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-9757255-B2
Publication Date
2017-09-12
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 vacuum pump systems for suspension of prosthetic devices from residual limbs, including mechanically activated pumps with a low profile design that use a compressible bladder positioned between first and second compression members. The coupling elements engage and connect the compression members about the outer perimeter of the bladder, avoiding the use of a large central tubular telescopic assembly. This design enables use of a larger diameter bladder with greater volume and less displacement, allowing placement above or below the knee in transfemoral prosthetic limbs, or compact placement in transtibial prosthetic limbs.
The invention also offers a hybrid pump system combining mechanically activated and electrically activated pumps connected within a fluid circuit to provide vacuum engagement between the prosthetic device and the residual limb. This hybrid configuration allows rapid initial evacuation by the electrical pump and maintenance of vacuum by the mechanical pump during movement, reducing battery recharging frequency and enabling a compact structure suitable for positioning above the knee joint. The invention addresses prior shortcomings of mechanically activated systems that are bulky, slow to create vacuum, and limited to below-knee use, as well as the limitations of solely electrically powered systems.
Claims Coverage
The patent includes multiple independent claims focusing on hybrid pump systems combining mechanically and electrically activated pumps for prosthetic limb suspension.
Mechanically activated pump coupled by perimeter coupling elements
The pump system includes a mechanically activated pump with pumping action requiring mechanical input from prosthetic movement, having a first compression member coupled to a second compression member via coupling elements disposed entirely about the outer perimeter of a compressible bladder located between them.
Hybrid pump system integrating mechanical and electrical pumps within a fluid circuit
A separate electrically activated pump with an electrical power source and pumping action requiring electrical input is connected within a fluid circuit with the compressible bladder and mechanically activated pump, forming a hybrid system for evacuating air from a transtibial residual limb receiving socket to provide vacuum suspension.
Configurations of compression member coupling and pump placement
The first compression member may be pivotally coupled or translationally movable relative to the second compression member. The electrically activated pump may be positioned outward from the outer perimeter of the compressible bladder and disposed above or below the mechanically activated pump.
Control system for vacuum maintenance and operation optimization
The system includes a controller configured to operate the electrically activated pump when the prosthetic device is not in use to walk and vacuum pressure is outside a predefined range, or upon initial limb insertion, thereby maintaining a preselected vacuum level while optimizing battery life.
Inclusion of biasing elements for compression member spacing
At least one spring or biasing element is disposed between the first and second compression members to maintain them in a spaced apart position, facilitating reliable compression and expansion cycles during walking or bouncing-type movements.
Overall, the claims cover a hybrid vacuum pump system combining a mechanically activated pump with perimeter-coupled compression members and compressible bladder, integrated with an electrically activated pump in a fluid circuit, featuring various coupling configurations, control methods, and physical arrangements that improve vacuum suspension for prosthetic limbs.
Stated Advantages
Compact, low profile mechanically activated pump designs that enable placement above or below the knee, including use in transfemoral prosthetic limbs.
Hybrid pump system offering rapid initial vacuum engagement via the electrical pump combined with maintenance of vacuum using mechanical pumping, reducing battery recharging needs.
Reduced system noise and unobtrusive configuration compared to solely electrically activated pumps.
Avoidance of external tubing, reducing interference and risk of snagging, improving user comfort and reliability.
Redundancy provided by dual pump operation enhances performance and ensures adequate suspension under diverse user activity conditions.
Documented Applications
Use in suspension systems for prosthetic devices including transfemoral and transtibial prosthetic limbs.
Placement within prosthetic limbs at locations above or below the knee joint to provide vacuum engagement between a prosthetic socket and residual limb.
Use in hybrid vacuum systems to rapidly establish and maintain vacuum suspension at selected vacuum pressure ranges during initial donning and ongoing use, including walking or stationary periods.
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