Systems and methods for postural control of a multi-function prosthesis

Abstract

Systems and methods for postural control of a multi-function prosthesis are provided. Various embodiments provide for a postural controller that use EMG signals to drive a point in a posture space and outputs continuously varying joint angles for a powered prosthetic hand. The postural controller can include an EMG signal processing unit to receive signals from electrodes for processing (e.g., band pass filtering, rectification, root mean square averaging, dynamic tuning, etc.). The processed EMG signals can then be combined or converted to produce a point in the postural control domain. The PC domain map defines the posture that corresponds to each PC cursor coordinate. This map can have limitless possible postures and limitless possible positions of the postures. The Joint Angle Transform converts the PC cursor coordinate into the joint angle array which is sent to the prosthetic hand thereby creating more natural movements.

What is claimed is: 
     
         1 . A prosthetic device comprising:
 a set of electrodes configured to monitor muscle contractions and generate EMG signals;   an EMG processing module configured to receive the EMG signals and generate processed EMG signals;   a set of actuators configured to control joint angles of the prosthetic device;   a postural controller configured to receive the processed EMG signals and determine desired set of joint angles defining a desired posture by controlling a point in a postural control space; and   a feedback controller to generate control signals to set the joint angles of the prosthetic device using the set of actuators.   
     
     
         2 . The prosthetic device of claim, wherein the postural controller comprises:
 a conversion module configured to receive processed EMG signals and map the processed EMG signals to a point in the postural control space, wherein the point in the postural control space  1  s between two postures. And   a joint angle transformer configured to transform the point in the postural control space into a set of desired joint angles by morphing the joint angles o€ the two postures.   
     
     
         3 . The prosthetic device of  claim 2 , wherein the conversion module uses a vector summation algorithm to map the processed EMG signals to a point in the postural control space. 
     
     
         4 . The prosthetic device of  claim 1 , wherein the set of electrodes include surface electrodes. 
     
     
         5 . The prosthetic device of  claim 1 , wherein the postural control space can be defined through graphical user interface by an anaplastologist. 
     
     
         6 . The prosthetic device of  claim 1 , wherein the prosthetic device includes at least six actuators to control the joint angles. 
     
     
         7 . The prosthetic device of  claim 1 , wherein the prosthetic device includes a pressure sensor and an encoder that generate signals that are used by the feedback controller to generate control signals to set the joint angles of the prosthetic device. 
     
     
         8 . A postural controller comprising:
 a processor;   a memory having stored thereon a postural control space having a set of pre-selected postures each defining joint angles of a mechanical device;   a conversion module configured to receive processed EMG signals and map the processed EMG signals to a point in the postural control space using the processor, wherein the point in the postural control space lies between two of the pre-selected postures; and   a joint angle transformer configured to use the processor to transform the point in the postural control space into a set of desired joint angles by morphing the joint angles of the two of the pre-selected postures that the point lies between in the postural control space.   
     
     
         9 . The postural controller of  claim 8 , further comprising a feedback controller to generate control signals cause a set of actuators to set the joint angles of the mechanical device. 
     
     
         10 . The postural controller of  claim 9 , wherein the feedback controller uses signals generated from an encoder or from a pressure sensor to generate the control signals. 
     
     
         11 . The postural controller of  claim 8 , wherein the conversion module uses a vector summation algorithm to map the processed EMG signals to a point in the postural control space. 
     
     
         12 . The postural controller of  claim 8 , wherein the postural control space includes attractive regions around the pre-selected postures. 
     
     
         13 . The postural controller of  claim 8 , further comprising a customization module configured to modify the postural control space based on indications of modifications received through a graphical user interface. 
     
     
         14 . The postural controller of  claim 6 , further comprising:
 a set of electrodes configured to monitor muscle contractions and generate EMG signals;   a means for generating the processed EMG signals by removing noise from the EMG signals and dynamically tuning the EMG signals based on an orientation of a prosthetic device.   
     
     
         15 . A processor-implemented method comprising:
 monitoring, using an electrode array, signals generated to set a posture of a prosthetic device;   mapping, using a processor, the signals to a point in a user specific posture space; and   setting the posture of the prosthetic device based on the point in the user specific posture space.   
     
     
         16 . The processor implemented method of  claim 15 , wherein the prosthetic device is a prosthetic hand, a prosthetic arm, a prosthetic foot, or a prosthetic leg. 
     
     
         17 . The processor-implemented method of  claim 15 , wherein mapping the signals to a point in the user specific posture space includes vector summation. 
     
     
         18 . The processor-implemented method of  claim 15 , further comprising generating, based on user specific information, the user specific posture space. 
     
     
         19 . Tice processor-implemented method of claim  78 , wherein the user specific information includes user preferences and descriptions of the signals, wherein the signals include EMG signals generated from the muscle contractions of a user, peripheral neuron signals, or computer generated signals. 
     
     
         20 . The processor-implemented method of  claim 15 , wherein the signals are filtered and dynamically tuned based on muscular contractions of a user.