Trunk control systems and wheelchairs comprising same
Inventors
Goldish, Gary • Hansen, Andrew • Fairhurst, Stuart R. • Voss, Gregory O. • Schneider, Urs
Assignees
Fraunhofer Gesellschaft zur Foerderung der Angewandten Forschung eV • US Department of Veterans Affairs
Publication Number
US-11654311-B2
Publication Date
2023-05-23
Expiration Date
2040-04-14
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Abstract
A trunk control system having a harness assembly and a flexion control assembly. The harness assembly has a backrest member and a harness secured to the backrest member. The backrest member is configured to be moveably coupled to a wheelchair. The backrest member is selectively moveable about and between a fully retracted position and a fully extended position. The harness cooperates with the backrest member to define a receiving space for receiving at least a portion of a torso of a wheelchair user. The flexion control assembly is coupled to the backrest member of the harness assembly. The flexion control assembly is configured to selectively permit or restrict movement of the backrest member about and between the fully retracted position and the fully extended position.
Core Innovation
The invention disclosed is a trunk control system that comprises a harness assembly and a flexion control assembly. The harness assembly includes a backrest member that is moveably coupled to a wheelchair and is selectively movable between a fully retracted position and a fully extended position. The harness cooperates with the backrest to define a space for receiving a portion of the torso of a wheelchair user. The flexion control assembly is coupled to the backrest member and is configured to selectively permit or restrict movement of the backrest member between the retracted and extended positions.
The problem being addressed is the lack of commercially available solutions that provide some trunk movement for wheelchair users with spinal cord injuries who have limited or no trunk control. Existing solutions, such as chest-level seat belts, are restrictive and limit functional reach, forward leaning, and pressure relief. Other approaches, including implanted electrodes, require surgery that not all users desire. Therefore, improved trunk control systems are needed that allow controlled torso movement without being restraining or requiring surgery.
Claims Coverage
The claims define multiple inventive features related to a trunk control system integrated with a wheelchair harness assembly and a flexion control assembly. The features cover mechanical structure, components, control methods, and integration with wheelchair systems.
Harness assembly with moveable backrest mapping torso movement
A harness assembly comprising a backrest member moveably coupled to a wheelchair, configured to be selectively movable between fully retracted and fully extended positions, and a harness secured to the backrest defining a receiving space for a user's torso.
Flexion control assembly using tensioning components
A flexion control assembly coupled to the backrest member, incorporating a tensioning component such as rope, cable, cord, or strap to selectively permit or restrict movement of the backrest member between positions.
Spool and motor actuated tensioning component control
A spool around which the tensioning component is wound, coupled to a motor configured to selectively release or retract the tensioning component, with the system comprising only a single motor.
Controller and user input device for dynamic control
A controller operatively coupled to the motor and communicatively coupled to a user input device, configured to receive inputs indicative of desired backrest movement and control the motor to move the spool accordingly, with user input devices including joysticks and sip-and-puff, among others.
Brake and non-backdriveable transmission for position stability
A brake subassembly or non-backdriveable transmission configured to prevent release or retraction of the tensioning component when the user input ceases, thereby maintaining the position of the backrest member without power consumption.
Slack control subassembly for tension management
A slack control subassembly comprising a guide channel, a spring-biased engagement element that applies tension between the guide and the spool while permitting slack between the guide and harness, and a switch controlling motor power based on tension state.
Integration with wheelchair components and power sources
The trunk control system incorporated into a wheelchair comprising a seat with a back support portion allowing the tensioning component to extend through, cable housing for Bowden cables, wheelchair motor and wheels powered by a shared power source, all controllable using a common user input device.
These inventive features together describe a trunk control system that provides adjustable torso support for wheelchair users through a harness and moveable backrest assembly controlled by a flexion control assembly employing tensioning components, motorized actuation, and user interfaces, with stability and integration features ensuring functional, controlled movement and wheelchair compatibility.
Stated Advantages
Allows controlled trunk movement while providing support for wheelchair users with limited torso control.
Does not require surgical intervention as with functional neuromuscular stimulation approaches.
Enables increased functional reach and freedom of movement compared to rigid restraint systems like chest-level seat belts.
Can reduce power consumption by employing a brake subassembly or non-backdriveable transmission to hold position without continuous power.
Documented Applications
Use in wheelchairs, particularly powered wheelchairs.
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