Vacuum pump systems for prosthetic limbs and methods of using the same
Inventors
Caldwell, Ryan J. • Hansen, Andrew H. • Wood, Sean M. • Chen, Wei • Radcliffe, Regan A. • Yngve, Kevin A. • Kuhar, Bennett E. • Nelson, Andrew J. • Nickel, Eric
Assignees
Northwestern University • US Department of Veterans Affairs
Publication Number
US-9066822-B2
Publication Date
2015-06-30
Expiration Date
2032-06-21
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Abstract
Pump systems for use in suspension of a prosthetic device from a residual limb and methods of suspending a prosthetic device from a residual limb are disclosed. The pump systems include a mechanically activated pump having a first compression member coupled to a second compression member, a compressible bladder disposed between the first and second compression members, and coupling elements that engage and couple together the first and second compression members. The mechanically activated pump may be connected with an electrically activated pump within a fluid circuit of a hybrid pump system to provide vacuum engagement between a prosthetic device and a residual limb.
Core Innovation
The invention provides pump systems for suspension of a prosthetic device from a residual limb, including a mechanically activated pump with a low-profile design. The mechanically activated pump includes a first compression member coupled to a second compression member, with a compressible bladder disposed between them. Coupling elements engage and couple the compression members about the outer perimeter of the bladder, avoiding a large central opening and allowing greater bladder volume and less displacement for pumping capacity. This design permits placement above or below the knee joint in transfemoral prosthetic limbs and compact placement in transtibial limbs.
The invention addresses problems in prior art where mechanically activated pumps require substantial length and have large telescopic assemblies unsuitable for above knee placement. Electrically activated pumps offer rapid vacuum establishment but require power sources and produce noise. The disclosed pump systems combine strengths of both types by introducing hybrid systems that connect mechanically and electrically activated pumps within a fluid circuit for vacuum engagement between a prosthetic device and residual limb. This modular hybrid pump system allows for rapid initial vacuum evacuation using the electrical pump and ongoing vacuum maintenance via the mechanical pump, reducing battery dependence.
The mechanically activated pump configurations include pivotal or translational coupling of the compression members with compressible bladders designed to maximize capacity while minimizing height. The hybrid systems permit compact, quiet, unobtrusive vacuum generation and maintenance with a preferred height of about 1.5 inches or less, enabling above-the-knee placement for transfemoral amputees. This enhances suspension performance, overcomes limitations of prior mechanical and electrical systems, improves user comfort and socket fit, and reduces the need for frequent battery recharging.
Claims Coverage
The independent claims define a hybrid pump system incorporating a mechanically activated pump and an electrically activated pump integrated within a prosthetic device for suspension from a transfemoral residual limb. The following inventive features are identified based on the claims.
Hybrid pump system with mechanical and electrical pumps in a fluid circuit
A prosthetic device having a transfemoral receiving socket and a knee joint. The system includes a mechanically activated pump requiring mechanical input via movement, and a separate electrically activated pump requiring electrical input from a power source, both connected within a fluid circuit that evacuates air from the transfemoral socket.
Mechanical pump structure with compression members and compressible bladder
The mechanically activated pump comprises a first compression member coupled to a second compression member with a compressible bladder disposed between them. Coupling elements engage and couple the compression members, with all coupling elements disposed about the outer perimeter of the compressible bladder.
Placement of mechanical pump between socket and knee joint
The mechanically activated pump is positioned between the transfemoral residual limb receiving socket and the knee joint.
Inclusion of electrical power source and user interfaces
The electrically activated pump includes an electrical power source such as a rechargeable battery and may include controllers and user interfaces to maintain vacuum levels and operate pumps based on vacuum pressure and user activity.
Configurations of compression member movement and coupling
The first compression member may translate or pivot relative to the second compression member. The mechanical coupling can include hinge knuckles and a hinge pin or parallel linkages, allowing for angular displacement or parallel translation.
Vacuum maintenance and operation control
The system maintains a preselected vacuum level within the socket by either the mechanically activated pump or the electrically activated pump. Controllers may automatically operate the electrical pump when the prosthetic is not in use or vacuum is outside a predetermined range.
The claims cover a prosthetic pump system integrating mechanical and electrical vacuum pumps within a fluid circuit, emphasizing innovative mechanical pump structures with outer perimeter coupling elements, specific placement between socket and knee joint, and system control features to maintain suspension vacuum effectively.
Stated Advantages
Provides a compact, quiet, and unobtrusive vacuum pump system with adjustable pressure.
Enables longer intervals between battery charging or replacement.
Permits placement of the pump system above the knee joint for transfemoral amputees due to low-profile design.
Reduces need for external tubing, thereby avoiding interference with knee flexion and reducing risk of snagging.
Combines strengths of mechanical and electrical pumps for rapid initial vacuum and maintenance without continuous battery use.
Documented Applications
Suspension of prosthetic devices, specifically prosthetic limbs for transfemoral (above knee) and transtibial (below knee) amputees.
Use within prosthetic devices that have sockets configured to receive residual limbs directly or over liners.
Implementation in hybrid pump systems combining mechanical and electrical vacuum pumps to secure prosthetic sockets to residual limbs.
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