46 research outputs found

    Anticipated impacts of voluntary assisted dying legislation on nursing practice

    Get PDF
    Background: The Voluntary Assisted Dying Act 2017 passed into law in Victoria, Australia, on the 29 November 2017. Internationally, nurses have been shown to be intimately involved in patient care throughout the voluntary assisted dying process. However, there is a paucity of research exploring Australian nurses’ perspectives on voluntary assisted dying and, in particular, how Victorian nurses anticipate the implementation of this ethically controversial legislation will impact their professional lives. Objectives: To explore Victorian nurses’ expectations of the ethical and practical impacts the voluntary assisted dying legislation will have on their professional lives. Research design: This qualitative study analysed nurses’ free text responses collected as part of a larger mixed methods online survey investigating staff views on the Voluntary Assisted Dying Act. Data were collected during the period between the passing of the voluntary assisted dying legislation and the start date and were analysed using inductive content analysis. Participants and research context: Free text survey responses were analysed from 1873 nurses employed across seven Victorian health services located in both metropolitan and regional areas of the state. Ethical considerations: The study obtained research ethics approval and all participants were informed of the voluntary and anonymous nature of their participation. Findings: This study identified three broad areas of Victorian nurses’ professional lives that they expected to be impacted by the implementation of voluntary assisted dying: professional identity, career development and workplace relationships. Conclusion: Participants anticipate diverse and nursing-specific impacts of the implementation of voluntary assisted dying in Victoria. Their insights can inform health services in jurisdictions considering or already implementing voluntary assisted dying, to develop policies, procedures and staff training programmes that safeguard the well-being and legal rights of their nursing staff

    Interactive Medical Image Segmentation using Deep Learning with Image-specific Fine-tuning

    Get PDF
    Convolutional neural networks (CNNs) have achieved state-of-the-art performance for automatic medical image segmentation. However, they have not demonstrated sufficiently accurate and robust results for clinical use. In addition, they are limited by the lack of image-specific adaptation and the lack of generalizability to previously unseen object classes. To address these problems, we propose a novel deep learning-based framework for interactive segmentation by incorporating CNNs into a bounding box and scribble-based segmentation pipeline. We propose image-specific fine-tuning to make a CNN model adaptive to a specific test image, which can be either unsupervised (without additional user interactions) or supervised (with additional scribbles). We also propose a weighted loss function considering network and interaction-based uncertainty for the fine-tuning. We applied this framework to two applications: 2D segmentation of multiple organs from fetal MR slices, where only two types of these organs were annotated for training; and 3D segmentation of brain tumor core (excluding edema) and whole brain tumor (including edema) from different MR sequences, where only tumor cores in one MR sequence were annotated for training. Experimental results show that 1) our model is more robust to segment previously unseen objects than state-of-the-art CNNs; 2) image-specific fine-tuning with the proposed weighted loss function significantly improves segmentation accuracy; and 3) our method leads to accurate results with fewer user interactions and less user time than traditional interactive segmentation methods.Comment: 11 pages, 11 figure

    Direct, live imaging of cortical spreading depression and anoxic depolarisation using a fluorescent, voltage-sensitive dye

    Get PDF
    Perilesion depolarisations, whether transient anoxic depolarisation (AD) or spreading depression (SD), occur in stroke models and in patients with acute brain ischaemia, but their contribution to lesion progression remains unclear. As these phenomena correspond to waves of cellular depolarisation, we have developed a technique for their live imaging with a fluorescent voltage-sensitive (VS) dye (RH-1838). Method development and validation were performed in two different preparations: chicken retina, to avoid any vascular interference; and cranial window exposing the cortical surface of anaesthetised rats. Spreading depression was produced by high-K medium, and AD by complete terminal ischaemia in rats. After dye loading, the preparation was illuminated at its excitation wavelength and fluorescence changes were recorded sequentially with a charge-coupled device camera. No light was recorded when the VS dye was omitted, ruling out the contribution of any endogenous fluorophore. With both preparations, the changes in VS dye fluorescence with SD were analogous to those of the DC (direct current) potential recorded with glass electrodes. Although some blood quenching of the emitted light was identified, the VS dye signatures of SD had a good signal-to-noise ratio and were reproducible. The changes in VS dye fluorescence associated with AD were more complex because of additional interferents, especially transient brain swelling with subsequent shrinkage. However, the kinetics of the AD-associated changes in VS dye fluorescence was also analogous to that of the DC potential. In conclusion, this method provides the imaging equivalent of electrical extracellular DC potential recording, with the SD and AD negative shifts translating directly to fluorescence increase

    New media user networks

    No full text

    Performance characteristics of an interventional multispectral photoacoustic imaging system for guiding minimally invasive procedures

    Get PDF
    Precise device guidance is important for interventional procedures in many different clinical fields including fetal medicine, regional anesthesia, interventional pain management, and interventional oncology. While ultrasound is widely used in clinical practice for real-time guidance, the image contrast that it provides can be insufficient for visualizing tissue structures such as blood vessels, nerves, and tumors. This study was centered on the development of a photoacoustic imaging system for interventional procedures that delivered excitation light in the ranges of 750 to 900 nm and 1150 to 1300 nm, with an optical fiber positioned in a needle cannula. Coregistered B-mode ultrasound images were obtained. The system, which was based on a commercial ultrasound imaging scanner, has an axial resolution in the vicinity of 100  μm and a submillimeter, depth-dependent lateral resolution. Using a tissue phantom and 800 nm excitation light, a simulated blood vessel could be visualized at a maximum distance of 15 mm from the needle tip. Spectroscopic contrast for hemoglobin and lipids was observed with ex vivo tissue samples, with photoacoustic signal maxima consistent with the respective optical absorption spectra. The potential for further optimization of the system is discussed
    corecore