be molded into the distal canted segment (2). A suspension
system can be affixed to the proximal ends of the medial and lateral
segments (3,4). A bowdin cable anchor (10) may be affixed to the one-piece
mounting platform (1) for the purposes of operating an actively controlled
terminal device (11) should one be employed. These operations need only
be performed one time and assembly of the below-the-elbow prosthetic
device utilizing the one-piece socketless mounting platform is complete.
These operations are performed by a prosthetist or prosthetic technician.
The second set of operations is the intimate fitting of the one-piece
mounting platform to the residual limb of the amputee, accomplished by
means of compression of the medial and lateral segrrlents (3,4) against
the natural anatomical blade shape of the ulna and radius in the human
forearm. The compression is accomplished by means of the compression
strap (8) and band toggle (7). This set of operations may be repeated
as often as necessary to keep the medial and lateral segments (3,4) and thus
the one-piece mounting platform in intimate contact with the residual
limb. They can be performed by either the prosthetist or the amputee.
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Conclusion, Ramifications, and Scope
Accordingly, it can be seen that the socketless mounting platform for
an upper extremity terminal device and prosthetic limb suspension system
is easy to assemble and fit, and provides for economy of manufacture.
The canted segment of the one-piece mounting platform enhances the range
of function where the prosthesis is to be employed in tasks close to the body
because it simulates the position of a slightly flexed wrist.
- it permits a single step assembly and fitting process, saving hours
of fabrication time and multiple production steps;
- it provides a means of fitting almost any below-the-elbow
amputee;
- it provides for growth or changes in the size of the residual limb
by means of compressible segments;
- it provides a means of preserving intimate fit between the
mounting platform and the residual limb without the use of
prosthetic socks;
- it provides a mounting platform that is extremely light weight,
because it does not employ a bulky socket;
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- it provides and open design that will not trap moisture or bacteria
and allows the skin to breathe
- it permits a natural range of pronation and supination by fitting
intimately against the blade shape created by the anatomical
position of the ulna and radius on the residual limb;
- it permits a full range of motion because there is no socket or
prosthetic sock bulk to reduce flexion or extension of the elbow
joint.
Although the description embodied above contains a number of
specificities, these should not be taken to limit the scope of the invention
herein described, but merely to provide illustrations of some of the present
preferred embodiments.
Therefore, the scope of the invention herein described should be
determined by the appended claims and their legal equivalents, rather
than by the examples herein given.
