Arm Position Research Articles

Differentiating Essential and Dystonic Head Tremor: Exploring Arm Position Effects.

Head tremor poses diagnostic problems, especially when present as an isolated or predominant symptom. To assess how maneuvers activating upper limb postural tremor can help differentiate head tremor in essential tremor (ET) from dystonic tremor (DT) in cervical dystonia. 48 patients with head tremor (25 ET, 23 DT), underwent clinical examination and accelerometric evaluation of head and upper limb tremor during routine tremor-inducing tasks. While accelerometric power and clinical scores of head tremor did not significantly differ between patient groups, task-induced variations revealed distinctions. ET patients exhibited increased head tremor power and clinical scores during forward outstretched and lateral wing-beating arm positions, unlike DT patients. Coherence between head and upper limb tremor remained consistent. Tremor stability index showed no significant differences. Task-induced changes in head tremor could aid in distinguishing between ET and DT. Further research is needed to refine diagnostic approaches for head tremor.

Supported bridge position in one-stop coronary and craniocervical CT angiography: A randomized clinical trial.

The routine patient arm position differs between coronary CT angiography (CTA) and craniocervical CTA protocols. To investigate the clinical feasibility of supported bridge position (SBP) in combined coronary and craniocervical CTA. Prospective enrollment included patients with suspected coronary artery disease (CAD) or craniocervical artery disease (CCAD) from February 2022 to November 2022. Patients were divided into three groups: coronary or craniocervical CTA according to CAD or CCAD using standard position (group 1), combined CTA with naturally arm-down position (group 2) and SBP (group 3). Statistical analysis of objective image quality, such as noise and contrast-to-noise ratio (CNR), subjective image quality, patient position and radiation dose was performed among the three groups. Two hundred and one patients (median age, 67 years; 138 men) were included. In terms of CNR for cardiac segment, group 1 and group 3 had no statistical difference, both significantly higher than group 2 (group 1, 12.56±2.05; group 2, 10.4±2.43; group 3, 11.94±2.22; P<0.05). Subjective image evaluation revealed no statistically significant differences among the three groups of coronary arteries (P>0.05). Additionally, the lateral project value of scout images at the heart level indicated a significant difference (119.48±12.19, 182.34±25.09, and 140.58±19.68 of patients, for group 1, group 2, and group 3, respectively, P<0.05). No statistical differences were observed in between group 1 and group 3 (cardiac scan, 15.77 [15.07-16.37] mGy vs. 14.88 [12.19-18.81] mGy; craniocervical scan, 7.85 [7.69-8.01] mGy vs. 7.88 [7.88-7.89] mGy; all P>0.05). However, group 2 had a higher dose (19.54 [16.86-22.85] mGy and 10.87 [10.86-10.87] mGy, for cardiac and craniocervical scans, respectively). In comparison with a naturally arm-down position, SBP, which aligns the humerus bones with the spinal column, can provide diagnostic image quality at routine dose level of standard position CTA.

Ötzi: abnormal arm position possibly to staunch bleeding following arrow injury

Ötzi: abnormal arm position possibly to staunch bleeding following arrow injury

Updating reduced-order dynamic model for flexible-joint arm to design adaptive feedback linearization control

This study deals with the construction of an enhanced dynamic model for a lever-arm with flexible-joint to design a feedback linearization controller. The uncertainties of reduced-order model with nominal parameters are compensated via a complementary term to upgrade it to the actual system. The proposed method uses data fusion of encoder/gyroscope to remove the measurement errors. Mathematical analyses are provided to show the stochastic stability of the proposed scheme. Accordingly, a fuzzy adaptive solution is presented to effectively schedule the free parameters of the algorithm. The enhanced reduced-order model is used to design a feedback linearization law for control of lever-arm position. The controller adapts itself to the actual system, and is reliable and cost-effective because of using less sensors. The simulation studies indicate a higher accuracy of the proposed system compared with the controller designed by the full-order model in the presence of parametric uncertainties and disturbances. Also, experimental results conducted on a fabricated platform demonstrate the effectiveness of the suggested system to control the arm position in different scenarios. The comparative results with prevalent controllers indicate higher accuracy with smaller control input for the proposed controller to reject the disturbances and other uncertainties.

Two-Stage Glenohumeral Fusion for the Paralytic Shoulder

BackgroundShoulder fusion after nerve injury can improve overall arm function, however high revision and low patient satisfaction rates have been described. The purpose of this study is to describe a two-stage shoulder fusion, first pinning in a position of function and then converting to a shoulder fusion. Our hypothesis is that temporary pinning improves overall satisfaction after shoulder fusion in comparison to satisfaction reported in the literature. MethodsA retrospective review was performed for patients receiving two-stage shoulder fusion between 2020 and 2023. Patient demographics and clinical outcomes were recorded. Univariate statistics were performed to compare pre- and postoperative values. ResultsEighteen patients with an average age of 47 +/- 17.3 years and average follow-up of 23.7 +/- 4.5 months were included. Preoperative diagnoses included brachial plexus injury (n=13; 72%), late presentation obstetric brachial plexus injury (n=2; 11%), traumatic brain injury (n=1; 14.2%), cervical spinal cord injury (n=1; 14.2%) and iatrogenic axillary nerve injury with advanced arthritis (n=1;14.2%). Twelve (67%) patients received unilateral shoulder fusion 2.7 +/- 1.9 days after their initial pinning. Six patients (28.6%) did not receive a second stage fusion. Reasons for not continuing with fusion were attributed to perceived hand function and arm position. Three patients received two shoulder pinnings prior to their fusion to adjust the fusion position to accommodate more internal rotation. After fusion, both SSV (5.2 +/- 5.5% versus 71.6 +/- 10.4%; p<0.001) and pain (2.3 ± 4.0 vs 0.5 ± 0.71; p=0.56) improved. Forward elevation (5 +/- 12 versus 108 +/-35; p=0.01), abduction (10 +/- 15 versus 78 +/-9; p<0.001)), and external rotation (5 +/- 12 versus 22 +/- 17; p=0.26) all improved postoperatively while internal rotation remained limited (1.3 +/- 0.9 versus 1.2 +/- 0.5; p=0.84). Time to union was 15.4 +/- 15.4 weeks confirmed with CT scan. There was one (5.5%) reoperation for non-union, and patient satisfaction was 92% (n=11/12). ConclusionShoulder fusion after neurologic injury provides improved function and patient outcomes, however some patients may be unsatisfied with their new arm position. Percutaneous pinning prior to fusion is tolerated and allows patients to trial potential fusion positions. This method may improve patient satisfaction and avoid excess morbidity in those that would not be satisfied with a shoulder fusion.

Clinical implementation of Cone-beam CT guided online adaptive radiotherapy in whole breast irradiation

PurposeIn postoperative breast irradiation, changes in the breast contour and arm positioning can result in patient positioning errors and offline re-planning. This can lead to increased treatment burden, and strain on departmental logistics due to the need for additional cone-beam CT images or even a new radiotherapy treatment plan (TP). Online daily adaptive radiotherapy (oART) could provide a solution to these challenges. We have clinically implemented and evaluated the feasibility of oART for whole breast irradiation. Methods and MaterialsTwenty patients treated with postoperative whole breast right irradiation (5 × 5.2 Gy) were included in BREAST-ART, a prospective single-arm trial. Dosimetry of the reference TP calculated on the daily anatomy and adaptive TP were compared. Duration of the oART workflow, in-house satisfaction questionnaires, and acute toxicity (CTCAE v5.0) was collected. The oART workflow was evaluated by investigating the impact of manual corrections of influencer and target contours on treatment time and quality. ResultsIn the first 17 patients (85 fractions), the on-couch time, i.e. time between the end of CBCT1 and CBCT3, was median 13.8 minutes (range=11–25). Retrospective evaluation of the use of the influencer (i.e. breast) in 4 patients (20 fractions) and manual correction of the most cranial and caudal target contours (i.e. 4 mm) in 10 patients (36 fractions) was done. This resulted in a reduced on-couch time in the last 3 clinical patients to a median of 13.0 minutes (range=11–19). No grade 3 or higher toxicity was observed, and 19/20 patients indicated to prefer the same treatment again. Skin marks for patient positioning during treatment were no longer necessary. ConclusionsThis study showed the feasibility, challenges, and practical solutions for the implementation of oART for breast cancer patients. Future work will focus on more complex breast indications such as whole breast including axillary nodes, to further investigate benefits and challenges of oART in breast cancer.

Comparative analysis of hand dynamometer measurements across different arm positions: implications for rehabilitation and functional assessment

Background and Study Aim. Grip strength is a crucial measure of human physical capability, affecting activities from daily tasks to athletic performance. Variations in arm position during grip strength measurement may influence the results, which has significant implications for both rehabilitation and functional assessment. This study explores the impact of different arm positions on grip strength to enhance understanding of human biomechanics and inform rehabilitation and sports training practices. Material and Methods. Forty right-handed male volunteers (mean age 18.27 ± 0.90 years) participated in the study. Grip strength was measured using a CAMRY Model: EH101 hand dynamometer. Measurements were taken across four arm positions: seated with elbow extension, 90-degree elbow flexion, 90-degree elbow flexion with pronation, and 90-degree elbow flexion with supination. Each position was tested three times. The highest recorded value for each position was used for analysis. Results. The dominant right hand exhibited higher grip strength across all positions compared to the non-dominant left hand. Significant differences were noted, with the greatest grip strength in the extension position. Statistical analysis using paired t-tests indicated significant differences (p &lt; 0.001) between the right and left hands across all positions. Pearson correlation coefficients highlighted strong relationships between different arm positions. Multiple linear regression analysis showed significant predictors of grip strength variability based on arm position, age, and BMI. Conclusions. Arm position significantly influences grip strength performance, underscoring the importance of standardized positioning in ergonomics. Standardizing arm position can optimize performance and mitigate injury risks in activities requiring robust grip strength. These findings have practical implications for rehabilitation protocols, sports training programs, and ergonomic assessments. The results emphasize the need for consistency in grip strength evaluations to ensure accurate and reliable results.

Do gestures have meaning? An empirical analysis on the gestures performed by Fidel Castro at the United Nations

In everyday conversations, there are said to be unconscious meanings that we convey through our body. For example, if a story is being told, our hands move according to the message, following a rhythm and forming shapes that we are unaware of. According to McNeill (1992), gestures are a form of language different from speech, but even though they have been regarded as individual entities, they are, in fact, parallel and work in synch with each other. This is the scope of the analysis of gestures. In the following paper, the objective was to test whether there is an association between gestures and meaning. Consequently, the gestures of former Cuban president, Fidel Castro, were extracted and analyzed from his intervention at the United Nations in 1979. The process of annotation was carried out on the program ELAN, based on a series of categories: the type of gesture and topic, the position and movement of both arms and hands as well as the orientation. Additionally, a series of quantitative and qualitative analysis were performed through the statistical program R. A Chi-squared test showed a significant relationship between the type of gestures and the topics which was further corroborated through a conditional inference tree and a multiple correspondence analysis, reaffirming the idea that these are form-meaning pairs. Moreover, there was a strong connection between the type of gesture and arm movement, suggesting that this is due to the intention of the message while the orientation of the hand was a clear indicator of arm movement.

Impact of arm position compared to tourniquet and general anesthesia on peripheral vein width in supine adult patients: a prospective, monocentric, cross-sectional study

BackgroundIV access is a commonly performed procedure that is often taught based on tradition rather than evidence. The effect of arm retroflexion on vein width, either alone or in combination with a tourniquet or general anesthesia (GA), remains unclear. In this case, the sonographically measured vein width is a surrogate parameter for the success of the puncture.MethodsProspective, cross-sectional study involving 57 patients scheduled for surgery in general anesthesia. We analyzed the impact of arm retroflexion, tourniquet, general anesthesia, and their combinations on the antebrachial veins in supine patients by ultrasound. Measurements were taken awake and during general anesthesia, each with and without the application of a tourniquet, and in three different arm positions (0°, 30°, and max° retroflexion) each. Data are presented as median and interquartile range [IQR].ResultsTourniquet application (AT) had the greatest single effect on Cubital vein outer diameter compared to the baseline value of all measures (3.9 mm [3.4–5.1]; 4.8 mm [4.1–5.7], P = 0.001, r = 0.515). This effect was surpassed by the combination of AT and GA (5.1 mm [4.6–6.6], P = 0.001, r = 0.889). In contrast, retroflexion alone did not result in an increase at either 30° (4.2 mm [3.7–5.1], p = 1.0, r = 0.12) or max° (4.2 mm [3.6–4.9], p = 0.72, r = 0.23). With GA and AT, no further enlargement was measurable by 30° (5.4 mm [4.6–6.6], p = 1.0, r = 0.15) or max° (5.4 mm [4.6–6.6], p = 1.0, r = 0.07) retroflexion compared to GA-AT-0° (5.1 mm [4.6–6.6], p = 1.0, r = 0.15).ConclusionsThis study provides evidence that retroflexion of the arm in supine patients, whether alone or in addition to a tourniquet or general anesthesia, does not have any additional effect on vein width as a surrogate parameter for successful IV success. It shows for the first time that general anesthesia effectively increases vein diameter.Trial registrationDRKS00029603 (date of registration 07.07.2022).

Bayesian inference in arm posture perception.

To configure our limbs in space the brain must compute their position based on sensory information provided by mechanoreceptors in the skin, muscles, and joints. Because this information is corrupted by noise, the brain is thought to process it probabilistically, and integrate it with prior belief about arm posture, following Bayes' rule. Here, we combined computational modeling with behavioral experimentation to test this hypothesis. The model conceives the perception of arm posture as the combination of a probabilistic kinematic chain composed by the shoulder, elbow, and wrist angles, compromised with additive Gaussian noise, with a Gaussian prior about these joint angles. We tested whether the model explains errors in a VR-based posture matching task better than a model that assumes a uniform prior. Human participants were required to align their unseen right arm to a target posture, presented as a visual configuration of the arm in the horizontal plane. Results show idiosyncratic biases in how participants matched their unseen arm to the target posture. We used maximum likelihood estimation to fit the Bayesian model to these observations and estimate key parameters including the prior means and its variance-covariance structure. The Bayesian model including a Gaussian prior explained the response biases and variance much better than a model with a uniform prior. The prior varied across participants, consistent with the idiosyncrasies in arm posture perception, and in alignment with previous behavioral research. Our work clarifies the biases in arm posture perception within a new perspective on the nature of proprioceptive computations.

Pose Estimation of a Cobot Implemented on a Small AI-Powered Computing System and a Stereo Camera for Precision Evaluation.

The precision of robotic manipulators in the industrial or medical field is very important, especially when it comes to repetitive or exhaustive tasks. Geometric deformations are the most common in this field. For this reason, new robotic vision techniques have been proposed, including 3D methods that made it possible to determine the geometric distances between the parts of a robotic manipulator. The aim of this work is to measure the angular position of a robotic arm with six degrees of freedom. For this purpose, a stereo camera and a convolutional neural network algorithm are used to reduce the degradation of precision caused by geometric errors. This method is not intended to replace encoders, but to enhance accuracy by compensating for degradation through an intelligent visual measurement system. The camera is tested and the accuracy is about one millimeter. The implementation of this method leads to better results than traditional and simple neural network methods.

Arm Position and Blood Pressure Readings

Guidelines for blood pressure (BP) measurement recommend arm support on a desk with the midcuff positioned at heart level. Still, nonstandard positions are used in clinical practice (eg, with arm resting on the lap or unsupported on the side). To determine the effect of different arm positions on BP readings. This crossover randomized clinical trial recruited adults between the ages of 18 and 80 years in Baltimore, Maryland, from August 9, 2022, to June 1, 2023. Participants were randomly assigned to sets of triplicate BP measurements with the arm positioned in 3 ways: (1) supported on a desk (desk 1; reference), (2) hand supported on lap (lap), and (3) arm unsupported at the side (side). To account for intrinsic BP variability, all participants underwent a fourth set of BP measurements with the arm supported on a desk (desk 2). The primary outcomes were the difference in differences in mean systolic BP (SBP) and diastolic BP (DBP) between the reference BP (desk 1) and the 2 arm support positions (lap and side): (lap or side - desk 1) - (desk 2 - desk 1). Results were also stratified by hypertensive status, age, obesity status, and access to health care within the past year. The trial enrolled 133 participants (mean [SD] age, 57 [17] years; 70 [53%] female); 48 participants (36%) had SBP of 130 mm Hg or higher, and 55 participants (41%) had a body mass index (calculated as weight in kilograms divided by height in meters squared) of 30 or higher. Lap and side positions resulted in statistically significant higher BP readings than desk positions, with the difference in differences as follows: lap, SBP Δ 3.9 (95% CI, 2.5-5.2) mm Hg and DBP Δ 4.0 (95% CI, 3.1-5.0) mm Hg; and side, SBP Δ 6.5 (95% CI, 5.1-7.9) mm Hg and DBP Δ 4.4 (95% CI, 3.4-5.4) mm Hg. The patterns were generally consistent across subgroups. This crossover randomized clinical trial showed that commonly used arm positions (lap or side) resulted in substantial overestimation of BP readings and may lead to misdiagnosis and overestimation of hypertension. ClinicalTrials.gov Identifier: NCT05372328.

Automatic tiling method for mosaic ceramic art images based on subpixel edge fitting localization and collaborative operation of multiple manipulators

Mosaic ceramics are not limited to use solely as building materials, they also possess artistic value. Artists can create images by arranging and combining mosaic ceramics, resulting in a perfect fusion of large-scale public art for external walls and ceramic materials. However, the current approach for artists to create mosaic ceramic exterior wall art images involves manual laying and assembling of individual mosaic ceramics. This manual process suffers from issues such as low efficiency, eye fatigue, selection errors, and the risk of high-altitude operations. These challenges significantly impact the quality and efficiency of creating mosaic ceramic exterior wall art image images. To address these problems, this paper proposes an automatic mosaic ceramic art image stitching method based on subpixel edge fitting positioning and collaborative operation of multiple robotic arms. Additionally, a new U + I type conveying method is designed for efficient and space-saving transportation of mosaic ceramics. Experimental results demonstrate a high success rate of recognition, absorption, and placement of multi-color mosaic ceramics using this method reaching 95.45%, with a positioning error within 0.5 mm. The method can also adapt to varying levels of light intensity or noise interference. This approach effectively enhances the quality and efficiency of creating mosaic ceramic exterior wall art images and promotes the development of mosaic ceramic exterior wall public art creation.

Design and Construction of 5-Dof EMG Based Robotic Arm System

Electromyography (EMG) is an alternate method of obtaining muscle signal outputs. As a result, the current development in designing my electric plans has piqued the attention of researchers in this subject. This is because Standard controllers lack essential components, limiting the use of limbs to operate equipment, namely an arm controlled by robotics. EMG signals are subject to noise, including crosstalk, motion artifacts, ambient noise, and intrinsic noise. Electromyography preparation requires careful selection of muscle groups, electrode placement, and environment quality, all of which impact the signal output. The goal of this study is to create an EMG-based robotic arm control system that can be used to help the elderly, individuals with impairments, and those who operate in dangerous places. Initially, a literature review on current human-robot interaction approaches and analysis of the kinematics of a 5 DOF robotic arm has been conducted. Then, utilizing Electromyogram (EMG) data obtained from the muscles of the elbow, away for controlling a 5 DOF robotic arm is provided. Two accelerometers are utilized to record the human arm's gesture and posture, this information is then communicated to the robotic arm as an input. In the experiments, wrist rotation, left, right, up, and down movements were used to establish controlled motion of a 5 DOF robotic arm. The project's goal has been met with the successful development of an EMG-controlled robotic arm. The robotic arm may yet be improved by including Implementing a wireless sensor network with multiple channels.

Characterization of Human Shoulder Joint Stiffness Across 3D Arm Postures and Its Sex Differences.

Understanding the characteristics of shoulder joint stiffness can offer insights into how the shoulder joint contributes to arm stability and assists in various arm postures and movements. This study aims to characterize posture-dependent shoulder stiffness in a three-dimensional (3D) space and investigate its potential sex differences. A multi-degree-of-freedom, parallel-actuated shoulder exoskeleton robot was used' to perturb the participant's shoulder joint and measure the resulting torque responses while participants relaxed their shoulder muscles. The group average results of 40 healthy individuals (20 males and 20 females) revealed that arm postures significantly affect shoulder stiffness, particularly in postures involving shoulder flexion/extension and horizontal flexion/extension. Shoulder stiffness consistently increased as the shoulder flexion angle decreased and the shoulder horizontal flexion/extension approached the limit of its range of motion. The comparative group results between males and females indicated that shoulder stiffness in males was greater than that in females across all 15 arm postures measured in this study. Even after normalizing the data by subject body mass, the female group showed significantly lower stiffness than the male group in 12 out of the 15 arm postures. The results highlight that 3D arm postures and sex significantly affect shoulder stiffness even under relaxed muscles. This study provides valuable foundations for future studies aimed at characterizing shoulder stiffness in the context of active muscles and dynamic movement tasks, evaluating changes in shoulder stiffness following neuromuscular injuries, and formulating rehabilitative training protocols for individuals suffering from shoulder problems.

Median nerve conduction study findings in various arm positions.

To investigate the effects of various arm positions on median nerve conduction studies (NCSs). This prospective cohort study, conducted at Adana City Training and Research Hospital between January and July 2023, included 20 healthy participants. Median NCSs were performed on the participants in three different standing positions with the elbow as the stimulation point: 1) with the arm adducted (P1), 2) with the arm anteflexed (P2), and 3) with the arm raised upwards (P3). We obtained median nerve compound muscle action potential (CMAP) latency, duration, peak-to-peak (PP) amplitude, onset-to-negative peak (OP) amplitude, negative area/duration. Three CMAPs were obtained in each position, and the mean and minimum/maximum values at each position were analyzed. The mean age (minimum-maximum) of the participants (11 male, 9 female) was 28.5±6.5 (20-42) years. Median nerve CMAP means (median) of latency/negative duration in the P1, P2, and P3 positions were 6.82±0.59 (6.83)/5.50±0.76 (5.39) ms, 6.99±0.56 (7.02)/5.72±0.73 (5.73) ms, and 7.03±0.58 (7.12)/5.79±0.80 (5.83) ms. Median nerve CMAP mean/minimum latency and negative duration were lowest in the P1 position (p<0.05). The mean median nerve CMAP OP amplitude was highest in P3 than P1 or P2 (p=0.042 and p=0.048). Median NCS results differed based on the position of the arm.

Pre-clinical training, technical adjustment and human case experience of transoral robotic surgery using Versius System

ObjectiveThis study describes the training experience with the Versius Robotic System (CMR Surgical) for Transoral Robotic Surgery (TORS), the setup of the robot and its applicability in a human case. MethodsA model mannequin with anatomical characteristics simulating the TORS working space was used for training purposes. Optimal docking, positioning of robotic arms and placement of instruments were defined using the mannequin. A human patient was selected based on the inclusion criteria, and a standardized protocol for robotic techniques was developed. The surgical procedure was conducted in accordance with ethical guidelines. ResultsThe synthetic polymer mannequin mimicking human tissues and anatomy was used to define the robot set up for TORS. The patient was indicated for bilateral tonsillectomy due to recurrent episodes of tonsillitis. Bipolar Maryland and monopolar scissors were used. The procedure was uneventful. The patient remained hospitalized for 1 day and returned to work activities within 6-days, with no complications. ConclusionThe specialized mannequin proved to be effective in the simulation, training proposal and set up standardization. Furthermore, the Versius robot was found to be safe and achieved excellent results during surgery. Despite being very promising, the Versius system is still in its developmental phase and requires larger-scale samples for a more comprehensive evaluation. Level of evidence4.

거동 불편한 환자의 전신 CT 검사 시 DLIR 기법의 유용성 평가

When whole-body computed tomography (WBCT) is performed after a single injection of contrast media, the arm's position is altered during each examination to minimize beam hardening artifacts caused by the arms. In this study, the image quality of neck CT images using the deep learning iterative reconstruction (DLIR) algorithm for patients whose arms were elevated during WBCT scans was compared with images reconstructed by FBP and IR algorithms in patients who were examined with their arms lowered. The Signal-to-Noise Ratio (SNR) and Contrast-to-Noise Ratio (CNR) of the reconstructed images were quantitatively compared, while the image quality and artifacts were qualitatively evaluated. As a result, TF-H was evaluated higher in both SNR and CNR in all organs compared to FBP. Compared to the ASIR-V at 40%, the CNR was high, and the SNR was similar. In the qualitative evaluation, it was confirmed that the quality of the image was higher when compared to the image examined with the arm lowered, surpassing that of the existing reconstruction method. Therefore, it is believed that enhancing the quality of the neck CT image through reconstruction using deep learning after the examination with the arm raised, without altering the posture, during the WBCT examination of patients with mobility impairments.

From novice to Expert: Reducing Breast Imaging rejection rates through physician mentorship in Advanced Practice Radiation therapy

PurposeThe study’s goal was to evaluate the impact of a Radiation Oncologist (RO)—Radiation Therapist (RTT) mentorship on image approval rates for a breast population undergoing radiation therapy in a high-volume practice. The mentorship was undertaken within a large health system in partial fulfillment of the Expert Practice Module for a Masters (MSc) in Advanced Practice Radiotherapy and Oncology. MethodsImages were retrieved from the MOSAIQ EMR on breast diagnostic code. 1,295 images/115 patients were reviewed pre-mentorship (October 2019-March 2020) and compared with 1,047 images/91patients during/post-mentorship (April 2020-September 2020). The Anderson-Gill (AG) model was used to estimate the hazard ratio for image rejection. Rejected images were classified by reason and compared using Fisher’s exact test. Concordance data (RO/RTT image rejection) were collected during Phase Three of the mentorship. ResultsOf 115 patients assessed pre-mentorship, 16 (14 %) had at least 1 image rejected at any session. Of 91 patients assessed post-mentorship, 8 (9 %) had at least 1 image rejected. Likelihood of image rejection decreased by 54 %, with a hazard ratio of 0.46 [95 % CI: 0.24, 0.88]; p = 0.0195. Reasons for image rejection differed pre- and post-mentorship. Poor imaging technique accounted for rejection of 9 of 24 images (37.5 %) before compared to 0 of 11 images (0 %) post-mentorship. Other reasons for image rejection: depth at isocenter (25 % pre-mentorship; 18 % post-mentorship), supraclavicular medial border position (12.5 % vs. 9.09 %), isocenter location (12.5 % vs. 0 %), arm position (4.17 % vs. 54.55 %); hip alignment (8.33 % vs. 18.18 %). Concordance rate was 100 %. ConclusionsThe mentorship proved successful in elevating the RTT’s skills and image approval rates, while contributing to improvements in departmental imaging best practices.

Theoretical Analysis of Viscoelastic Friction System Characteristics of Robotic Arm Brake Based on Fractional Differential Theory

In engineering practice, the nonlinear vibration effect can easily lead to chaos in the system, which will not only reduce the performance of the system but also lead to premature fatigue of components, control failure, and increased safety risks. In view of the core position of the robotic arm in modern industry, this study relies on the robotic arm brake system to explore the theoretical basis of integrated viscoelastic materials as a vibration isolation layer. By analyzing the dynamic characteristics of the friction braking system with fractional differential terms, it aims to provide a new perspective for understanding and controlling the chaotic phenomena of a class of nonlinear friction systems. Firstly, we construct a model of a friction system and analyze its dynamic characteristics in detail. The self-excited vibration of the system under disturbance is studied. The relationship between amplitude and frequency is calculated by a nonlinear approximate analytical algorithm, and the accuracy of this relationship is verified by a numerical algorithm. Then, we compare the differences between non-fractional systems and fractional systems. It is found that with the increase in the fractional order term, the vibration amplitude of the system decreases significantly, which helps to reduce the nonlinear characteristics generated by the friction system and narrow the range of unstable solutions. Secondly, we also study the influence of parameter coefficients on the amplitude–frequency characteristics and analyze the local static bifurcation characteristics through singularity theory. Finally, we study the dynamic bifurcation behavior under different parameter perturbations and find that the change in system parameters will lead to the alternation of periodic motion and chaotic motion.