While much attention is being given in the application of advanced technologies to improve upper extremity prostheses, traditional body-powered prostheses still remain the most popular by people with an amputation. A ...While much attention is being given in the application of advanced technologies to improve upper extremity prostheses, traditional body-powered prostheses still remain the most popular by people with an amputation. A body-powered prosthesis provides the user with a reasonable solution for limb loss given their simple design, lower maintenance and initial cost. The two major types of body-powered prosthesis use either voluntary opening or voluntary closing control of the terminal device (or prehensor) used for holding and manipulating objects. What differentiates these two types of control is the relationship between the muscular force used to apply tension on the cable attached to the prehensor and the force produced by the prehensor. It has been argued that the voluntary closing prosthesis has more optimal compatibility between the muscle force and grip force of the prehensor. As a result, it may provide an advantage to the user in tasks requiring the control of grip force. To determine the effectiveness of the voluntary closing and voluntary opening prosthesis, we asked a person with a congenital quadruple limb deficiency who is right hand dominant, and that uses voluntary opening prostheses to participate in a study investigating grip force control. The participant was required to match different target grip forces displayed on a computer monitor by manipulating the pressure exerted on a hand dynamometer using either a voluntary closing or voluntary opening prosthesis. The participant only had previous experience with a voluntary opening prosthesis. The results showed that in several measures, the participant performed better with the voluntary closing prosthesis. These results provided support for the muscular force-grip force compatibility hypothesis.展开更多
Time–domain feature representation for imagined grip force movement-related cortical potentials(MRCP)of the right or left hand and the decoding of imagined grip force parameters based on electroencephalogram(EEG)acti...Time–domain feature representation for imagined grip force movement-related cortical potentials(MRCP)of the right or left hand and the decoding of imagined grip force parameters based on electroencephalogram(EEG)activity recorded during a single trial were here investigated.EEG signals were acquired from eleven healthy subjects during four different imagined tasks performed with the right or left hand.Subjects were instructed to execute imagined grip movement at two different levels of force.Each task was executed 60 times in random order.The imagined grip force MRCP of the right or left hand was analyzed by superposition and averaging technology,a single-trial extraction method,analysis of variance(ANOVA),and multiple comparisons.Significantly different features were observed among different imagined grip force tasks.These differences were used to decode imagined grip force parameters using Fisher linear discrimination analysis based on kernel function(k-FLDA)and support vector machine(SVM).Under the proposed experimental paradigm,the study showed that MRCP may characterize the dynamic processing that takes place in the brain during the planning,execution,and precision of a given imagined grip force task.This means that features related to MRCP can be used to decode imagined grip force parameters based on EEG.ANOVA and multiple comparisons of time–domain features for MRCP showed that movement-monitoring potentials(MMP)and specific interval(0–150 ms)average potentials to be significantly different among 4 different imagined grip force tasks.The minimum peak negativity differed significantly between high and low amplitude grip force.Identification of the 4different imagined grip force tasks based on MMP was performed using k-FLDA and SVM,and the average misclassification rates of 27%±5%and 24%±4%across 11 subjects were achieved respectively.The minimum misclassification rate was 15%,and the average minimum misclassification rate across 11 subjects was24%±4.5%.This investigation indicates that imagined gri展开更多
文摘While much attention is being given in the application of advanced technologies to improve upper extremity prostheses, traditional body-powered prostheses still remain the most popular by people with an amputation. A body-powered prosthesis provides the user with a reasonable solution for limb loss given their simple design, lower maintenance and initial cost. The two major types of body-powered prosthesis use either voluntary opening or voluntary closing control of the terminal device (or prehensor) used for holding and manipulating objects. What differentiates these two types of control is the relationship between the muscular force used to apply tension on the cable attached to the prehensor and the force produced by the prehensor. It has been argued that the voluntary closing prosthesis has more optimal compatibility between the muscle force and grip force of the prehensor. As a result, it may provide an advantage to the user in tasks requiring the control of grip force. To determine the effectiveness of the voluntary closing and voluntary opening prosthesis, we asked a person with a congenital quadruple limb deficiency who is right hand dominant, and that uses voluntary opening prostheses to participate in a study investigating grip force control. The participant was required to match different target grip forces displayed on a computer monitor by manipulating the pressure exerted on a hand dynamometer using either a voluntary closing or voluntary opening prosthesis. The participant only had previous experience with a voluntary opening prosthesis. The results showed that in several measures, the participant performed better with the voluntary closing prosthesis. These results provided support for the muscular force-grip force compatibility hypothesis.
基金the National Natural Science Foundation of China (60705021)the research project of State Key Laboratory of Robotics of Shenyang Institute of Automation (SIA),Chinese Academy of Science (CAS) (08A120C101)+2 种基金Research project for application foundation of Yunnan Province (2013FB02b)Cultivation Program of Talents of Yunnan Province (KKSY201303048)Focal Program for Education Office of Yunnan Province (2013Z130)
文摘Time–domain feature representation for imagined grip force movement-related cortical potentials(MRCP)of the right or left hand and the decoding of imagined grip force parameters based on electroencephalogram(EEG)activity recorded during a single trial were here investigated.EEG signals were acquired from eleven healthy subjects during four different imagined tasks performed with the right or left hand.Subjects were instructed to execute imagined grip movement at two different levels of force.Each task was executed 60 times in random order.The imagined grip force MRCP of the right or left hand was analyzed by superposition and averaging technology,a single-trial extraction method,analysis of variance(ANOVA),and multiple comparisons.Significantly different features were observed among different imagined grip force tasks.These differences were used to decode imagined grip force parameters using Fisher linear discrimination analysis based on kernel function(k-FLDA)and support vector machine(SVM).Under the proposed experimental paradigm,the study showed that MRCP may characterize the dynamic processing that takes place in the brain during the planning,execution,and precision of a given imagined grip force task.This means that features related to MRCP can be used to decode imagined grip force parameters based on EEG.ANOVA and multiple comparisons of time–domain features for MRCP showed that movement-monitoring potentials(MMP)and specific interval(0–150 ms)average potentials to be significantly different among 4 different imagined grip force tasks.The minimum peak negativity differed significantly between high and low amplitude grip force.Identification of the 4different imagined grip force tasks based on MMP was performed using k-FLDA and SVM,and the average misclassification rates of 27%±5%and 24%±4%across 11 subjects were achieved respectively.The minimum misclassification rate was 15%,and the average minimum misclassification rate across 11 subjects was24%±4.5%.This investigation indicates that imagined gri
