Plan quality assessment of modern radiosurgery technologies in the treatment of multiple brain metastases.

Stereotactic radiosurgery (SRS) of multiple brain metastases has evolved over the last 40 years allowing centres to treat an increasing number of brain metastases in a single treatment fraction. HyperArcTMplanning optimisation technique is one such development that streamlines the treatment of multiple metastases with a single isocentre. Several studies have investigated the plan quality of HyperArc compared to CyberKnife or Gamma Knife, however there are limited number of studies that include all three modalities. It is the aim of this study to provide an assessment of plan quality between the three SRS platforms across ten patients with multiple brain metastases ranging from three to eight metastases per patient. Strict planning workflows were established to avoid bias towards any particular treatment platform. Plan quality was assessed through dose to organs at risk, Paddick conformity index (PCI), gradient index (GI), global efficiency index (Gη) and dose to normal brain tissue. Results from this study found mean PCI observed across Gamma Knife plans was significantly lower than HyperArc and CyberKnife. HyperArc plans observed significantly shorter beam-on times which were 10 to 20 times faster than CyberKnife and Gamma Knife plans. Gamma Knife and CyberKnife were found to produce plans with significantly superior GI, global efficiency index and the volume of healthy brain receiving greater than 12 Gy (V12Gy) when compared to HyperArc plans. Lesion volume was seen to influence the relative difference in dose metrics between systems. The study revealed that all three treatment modalities produced high quality plans for the SRS treatment of multiple brain metastases, each with respective benefits and limitations.

Power on: The rapid transition of a large interdisciplinary behavioral health department to telemental health during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic necessitated a rapid transition to telemental health (TMH) for behavioral health services in the behavioral health department of a large integrated primary care organization. Although the COVID-19 pandemic was the initial trigger for rapid organizational change, systems were developed with a focus on longer term scalability and sustainability. METHODS: This paper discusses the process of organizational change within our healthcare delivery system using the Strengths, Opportunities, Aspirations, and Results (SOAR) framework. Within this framework a structured mixed methods survey of 38 clinicians representing 5 different disciplines was conducted. Internal and survey data were analyzed to evaluate and guide the iterative change process. RESULTS: The majority of BH clinicians reported that they were as or more effective with TMH. The transition to TMH in our organization resulted in increased access to care, with a 10.3% increase in BH visit completions. The transition to TMH may benefit clinician work-life balance, but requires resources to support clinical, technological, and communication/teamwork changes. IMPLICATIONS/CONCLUSIONS: TMH is a feasible treatment modality for integrated care settings. It is cost-effective and well-accepted by clinicians. The SOAR framework can be used to guide rapid organizational change and ongoing QI processes.

Dynamics of a Fermi Gas Quenched to Unitarity.

We present an experimental study of a two component Fermi gas following an interaction quench into the superfluid phase. Starting with a weakly attractive gas in the normal phase, interactions are ramped to unitarity at a range of rates and we measure the subsequent dynamics as the gas approaches equilibrium. Both the formation and condensation of fermion pairs are mapped via measurements of the pair momentum distribution and can take place on very different timescales, depending on the adiabaticity of the quench. The contact parameter is seen to respond very quickly to changes in the interaction strength, indicating that short-range correlations, based on the occupation of high-momentum modes, evolve far more rapidly than the correlations in low-momentum modes necessary for pair condensation.

The anesthetist as cardiologist: a case of heart block identified in the peripartum period.

We describe a case of undiagnosed heart block which was detected during the postpartum surgical repair of a vaginal tear, and the subsequent investigations that confirmed diagnosis of atrio-ventricular heart block.

Anxiety and threat-related attentional biases in adolescents with fragile X syndrome.

BACKGROUND: Fragile X syndrome (FXS) is a single-gene disorder highly associated with anxiety; however, measuring anxiety symptoms in FXS and other neurogenetic syndromes is challenged by common limitations in language, self-awareness and cognitive skills required for many traditional assessment tasks. Prior studies have documented group-level differences in threat-related attentional biases, assessed via eye tracking, in FXS and non-FXS groups. The present study built on this work to test whether attentional biases correspond to clinical features of anxiety among adolescents and young adults with FXS. METHODS: Participants included 21 male adolescents with FXS ages 15-20 years who completed an adapted eye-tracking task that measured attentional bias towards fearful faces of varied emotional intensity. RESULTS: Among participants without anxiety disorders, attentional bias towards fear increased across age, similar to non-FXS paediatric anxiety samples. In contrast, participants with anxiety disorders exhibited greater stability in fear-related attentional biases across age. Across analyses, subtle fear stimuli were more sensitive to within-group anxiety variability than full-intensity stimuli. CONCLUSIONS: Our results provide novel evidence that although threat-related attentional biases may correspond with anxiety outcomes in FXS, these associations are complex and vary across developmental and task factors. Future studies are needed to characterise these associations in more robust longitudinal samples, informing whether and how eye-tracking tasks might be optimised to reliably predict and track anxiety in FXS.

Neuromuscular characterisation in Cerebral Palsy using hybrid Hill-type models on isometric contractions.

BACKGROUND: Muscles of individuals with Cerebral Palsy (CP) undergo structural changes over their lifespan including an increase in muscle stiffness, decreased strength and coordination. Being able to identify these changes non-invasively would be beneficial to improve understanding of CP and assess therapy effectiveness over time. This study aims to adapt an existing EMG-driven Hill-type muscle model for neuromuscular characterisation during isometric contractions of the elbow joint. METHODS: Participants with (n = 2) and without CP (n = 8) performed isometric force ramps with contraction levels ranging between 15 and 70% of their maximum torque. During these contractions, high-density EMG data were collected from the M. Biceps and Triceps brachii with 64 electrodes on each muscle. The EMG-driven Hill-type muscle model was used to predict torques around the elbow joint, and muscle characterisation was performed by applying a genetic algorithm that tuned individuals' parameters to reduce the RMS error between observed and predicted torque data. RESULTS: Observed torques could be predicted accurately with an overall mean error of 1.24Nm ± 0.53Nm when modelling individual force ramps. The first four parameters of the model could be identified relatively reliably across different experimental protocols with a full-scale variation of below 20%. CONCLUSION: An HD-EMG muscle modelling approach to evaluating neuromuscular properties in participants with and without CP has been presented. This pilot study confirms the feasibility of the experimental protocol and demonstrates some parameters can be identified robustly using the isometric contraction force ramps.

Impact of high-fidelity e-learning on knowledge acquisition and satisfaction in radiation oncology trainees.

Background: e-Learning is an underutilized tool in education for the health professions, and radiation medicine, given its reliance on technology for clinical practice, is well-suited to training simulation in online environments. The purpose of the present study was to evaluate the knowledge impact and user interface satisfaction of high-(hf) compared with low-fidelity (lf) e-learning modules (e-modules) in radiation oncology training. Methods: Two versions of an e-module on lung radiotherapy (lf and hf) were developed. Radiation oncology residents and fellows were invited to be randomized to complete either the lf or the hf module through individual online accounts over a 2-week period. A 25-item multiple-choice knowledge assessment was administered before and after module completion, and user interface satisfaction was measured using the Questionnaire for User Interaction Satisfaction (quis) tool. Results: Of 18 trainees, 8 were randomized to the lf module, and 10, to the hf module. Overall, knowledge assessment performance increased (11%, p < 0.05), with hf-group participants reporting a 13% improvement (p = 0.02), and senior participants reporting an almost 15% improvement (p < 0.01). Scores on the quis indicated that participants were satisfied with various aspects of the user interface. Conclusions: The hf e-module had a greater impact on knowledge acquisition, and users expressed satisfaction with the interface in both the hf and lf situations. The use of e-learning in a competency-based curriculum could have educational advantages; participants expressed benefits and drawbacks. Preferences for e-learning integration in education for the health professions should be explored further.

Reusable High Aspect Ratio 3-D Nickel Shadow Mask.

Shadow Mask technology has been used over the years for resistless patterning and to pattern on unconventional surfaces, fragile substrate and biomaterial. In this work, we are presenting a novel method to fabricate high aspect ratio (15:1) three-dimensional (3D) Nickel (Ni) shadow mask with vertical pattern length and width of 1.2 mm and 40 µm respectively. The Ni shadow mask is 1.5 mm tall and 100 µm wide at the base. The aspect ratio of the shadow mask is 15. Ni shadow mask is mechanically robust and hence easy to handle. It is also reusable and used to pattern the sidewalls of unconventional and complex 3D geometries such as microneedles or neural electrodes (such as the Utah array). The standard Utah array has 100 active sites at the tip of the shaft. Using the proposed high aspect ratio Ni shadow mask, the Utah array can accommodate 300 active sites, 200 of which will be along and around the shaft. The robust Ni shadow mask is fabricated using laser patterning and electroplating techniques. The use of Ni 3D shadow mask will lower the fabrication cost, complexity and time for patterning out-of-plane structures.

Pregnancy after laparoscopic ventral mesh rectopexy: implications and outcomes.

AIM: Surgical management of rectal prolapse varies considerably. Most surgeons are reluctant to use ventral mesh rectopexy in young women until they have completed their family. The aim of the present study was to review outcomes of pregnancy following laparoscopic ventral mesh rectopexy from a tertiary referral centre over a 10-year period (2006-2016) and to review the impact on pelvic floor symptoms. METHOD: We undertook a retrospective review of a prospectively compiled database of patients who had undergone laparoscopic ventral rectopexy in a single centre over a 10-year period. Pelvic floor symptom scores (Vaizey for incontinence and Longo for obstructive defaecation) were collected at initial presentation (pre-intervention), post-intervention and after child birth. RESULTS: In all, 954 rectopexies were performed over this 10-year period. 225 (24%) patients were women and under 45 years of age (taken as an arbitrary cut-off for decreased likelihood of pregnancy). Eight (4%) of these patients became pregnant following rectopexy. The interval between rectopexy and delivery was 42 months (21-50). Six patients delivered live babies by elective lower segment caesarean section and two by spontaneous vaginal delivery. Six were first babies and two were second. No mesh related adverse outcome was reported. No difference in pelvic floor symptoms was demonstrated on comparison of post-rectopexy and post-delivery scores. CONCLUSION: This study provides the first description in the English language literature of safe delivery by elective lower segment caesarean section or spontaneous vaginal delivery following laparoscopic ventral mesh rectopexy. No adverse impact on pelvic floor related quality of life was detected.

Iatrogenic common bile duct injuries: Increasing complexity in the laparoscopic era: A prospective cohort study.

PURPOSE: Iatrogenic bile duct injury (BDI) is the most significant associated complication to laparoscopic cholecystectomy (LC). Little is known about the evolution of the pattern of BDI in the era of laparoscopy. The aim of the study is to assess the pattern of post-LC BDIs managed in a tertiary referral centre. METHODS: Post-LC BDI referred over two decades were studied. Demographic data, type of BDI (classified using the Strasberg System), clinical symptoms, diagnostic investigations, timing of referral, post-referral management and morbidity were analysed. The pattern of injury, associated vascular injuries rate and their management were compared over two time periods (1992-2004,2005-2014). RESULTS: 78 BDIs were referred. During the second time period Strasberg A injuries decreased from 14% to 0 and Strasberg E1increased from 4% to 23%, the rate of associated vascular injury was six time higher (3.6% versus 22.7%), more patients had an attempted repair at the index hospital (16% versus 35%) sand fewer patients could be managed without surgical intervention at the referral hospital (28% versus 4%). CONCLUSION: Complexity of referred BDIs and rate of associated vascular injuries have increased over time. These findings led to more patients managed requiring surgical intervention at the referral hospital.

Different methods to alter surface morphology of high aspect ratio structures.

In various applications such as neural prostheses or solar cells, there is a need to alter the surface morphology of high aspect ratio structures so that the real surface area is greater than geometrical area. The change in surface morphology enhances the devices functionality. One of the applications of altering the surface morphology is of neural implants such as the Utah electrode array (UEA) that communicate with single neurons by charge injection induced stimulation or by recording electrical neural signals. For high selectivity between single cells of the nervous system, the electrode surface area is required to be as small as possible, while the impedance is required to be as low as possible for good signal to noise ratios (SNR) during neural recording. For stimulation, high charge injection and charge transfer capacities of the electrodes are required, which increase with the electrode surface. Traditionally, researchers have worked with either increasing the roughness of the existing metallization (Platinum grey, black) or other materials such as Iridium Oxide and PEDOT. All of these previously investigated methods lead to more complicated metal deposition processes that are difficult to control and often have a critical impact on the mechanical properties of the metal films. Therefore, a modification of the surface underneath the electrode's coating will increase its surface area while maintaining the standard and well controlled metal deposition process. In this work, the surfaces of the Silicon micro-needles were engineered by creating a defined microstructure on the electrodes surface using several methods such as Laser ablation, focused ion beam, sputter etching, reactive ion etching (RIE) and deep reactive ion etching (DRIE). The surface modification processes were optimized for the high aspect ratio Silicon structures of the UEA. The increase in real surface area while maintaining the geometrical surface area was verified using scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The best results were obtained by DRIE induced surface morphology. Decreases in impedance values of electrodes up to 76 % indicate the successful surface engineering of the high aspect ratio Silicon structures.