Prosthesis (i.e. – artificial body members) – parts thereof – or ai – Having fluid actuator
Reexamination Certificate
2001-02-21
2003-11-11
Willse, David H. (Department: 3738)
Prosthesis (i.e., artificial body members), parts thereof, or ai
Having fluid actuator
C623S034000, C623S035000
Reexamination Certificate
active
06645253
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to prosthetic devices and more particularly to various embodiments of a vacuum pump and shock absorber for an artificial limb.
An amputee is a person who has lost part of an extremity or limb such as a leg or arm which commonly may be termed as a residual limb. Residual limbs come in various sizes and shapes with respect to the stump. That is, most new amputations are either slightly bulbous or cylindrical in shape while older amputations that may have had a lot of atrophy are generally more conical in shape. Residual limbs may further be characterized by their various individual problems or configurations including the volume and shape of a stump and possible scar, skin graft, bony prominence, uneven limb volume, neuroma, pain, edema or soft tissue configurations.
Referring to
FIGS. 1 and 2
, a below the knee residual limb
10
is shown and described as a leg
12
having been severed below the knee terminating in a stump
14
. In this case, the residual limb
10
includes soft tissue as well as the femur
16
, knee joint
18
, and severed tibia
20
and fibula
22
. Along these bone structures surrounded by soft tissue are nerve bundles and vascular routes which must be protected against external pressure to avoid neuromas, numbness and discomfort as well as other kinds of problems. A below the knee residual limb
10
has its stump
14
generally characterized as being a more bony structure while an above the knee residual limb may be characterized as including more soft tissue as well as the vascular routes and nerve bundles.
Referring to
FIG. 2
, amputees who have lost a part of their arm
26
, which terminates in a stump
28
also may be characterized as having vascular routes, nerve bundles as well as soft and bony tissues. The residual limb
10
includes the humerus bone
30
which extends from below the shoulder to the elbow from which the radius
34
and ulna
36
bones may pivotally extend to the point of severance. Along the humerus bone
30
are the biceps muscle
38
and the triceps muscle
40
which still yet may be connected to the radius
34
and the ulna,
36
, respectively.
In some respects, the residual limb amputee that has a severed arm
26
does not have the pressure bearing considerations for an artificial limb but rather is concerned with having an artificial limb that is articulable to offer functions typical of a full arm, such as bending at the elbow and grasping capabilities. An individual who has a paralyzed limb would also have similar considerations wherein he or she would desire the paralyzed limb to having some degree of mobility and thus functionality.
Historically, artificial limbs typically used by a leg amputee were for the most part all made out of wood such as an Upland Willow. The limbs were hand carved with sockets for receiving the stump
14
of the residual limb
10
. Below the socket would be the shin portion with the foot below the shin. These wooden artificial limbs were covered with rawhide which often were painted. The sockets of most wood limbs were hollow as the limbs were typically supported in the artificial limb by the circumferential tissue adjacent the stump
14
rather than at the distal end of the stump
14
.
Some artificial limbs in Europe were also made from forged pieces of metal that were hollow. Fiber artificial limbs were also used which were stretched around a mold after which they were permitted to dry and cure. Again, these artificial limbs were hollow and pretty much supported the residual limb about the circumferential tissue adjacent the stump
14
.
All of these various artificial limbs have sockets to put the amputee's stump
14
thereinto. There are generally two categories of sockets. There are hard sockets wherein the stump goes right into the socket actually touching the socket wall without any type of liner or stump sock. Another category of sockets is a socket that utilizes a liner or insert. Both categories of sockets typically were opened ended sockets where they had a hollow chamber in the bottom and no portion of the socket touched the distal end of the stump
14
. So, the stump was supported about its circumferential sides as it fits against the inside wall of the sockets.
These types of sockets caused a lot of shear force on the stump
14
as well as had pressure or restriction problems on the nerve bundles and vascular flow of fluid by way of the circumferential pressure effect of the socket on the limb. This pressure effect could cause a swelling into the ends of the socket where an amputee may develop severe edema and draining nodules at the end of their stump
14
.
With time, prosthetists learned that by filling in the socket's hollow chamber and encouraging a more total contact with the stump and the socket, the swelling and edema problems could be eliminated. However, the problematic tissue configurations, such as bony prominences, required special consideration such as the addition of soft or pliable materials to be put into the socket.
Today, most artificial limbs are constructed from thermoset plastics such as polyester resins, acrylic resins, polypropylenes and polyethylenes, which are perhaps laminated over a nylon stockinette which also may be impregnated by the various resins.
In the past, most artificial limbs were suspended from the amputee's body by some form of pulley, belt or strap suspension often used with various harnesses and perhaps leather lacers or lacings. Another method of suspending artificial limbs is known as the wedge suspension wherein an actual wedge is built into the socket which is more closed at its top opening. The wedge in the socket cups the medial femoral condyle or knuckle at the abductor tubical. Yet another form of suspension is referred to as the shuttle system or a mechanical hookup or linkup wherein a thin suction liner is donned over the stump that has a docking device on the distal end which mechanically links up with its cooperative part in the bottom of the socket chamber. Sleeve suspensions were also used wherein the amputee may use a latex rubber tube which forms into a rubber-like sleeve which would be rolled on over both the top of the artificial limb and onto the amputee's thigh. The sleeve suspensions have been used in combination with other forms of suspensions techniques.
Both the use of a positive pressure system and the use of a negative pressure system (or hypobaric closed chamber) have been utilized in the field of prosthetics. At one time, for pressure systems “inflatable inner tubes” were used to fit into sockets. Presently, there are pneumatic “bags” which are strategically placed over what people consider to be good weight-bearing areas to increase pressure to help accommodate for volume changes within the socket.
The problem with this is that it is a very specific pressure and creates atrophy and loss of tissue dramatically over these high pressure areas. None of these systems employs positive pressure distributed over the total contact area between the residual limb and the artificial limb socket to accommodate volume changes within the socket.
The negative pressure aspects have been utilized for a closed chamber in that a socket is donned by pulling in with a sock, pulling the sock out of the socket and then closing the opening with a valve. This creates a seal at the bottom and the stump is held into the socket by the hypobaric seal. However, there are no systems that employ a negative pressure produced by a vacuum pump to lock the residual limb to the artificial limb.
The older systems were initially started in Germany. They were an open-ended socket, meaning there was an air chamber in the bottom of the socket. This did not work particularly well because it would cause swelling of the residual limb into the chamber created by the negative draw of suspending the weight of the leg and being under a confined area. This would lead to significance edema which would be severe enough to cause stump breakdown and drainage.
It was later discovered in Ameri
Briggs and Morgan
Capes Nelson R.
Helget Gerald E.
Willse David H.
LandOfFree
Vacuum pump and shock absorber for artificial limb does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Vacuum pump and shock absorber for artificial limb, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vacuum pump and shock absorber for artificial limb will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3179907