Systems and methods for approximating musculoskeletal dynamics

Inventors

Sobinov, Anton • Yakovenko, Sergiy • Gritsenko, Valeriya • Boots, Matthew • Gaunt, Robert • Collinger, Jennifer • Fisher, Lee

Abstract

A system and method for controlling a device, such as a virtual reality (VR) and/or a prosthetic limb are provided. A biomimetic controller of the system comprises a signal processor and a musculoskeletal model. The signal processor processes M biological signals received from a residual limb to transform the M biological signals into N activation signals, where M and N are integers and M is less than N. The musculoskeletal model transforms the N activation signals into intended motion signals. A prosthesis controller transforms the intended motion signals into three or more control signals that are outputted from an output port of the prosthesis controller. A controlled device receives the control signals and performs one or more tasks in accordance with the control signals.

Core Innovation

The invention relates to a biomimetic controller that receives a biological signal from a residual limb and expands the biological signal into one or more activation signals based at least in part on a scaling coefficient and a number of degrees of freedom (DOFs). The biomimetic controller performs a modeling algorithm that transforms the one or more activation signals into one or more intended motion signals, and then performs a control algorithm that transforms the intended motion signals into control signals. The biomimetic controller sends the control signals to a controlled device.

The invention further uses feedback and signal routing to support different device modes, including a virtual reality (VR) prosthesis system and a prosthetic limb. A switching device selectively places the selected component in communication with a prosthesis controller so it receives the control signals for performing one or more tasks. In corresponding switching configurations, feedback signals associated with virtual motion and actual motion are provided to a processor to be used in transforming the biological signal into the activation signals.

A core technical contribution described is a musculoskeletal-dynamics approximation approach based on polynomial approximation and constrained relationships between muscle length and moment arms, with optimization using corrected Akaike Information Criterion (AICc) to select polynomial structures. The document also describes real-time or near real-time applicability and includes similarity/structure analyses such as similarity index (SI), hierarchical clustering, and principal component analysis (PCA) for comparing structures. Experimental and simulation validation for multi-DOF hand motion is reported using root mean squared (RMS) error.

Claims Coverage

The independent claims are system claim 1 and method claim 12. Across these independent claims, the document includes multiple inventive features centered on residual-limb biological signal processing into activation signals with scaling and DOFs, transforming activation signals into intended motion signals, transforming intended motion signals into control signals, and sending the control signals to a controlled device; additional inventive features specify switching between VR prosthesis and prosthetic limb and include polynomial-approximation-based handling conditioned on switching configurations, as described in dependent claims.

The independent claim set covers a biomimetic controller and corresponding method that process a residual-limb biological signal into activation signals using a scaling coefficient and DOFs, transform activation signals into intended motion signals via a modeling algorithm, convert intended motion signals into control signals via a control algorithm, and send the control signals to a controlled device; dependent inventive features additionally include switching between VR prosthesis and a prosthetic limb with configuration-dependent feedback and a polynomial approximation (Poly) block for muscle dynamics handling conditioned on the switching configuration.

Stated Advantages

Documented Applications