Vacuum pump systems for prosthetic limbs and methods of using the same
Inventors
Caldwell, Ryan J. • Major, Matthew J.
Assignees
Northwestern University • US Department of Veterans Affairs
Publication Number
US-11877938-B2
Publication Date
2024-01-23
Expiration Date
2036-08-19
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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 diaphragm 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, forming a hybrid pump system to provide vacuum engagement between a prosthetic device and a residual limb.
Core Innovation
The invention provides pump systems for suspending a prosthetic device from a residual limb, including a mechanically activated pump with a low profile design that uses a diaphragm shaped like a dome or suction cup. This diaphragm is disposed between first and second compression members, with coupling elements around its outer perimeter to guide translation of the compression members. This design avoids the need for a large central opening or a broad bladder that may flex outward, enabling a compact arrangement suitable for placement above or below the knee in transfemoral prosthetic limbs or within transtibial limbs.
The problem addressed by the invention is that previous vacuum pump systems for prosthetic limbs either relied solely on electrically activated pumps, which require power sources and may generate noise, or on mechanically activated pumps that can be long, bulky, slow to achieve vacuum, and typically suited only for below-knee prostheses. There is a need for a compact, quiet, unobtrusive vacuum pump system with adjustable pressure and minimal battery recharging that can evacuate air effectively between a prosthetic socket and residual limb, especially for active users like military personnel.
The invention also encompasses hybrid pump systems combining the mechanically activated pump with an electrically activated pump to utilize the strengths of both. The hybrid system allows rapid initial vacuum establishment via the electrical pump and maintenance of vacuum through mechanical movement, reducing battery usage and enabling a redundant, efficient suspension system. The modular design permits flexible configurations, including positioning above or below the knee, to improve usability for transfemoral amputees.
Claims Coverage
The patent includes several independent claims covering the mechanically activated pump and pump systems, including hybrid systems with mechanical and electrical pumps. The main inventive features are related to the unique mechanical pump construction, vacuum pressure range, and hybrid system configuration.
Mechanically activated pump with diaphragm and coupling elements
A mechanically activated pump comprising a first compression member coupled to a second compression member with a diaphragm between them. Coupling elements are disposed about the diaphragm's outer perimeter, guiding translation of the first compression member relative to the second. Relative movement toward each other compresses the diaphragm to evacuate air from a void space defined with the second compression member, which includes a one-way valve engaged with a prosthetic socket evacuation port and a second one-way valve for air exhaust.
Low profile mechanically activated pump suitable for transfemoral placement
The mechanically activated pump is designed to generate a vacuum from 15 mmHg to 25 mmHg and be positioned above or below the knee joint in a transfemoral prosthetic limb device, facilitating compact incorporation into prosthetic systems.
Pump system comprising mechanical pump with vacuum control
A pump system including the mechanical pump as described, with the diaphragm defining a void space and coupling elements coupling the compression members. The system actively evacuates air via compression member movement, maintaining vacuum in the specified range.
Hybrid pump system with electrical pump disposed outward from diaphragm perimeter
A pump system combining the mechanical pump with an electrical pump disposed outward from the diaphragm's outer perimeter. The electrical pump includes a battery, optionally rechargeable, and may be positioned above or below the mechanically activated pump to provide modular dual vacuum sources for the suspension system.
Overall, the claims cover a mechanically activated pump with a novel diaphragm and coupling structure enabling compact design and vacuum generation suitable for transfemoral placement, pump systems maintaining vacuum within desired ranges, and hybrid systems integrating electrical and mechanical pumps to optimize performance and battery usage.
Stated Advantages
The compact, low profile design of the mechanically activated pump allows placement above or below the knee, including transfemoral prosthetic limbs.
The diaphragm design avoids large central openings and reduces flexing or bulging, improving efficiency and pump capacity.
Hybrid systems leverage mechanical and electrical pumps to provide rapid vacuum engagement, reduce battery usage, and maintain consistent vacuum levels.
The modular pump design permits longer intervals between battery recharging or replacement and reduces noise compared to solely electrical pumps.
Documented Applications
Suspending a prosthetic device from a residual limb, including transfemoral and transtibial prosthetic limbs.
Use in prosthetic devices requiring vacuum suspension systems to maintain socket engagement with residual limbs.
Hybrid pump systems combining mechanical and electrical pumps for improved suspension in prosthetic limbs.
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