Tele-Impedance control of a virtual avatar based on EMG and M-IMU sensors: a proof-of-concept.

The broad spread of cooperative robots into many application domains has resulted in a demand for intuitive and effective solutions for teleoperated control. A relevant role in teleoperation has been assumed by impedance controllers, that allow the increase of stability and accuracy during interaction. This paper aims to test a teleoperation method based on an impedance controller, namely tele-impedance control, that is usable in unstructured environments since it relies only on wearable sensors. The proposed solution maps the joint stiffness and position of the human user, computed through six EMG and two M-IMU sensors, into the remote system to be teleoperated. We developed a 2-DoFs virtual task involving virtual physical interactions to compare the performance of our solution with the one of a traditional position-based controller. The study has been conducted on five healthy participants, who experienced both controllers in two different sessions. The tele-impedance approach has proved to be less physically demanding and more intuitive than the position-based one. Experimental data also allow us to investigate the strategy employed by the volunteers in the case of remote interactions, while using the two controllers. Of note, even though with the position controller the variation of subject impedance has no effect on the virtual arm, participants still tend to regulate both impedance and position of their own arm.

Increasing Serotonin to Reduce Parkinsonian Tremor.

While current dopamine-based drugs seem to be effective for most Parkinson's disease (PD) motor dysfunctions, they produce variable responsiveness for resting tremor. This lack of consistency could be explained by considering recent evidence suggesting that PD resting tremor can be divided into different partially overlapping phenotypes based on the dopamine response. These phenotypes may be associated with different pathophysiological mechanisms produced by a cortical-subcortical network involving even non-dopaminergic areas traditionally not directly related to PD. In this study, we propose a bio-constrained computational model to study the neural mechanisms underlying a possible type of PD tremor: the one mainly involving the serotoninergic system. The simulations run with the model demonstrate that a physiological serotonin increase can partially recover dopamine levels at the early stages of the disease before the manifestation of overt tremor. This result suggests that monitoring serotonin concentration changes could be critical for early diagnosis. The simulations also show the effectiveness of a new pharmacological treatment for tremor that acts on serotonin to recover dopamine levels. This latter result has been validated by reproducing existing data collected with human patients.

Postbariatric Brachioplasty with Posteromedial Scar: Physical Model, Technical Refinements, and Clinical Outcomes.

BACKGROUND: Brachioplasty is an increasingly performed procedure following massive weight loss. A visible scar is the main hindrance to this surgery. The aims of the study were to develop a physical model to investigate the ideal location of the surgical incision and to present the authors' technical refinements with the posteromedial scar approach. METHODS: Twenty-four postbariatric patients underwent brachioplasty with posteromedial scar placement, concomitant liposuction, fascial plication, and axillary Z-plasty. Skin specimens were tested and a physical model of the arm was set up to investigate the difference in mechanical stress on the posteromedial and medial scars. The validated Patient and Observer Scar Assessment Scale, the Vancouver Scar Scale, and a questionnaire assessing subjective improvements were administered to patients. Preoperative and postoperative photographs were assessed by three independent plastic surgeons. RESULTS: The physical model showed that stress intensity and distribution along the scar were reduced in the posteromedial location, with smaller scar displacement in the loading simulations. Twenty-three patients healed uneventfully. One (4.1 percent) had a 2-cm dehiscence. Mean Patient and Observer Scar Assessment Scale scores were, respectively, 2 ± 0.76 and 2.13 ± 0.64 in the patients' and observers' questionnaires. The mean Vancouver Scar Scale value was 3.5 ± 1.7. Questionnaires assessing the subjective outcomes showed a mean value of 3.45 ± 0.63 of 4. The surgeons' assessment resulted in a score of 4.5 ± 0.4 of 5. CONCLUSIONS: The physical model demonstrated that the posteromedial scar was subjected to lower mechanical stress and displacement. The reported technical refinements allowed pleasant arm recontouring to be achieved with acceptable scarring and a low incidence of complications. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.