Upper-limb Amputees Research Articles

Fascicle-Specific Targeting of Longitudinal Intrafascicular Electrodes for Motor and Sensory Restoration in Upper-Limb Amputees.

Multichannel longitudinal intrafascicular electrode (LIFE) interfaces provide optimized balance of invasiveness and stability for chronic sensory stimulation and motor recording/decoding of peripheral nerve signals. Using a fascicle-specific targeting (FAST)-LIFE approach, where electrodes are individually placed within discrete sensory- and motor-related fascicular subdivisions of the residual ulnar and/or median nerves in an amputated upper limb, FAST-LIFE interfacing can provide discernment of motor intent for individual digit control of a robotic hand, and restoration of touch- and movement-related sensory feedback. The authors describe their findings from clinical studies performed with 6 human amputee trials using FAST-LIFE interfacing of the residual upper limb.

A Review of the Performance of Extrinsically Powered Prosthetic Hands

Extrinsically powered prosthetic hands offer the potential to replicate the capabilities of a human hand and thus enable an upper limb amputee to complete activities of daily living. Over the past 20 years however, amputees have consistently indicated that several user needs have not been met. Many of these user needs are related to the hardware of the prosthetic hand, and in particular, its actuators and transmissions. These needs include reduced weight and improved dexterity, hand speed, hand strength, and functionality. To understand why these user needs have not been adequately addressed, we first seek to investigate the state of the art in extrinsically powered prosthetic hands through a comprehensive review of the research, commercial, and open-source literature. This review focuses specifically on actuation of the prosthetic hands because actuation is central to addressing the above user needs. This review, based on actuation strategies, enables a characterization and exploration of the actuation design space. We also compare the performance of the reviewed prosthetic hands with both the human hand and ideal recommendations for prosthetic hands to conclude that existing prosthetic hands do not adequately address user needs. This systematic characterization of the actuation design space helps identify that improvements to transmission pathways are the most promising avenue of further research and innovation to enable future prosthetic hands that adequately address user needs.

Upper and lower limb amputations in vehicle-related fatalities

Traumatic limb amputation is rare in occupants following a motor vehicle collision (MVC). A retrospective analysis of autopsy reports at Forensic Science South Australia (FSSA) over a 19 year period from January 2000 to December 2018 was performed to determine the incidence of limb amputation in lethal collisions and to identify predisposing factors. Only 18 cases (1.54%) of occupant fatalities had a traumatic limb amputation with an age range of 18–78 years (mean 44.2 years), male to female ratio 13:5, and an average body mass index (BMI) of 28.5 (overweight). There were nine cases of upper limb amputation and nine cases of lower limb amputation (one case had both upper and lower limb amputations). Head on impacts without subsequent rollover were the most common collision type in both upper and lower amputation. The likely cause of limb amputation in vehicle crashes is, therefore, speed on impact rather than rollovers as has been previously suggested.

Immediate Effects of a Continuous Peripheral Nerve Block on Postamputation Phantom and Residual Limb Pain: Secondary Outcomes From a Multicenter Randomized Controlled Clinical Trial.

We recently reported that a 6-day continuous peripheral nerve block reduced established postamputation phantom pain 3 weeks after treatment ended. However, the immediate effects of perineural infusion (secondary outcomes) have yet to be reported. Participants from 5 enrolling academic centers with an upper or lower limb amputation and established phantom pain received a single-injection ropivacaine peripheral nerve block(s) and perineural catheter insertion(s). They were subsequently randomized to receive a 6-day ambulatory perineural infusion of either ropivacaine 0.5% or normal saline in a double-masked fashion. Participants were contacted by telephone 1, 7, 14, 21, and 28 days after the infusion started, with pain measured using the Numeric Rating Scale. Treatment effects were assessed using the Wilcoxon rank-sum test at each time point. Adjusting for 4 time points (days 1, 7, 14, and 21), P < .0125 was deemed statistically significant. Significance at 28 days was reported using methods from the original, previously published article. Pretreatment average phantom and residual pain scores were balanced between the groups. The day after infusion initiation (day 1), average phantom, and residual limb pain intensity was lower in patients receiving local anesthetic (n = 71) versus placebo (n = 73): median [quartiles] of 0 [0-2.5] vs 3.3 [0-5.0], median difference (98.75% confidence interval [CI]) of -1.0 (-3.0 to 0) for phantom pain (P = .001) and 0 [0-0] vs 0 [0-4.3], and median difference 0.0 (-2.0 to 0.0) for residual limb pain (P < .001). Pain's interference with physical and emotional functioning as measured with the interference domain of the Brief Pain Inventory improved during the infusion on day 1 for patients receiving local anesthetic versus placebo: 0 [0-10] vs 10 [0-40], median difference (98.75% CI) of 0.0 (-16.0 to 0.0), P = .002. Following infusion discontinuation (day 6), a few differences were found between the active and placebo treatment groups between days 7 and 21. In general, sample medians for average phantom and residual limb pain scores gradually increased after catheter removal for both treatments, but to a greater degree in the control group until day 28, at which time the differences between the groups returned to statistical significance. This secondary analysis suggests that a continuous peripheral nerve block decreases phantom and residual limb pain during the infusion, although few improvements were again detected until day 28, 3 weeks following catheter removal.

Improving sEMG-based motion intention recognition for upper-limb amputees using transfer learning

Improving sEMG-based motion intention recognition for upper-limb amputees using transfer learning

Understanding the Relationship Between Patient-Reported Function and Actual Function in the Upper Limb Prosthesis User Population: A Preliminary Study

ObjectiveTo understand how perceived function relates to actual function at a specific stage in the rehabilitation process for the population using upper limb prostheses. DesignQuantitative clinical descriptive study. SettingClinical offices. ParticipantsA sample of 61 participants (N=61; mean age, 43.0±12.8y; 51 male/10 female) with upper limb amputation who use a prosthetic device and were in the definitive stage of a prosthesis fitting process. InterventionsNot applicable. Main Outcome MeasuresA patient-reported outcome measure, the Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH), and 2 performance-based outcome measures, Box and Blocks Test (BBT) and Capacity Assessment of Prosthesis Performance for the Upper Limb (CAPPFUL), were used as variables in multiple linear regression models. ResultsThe multiple linear regression models, which controlled for prosthesis type and amputation level, did not show evidence that changes in the independent variable (DASH) are significantly associated with changes in the dependent variables (log(BBT) (B=−0.007; 95% confidence interval [CI], −0.015 to 0.001; P=.0937) and CAPPFUL (B=−0.083, 95% CI, −0.374 to 0.208; P=.5623)). In both models, individuals with elbow, transhumeral (above elbow), and shoulder disarticulation showed a significant negative association with the dependent variable (CAPPFUL or logBBT). In the CAPPFUL model, there was a significant negative association with individuals using a hybrid prosthesis (B=−20.252; 95% CI, −36.562 to −3.942; P=.0170). In the logBBT model, there was a significant positive association with individuals using body-powered prostheses (B=0.430; 95% CI, 0.089-0.771; P=.0157). ConclusionsAlthough additional data and analyses are needed to more completely assess the association between self-reported measures and performance-based measures of functional abilities, these preliminary results indicate that patient-reported outcomes alone may not provide a complete assessment of an upper limb prosthesis users’ functional ability and should be accompanied by population-specific performance-based measures.

Parietal Lobe Reorganization and Widespread Functional Connectivity Integration in Upper-Limb Amputees: A rs-fMRI Study

The right parietal lobe plays an important role in body image, and disorders of body image emerge after lesions in the parietal lobe or with parietal lobe epilepsy. Body image disorder also often accompanies upper-limb amputation, in which the patient misperceives that their missing limb is still part of their body. Cortical reorganization is known to occur after upper-limb amputation, but it is not clear how widespread and to what degree functional connectivity (FC) is reorganized post-amputation, nor whether such changes might be related to misperceptions of body image. Twenty-four subjects who had a traumatically upper-limb amputees (ULAs) and 24 age-matched healthy controls (HCs) underwent resting-state functional magnetic resonance imaging (rs-fMRI) scans. Regions of interest (ROIs) in the right superior parietal gyrus (SPG_R) and right inferior parietal lobule (IPL_R) were defined using BrainNet Viewer. We calculated the amplitude of low-frequency fluctuations (ALFF) in ROIs and correlated the ROI mean amplitude of low-frequency fluctuations (mALFF) and mean scores on the phantom limb sensation (PLS) scale and beck depression index (BDI). We also calculated ROIs and whole-brain FC. Compared to the HC group, we observed significantly increased activation (mALFF) in ROIs of the ULA group. Moreover, correlation analyses revealed a significant positive correlation between ROI mALFF and scores on the PLS. There was a significant negative correlation between the SPG_R mALFF and BDI scores. Seed-based, whole-brain FC analysis revealed that FC in the ULA group significantly decreased in many brain regions across the entire brain. The right parietal lobe appears to be involved in some aspect of body awareness and depression in amputation patients. Upper-limb amputation results not only in reorganization in the local brain area formerly representing the missing limb, but also results in more widespread reorganization through FC changes in whole brain.

Face-Computer Interface (FCI): Intent Recognition Based on Facial Electromyography (fEMG) and Online Human-Computer Interface With Audiovisual Feedback.

Patients who have lost limb control ability, such as upper limb amputation and high paraplegia, are usually unable to take care of themselves. Establishing a natural, stable, and comfortable human-computer interface (HCI) for controlling rehabilitation assistance robots and other controllable equipments will solve a lot of their troubles. In this study, a complete limbs-free face-computer interface (FCI) framework based on facial electromyography (fEMG) including offline analysis and online control of mechanical equipments was proposed. Six facial movements related to eyebrows, eyes, and mouth were used in this FCI. In the offline stage, 12 models, eight types of features, and three different feature combination methods for model inputing were studied and compared in detail. In the online stage, four well-designed sessions were introduced to control a robotic arm to complete drinking water task in three ways (by touch screen, by fEMG with and without audio feedback) for verification and performance comparison of proposed FCI framework. Three features and one model with an average offline recognition accuracy of 95.3%, a maximum of 98.8%, and a minimum of 91.4% were selected for use in online scenarios. In contrast, the way with audio feedback performed better than that without audio feedback. All subjects completed the drinking task in a few minutes with FCI. The average and smallest time difference between touch screen and fEMG under audio feedback were only 1.24 and 0.37 min, respectively.

The Prevalence and Impact of Back and Neck Pain in Veterans With Upper Limb Amputation.

The aims of the study were (1) to describe frequency of back pain only, neck pain only, and co-occurring pain in veterans with upper limb amputation, (2) to examine changes in pain over 1 yr, and (3) to quantify the association of pain and health-related quality of life and disability. This is an observational cohort study with a survey of a sample of 792 veterans with upper limb amputation, with 1-yr reassessment of 585 (85.3%) of 777 eligible participants. Pain prevalence and intensity were examined. Logistic and linear regressions identified variables associated with pain and examined associations between intensity and veterans RAND-12 mental component score and physical component score and QuickDASH. At baseline, 52.3% had co-occurring pain, 20.0% had back pain, and 8.3% had neck pain. Persistent back and neck pain is present in 60.8% and 48.1% respondents, respectively. Pain intensity was unchanged for 59.1% with back pain and 61.3% with neck pain. Mental component score and QuickDASH were significantly worse with severe and moderate back and neck pain, compared with no pain. Severe/moderate back pain intensity was associated with lower physical component score. Back and neck pain is highly prevalent and persistent in veterans with upper limb amputation. Pain intensity is negatively associated with health-related quality of life and disability. Pain prevention and intervention are needed in this population.

A User-Driven Approach to Prosthetic Upper Limb Development in Korea.

Despite recent significant advances in technology and medicine, the number of patients who undergo amputation of body parts for various reasons continues to increase. Assistive devices such as prosthetic arms can enable limited activities in upper limb amputees and improve their quality of life. This study aims to help in the development of user-centered prosthetics by identifying user requirements and key considerations during selection of prosthetics. This study conducted a questionnaire survey after obtaining prior consent for persons with disabilities with upper limb amputation who visited orthosis companies, rehabilitation centers for the disabled, veteran’s hospitals, and labor welfare corporations. A modified questionnaire was conducted to upper limb prosthetic users and results were analysed using descriptive statistics and t-test. Results of the study showed that the main reasons for discontinuing the use of prosthetics were discomfort (discomfort in wear, weight, and difficulty of detachment) and complaints regarding design and function. Regardless of the prosthesis type, the color and design of the prosthesis were key considerations in prosthesis choices. Respondents indicated that they needed various prostheses designed according to the purpose and situation, such as for sports like golf and cycling as well as everyday use. Most of the respondents answered that buttoning shirts, tying knots, and using chopsticks were challenging or impossible to do on their own. Based on the results of this study, the quality of life of upper limb amputees can be improved if a prosthetic arm with various functions that can satisfy both the user’s needs and wants is developed.

Machine Learning for the Control of Prosthetic Arms: Using Electromyographic Signals for Improved Performance

The human hand can perform many precise functions and is relied upon for countless aspects of daily life. When upperlimb amputation is necessitated, an affected individual's sense of independence is understandably impacted.

Prosthetic Arm using Force Sensor

An Upper limb amputation causes a severe reduction in lifestyle of the affected individual due to inability to perform activities of daily lifestyle. This is a devastating occurrence that limits human activity which can result into physical or mental trauma. In order to provide assistance to the amputee, use of prosthetic devices is becoming more popular. Prosthetic devices can be mechanical or electromechanical devices that mimic the ordinary movement of human parts. In this research work, to mimic the function of the human arm for disabled people and stroke patients, a portable lightweight device which offers automatic, integrated easy to use bionic arm is designed and implemented. By using the concepts of Mechatronics and Robotics in this project aims for a functional prosthetic affordable to everyone.

A Study on Various Trans-Humeral Prostheses Using Surface EMG

Upper limb amputation arise due to cardiovascular defects, trauma, health problems, or inborn defects. A disabled person needs an assistive mechanism like the prosthetic arm to perpetrate in their day-to-day activities. A Prosthetic Arm is an artificial system for interfacing my generated signals with external physical activities, which is extensively used to communicate and control the interactions between humans and machines. Many bio-generated signals can be utilized to control prosthetic arm like Surface Electromyogram, Electro Encephalogram, etc. but here using Surface Electromyography (s EMG) signal to control Prosthetic arm. s EMG is an inquiry of electrical activity of the striated muscle which is monitored at the surface of the skin. This signal is interfaced with a prosthetic device which helps to improve the quality level of amputees. Maximum movements are the target, which includes movements of fingers, forearm, and trans-humeral areas. The body-generated signal can be extracted using various electronic equipment and can be analyzed actual brain intention on various hand movements. With the support of artificial devices, one can achieve the goal. Neural networks and advanced Embedded System applications are also included in this prostheses implementation. This paper involves the study of various trans-humeral prostheses using electromyogram.

Intuitive real-time control strategy for high-density myoelectric hand prosthesis using deep and transfer learning

Myoelectric hand prostheses offer a way for upper-limb amputees to recover gesture and prehensile abilities to ease rehabilitation and daily life activities. However, studies with prosthesis users found that a lack of intuitiveness and ease-of-use in the human-machine control interface are among the main driving factors in the low user acceptance of these devices. This paper proposes a highly intuitive, responsive and reliable real-time myoelectric hand prosthesis control strategy with an emphasis on the demonstration and report of real-time evaluation metrics. The presented solution leverages surface high-density electromyography (HD-EMG) and a convolutional neural network (CNN) to adapt itself to each unique user and his/her specific voluntary muscle contraction patterns. Furthermore, a transfer learning approach is presented to drastically reduce the training time and allow for easy installation and calibration processes. The CNN-based gesture recognition system was evaluated in real-time with a group of 12 able-bodied users. A real-time test for 6 classes/grip modes resulted in mean and median positive predictive values (PPV) of 93.43% and 100%, respectively. Each gesture state is instantly accessible from any other state, with no mode switching required for increased responsiveness and natural seamless control. The system is able to output a correct prediction within less than 116 ms latency. 100% PPV has been attained in many trials and is realistically achievable consistently with user practice and/or employing a thresholded majority vote inference. Using transfer learning, these results are achievable after a sensor installation, data recording and network training/fine-tuning routine taking less than 10 min to complete, a reduction of 89.4% in the setup time of the traditional, non-transfer learning approach.

Development of overuse musculoskeletal conditions after combat-related upper limb amputation: a retrospective cohort study

Study designRetrospective cohort study IntroductionService members who have sustained traumatic amputations are typically young and otherwise healthy. Beyond standard care, these individuals desire long, highly active, and relatively pain-free lifestyle, whether that is returning to active duty or transitioning to civilian life. Development of overuse musculoskeletal conditions could have a significant influence on quality of life for Service members with traumatic upper limb amputation. Purpose of the studyCompare one-year incidence of overuse musculoskeletal injuries in Service members with different levels of combat-related upper limb amputation to Service members with minor combat-related upper limb injuries. MethodsService members with deployment-related upper limb injury (N = 519), 148 major upper limb amputation (55 with amputation at or above elbow, 93 with amputation below elbow) and 371 minor upper limb injury were included in the study. Outcomes of interest clinical diagnosis codes associated with overuse conditions of the upper limb, neck and upper back, lower limb, low back pain, and all regions combined, one year before and one year after injury. ResultsOverall, the one-year incidence of developing at least one musculoskeletal overuse condition after upper limb amputation was between 60% and 65%. Service members with upper limb amputations were 2.7 to 4.7 times more likely to develop an overuse upper limb condition, 3.6 to 3.8 times more likely to develop a neck and upper back condition, 2.8 to 4.4 times more likely to develop a lower limb condition, and 3.3 to 3.9 times more likely to develop low back pain as compared those who sustained minor combat-related injuries. No significant differences in the odds of developing a musculoskeletal condition was found between the above elbow and below elbow amputation groups. ConclusionsIncidence of secondary overuse conditions is elevated in Service members with upper limb amputation and warrants focused research efforts toward preventative and rehabilitative interventions.

Pattern of upper limb amputation associated with lower limb amputation: the UK military experience from Iraq and Afghanistan

IntroductionThe conflicts in Iraq and Afghanistan resulted in large numbers of personnel sustaining extremity injuries. In the context of polytrauma, partial hand amputation is often unrecorded. The aim of this...

The client satisfaction with device: a Rasch validation of the Arabic version in patients with upper and lower limb amputation

BackgroundThe Client Satisfaction with Devices (CSD) module of the Orthotics and Prosthetics Users’ Survey is an extensively used questionnaire that measures patients’ satisfaction with orthosis and prosthesis. However, the validated version for Arabic speakers (CSD-Ar) is only applicable for orthosis users.ObjectivesThe aim of this study was to evaluate the psychometric proprieties of the CSD-Ar for prosthetics users.MethodsThe study used a convenience sample of prosthesis users from Saudi Arabia and Turkey (N = 183), who completed the CSD-Ar. The collected data were analysed using Rasch analysis to evaluate item fit, reliability indices, item difficulty, local item dependency, and differential item functioning (DIF) using WINSTEPS version 4.6.1.ResultsBased on the analysis, the four-response Likert-scale was acceptable, as shown by the category functioning test, All eight items did achieve a fit to the Rasch Model [(infit) and (outfit) mean-square 0.75 to 1.3]. Person separation reliability was 0.76, and item separation reliability was 0.94. A principal component analysis (PCA) showed satisfactory unidimensionality and no local item dependency. The DIF analysis showed no notable dependency among items on participant characteristics in terms of age, gender, duration of use, country, and level of amputation.ConclusionThis study contributes to the confidence of using CSD-Ar to evaluate users’ satisfaction with different prostheses, affirming the need for further refinement of the quality of the outcome measure.

Changes in Temporal and Spatial Patterns of Intrinsic Brain Activity and Functional Connectivity in Upper-Limb Amputees: An fMRI Study.

Background Amputation in adults is a serious procedure or traumatic outcome, one that leads to a possible “remapping” of limb representations (somatotopy) in the motor and sensory cortex. The temporal and spatial extent underlying reorganization of somatotopy is unclear. The aim of this study was to better understand how local and global structural plasticity in sensory-motor cortical networks changes temporally and spatially after upper-limb amputation. Methods We studied 8 healthy nonamputee control subjects and 16 complete upper-limb amputees. Resting-state MRI (rs-fMRI) was used to measure local and large-scale relative differences (compared to controls) in both the amplitude of low-frequency fluctuations (ALFF) and degree of centrality (DC) at 2 months, 6 months, and 12 months after traumatic amputation. Results In amputees, rs-fMRI scans revealed differences in spatial patterns of ALFF and DC among brain regions over time. Significant relative increases in ALFF and DC were detected not only in the sensory and motor cortex but also in related cortical regions believed to be involved in cognition and motor planning. We observed changes in the magnitude of ALFFs in the pre- and postcentral gyrus and primary sensory cortex, as well as in the anterior cingulate, parahippocampal gyrus, and hippocampus, 2 months after the amputation. The regional distribution of increases/decreases in ALFFs and DC documented at 2-month postamputation was very different from those at 6 and 12-month postamputation. Conclusion Local and wide-spread changes in ALFFs in the sensorimotor cortex and cognitive-related brain regions after upper-limb amputation may imply dysfunction not only in sensory and motor function but also in areas responsible for sensorimotor integration and motor planning. These results suggest that cortical reorganization after upper extremity deafferentation is temporally and spatially more complicated than previously appreciated, affecting DC in widespread regions.

An integrated deep learning model for motor intention recognition of multi-class EEG Signals in upper limb amputees

Background and objectiveRecognition of motor intention based on electroencephalogram (EEG) signals has attracted considerable research interest in the field of pattern recognition due to its notable application of non-muscular communication and control for those with severe motor disabilities. In analysis of EEG data, achieving a higher classification performance is dependent on the appropriate representation of EEG features which is mostly characterized by one unique frequency before applying a learning model. Neglecting other frequencies of EEG signals could deteriorate the recognition performance of the model because each frequency has its unique advantages. Motivated by this idea, we propose to obtain distinguishable features with different frequencies by introducing an integrated deep learning model to accurately classify multiple classes of upper limb movement intentions. MethodsThe proposed model is a combination of long short-term memory (LSTM) and stacked autoencoder (SAE). To validate the method, four high-level amputees were recruited to perform five motor intention tasks. The acquired EEG signals were first preprocessed before exploring the consequence of input representation on the performance of LSTM-SAE by feeding four frequency bands related to the tasks into the model. The learning model was further improved by t-distributed stochastic neighbor embedding (t-SNE) to eliminate feature redundancy, and to enhance the motor intention recognition. ResultsThe experimental results of the classification performance showed that the proposed model achieves an average performance of 99.01% for accuracy, 99.10% for precision, 99.09% for recall, 99.09% for f1_score, 99.77% for specificity, and 99.0% for Cohen's kappa, across multi-subject and multi-class scenarios. Further evaluation with 2-dimensional t-SNE revealed that the signal decomposition has a distinct multi-class separability in the feature space. ConclusionThis study demonstrated the predominance of the proposed model in its ability to accurately classify upper limb movements from multiple classes of EEG signals, and its potential application in the development of a more intuitive and naturalistic prosthetic control.

A case of rapidly progressive upper limb ischemic necrosis in a patient with COVID-19

BackgroundFor more than a year, health systems all over the world have been combating the global coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The disease was first described in the city of Wuhan in China, presenting as an atypical infection of the lower respiratory tract. MethodsCOVID-19 is characterized by multisystemic involvement, and mortality is attributed mainly to the respiratory system involvement, which may lead to severe acute respiratory distress syndrome and respiratory failure. Several COVID-19-associated complications are being increasingly reported, including arterial and venous thromboembolic events that may lead to amputation of the affected limbs. So far, a large number of reports have described hypercoagulability crises leading to amputation of the lower limbs. However, a search of the National Library of Medicine (MEDLINE) revealed no cases of urgent upper limb amputation in COVID-19 patients. ResultsThis article describes a novel case of upper limb ischemia in a COVID-19 patient, with rapid progression to hand necrosis, requiring urgent through-arm amputation of the upper limb. ConclusionsThis case emphasizes the need for anticoagulant therapy in COVID-19 patients and to maintain a constant awareness of the possible thromboembolic COVID-19-related sequelae.