OHO: A Multi-Modal, Multi-Purpose Dataset for Human-Robot Object Hand-Over.

In the context of collaborative robotics, handing over hand-held objects to a robot is a safety-critical task. Therefore, a robust distinction between human hands and presented objects in image data is essential to avoid contact with robotic grippers. To be able to develop machine learning methods for solving this problem, we created the OHO (Object Hand-Over) dataset of tools and other everyday objects being held by human hands. Our dataset consists of color, depth, and thermal images with the addition of pose and shape information about the objects in a real-world scenario. Although the focus of this paper is on instance segmentation, our dataset also enables training for different tasks such as 3D pose estimation or shape estimation of objects. For the instance segmentation task, we present a pipeline for automated label generation in point clouds, as well as image data. Through baseline experiments, we show that these labels are suitable for training an instance segmentation to distinguish hands from objects on a per-pixel basis. Moreover, we present qualitative results for applying our trained model in a real-world application.

Automatic Multiview Alignment of RGB-D Range Maps of Upper Limb Anatomy.

Digital representations of anatomical parts are crucial for various biomedical applications. This paper presents an automatic alignment procedure for creating accurate 3D models of upper limb anatomy using a low-cost handheld 3D scanner. The goal is to overcome the challenges associated with forearm 3D scanning, such as needing multiple views, stability requirements, and optical undercuts. While bulky and expensive multi-camera systems have been used in previous research, this study explores the feasibility of using multiple consumer RGB-D sensors for scanning human anatomies. The proposed scanner comprises three Intel® RealSenseTM D415 depth cameras assembled on a lightweight circular jig, enabling simultaneous acquisition from three viewpoints. To achieve automatic alignment, the paper introduces a procedure that extracts common key points between acquisitions deriving from different scanner poses. Relevant hand key points are detected using a neural network, which works on the RGB images captured by the depth cameras. A set of forearm key points is meanwhile identified by processing the acquired data through a specifically developed algorithm that seeks the forearm's skeleton line. The alignment process involves automatic, rough 3D alignment and fine registration using an iterative-closest-point (ICP) algorithm expressly developed for this application. The proposed method was tested on forearm scans and compared the results obtained by a manual coarse alignment followed by an ICP algorithm for fine registration using commercial software. Deviations below 5 mm, with a mean value of 1.5 mm, were found. The obtained results are critically discussed and compared with the available implementations of published methods. The results demonstrate significant improvements to the state of the art and the potential of the proposed approach to accelerate the acquisition process and automatically register point clouds from different scanner poses without the intervention of skilled operators. This study contributes to developing effective upper limb rehabilitation frameworks and personalized biomedical applications by addressing these critical challenges.

A rollover safety margin-based approach for quantifying the tractor-semitrailers' emergency lane-changing response on expressway curves.

In emergency scenarios, lane changing can provide a considerable advantage over braking by aiding in the prevention of rear-end collisions. However, executing lane changes on horizontal curves might lead to rollover collisions. This study proposes a systematic methodology for quantifying the rollover safety margin during lane-changing maneuvers by encompassing the complex characteristics of vehicle-road interactions. Specifically, an enhanced six-degree-of-freedom vehicle dynamics model was developed for a tractor-semitrailer and integrates road superelevation. Using this model, the rollover safety margin reduction rate (fS) was calculated. The fS represents the ratio of the difference between the lateral load transfer ratio margins under both reference state and emergency lane change conditions to the lateral load transfer ratio margin in the reference state. The reference state corresponds to vehicles maintaining 80 km·h-1 on a 270 m radius curve, while the emergency condition is defined as lane change durations of less than 4 seconds. The results reveal that emergency lane change maneuvers and roadway alignment significantly affect rollover safety margin. Shorter lane change duration, higher speed, and smaller radius worsen the rollover safety margin; these effects are further amplified when the lane change direction is opposite to the curve's bending direction. When the tractor-semitrailer performs a lane change at 60 km·h-1 within a 4-second duration on a 600 m radius curve, the fS exceeds 100%, indicating an imminent rollover. Consequently, this study contributes valuable evidence to the development of more reliable and secure lane-change strategies.

The social relevance and the temporal constraints of motor resonance in humans.

In humans, motor resonance effects can be tracked by measuring the enhancement of corticospinal excitability by action observation. Uncovering factors driving motor resonance is crucial for optimizing action observation paradigms in experimental and clinical settings. In the present study, we deepen motor resonance properties for grasping movements. Thirty-five healthy subjects underwent an action observation task presenting right-hand grasping movements differing from their action goal. Single-pulse transcranial magnetic stimulation was applied over the left primary motor cortex at 100, 200, or 300 ms from the onset of the visual stimulus depicting the action. Motor-evoked potentials were recorded from four muscles of the right hand and forearm. Results show a muscle-specific motor resonance effect at 200 ms after movement but selectively for observing a socially relevant grasp towards another human being. This effect correlates with observers' emotional empathy scores, and it was followed by inhibition of motor resonance at 300 ms post-stimulus onset. No motor resonance facilitation emerged while observing intransitive hand movement or object grasping. This evidence highlights the social side of motor resonance and its dependency on temporal factors.

Automated fracture detection in the ulna and radius using deep learning on upper extremity radiographs.

OBJECTIVES: This study aimed to detect single or multiple fractures in the ulna or radius using deep learning techniques fed on upper-extremity radiographs. MATERIALS AND METHODS: The data set used in the retrospective study consisted of different types of upper extremity radiographs obtained from an open-source dataset, with 4,480 images with fractures and 4,383 images without fractures. All fractures involved the ulna or radius. The proposed method comprises two distinct stages. The initial phase, referred to as preprocessing, involved the removal of radiographic backgrounds, followed by the elimination of nonbone tissue. In the second phase, images consisting only of bone tissue were processed using deep learning models, such as RegNetX006, EfficientNet B0, and InceptionResNetV2. Thus, whether one or more fractures of the ulna or the radius are present was determined. To measure the performance of the proposed method, raw images, images generated by background deletion, and bone tissue removal were classified separately using RegNetX006, EfficientNet B0, and InceptionResNetV2 models. Performance was assessed by accuracy, F1 score, Matthew's correlation coefficient, receiver operating characteristic area under the curve, sensitivity, specificity, and precision using 10-fold cross-validation, which is a widely accepted technique in statistical analysis. RESULTS: The best classification performance was obtained with the proposed preprocessing and RegNetX006 architecture. The values obtained for various metrics were as follows: accuracy (0.9921), F1 score (0.9918), Matthew's correlation coefficient (0.9842), area under the curve (0.9918), sensitivity (0.9974), specificity (0.9863), and precision (0.9923). CONCLUSION: The proposed preprocessing method is able to detect fractures of the ulna and radius by artificial intelligence.

Clinical differences between nasogastric tube and Hunter's rod for staged Zone II flexor tendon reconstruction.

OBJECTIVES: This study aims to compare the outcomes of two-stage flexor tendon reconstruction in Zone II of the hand and to evaluate the results of a nasogastric tube as a potential alternative to Hunter's rod. PATIENTS AND METHODS: Between November 2012 and January 2022, a total of 45 patients (26 males, 19 females; median age: 31 years; range, 12 to 61 years) who underwent two-stage flexor tendon reconstruction were retrospectively analyzed. Of the patients 24 underwent nasogastric tube reconstruction (NT group) and 21 underwent Hunter's rod reconstruction (HR group). Patients' demographic and clinical characteristics, the number of surgeries, the occurrence of complications, the presence of infection during the procedure, and the range of motion of the finger joints at the final follow-up examination were recorded. The assessment of the cases was conducted using the total active motion system. RESULTS: Twenty-four digits underwent two-stage flexor tendon reconstruction with the nasogastric tube. Among these, three index fingers, nine middle fingers, seven ring fingers, and five little fingers were operated. Twenty-one digits underwent two-stage flexor tendon reconstruction using Hunter's rod. Among these, two index fingers, eight middle fingers, six ring fingers, and five little fingers were operated. In the NT group, excellent results were observed in 58.3% (14 digits), good results in 25% (six digits), fair results in 8.3% (two digits), and poor results in 8.3% (two digits). In the HR group, excellent results were seen in 57.1% (12 digits), good results in 33.3% (seven digits), fair results in 4.7% (one digit), and poor results in 4.7% (one digit). CONCLUSION: The utilization of a nasogastric tube offers a convenient and cost-effective option to Hunter's rod in the two-stage flexor tendon reconstruction, leading to favorable outcomes characterized by high rates of excellence and improvement, while effectively minimizing the occurrence of complications.

Neurostimulation in severe carpal tunnel release: A more precise technique for opponensplasty decision-making.

OBJECTIVES: In this study, we aimed to investigate the relationship between intraoperative thenar muscle neurostimulation responses and postoperative thumb function recovery in patients with severe carpal tunnel syndrome (CTS). PATIENTS AND METHODS: Between January 2019 and December 2021, a total of 21 severe CTS cases in 20 patients (7 males, 13 females; mean age: 56.3±19.3 years; range, 52 to 76 years) based on clinical and electrophysiological findings were retrospectively analyzed. The median nerve motor branch (MNMB) was stimulated intraoperatively with a nerve stimulator. The patients were divided into two groups according to contraction response on abductor pollicis brevis (APB) muscle: Group C (contractile, n=13) and Group NR (non-responsive, n=7) with and without muscular contraction. The Levine Functional Severity Scale (LFSS) was used to measure the functional status of CTS patients. The Manual Muscle Testing (MMT) was used to assess muscle strength. Clinical outcomes were compared between the groups at one year of follow-up. RESULTS: The mean total preoperative LFSS score was significantly higher in Group NR than in Group C (p=0.010). The mean postoperative MMT score was significantly higher in Group C than in Group NR (p<0.001). There was no positive result in pick-up, button fastening, and needle pinch tests in Group NR (p<0.001). However, there were significant improvements in postoperative LFSS scores in Group C (p<0.05), while the scores remained unchanged in Group NR (p>0.05). CONCLUSION: Direct stimulation of the median nerve motor branch and observation of contraction response on APB muscle can be used to predict clinical recovery and facilitates making the decision for opponensplasty in severe CTS.

Comparing the outcomes of tripod technique and locked plate fixation for the treatment of Mason type 3 radial head fractures.

OBJECTIVES: In this study, we aimed to compare functional outcomes and complication rates of tripod technique and locked plate fixation used in Mason type 3 radial head fractures. PATIENTS AND METHODS: Between January 2012 and December 2019, a total of 27 patients (16 males, 11 females; median age: 43.2 years; range, 20 to 68 years) with Mason type 3 radial head fractures were retrospectively analyzed. The patients were divided into two groups according to fixation method used. Group 1 consisted of 12 patients who were treated with tripod technique, and Group 2 consisted of 15 patients who were treated with locked plate fixation. Operation time, follow-up period, length of hospital stay, union time, Disabilities of Arm, Shoulder and Hand (DASH) scores, range of motions and complications were recorded. RESULTS: The median time to bone union was 46.7 days in Group 1, which was significantly shorter than Group 2 (p<0.001). The median forearm pronation-supination arc was 123.75° (range, 30° to 180°) in Group 1 and was 94° (range, 45° to 180°) in Group 2. There was no significant difference in the forearm rotation between the groups. The median elbow flexion-extension arc was 99.17° (range, 65° to 130°) in Group 1 and was 80.33° (range, 30° to 130°) in Group 2. No statistically significant difference was found in the flexion-extension and pronation-supination arc degrees. There was no significant difference in the postoperative DASH scores between the groups (p=0.464). CONCLUSION: Our study results demonstrate that comparable results can be achieved in both techniques regarding functional outcome and range of motion. With a shorter union time and less complication rates, the tripod technique should be considered as the primary treatment method for the comminuted radial head fractures without a metaphyseal defect.

Dupuytren contracture after acute traumatic hand injury in an adolescent: A case report.

Dupuytren's disease is a fibroproliferative disease that affects the palmar hand, causing progressive, permanent, and symptomatic flexion contracture of the digits. It is a disorder of polygenetic and multifactorial origin, usually affecting middle-aged males. Dupuytren's disease developing as a result of hand trauma in younger ages is rarely reported. In this case, we present a 14-year-old male patient with Dupuytren's disease following acute traumatic injury. We performed the fasciectomy and Z-plasty with full thickness skin graft. He recovered completely additional injection of triamcinolone for one year.

Cancer survivors post-chemotherapy exhibit unimpaired short-latency stretch reflexes in the proximal upper extremity.

Oxaliplatin (OX) chemotherapy can lead to long-term sensorimotor impairments in cancer survivors. The impairments are often thought to be caused by OX-induced progressive degeneration of sensory afferents known as length-dependent dying-back sensory neuropathy. However, recent preclinical work has identified functional defects in the encoding of muscle proprioceptors and in motoneuron firing. These functional defects in the proprioceptive sensorimotor circuitry could readily impair muscle stretch reflexes, a fundamental building block of motor coordination. Given that muscle proprioceptors are distributed throughout skeletal muscle, defects in stretch reflexes could be widespread, including in the proximal region where dying-back sensory neuropathy is less prominent. All previous investigations on chemotherapy-related reflex changes focused on distal joints, leading to results that could be influenced by dying-back sensory neuropathy rather than more specific changes to sensorimotor circuitry. Our study extends this earlier work by quantifying stretch reflexes in the shoulder muscles in 16 cancer survivors and 16 healthy controls. Conduction studies of the sensory nerves in hand were completed to detect distal sensory neuropathy. We found no significant differences in the short-latency stretch reflexes (amplitude and latency) of the shoulder muscles between cancer survivors and healthy controls, contrasting with the expected differences based on the preclinical work. Our results may be linked to differences between the human and preclinical testing paradigms including, among many possibilities, differences in the tested limb or species. Determining the source of these differences will be important for developing a complete picture of how OX chemotherapy contributes to long-term sensorimotor impairments.NEW & NOTEWORTHY Our results showed that cancer survivors after oxaliplatin (OX) treatment exhibited stretch reflexes that were comparable with age-matched healthy individuals in the proximal upper limb. The lack of OX effect might be linked to differences between the clinical and preclinical testing paradigms. These findings refine our expectations derived from the preclinical study and guide future assessments of OX effects that may have been insensitive to our measurement techniques.

Impact of Verbal Suggestions on Finger Flexor Activation and Strength in Healthy Individuals.

BACKGROUND Words uttered by other people can have an enormous influence on how we perceive our surroundings, what we expect, what we experience, and how we behave. This study aimed to evaluate the effect of verbal reinforcement on the placebo effect in the context of finger flexor muscle activation measured with surface electromyography (sEMG) and hand grip strength measured with a hand dynamometer in healthy subjects. MATERIAL AND METHODS Eighty-eight individuals aged 22.64±5.2 years took part in the study. For each person, paper tape was applied (placebo). The participants were randomly assigned to 1 of the 3 groups: positive information group (P) - "the tape increases hand muscle strength", negative information group (N) - "the tape decreases hand muscle strength", and control group (C) - "the effect of the tape on hand muscle strength is unknown." The activation of muscles was assessed using surface electromyography (sEMG) while measuring the strength of wrist and finger flexors with a hand dynamometer. Each participant was examined twice - prior to and immediately after taping and providing verbal reinforcement. RESULTS Only group N manifested a decrease in muscle strength, from 39.7N to 37.6N (P=0.003). Group C displayed an increase in muscle strength from 34.3N to 36.4N (P=0.035). None of the groups demonstrated statistically significant changes in bioelectrical activity of the muscles. At no stage of examination were the differences between the groups significant. CONCLUSIONS Negative verbal information combined with the placebo intervention resulted in a significant decrease in the strength of finger flexors.

Hafted technologies likely reduced stone tool-related selective pressures acting on the hominin hand.

The evolution of the hominin hand has been widely linked to the use and production of flaked stone tool technologies. After the earliest handheld flake tools emerged, shifts in hominin hand anatomy allowing for greater force during precision gripping and ease when manipulating objects in-hand are observed in the fossil record. Previous research has demonstrated how biometric traits, such as hand and digit lengths and precision grip strength, impact functional performance and ergonomic relationships when using flake and core technologies. These studies are consistent with the idea that evolutionary selective pressures would have favoured individuals better able to efficiently and effectively produce and use flaked stone tools. After the advent of composite technologies during the Middle Stone Age and Middle Palaeolithic, fossil evidence reveals differences in hand anatomy between populations, but there is minimal evidence for an increase in precision gripping capabilities. Furthermore, there is little research investigating the selective pressures, if any, impacting manual anatomy after the introduction of hafted composite stone technologies ('handles'). Here we investigated the possible influence of tool-user biometric variation on the functional performance of 420 hafted Clovis knife replicas. Our results suggest there to be no statistical relationships between biometric variables and cutting performance. Therefore, we argue that the advent of hafted stone technologies may have acted as a 'performance equaliser' within populations and removed (or reduced) selective pressures favouring forceful precision gripping capabilities, which in turn could have increased the relative importance of cultural evolutionary selective pressures in the determination of a stone tool's performance.

Evaluation des Charlson Komorbiditätsindex als prognostisches Hilfsmittel zur Einschätzung des Verlaufes von Handinfektionen.

BACKGROUND: The Charlson Comorbidity Index (CCI) is used for the prognostic analysis of comorbidities. Comorbidities, especially diabetes mellitus, are a decisive factor for the development and course of hand infections. This study aimed to determine the CCI in patients with hand infections in order to examine how comorbidities influence the course and severity of hand infections. MATERIAL AND METHODS: Ninety patients with hand infections requiring surgery but without previous antibiotic treatment were studied prospectively. The respective CCI was determined on admission to hospital. A total score of zero points was defined as "low", a score of one to three as "medium" and a score of four to nine points as a "high" index. Age, CRP level, duration of inpatient stay and the number of performed surgeries were documented and statistically evaluated. RESULTS: The median CCI was 0,5 points with a range of 0-9 points. The most common comorbidity was diabetes mellitus without end-organ damage, followed by heart failure and chronic lung disease. Patients with a low total score (median 51 years) were significantly younger than those with a medium score (median 60 years; p=0,018) or a high score (median 66,5 years; p=0,018). In addition, patients with a low or medium score had a shorter hospital stay (median 6 vs. 11,5 days; plow=0,003; pmean=0,005), required fewer surgeries (median 1 vs. 3 surgeries; plow=0,002; pmean=0,003) and had a lower CRP level (median 8,3 mg/l vs. 7,1 mg/l vs. 86,25 mg/l; plow=pmean=0,001) than those with a high index. A significant positive correlation was found between the CCI and patient age (Spearman's ρ=0,367; p<0,001) as well as the length of hospital stay (Spearman's ρ=0,261; p=0,013), the number of surgeries (Spearman's ρ=0,219; p=0,038) and the CRP level (Spearman's ρ=0,212; p=0,045). CONCLUSIONS: The CCI is an appropriate questionnaire for the prognostic assessment of the course and severity of hand infections, particularly with regard to the length of hospital stay, the number of surgeries and the CRP level.

Scapular kinesiotaping improves upper extremity functionality in healthy active subjects.

OBJECTIVE: The aim of this study was to investigate the effect of scapular kinesiotaping and sham-taping applications on upper extremity functionality in healthy active subjects. METHODS: In total, 60 participants were randomly divided into two groups: scapular kinesiotaping group (n=30) and sham-taping group (n=30). While scapular kinesiotaping was applied to the kinesiotaping group, scapular rigid taping was applied to the sham-taping group. At the end of the third day of the taping application, the individuals were re-evaluated. RESULTS: Participants in the scapular kinesiotaping group showed improvement in upper extremity functionality and quality of life after taping (p<0.05). In the sham-taping group, there was no statistically significant difference after taping (p>0.05). CONCLUSION: Scapular kinesiotaping is effective in improving upper extremity functionality in healthy active subjects.

Investigation of the effects of upper extremity home exercises on grip strength, range of motion, activity performance, and functionality in individuals with systemic sclerosis: a randomized controlled trial.

OBJECTIVE: This study aimed to investigate the effects of upper extremity home exercises on grip strength, range of motion, activity performance, and functionality in individuals with systemic sclerosis and to compare with patient education. METHODS: A total of 46 individuals with systemic sclerosis (55.52±11.54 years) were included. Individuals were randomly assigned into intervention (n=23) and control (n=23) groups. Dynamometer, goniometer, Canadian Occupational Performance Measurement, Disabilities of the Arm, Shoulder, and Hand, Score for Assessment and Quantification of Chronic Rheumatic Affections of the Hands, and Duruoz Hand Index were used for evaluation. RESULTS: Post-treatment, in terms of delta (Δ) values, hand grip and pinch strengths (p: 0.000-0.016), active (p: 0.000-0.032) and passive (p: 0.000-0.043) total range of motions, Canadian Occupational Performance Measurement performance and satisfaction, Disabilities of the Arm, Shoulder, Score for Assessment and Quantification of Chronic Rheumatic Affections of the Hands, and Duruoz Hand Index (p: 0.000) were in favor of the intervention group. CONCLUSION: Upper extremity home exercises increase grip strength, range of motion, activity performance, and functionality in patients with systemic sclerosis. We recommend that rehabilitation programs include not only hand exercises but also upper extremity exercises.

Direction of visual shift and hand congruency enhance spatial realignment during visuomotor adaptation.

Although prism adaptation has been studied extensively for over 100 years to better understand how the motor system adapts to sensory perturbations, very few studies have systematically studied how the combination of the hand used to adapt, and the direction of visual shift, might influence adaptation. Given that sensory inputs and motor outputs from the same side are processed (at least initially) in the same hemisphere, we wondered whether there might be differences in how people adapt when the hand used and the direction of visual shift were congruent (e.g., adapting to rightward shifting prisms with the right hand), compared to incongruent (e.g., adapting to rightward shifting prisms with the left hand). In Experiment 1 we re-analyzed a previously published dataset (Striemer, Enns, and Whitwell Striemer et al., Cortex 115:201-215, 2019a) in which healthy adults (n = 17) adapted to 17° leftward or rightward optically displacing prisms using their left or right hand (tested in separate sessions, counterbalanced). Our results revealed a "congruency effect" such that adaptation aftereffects were significantly larger for reaches performed without visual feedback (i.e., straight-ahead pointing) when the direction of prism shift and the hand used were congruent, compared to incongruent. We replicated this same congruency effect in Experiment 2 in a new group of participants (n = 25). We suggest that a better understanding of the cognitive and neural mechanisms underlying the congruency effect will allow researchers to build more precise models of visuomotor learning, and may lead to the development of more effective applications of prism adaptation for the treatment of attentional disorders following brain damage.

[Surgical reconstruction of arm and hand functions in tetraplegia : Current concepts]. / Chirurgische Rekonstruktion der Arm- und Handfunktion bei Tetraplegie : Aktuelle Konzepte.

The reconstruction of arm and hand functions is of enormous importance for tetraplegic patients as it enables at least some degree of independence. Depending on the level of the spinal cord injury, certain residual functions are present in the arms which can be used for surgical reconstruction of upper extremity functions. By utilizing tendon and nerve transfers missing functions can at least be partially reconstructed. Tendon transfers are a proven technique with reliable results that can be performed at any time regardless of the type of accident. Due to the frequent presence of lower motor neuron damage, it is essential to consider the optimal time window for nerve transfer interventions. From the multitude of surgical options, an individual reconstruction plan must be created for each patient, which considers multiple factors. The combination of nerve transfers and later completing the functional reconstruction by tendon transfers is the preferred concept of the authors of this article.

Autonomy support encourages use of more-affected arm post-stroke.

BACKGROUND: Autonomy support, which involves providing individuals the ability to control their own behavior, is associated with improved motor control and learning in various populations in clinical and non-clinical settings. This study aimed to investigate whether autonomy support combined with an information technology (IT) device facilitated success in using the more-affected arm during training in individuals with stroke. Consequently, we examined whether increased success influenced the use of the more-affected arm in mild to moderate subacute to chronic stroke survivors. METHODS: Twenty-six participants with stroke were assigned to the autonomy support or control groups. Over a 5-week period, training and test sessions were conducted using the Individualized Motivation Enhancement System (IMES), a device developed specifically for this study. In the autonomy support group, participants were able to adjust the task difficulty parameter, which controlled the time limit for reaching targets. The control group did not receive this option. The evaluation of the more-affected arm's use, performance, and impairment was conducted through clinical tests and the IMES. These data were then analyzed using mixed-effect models. RESULTS: In the IMES test, both groups showed a significant improvement in performance (p < 0.0001) after the training period, without any significant intergroup differences (p > 0.05). However only the autonomy support group demonstrated a significant increase in the use of the more-affected arm following the training (p < 0.001). Additionally, during the training period, the autonomy support group showed a significant increase in successful experiences with using the more-affected arm (p < 0.0001), while the control group did not exhibit the same level of improvement (p > 0.05). Also, in the autonomy support group, the increase in the use of the more-affected arm was associated with the increase in the successful experience significantly (p = 0.007). CONCLUSIONS: Combining autonomy support with an IT device is a practical approach for enhancing performance and promoting the use of the more-affected upper extremity post-stroke. Autonomy support facilitates the successful use of the more-affected arm, thereby increasing awareness of the training goal of maximizing its use. TRIAL REGISTRATION: The study was registered retrospectively with the Clinical Research Information Service (KCT0008117; January 13, 2023; https://cris.nih.go.kr/cris/search/detailSearch.do/23875 ).

Effective Delivery of Vagus Nerve Stimulation Requires Many Stimulations Per Session and Many Sessions Per Week Over Many Weeks to Improve Recovery of Somatosensation.

BACKGROUND: Chronic sensory loss is a common and undertreated consequence of many forms of neurological injury. Emerging evidence indicates that vagus nerve stimulation (VNS) delivered during tactile rehabilitation promotes recovery of somatosensation. OBJECTIVE: Here, we characterize the amount, intensity, frequency, and duration of VNS therapy paradigms to determine the optimal dosage for VNS-dependent enhancement of recovery in a model of peripheral nerve injury (PNI). METHODS: Rats underwent transection of the medial and ulnar nerves in the forelimb, resulting in chronic sensory loss in the paw. Eight weeks after injury, rats were implanted with a VNS cuff and received tactile rehabilitation sessions consisting of repeated mechanical stimulation of the previously denervated forepaw paired with short bursts of VNS. Rats received VNS therapy in 1 of 6 systematically varied dosing schedules to identify a paradigm that balanced therapy effectiveness with a shorter regimen. RESULTS: Delivering 200 VNS pairings a day 4 days a week for 4 weeks produced the greatest percent improvement in somatosensory function compared to any of the 6 other groups (One Way analysis of variance at the end of therapy, F[4 70] P = .005). CONCLUSIONS: Our findings demonstrate that an effective VNS therapy dosage delivers many stimulations per session, with many sessions per week, over many weeks. These results provide a framework to inform the development of VNS-based therapies for sensory restoration.