Prosthetic socket stabilization apparatus and technique
Inventors
Assignees
Publication Number
US-8911505-B2
Publication Date
2014-12-16
Expiration Date
2030-11-18
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Abstract
A portable device, with method, advantageously applies dynamic stimulation of enclosed muscle tissue to stabilize a prosthetic socket on a residual limb. Dynamic stimulation is in response to physical conditions such as prosthesis motion, position and/or internal pressures. Tissue volume contained within the socket may be stabilized by varying average stimulation levels in response to internal socket pressure.
Core Innovation
The invention provides apparatus and methods for actively stabilizing a prosthesis on a biological limb through dynamic stimulation of residual limb muscle in response to physical conditions of the prosthesis. The invention features a portable device that applies dynamic stimulation to the enclosed muscle tissue to stabilize the prosthetic socket on the residual limb, with stimulation responsive to factors such as prosthesis motion, position, and internal pressures. Tissue volume within the socket may be stabilized by varying average stimulation levels based on internal socket pressure.
The problem addressed by this invention is the instability and discomfort associated with current methods of affixing prosthetic sockets to residual limbs. Existing solutions such as suction, vacuum pumps, and mechanical fixation methods have issues, including failure to accommodate changes in limb volume, loss of vacuum due to leaks, poor force distribution leading to tissue disruption, and the resultant atrophy and dysfunction of residual limb muscles. Furthermore, such techniques do not address control, protection, or circulation issues resulting from the disuse of residual muscle tissue.
In the presented device and technique, sensors measure spatial orientation, motion, and internal socket pressure, transmitting this information to a controller which, in turn, controls stimulation pads in contact with the residual limb. The controller dynamically adjusts stimulation energy to localized muscle areas, stabilizing the prosthetic socket by inducing contractions that respond to changing physical conditions. This process aims to maintain socket fit, enhance movement and positional control, and optionally stabilize muscle volume by modulating stimulation in relation to averaged internal pressure.
Claims Coverage
There are three independent claims with key inventive features that address stabilization of a prosthesis via dynamic muscle stimulation responsive to measured physical conditions.
System for stabilizing a prosthesis using dynamic muscle stimulation controlled by sensed spatial and pressure attributes
A system comprises a shell that interfaces an appendage to a prosthesis, means to measure spatial attributes and/or force on the shell, means to measure average pressure within the shell, means to dynamically stimulate muscle tissue within the shell to stabilize the interface, and means to control stimulation in response to average pressure and measured spatial or force attributes.
Prosthesis with sensors and controller to determine force and environmental conditions for controlling stimulation energy
A prosthesis includes first and second sensor nodes and a controller. The controller determines a first force over a time period from the first sensor node, determines an environmental condition (including force) from the second sensor node, calculates a first component of stimulus energy based on these conditions, and stimulates muscle tissue with this energy to stabilize the interface. The stimulus energy is adjusted such that pulse amplitude is inversely proportional to the sensed force, which includes a composite and/or average force.
System with shell, multiple sensors, stimulation nodes, and controller for spatial and pressure-based stimulation control
A system includes a shell forming the interface between an appendage and prosthesis, a plurality of sensors, a plurality of stimulation nodes, and a controller. The controller determines spatial attributes and force relating to the shell, determines average pressure, applies stimulation to the appendage via the stimulation nodes to stabilize the interface, and determines the stimulation based on the spatial attributes, force, and average pressure.
The inventive features focus on actively stabilizing a prosthesis through closed-loop, sensor-driven dynamic muscle stimulation, integrated with real-time measurement of spatial, pressure, and force attributes at the socket-limb interface.
Stated Advantages
The invention allows stabilization of a prosthetic socket on a residual limb during normal activities with minimal impact on residual physiology.
Dynamic stimulation provides biologically enhanced movement and positional control of the prosthesis.
Muscle stimulation can help maintain residual limb muscle at a relatively constant average volume.
The device and method can replicate more closely intact biological activity by causing muscle contractions to follow prosthesis movement.
The technique may reduce phantom sensations and improve fluid circulation.
Documented Applications
Actively stabilizing prosthetic sockets on biological limbs during normal activities.
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