Assessing Tissue Damage Around a Tape Spring Steerable Needle With Sharp Turn Radii.

Steerable needles are a novel technology that offers a wide range of uses in medical diagnostics and therapeutics. Currently, there exist several steerable needle designs in the literature, however, they are limited in their use by the number of possible turns, turn radius, and tissue damage. We introduce a novel design of a tape spring steerable needle, capable of multiple turns, that minimizes tissue damage. In this study, we measure the turning radius of our steerable needle in porcine liver tissue in vitro with ultrasound and estimate tissue damage in gel blocks using image analysis and 3D plaster casting. We were able to demonstrate our steerable needle's ability to steer through biological tissue, as well as introduce a novel method for estimating tissue damage. Our findings show that our needle design showed lower damage compared to similar designs in literature, as well as tissue stiffness being a protective factor against tissue damage.

Piloting the 'Youth Early-intervention Study' ('YES'): Preliminary functional outcomes of a randomized controlled trial targeting social participation and physical well-being in young people with emerging mental disorders.

INTRODUCTION: Young people with mental disorders present with diverse social, vocational, physical, and developmental needs. However, multifaceted interventions are rare. We examine the effectiveness of a clinical trial targeting social participation and physical well-being in young people accessing clinical services. METHODS: The 'Youth Early-intervention Study' ('YES') was an unblinded, two-phase, pilot randomized controlled trial offered as an adjunct to standard clinical care, consisting of group activities. Mixed effects models were used to examine functional outcomes over time measured by the 'Social and Occupational Functioning Assessment Scale', 'Functioning Assessment Short Test', and 'Brief Disability Questionnaire' (items 7 and 8). RESULTS: 133 participants aged 14-25 were recruited. 87 participants completed both arms and 83 participants completed a 12-month post-trial assessment. Functioning improved across all outcomes. While diagnoses differed in functioning at baseline (lower functioning in psychotic and bipolar disorders compared to depression), they did not differ in the rate of improvement across any measure. Randomization groups did not differ in baseline functioning or the rate of improvement, suggesting a non-specific impact of the intervention. Engagement with education increased from 11% at baseline to 51% at 12-months post-trial and full-time employment increased from 8% at baseline to 20% at 12-months post-trial. LIMITATIONS: Small sample, no control group, and unmeasured potential moderators (e.g. neurocognitive impairment). CONCLUSIONS: 'YES' was effective and preliminary positive outcomes were observed across all functional outcomes. Future studies should compare the 'YES' intervention to a treatment-as-usual control condition and conduct a multi-centre trial across early intervention service sites.

Subcaudate Tractotomy White Matter Anatomy and Variability: A Diffusion Tensor Imaging Study.

BACKGROUND: Subcaudate tractotomy is a functional ablative procedure performed for treatment-resistant psychiatric disease, targeting the white matter tracts ventral to the head of the caudate nucleus. The white matter anatomy of this region has extensive interindividual variability, and this is thought to impact upon the treatment response to ablative and deep brain stimulation procedures. OBJECTIVE: We aim to assess in detail the white matter tract anatomy and topographic variability underlying subcaudate tractotomy. METHODS: 74 non-depressed adult volunteers underwent MRI including diffusion tensor imaging. Individualized regions of interest were formed in both hemispheres using native non-normalized data to simulate a subcaudate tractotomy. Tractography and analysis were performed and the exact tract locations measured including mean distances and standard deviations to assess variability. RESULTS: The cingulum bundle, uncinate fasciculus, corticostriatal fibres, and corticothalamic fibres were consistently demonstrated. The location of the cingulum bundle was consistent across subjects, but there was extensive interindividual variability in the topographic location of the other tracts. CONCLUSION: We have demonstrated a detailed analysis of the white matter tracts and their anatomical variability underlying subcaudate tractotomy. This has significant implications for neurosurgical targeting.

Reduced integrity of the uncinate fasciculus and cingulum in depression: A stem-by-stem analysis.

INTRODUCTION: The subgenual cingulate gyrus (Brodmann's Area 25: BA25) is hypermetabolic in depression and has been targeted successfully with deep brain stimulation. Two of the white matter tracts that play a role in treatment response are the uncinate fasciculus (UF) and the cingulum bundle. The UF has three prefrontal stems, the most medial of which extends from BA25 (which deals with mood regulation) and the most lateral of which extends from the dorso-lateral prefrontal cortex (concerned with executive function). The cingulum bundle has numerous fibers connecting the lobes of the cerebrum, with the longest fibers extending from BA25 to the amygdala. We hypothesize that there is reduced integrity in the UF, specific to the medial prefrontal stems, as well as in the subgenual and amygdaloid fibers of the cingulum bundle. Our secondary hypothesis is that these changes are present from the early stages of depression. OBJECTIVE: Compare the white matter integrity of stems of the UF and components of the cingulum bundle in first-onset depressed, recurrent/chronic depressed, and non-depressed control subjects. METHODS: Depressed patients (n = 103, first-onset = 57, chronic = 46) and non-depressed control subjects (n = 74) underwent MRI with 32-directional DTI sequences. The uncinate fasciculi and cingulum bundles were seeded, and the fractional anisotropy (FA) measured in each of the three prefrontal stems and the body of the UF, as well as the subgenual, body, and amygdaloid fiber components of the cingulum bundle. FA measurements were compared between groups using ANOVA testing with post-hoc Tukey analysis. RESULTS: There were significant reductions in FA in the subgenual and polar stems of the UF bilaterally, as well as the subgenual and amygdaloid fibers of the cingulum bundle, in depressed patients compared with controls (p < 0.001). There was no significant difference seen in the lateral UF stem or the main body of the cingulum. No significant difference was demonstrated in any of the tracts between first-onset and chronic depression patients. CONCLUSION: Depressed patients have reduced white matter integrity in the subgenual and polar stems of the uncinate fasciculi but not the lateral stems, as well as in the subgenual and amygdaloid cingulum fibers. These changes are present from the first-onset of the disease.

Stakeholders' Perceptions Sought to Inform the Development of a Low-Cost Mobile Robot for Older Adults: A Qualitative Descriptive Study.

Creative solutions are needed to support community-dwelling older adults residing in a variety of settings including their house, apartment, or Supportive Apartment Living (SAL) to promote independence and reduce the risk of nursing home replacement. The objective of this study was to gain an understanding of older adults' needs for physical, mental, and social activities to support the design and functionality of a low-cost mobile assistive robot. A qualitative descriptive study was designed which included three stakeholder focus groups (caregivers, clinicians, and older adults). We held three focus groups with a total of 19 participants: one with paid caregivers ( n = 6), one with interdisciplinary clinicians ( n = 8), and one with older adults residing in SAL ( n = 5). Conventional content analysis was the analytical technique. Four themes emerged: (a) Accomplishing Everyday Tasks: activities of daily living (ADLs) and instrumental activities of daily living (IADLs) were important from the perspectives of all three groups for the older adults to accomplish daily, as well as the "use it or lose it" attitude of the older adults; (b) Personal Connections and Meaningful Activities: for the older adults, it was important for them to engage in socialization and leisure activities, and for the caregivers and clinicians, they work to build personal relationships with the older adults; (c) Cognitive Interventions: the clinicians provided cognitive tools (including reminders, routine and designing interventions) to older adults so they can remain as safe and independent as possible in the SAL; and (d) Safety Measures: encompassed clinicians addressing safety and injury prevention and the caregivers checking in on the older adults in their SAL apartments. This work contributed to the design and functionality specifications for an autonomous low-cost mobile robot for deployment to increase the independence of older adults.

An integrated system for perception-driven autonomy with modular robots.

The theoretical ability of modular robots to reconfigure in response to complex tasks in a priori unknown environments has frequently been cited as an advantage and remains a major motivator for work in the field. We present a modular robot system capable of autonomously completing high-level tasks by reactively reconfiguring to meet the needs of a perceived, a priori unknown environment. The system integrates perception, high-level planning, and modular hardware and is validated in three hardware demonstrations. Given a high-level task specification, a modular robot autonomously explores an unknown environment, decides when and how to reconfigure, and manipulates objects to complete its task. The system architecture balances distributed mechanical elements with centralized perception, planning, and control. By providing an example of how a modular robot system can be designed to leverage reactive reconfigurability in unknown environments, we have begun to lay the groundwork for modular self-reconfigurable robots to address tasks in the real world.

Diffusion Tensor Imaging Investigation of Uncinate Fasciculus Anatomy in Healthy Controls: Description of a Subgenual Stem.

The uncinate fasciculus is the largest white matter association tract connecting the prefrontal cortex and the anteromedial temporal lobe. The traditional anatomical description outlines a temporal stem that hooks around the posterior insula, a subinsular body, and 2 prefrontal stems extending to the lateral orbital gyri and the frontopolar cortex. Recent imaging studies of the white matter tracts deep to the subgenual cingulate gyrus (Brodmann area 25: BA25) suggest the presence of white matter fibers extending from BA25 to the amygdala, via a route that would run in close proximity to the uncinate fasciculus, that are of functional importance in mood disorders. We hypothesized that these fibers represent a third, medial prefrontal stem of the uncinate fasciculus. Using diffusion tensor imaging in 74 healthy volunteer humans, we seeded the uncinate fasciculus using 2 regions of interest centered over the temporal stem and the caudal body of the uncinate fasciculus in the coronal plane at the level of the anterior commissure. A medial prefrontal stem extending to the subgenual cingulate gyrus was demonstrated in 65/74 left and 70/74 right cerebral hemispheres, and had a mean fractional anisotropy value of 0.43 (95% CI 0.40-0.47). The medial subgenual stem fibers were inseparable from the caudal body and temporal stem of the main uncinate fasciculus and followed the same hook-shaped morphology. A probable medial subgenual prefrontal stem of the uncinate fasciculus was demonstrated in a cohort of healthy volunteers and is of potential significance in our understanding of neuropsychiatry and mood disorders.