Needle Tip Force Estimation using an OCT Fiber and a Fused convGRU-CNN Architecture

Needle insertion is common during minimally invasive interventions such as biopsy or brachytherapy. During soft tissue needle insertion, forces acting at the needle tip cause tissue deformation and needle deflection. Accurate needle tip force measurement provides information on needle-tissue interaction and helps detecting and compensating potential misplacement. For this purpose we introduce an image-based needle tip force estimation method using an optical fiber imaging the deformation of an epoxy layer below the needle tip over time. For calibration and force estimation, we introduce a novel deep learning-based fused convolutional GRU-CNN model which effectively exploits the spatio-temporal data structure. The needle is easy to manufacture and our model achieves a mean absolute error of 1.76 +- 1.5 mN with a cross-correlation coefficient of 0.9996, clearly outperforming other methods. We test needles with different materials to demonstrate that the approach can be adapted for different sensitivities and force ranges. Furthermore, we validate our approach in an ex-vivo prostate needle insertion scenario.Comment: Accepted for Publication at MICCAI 201

Laser Generation of Narrow Band Ultrasound

Laser based sensor systems to replace conventional piezoelectric contact transducers for ultrasonic testing continue under development for applications where contact with the specimen surface is undesirable or impossible. To date, such systems are considerably less sensitive than their piezoelectric counterparts. As a result, a great deal of effort has contributed to the development of a number of interferoroetric transducer systems to detect ultrasound. Increasingly, however, researchers have begun looking at laser ultrasonic sources to see what improvements might be made to enhance overall system sensitivity for laser generation and detection of ultrasound

Low-dose x-ray phase contrast tomography: Experimental setup, image reconstruction and applications in biomedicine

An unmet demand for high resolution tomographic imaging modalities providing enhanced soft tissue contrast exists in a number of biomedical disciplines. X-ray phase contrast imaging (XPCi) methods can provide a solution: contrast is driven by phase (refraction) effects rather than attenuation effects, the formers being much larger than the latters for weakly attenuating materials and energies typically used for biomedical imaging. However, the majority of the existing XPCi methods suffer from drawbacks affecting their implementation outside specialized facilities such as synchrotrons and therefore their applicability to biomedical research. The Edge Illumination (EI) XPCi method has the potential to overcome or at least mitigate most of these drawbacks. Its major strengths are its simple setup, compatibility with commercially available x-ray tubes and potential for low-dose imaging. EI XPCi has recently been implemented as a tomographic modality, and it was demonstrated that the method can provide quantitatively accurate volumetric images acquired with low entrance doses. This paper explains the experimental requirements for tomographic EI XPCi, outlines the image reconstruction process and discusses potential applications in biomedicine. As an example, first experimental images of an atherosclerotic plaque specimen are presented

A prospective case control study of functional outcomes and related quality of life after colectomy for neoplasia.

AIM: Our aim was to assess bowel function and its effect on overall quality of life (QOL) when compared to healthy controls after colectomy. METHODS: Patients undergoing resection of colorectal neoplasia were recruited pre-operatively and followed up at 6 and 12 months, to assess 'early' bowel function. Patients who underwent surgery 2 to 4 years previously were recruited for assessment of 'intermediate' bowel function. Healthy relatives were recruited as controls. The Memorial Sloan-Kettering Cancer Centre and EQ-5D questionnaires were used to assess bowel function and QOL, respectively. Statistical assessment included regression analyses, parametric and non-parametric tests. The association between QOL and Memorial Sloan-Kettering Cancer Centre (MSKCC) scores was evaluated using Spearman's rank correlation. RESULTS: Ninety-one patients were recruited for assessment of 'early' and 85 for 'intermediate' bowel function. There were 85 controls. Patients had a significantly higher number of bowel movements at each follow-up (p < 0.001). At 12 months after surgery, patients reported difficulty with gas-stool discrimination. The 'intermediate' group were found to have lower scores for flatus control (<0.001) and total frequency score (p 0.03), indicating worse function. Patients with higher total MSKCC scores, no symptoms of urgency and those able to control flatus reported better QOL (p 0.006, 0.007 and 0.005, respectively) at 6 and 12 months. Gas-stool differentiation and complete evacuation correlated with better QOL in the 'intermediate' bowel function group (p 0.02 and 0.02, respectively). CONCLUSION: Colonic resection adversely affects elements of bowel function up to 4 years after surgery. Good colonic function, represented by higher MSKCC scores, correlates with better QOL

"After my husband's circumcision, I know that I am safe from diseases": Women's Attitudes and Risk Perceptions Towards Male Circumcision in Iringa, Tanzania.

While male circumcision reduces the risk of female-to-male HIV transmission and certain sexually transmitted infections (STIs), there is little evidence that circumcision provides women with direct protection against HIV. This study used qualitative methods to assess women's perceptions of male circumcision in Iringa, Tanzania. Women in this study had strong preferences for circumcised men because of the low risk perception of HIV with circumcised men, social norms favoring circumcised men, and perceived increased sexual desirability of circumcised men. The health benefits of male circumcision were generally overstated; many respondents falsely believed that women are also directly protected against HIV and that the risk of all STIs is greatly reduced or eliminated in circumcised men. Efforts to engage women about the risks and limitations of male circumcision, in addition to the benefits, should be expanded so that women can accurately assess their risk of HIV or STIs during sexual intercourse with circumcised men

Climate Dynamics: A Network-Based Approach for the Analysis of Global Precipitation

Precipitation is one of the most important meteorological variables for defining the climate dynamics, but the spatial patterns of precipitation have not been fully investigated yet. The complex network theory, which provides a robust tool to investigate the statistical interdependence of many interacting elements, is used here to analyze the spatial dynamics of annual precipitation over seventy years (1941-2010). The precipitation network is built associating a node to a geographical region, which has a temporal distribution of precipitation, and identifying possible links among nodes through the correlation function. The precipitation network reveals significant spatial variability with barely connected regions, as Eastern China and Japan, and highly connected regions, such as the African Sahel, Eastern Australia and, to a lesser extent, Northern Europe. Sahel and Eastern Australia are remarkably dry regions, where low amounts of rainfall are uniformly distributed on continental scales and small-scale extreme events are rare. As a consequence, the precipitation gradient is low, making these regions well connected on a large spatial scale. On the contrary, the Asiatic South-East is often reached by extreme events such as monsoons, tropical cyclones and heat waves, which can all contribute to reduce the correlation to the short-range scale only. Some patterns emerging between mid-latitude and tropical regions suggest a possible impact of the propagation of planetary waves on precipitation at a global scale. Other links can be qualitatively associated to the atmospheric and oceanic circulation. To analyze the sensitivity of the network to the physical closeness of the nodes, short-term connections are broken. The African Sahel, Eastern Australia and Northern Europe regions again appear as the supernodes of the network, confirming furthermore their long-range connection structure. Almost all North-American and Asian nodes vanish, revealing that extreme events can enhance high precipitation gradients, leading to a systematic absence of long-range patterns

Information management for high content live cell imaging.

BACKGROUND: High content live cell imaging experiments are able to track the cellular localisation of labelled proteins in multiple live cells over a time course. Experiments using high content live cell imaging will generate multiple large datasets that are often stored in an ad-hoc manner. This hinders identification of previously gathered data that may be relevant to current analyses. Whilst solutions exist for managing image data, they are primarily concerned with storage and retrieval of the images themselves and not the data derived from the images. There is therefore a requirement for an information management solution that facilitates the indexing of experimental metadata and results of high content live cell imaging experiments. RESULTS: We have designed and implemented a data model and information management solution for the data gathered through high content live cell imaging experiments. Many of the experiments to be stored measure the translocation of fluorescently labelled proteins from cytoplasm to nucleus in individual cells. The functionality of this database has been enhanced by the addition of an algorithm that automatically annotates results of these experiments with the timings of translocations and periods of any oscillatory translocations as they are uploaded to the repository. Testing has shown the algorithm to perform well with a variety of previously unseen data. CONCLUSION: Our repository is a fully functional example of how high throughput imaging data may be effectively indexed and managed to address the requirements of end users. By implementing the automated analysis of experimental results, we have provided a clear impetus for individuals to ensure that their data forms part of that which is stored in the repository. Although focused on imaging, the solution provided is sufficiently generic to be applied to other functional proteomics and genomics experiments. The software is available from: fhttp://code.google.com/p/livecellim/RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

DUNDRUM-2: Prospective validation of a structured professional judgment instrument assessing priority for admission from the waiting list for a forensic mental health hospital

<p>Abstract</p> <p>Background</p> <p>The criteria for deciding who should be admitted first from a waiting list to a forensic secure hospital are not necessarily the same as those for assessing need. Criteria were drafted qualitatively and tested in a prospective 'real life' observational study over a 6-month period.</p> <p>Methods</p> <p>A researcher rated all those presented at the weekly referrals meeting using the DUNDRUM-1 triage security scale and the DUNDRUM-2 triage urgency scale. The key outcome measure was whether or not the individual was admitted.</p> <p>Results</p> <p>Inter-rater reliability and internal consistency for the DUNDRUM-2 were acceptable. The DUNDRUM-1 triage security score and the DUNDRUM-2 triage urgency score correlated r = 0.663. At the time of admission, after a mean of 23.9 (SD35.9) days on the waiting list, those admitted had higher scores on the DUNDRUM-2 triage urgency scale than those not admitted, with no significant difference between locations (remand or sentenced prisoners, less secure hospitals) at the time of admission. Those admitted also had higher DUNDRUM-1 triage security scores. At baseline the receiver operating characteristic area under the curve for a combined score was the best predictor of admission while at the time of admission the DUNDRUM-2 triage urgency score had the largest AUC (0.912, 95% CI 0.838 to 0.986).</p> <p>Conclusions</p> <p>The triage urgency items and scale add predictive power to the decision to admit. This is particularly true in maintaining equitability between those referred from different locations.</p