Digital Sensing Systems for Electromyography

Surface electromyogram (EMG) signals find diverse applications in movement rehabilitation and human-computer interfacing. For instance, future advanced prostheses, which use artificial intelligence, will require EMG signals recorded from several sites on the forearm. This requirement will entail complex wiring and data handling. We present the design and evaluation of a bespoke EMG sensing system that addresses the above challenges, enables distributed signal processing, and balances local versus global power consumption. Additionally, the proposed EMG system enables the recording and simultaneous analysis of skin-sensor impedance, needed to ensure signal fidelity. We evaluated the proposed sensing system in three experiments, namely, monitoring muscle fatigue, real-time skin-sensor impedance measurement, and control of a myoelectric computer interface. The proposed system offers comparable signal acquisition characteristics to that achieved by a clinically-approved product. It will serve and integrate future myoelectric technology better via enabling distributed machine learning and improving the signal transmission efficiency

Improved prosthetic hand control with concurrent use of myoelectric and inertial measurements

Abstract Background Myoelectric pattern recognition systems can decode movement intention to drive upper-limb prostheses. Despite recent advances in academic research, the commercial adoption of such systems remains low. This limitation is mainly due to the lack of classification robustness and a simultaneous requirement for a large number of electromyogram (EMG) electrodes. We propose to address these two issues by using a multi-modal approach which combines surface electromyography (sEMG) with inertial measurements (IMs) and an appropriate training data collection paradigm. We demonstrate that this can significantly improve classification performance as compared to conventional techniques exclusively based on sEMG signals. Methods We collected and analyzed a large dataset comprising recordings with 20 able-bodied and two amputee participants executing 40 movements. Additionally, we conducted a novel real-time prosthetic hand control experiment with 11 able-bodied subjects and an amputee by using a state-of-the-art commercial prosthetic hand. A systematic performance comparison was carried out to investigate the potential benefit of incorporating IMs in prosthetic hand control. Results The inclusion of IM data improved performance significantly, by increasing classification accuracy (CA) in the offline analysis and improving completion rates (CRs) in the real-time experiment. Our findings were consistent across able-bodied and amputee subjects. Integrating the sEMG electrodes and IM sensors within a single sensor package enabled us to achieve high-level performance by using on average 4-6 sensors. Conclusions The results from our experiments suggest that IMs can form an excellent complimentary source signal for upper-limb myoelectric prostheses. We trust that multi-modal control solutions have the potential of improving the usability of upper-extremity prostheses in real-life applications

Pain distress : the negative emotion associated with procedures in ICU patients

The intensity of procedural pain in intensive care unit (ICU) patients is well documented. However, little is known about procedural pain distress, the psychological response to pain. Post hoc analysis of a multicenter, multinational study of procedural pain. Pain distress was measured before and during procedures (0-10 numeric rating scale). Factors that influenced procedural pain distress were identified by multivariable analyses using a hierarchical model with ICU and country as random effects. A total of 4812 procedures were recorded (3851 patients, 192 ICUs, 28 countries). Pain distress scores were highest for endotracheal suctioning (ETS) and tracheal suctioning, chest tube removal (CTR), and wound drain removal (median [IQRs] = 4 [1.6, 1.7]). Significant relative risks (RR) for a higher degree of pain distress included certain procedures: turning (RR = 1.18), ETS (RR = 1.45), tracheal suctioning (RR = 1.38), CTR (RR = 1.39), wound drain removal (RR = 1.56), and arterial line insertion (RR = 1.41); certain pain behaviors (RR = 1.19-1.28); pre-procedural pain intensity (RR = 1.15); and use of opioids (RR = 1.15-1.22). Patient-related variables that significantly increased the odds of patients having higher procedural pain distress than pain intensity were pre-procedural pain intensity (odds ratio [OR] = 1.05); pre-hospital anxiety (OR = 1.76); receiving pethidine/meperidine (OR = 4.11); or receiving haloperidol (OR = 1.77) prior to the procedure. Procedural pain has both sensory and emotional dimensions. We found that, although procedural pain intensity (the sensory dimension) and distress (the emotional dimension) may closely covary, there are certain factors than can preferentially influence each of the dimensions. Clinicians are encouraged to appreciate the multidimensionality of pain when they perform procedures and use this knowledge to minimize the patient's pain experience.Peer reviewe

Validation of the Greek version of the distress thermometer compared to the clinical interview for depression

Funding text This study was partly supported by research grants funded by the Cyprus University of Technology (statistical analysis) and Papageorgiou General Hospital (copyright expenses to NCCN). No funding sources were used in the design of the study, interpretation of data and in writing of the manuscript. AcknowledgementsBackground: The Distress Thermometer (DT) is worldwide the most commonly used instrument for quick screening of emotional burden in patients with cancer. In order to validate the Greek version of the DT in the Greek population we aimed to explore the capacity of the DT to identify patients with comorbid depressive diagnosis. Methods: We analyzed the routinely collected clinical data from 152 patients with cancer who had been evaluated by the consultation-liaison psychiatric service and had received a diagnosis of either depressive disorder or no psychiatric diagnosis. The score of the DT accompanied by the list of problems in the Problem List, the depression status, and the clinical and demographic characteristics entered the data sheet. Results: The ROC analysis revealed that the DT achieved a significant discrimination with an area under the curve of 0.79. At a cut-off point of 4, the DT identified 85% of the patients with an ICD-10 depressive diagnosis (sensitivity) and 60% of the patients without a psychiatric diagnosis (specificity). The positive predictive value was 44%, the negative predictive value 92% and the diagnostic odd ratio 8.88. Fatigue and emotional difficulties were the most commonly reported problems by the patients. Conclusion: The Greek version of the DT has a sufficient overall accuracy in classifying patients regarding the existence of depressive disorders, in the oncology setting. Therefore, it can be considered as a valid initial screening tool for depression in patients with cancer; patients scoring ≥4 should be assessed by a more thorough mental evaluation

Trajectories of Depressive Symptoms in Women Prior to and for Six Months After Breast Cancer Surgery.

Depressive symptoms are common in women with breast cancer. This study evaluated how ratings of depressive symptoms changed from the time of the preoperative assessment to 6 months after surgery and investigated whether specific demographic, clinical, and symptom characteristics predicted preoperative levels of and/or characteristics of the trajectories of depressive symptoms. Characteristics that predicted higher preoperative levels of depressive symptoms included being married/partnered; receipt of adjuvant chemotherapy; more fear of metastasis; higher levels of trait anxiety, state anxiety, sleep disturbance, problems with changes in appetite; more hours per day in pain; and lower levels of attentional function. Future studies need to evaluate associations between anxiety, fears of recurrence, and uncertainty, as well as personality characteristics and depressive symptoms

Co-occurrence of anxiety and depressive symptoms following breast cancer surgery and its impact on quality of life

PURPOSE: Little is known about the prevalence of combined anxiety and depressive symptoms (CADS) in breast cancer patients. Purpose was to evaluate for differences in demographic and clinical characteristics and quality of life (QOL) prior to breast cancer surgery among women classified into one of four distinct anxiety and/or depressive symptom groups. METHODS: A total of 335 patients completed measures of anxiety and depressive symptoms and QOL prior to and for 6 months following breast cancer surgery. Growth Mixture Modelling (GMM) was used to identify subgroups of women with distinct trajectories of anxiety and depressive symptoms. These results were used to create four distinct anxiety and/or depressive symptom groups. Differences in demographic, clinical, and symptom characteristics, among these groups were evaluated using analyses of variance and Chi square analyses. RESULTS: A total of 44.5% of patients were categorized with CADS. Women with CADS were younger, non-white, had lower performance status, received neoadjuvant or adjuvant chemotherapy, had greater difficulty dealing with their disease and treatment, and reported less support from others to meet their needs. These women had lower physical, psychological, social well-being, and total QOL scores. Higher levels of anxiety with or without subsyndromal depressive symptoms were associated with increased fears of recurrence, hopelessness, uncertainty, loss of control, and a decrease in life satisfaction. CONCLUSIONS: Findings suggest that CADS occurs in a high percentage of women following breast cancer surgery and results in a poorer QOL. Assessments of anxiety and depressive symptoms are warranted prior to surgery for breast cancer