SHOCK ABSORBING APPARATUS AND METHOD
The present invention in one embodiment is a vacuum pump including a compressible elastomeric member with an internal reservoir enclosing a volume of fluid, an outlet port providing fluid communication between the internal reservoir and a fluid sink, and an inlet port providing fluid communication between the internal reservoir and a fluid source. The pump further includes first and second pressure elements coupled to the elastomeric member on opposing sides. At least one of the first and second pressure elements is adapted to apply a longitudinal force along, and a rotational force about, an axis extending through the compressible elastomeric member. Upon the application of a longitudinal compression force to the compressible elastomeric member, fluid flows from the internal reservoir to the fluid sink and upon the application of a longitudinal expansion force, fluid flows from the fluid source to the internal reservoir. Upon the application of a rotational force, the elastomeric member exerts a counter-rotational force.
This application is a continuation of U.S. patent application Ser. No. 12/184,329, filed on 1 Aug. 2008, which application claims the benefit under 35 U.S.C. §119(e) of Provisional Application No. 60/953,400, filed 1 Aug. 2007, which is herein incorporated by reference in its entirety.
TECHNICAL FIELDThe present invention relates generally to prosthetic devices, and more particularly to vacuum pumps used to generate a vacuum attachment of the prosthetic device to the residual limb of a user.
BACKGROUNDAn ongoing challenge in the development of prosthetic limbs is the attachment of the prosthetic limb to the residual limb of a user. For prosthetic legs, it is often difficult to securely attach the prosthetic leg to the residual leg without exerting too much or uneven pressure on the residual limb. On the one hand, the lack of a secure attachment can adversely affect the user's ability to walk. On the other hand, an improper fit can cause sores, swelling and pain for the user.
One approach for overcoming this challenge has been the application of a negative pressure vacuum in a space between the limb (or a liner donned on the limb) and a socket or receptacle coupled to the prosthetic limb (see
Mechanical pumps are often in-line systems that utilize the movement of the user to generate the negative pressure vacuum in the socket. For example, the force generated by contacting the ground during a user's walking motion can be used to generate a vacuum in the socket space to hold the prosthesis to the user's limb. However, in utilizing the motion of the user, such pumps should not inhibit, and should ideally aid in, as natural and pain-free of a movement as possible for the user.
SUMMARYOne embodiment of the present invention provides a vacuum pump including a compressible elastomeric member. The compressible elastomeric member includes an internal reservoir enclosing a volume of fluid, an outlet port providing fluid communication between the internal reservoir and a fluid sink, and an inlet port providing fluid communication between the internal reservoir and a fluid source. The pump further includes first and second pressure elements coupled to the elastomeric member on opposing sides.
At least one of the first and second pressure elements is adapted to apply a longitudinal force along, and a rotational force about, an axis extending through the compressible elastomeric member. Upon the application of a longitudinal compression force to the compressible elastomeric member, fluid flows from the internal reservoir to the fluid sink and upon the application of a longitudinal expansion force, fluid flows from the fluid source to the internal reservoir. Upon the application of a rotational force, the elastomeric member exerts a counter-rotational force. The inlet may be attached to an enclosed space such that upon the application of the expansion force, a negative pressure vacuum is applied to the enclosed space.
Another embodiment of the present invention provides a prosthetic device for attachment to a residual limb. The prosthetic device includes a vacuum pump having a compressible elastomeric member including an internal reservoir enclosing a volume of fluid, an outlet port providing fluid communication between the internal reservoir and a fluid sink and an inlet port providing fluid communication between the internal reservoir and a fluid source. The prosthetic device also includes a first support member having a proximal end configured for attachment to the residual limb and a distal end coupled to a first side of the elastomeric housing, and a second support member having a proximal end coupled to a second opposing side of the elastomeric member.
One or both of the first and second support members are adapted to apply a longitudinal force along, and a rotational force about, an axis extending through the compressible elastomeric member. Upon the application of a longitudinal compression force to the compressible elastomeric member, fluid flows from the internal reservoir to the fluid sink and upon the application of a longitudinal expansion force, fluid flows from the fluid source to the internal reservoir. Additionally, upon the application of a rotational force the elastomeric member exerts a counter-rotational force. The fluid source may be an enclosed space formed between the residual limb of a user and a receptacle attached to the upper support, such that a negative pressure vacuum is formed in the enclosed space to maintain the attachment of the prosthesis.
A further embodiment of the present invention provides a leg prosthesis for attachment to a residual portion of a leg. The leg prosthesis includes a receptacle for receiving the limb, a foot portion and a vacuum pump. The vacuum pump includes a housing having an interior compartment and a shaft member having a portion disposed in the interior compartment of the housing. The housing and shaft member are coupled to provide reciprocating movement along a longitudinal axis extending through the housing and shaft member.
The vacuum pump further includes a compressible elastomeric member having an internal reservoir enclosing a volume of fluid, an outlet port providing fluid communication between the internal reservoir and a fluid sink and an inlet port providing fluid communication between the internal reservoir and a fluid source. Upon the application of a compression force along the longitudinal axis, the shaft moves relative to the housing to compress the elastomeric member such that fluid flows from the internal reservoir to the fluid sink, and upon the application of an expansion force, the shaft moves relative to the housing to expand the elastomeric member such that fluid flows from the fluid source to the internal reservoir.
Yet another embodiment of the present invention provides a foot prosthesis including an upper plate configured for attachment to a lower leg prosthesis or residual limb and a lower plate adapted to contact a walking surface. The upper plate extends between an ankle portion and a toe portion and the lower plate extends between a heel portion and a toe portion. The lower and upper plates are coupled such that a space is defined between the ankle portion and the heel portion. Upon the application of a compression force to the ankle portion or heel portion, the space is reduced.
The foot prosthesis also includes a vacuum pump disposed in the space between the ankle and heel portions. The vacuum pump includes an elastomeric member with an internal reservoir adapted to enclose a volume of fluid, an outlet port in fluid communication with the internal reservoir and a fluid sink, and an inlet port in fluid communication with the internal reservoir and a fluid source. Upon the application of the compression force the elastomeric member compresses such that fluid flows from the reservoir to the fluid sink, and wherein upon the termination of the compression force, the upper or lower plate cause the application of an expansion force to the elastomeric member such that fluid flows from the fluid source into the reservoir.
A further embodiment provides a vacuum pump including an elongated upper pylon and an elongated lower pylon adapted to move axially and rotationally with respect to said upper pylon, wherein the longitudinal axis of the upper pylon and the longitudinal axis of the lower pylon are maintained in a generally colinear alignment. The vacuum pump further includes a resilient compressible elastic member coupled to and disposed between respective ends of the upper and lower pylons to resist the axial and rotational movement of the lower pylon. The elastic member includes an internal reservoir enclosing a volume of fluid, which may be formed by a substantially continuous elastic wall enclosing the internal reservoir.
An outlet port provides fluid communication between the internal reservoir and a fluid sink and an inlet port providing fluid communication between the internal reservoir and a fluid source. Upon the application of a compression force along the longitudinal axis, the upper pylon moves relative to the the lower pylon to compress the elastomeric member such that fluid flows from the internal reservoir to the fluid sink. Upon the application of an expansion force, the upper pylon moves relative to the lower pylon to expand the elastomeric member such that fluid flows from the fluid source to the internal reservoir.
The present invention also provides methods of using the vacuum pump described above to apply a vacuum to a space between a user's residual limb and a receptacle of a prosthetic device. While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
Various modifications and additions can be made to the exemplary embodiments discussed below without departing from the scope of the present invention. For example, while the embodiments described below refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the above described features.
One embodiment of the present invention is a vacuum pump that can be used with an artificial limb, such as an artificial leg, artificial arm or other prosthetic device.
As further shown in
When the pump 100 is compressed by an external force along a longitudinal axis extending through the pump, such as during the step phase of the user, the toroid 160 is compressed and a substantial volume of the fluid within its internal reservoir 162 is forced out through an outlet 164 to a fluid sink, which may be an external fluid atmosphere. When the external force on the pump 100 lessens or is removed, the elastomeric material, and particularly the side wall 163, of the toroid 160 causes the toroid 160 to return or expand back to its initial configuration due to its elastic memory and/or resiliency. As a result, the toroid 160 draws fluid from a fluid source into the internal cavity 162 through an inlet 166. An outlet check valve 165, such as a one-way expulsion valve, and a one-way intake check valve 167, can be connected to the internal cavity 162 at the outlet 164 and the inlet 166, respectively.
When the intake valve 167 is connected to a vessel, such as the space adjacent to socket 52, fluid is evacuated from the vessel/socket 52 by the pump 100. Since the residuum 60 and liner 62 are substantially sealed to the socket 52 about the periphery of the residuum 60, evacuation of fluid from the sealed socket 52 results in negative pressure or a vacuum being formed in the socket 52 about the residuum 60. As a result, the pump 100, functions as a vacuum pump that holds the socket 52 to the liner 62 and/or residuum 60. In this manner, the vacuum pump 100 removes the fluid, in this case air (which may include moisture from the limb), from the space between the prosthetic liner 62 and the socket 52 after placement of the residuum 60 and liner 62 within the socket 52. The socket 52 can also be arranged so that fluid is removed from between the liner 62 and skin of the residuum 60, which would further facilitate removal of perspiration.
In an artificial limb, such as the limb 50 shown in
Besides aiding in the retention of the artificial leg 50 on the residuum 60, removal of the fluid from between the socket 52 and liner 62 increases the intimacy of the socket fit, improving the user's ability to feel shock waves passed through the prosthetic structure, or artificial leg 50, and into the residuum 60. This can result in a “feeling” sensation and in increased awareness as to the location of the artificial leg 50 under the user. Although the fluid described with respect to
The elastomeric toroid 160 is preferably formed from an elastomeric material, including but not limited to thermoset urethane, thermoplastic urethane or other suitable elastomers. In one embodiment, the toroid 160 is molded from a thermoset urethane in two halves that are bonded together to form an air-tight seal 171 around the circumference of outer wall 163 and a similar seal (not shown) along the circumference of inner wall 163. Other than the seals formed during production, the toroid 160, the inner and outer wall 163 form a substantially continuous elastomeric wall enclosing the internal reservoir 162.
In one embodiment the toroid 160 has an outer diameter of about 2.00 to 2.50 inches and an inner diameter of about 1.00 to about 1.50 inches, more particularly, about 1.13 inches. The wall thickness is about 0.10 to about 0.20 inches, more particularly, about 0.13 inches thick. The wall thicknesses of the toroid 160 determine its compression and expansion properties, as well as its rotational resilience about the longitudinal access extending through the pump 100, which is discussed in greater detail below. The rotational resilience is dependent primarily on the outer wall thickness, and the compression/expansion resilience is dependent primarily on the total wall thickness.
In the embodiment shown in
At the other end of the shaft 120, the end attachment 130 moves with the shaft 120 as it moves within the compartment 142. The end attachment 130 includes a mounting structure 132 configured for attachment to another prosthetic component using a prosthetic coupler, including but not limited to a pyramid connector (not shown). The mounting structure 132 includes a plurality of screws 134 for securing the pump 100 to the other prosthetic component, for example, a socket, a pylon, a foot and/or any other suitable component.
The housing 140 is also configured for connection to another prosthetic component. As shown in
The prosthetic end attachments of the pump 100 can vary significantly depending on the components to which the pump 100 is intended to be attached. However, the current tube clamp in the housing is a space efficient design which allows a continuous length adjustment by cutting the attachment tube to the correct length.
In the embodiment shown in
The toroid 160 is provided with a plurality of protrusions, such as torsion ribs 168, 169 extending from both surfaces of the toroid. One set of protrusions 168 engage or interlock with recesses or grooves (not shown) in the end attachment 130, which are sized and shaped to receive the ribs 168. In a similar manner, the other set of torsion ribs 169 engage with openings or grooves 155 formed in the top surface 143, or toroid end, of the housing 140. These torsion ribs 168, 169 keep the end attachment 130 and the housing 140 from rotating independently. However, when a torsional force is applied to the artificial limb, the components connected to the pump 100 at the end attachment 130 can twist relative to the components connected to the pump 100 at the housing 140. The resilient, elastomeric material of the toroid 160 allows for the twisting motion and also returns the components to their initial alignment upon withdrawal of the torsional force. In one embodiment, the toroid 160 provides gradually increasing resistance to the rotation. This ability also increased the comfort and usability of the artificial limb for the user. The amount of rotation can be controlled by the geometry of the ribs 168, 169 and toroid 160, or by the material and/or durometer of the toroid 160.
The pump 100 in accordance with the present invention has significant advantages over previous pump designs. One advantage is the small number of parts required, which means that the pump is more simple and cost effective to manufacture, and service. Another advantage is that the fluid passing through the pump is only in contact with the interior of the toroid 160 and the check valves 165, 167. The toroid 160 is constructed of an elastomer which has excellent corrosion resistance. Thus, the design can pump corrosive fluids without significant deleterious effects. In the example shown in
The pump 200 shown in
In the embodiment shown in
The embodiment shown in
The resilient member 430 performs a similar function to the toroid in the above described embodiments. Intake and outlet one-way check valves 431, 432 are positioned in fluid connection with the hollow interior space 434 of member 430. Both the top component 410 and the bottom component 420 include connecting members 415, 425, respectively, that engage the resilient member 430 and transfer compression forces to it. When the pump 400 is subjected to a compression force, the top component 420 and the bottom component 420 move relative to each other causing compression of the resilient member 430 and transfer of fluid from the interior space 434. Upon removal of the compression force, the eye-shaped spring portion 406 aids in the expansion of the resilient member 430, transferring fluid out of a fluidly connected vessel and into the interior space 434.
The vacuum pump of the present invention basically includes a resilient hollow member fluidly connected to intake and outlet valves. This resilient member is positioned within a structure having at least two surfaces that move relative to each other in a reciprocating manner. The resilient member repeatedly compresses and expands between the two surfaces due to the application and removal of a compression force applied to the pump. Each compression forces fluid out of the hollow internal space within the resilient member and each expansion draws fluid back into the internal space through the intake valve. When the intake valve is fluidly connected to a vessel, the compressive action of the pump will draw fluid out of the vessel. If the vessel is sealed, a vacuum is formed. In the case of an artificial limb, inclusion of the pump within the components of the limb will provide generally continuous vacuum to be applied to a residuum positioned within the socket during normal use of the limb, such as during walking. Moreover, the pump may lessen the impact of shocks to the residual limb and provide gradually increasing resistance to torsional movement.
Claims
1. A shock absorbing member configured for use in a prosthetic device, the shock absorbing member comprising:
- a toroid shaped body having: a top end having a top surface; a bottom end having a bottom surface; a outer sidewall extending from the top surface to the bottom surface; an interior cavity;
- at least one inlet opening arranged in fluid communication with the interior cavity;
- wherein the body is compressible to absorb shock.
2. The shock absorbing member of claim 1, wherein the top and bottom ends are elastically rotatable relative to each other to absorb rotational forces applied to the body.
3. The shock absorbing member of claim 1, further comprising an inner sidewall defining a central aperture extending from the top surface to the bottom surface.
4. The shock absorbing member of claim 1, wherein the outer sidewall includes a contoured portion.
5. The shock absorbing member of claim 1, further comprising at least one top protrusion extending from the top surface, and at least one bottom protrusion extending from the bottom surface, wherein the top and bottom protrusions operate to apply rotational forces to the top and bottom ends of the body.
6. The shock absorbing member of claim 5, wherein the at least one top protrusion and the at least one bottom protrusion interface with a prosthetic device.
7. The shock absorbing member of claim 1, further comprising at least one outlet opening arranged in fluid communication with the interior cavity.
8. The shock absorbing member of claim 7, wherein one of the at least one inlet opening and at least one outlet opening is positioned at the top end, and the other of the at least one inlet opening and the at least one outlet opening is positioned at the bottom end.
9. The shock absorbing member of claim 7, wherein the at least one inlet opening and the at least one outlet opening are each positioned at one of the outer sidewall, the top surface, or the bottom surface.
10. A prosthetic device, comprising:
- a compressible shock absorbing member including: a body portion defined by opposing top and bottom ends and an outer sidewall extending between the top and bottom ends, the outer sidewall being configured to collapse upon application of at least one of a compression force and a torsional force; at least one top protrusion extending from the top end and being configured to connect the compressible shock absorbing member to a first portion of the prosthetic device; at least one bottom protrusion extending from the bottom end and being configured to connect the compressible shock absorbing member to a second portion of the prosthetic device;
- wherein relative movement between the first and second portions of the prosthetic device applies the compression force or torsional force.
11. The prosthetic device of claim 10, wherein the body portion further defines an interior cavity, the interior cavity being accessible through at least one of a first opening and a second opening that are each located in the outer sidewall, the top end or the bottom end.
12. The prosthetic device of claim 10, wherein the body portion further includes an aperture extending from the top end to the bottom end, the aperture being defined by an inner sidewall of the body portion.
13. The prosthetic device of claim 10, wherein the outer sidewall is contoured radially outward and the body portion is toroid shaped.
14. The prosthetic device of claim 10, wherein the outer sidewall comprises an elastomeric material.
15. The prosthetic device of claim 10, wherein the at least one top protrusion includes a plurality of circumferentially spaced apart top protrusions, and the at least one bottom protrusion includes a plurality of circumferentially spaced apart bottom protrusions.
16. A spring member for use at an interface between components of a prosthetic device, the spring member comprising:
- an elastomeric body being deformable from a rest position to a deformed position upon application of at least one of a compression force and a torsional force, and being configured to return to the rest position after removal of the at least one of the compression force and torsional force;
- projections extending from opposing ends of the elastomeric body, the projections being configured to connect the spring member to the components of the prosthetic device, wherein at least the torsional force is applied to the elastomeric body through the projections.
17. The spring member of claim 16, wherein the elastomeric body includes a contoured sidewall that is deformable upon application of at least one of the compression force and the torsional force to the elastomeric body.
18. The spring member of claim 17, wherein the elastomeric body defines a hollow cavity configured to contain a volume of fluid.
19. The spring member of claim 18, wherein the elastomeric body includes at least one inlet opening and at least one outlet opening, the inlet and outlet openings being in fluid communication with the hollow cavity.
20. The spring member of claim 16, wherein the elastomeric body includes a planar top surface and a planar bottom surface, and the projections extend away from the top and bottom surfaces of the elastomeric body.
21. The spring member of claim 16, wherein the elastomeric body provides gradually increasing resistance to deformation upon application of the torsional force.
22. The spring member of claim 16, wherein the elastomeric body includes an outer sidewall and an inner sidewall, at least one of the outer and inner sidewalls being bowed radially outward.
23. The spring member of claim 16, wherein the elastomeric body is symmetrical about a central longitudinal axis thereof.
24. A method of absorbing forces in a prosthetic device, comprising:
- providing an elastomeric force absorbing member having a top and a bottom end and at least one sidewall extending between the top end and the bottom end;
- positioning the elastomeric force absorbing member between components of the prosthetic device;
- distorting a shape of the elastomeric force absorbing member from a rest shape by compressing the at least one sidewall to absorb compression forces between the components;
- distorting the shape of the elastomeric force absorbing member from the rest shape by twisting the top and bottom ends relative to each other to absorb torsional forces between the components;
- moving fluid into and out of the elastomeric force absorbing member;
- returning the elastomeric force absorbing member to the rest shape.
25. The method of claim 24, wherein the elastomeric force absorbing member includes projections extending from the top and bottom ends, and positioning the elastomeric force absorbing member includes placing the projections into contact with the components of the prosthetic device.
26. The method of claim 24, wherein the elastomeric force absorbing member includes a cavity, and moving fluid into and out of the cavity occurs when distorting the shape of the elastomeric force absorbing member during at least one of compressing the at least one sidewall and twisting the top and bottom ends relative to each other.
27. The method of claim 24, wherein the elastomeric force absorbing member includes a cavity and at least one opening in fluid communication with the cavity, the method comprising creating fluid flow through the at least one opening.
28. The method of claim 24, wherein the elastomeric force absorbing member includes a hollow interior, and changing the elastomeric force absorbing member between a rest shape and a distorted shape changes a volume of the hollow interior and causes fluid to move into and out of the hollow interior.
Type: Application
Filed: May 18, 2011
Publication Date: Sep 15, 2011
Applicant: OttoBock HealthCare LP (Minneapolis, MN)
Inventors: Robert Edward Finlinson (Salt Lake City, UT), Douglas E. Rush (Draper, UT), Lüder Mosler (Duderstadt)
Application Number: 13/110,736