Daniel Leff

Diffuse optical imaging of the healthy and diseased breast: A systematic review

Screening X-ray mammography is limited by false positives and negatives leading to unnecessary physical and psychological morbidity. Diffuse Optical Imaging using harmless near infra red light, provides lesion detection based on functional abnormalities and represents a novel diagnostic arm that could complement traditional mammography. Reviews of optical breast imaging have not been systematic, are focused mainly on technological developments, and have become superseded by rapid technological advancement. The aim of this study is to review clinically orientated studies involving approximately 2,000 women in whom optical mammography has been used to evaluate the healthy or diseased breast. The results suggest that approximately 85% of breast lesions are detectable on optical mammography. Spectroscopic resolution of tissue haemoglobin composition and oxygen saturation may improve the detectability of breast diseases. Results suggest that breast lesions contain approximately twice the haemoglobin concentration of background tissue. Current evidence suggests that it is not possible to distinguish benign from malignant disease using optical imaging techniques in isolation. Methods to improve the performance of Diffuse Optical Imaging, such as better spectral coverage with additional wavelengths, improved modelling of light transport in tissues and the use of extrinsic dyes may augment lesion detection and characterisation. Future research should involve large clinical trials to determine the overall sensitivity and specificity of optical imaging techniques as well as to establish patient satisfaction and economic viability.

Assessment of the cerebral cortex during motor task behaviours in adults: a systematic review of functional near infrared spectroscopy (fNIRS) studies.

Functional near infrared spectroscopy (fNIRS) is an emerging tool for non-invasively monitoring the haemodynamic response to brain activation. The technique has been widely adopted to investigate cortical responses during motor tasks in health and disease. This systematic review provides a critical analysis of the research findings in the hope of summating relevant information, identifying consistent outcomes acquired using different spectrometers, clarifying data inconsistencies, and learning from the common challenges across disciplines. The spatiotemporal characteristics, reliability, repeatability and modulation of typical cortical response evoked by motor stimulation are all evaluated in detail. The review assesses the contribution of the technique to advancing our understanding of motor skill learning and control in the context of tasks of everyday living, athletic performance, and recovery from neurological illness. Finally, the limitations of current fNIRS technologies are examined and a series of recommendations for future studies are provided based upon the reviewed literature.

From Wearable Sensors to Smart Implants-–Toward Pervasive and Personalized Healthcare

Objective: This paper discusses the evolution of pervasive healthcare from its inception for activity recognition using wearable sensors to the future of sensing implant deployment and data processing. Methods: We provide an overview of some of the past milestones and recent developments, categorized into different generations of pervasive sensing applications for health monitoring. This is followed by a review on recent technological advances that have allowed unobtrusive continuous sensing combined with diverse technologies to reshape the clinical workflow for both acute and chronic disease management. We discuss the opportunities of pervasive health monitoring through data linkages with other health informatics systems including the mining of health records, clinical trial databases, multiomics data integration, and social media. Conclusion: Technical advances have supported the evolution of the pervasive health paradigm toward preventative, predictive, personalized, and participatory medicine. Significance: The sensing technologies discussed in this paper and their future evolution will play a key role in realizing the goal of sustainable healthcare systems.

Changes in prefrontal cortical behaviour depend upon familiarity on a bimanual co-ordination task: an fNIRS study.

To investigate neurocognitive mechanisms associated with task-related expertise development, this paper investigates serial changes in prefrontal activation patterns using functional near infrared spectroscopy (fNIRS). We evaluate cortical function in 62 healthy subjects with varying experience during serial evaluations of a knot-tying task. All tasks were performed bimanually and self paced, with fixed episodes of motor rest for five repetitions. Improvements in technical skill were evaluated using dexterity indices to quantify time, total movements and pathlength required to complete trials. Significant improvements in technical skills were observed in novices between the 2nd and 3rd trials, associated with increasing task familiarity. In trained subjects, minimal fluctuation in task-related oxyhaemoglobin (HbO(2)) and deoxyhaemoglobin (HHb) changes were observed in association with more stable task performance. In contrast, two significant transitions in prefrontal haemodynamic change were observed in novices. Greater task-related increases in HbO(2) and decreases in HHb were identified on the second trial compared to the first. Relative decreases in HbO(2) and increases in HHb change were observed between the third and fourth, and fourth and fifth trials respectively. These data suggest that prefrontal processing across five knot-tying trials is influenced by the level of experience on a task. Modifications in prefrontal activation appear to confer technical performance adaptation in novices.

Quality control and assurance in functional near infrared spectroscopy (fNIRS) experimentation

Functional near infrared spectroscopy (fNIRS) is a rapidly developing neuroimaging modality for exploring cortical brain behaviour. Despite recent advances, the quality of fNIRS experimentation may be compromised in several ways: firstly, by altering the optical properties of the tissues encountered in the path of light; secondly, through adulteration of the recovered biological signals (noise) and finally, by modulating neural activity. Currently, there is no systematic way to guide the researcher regarding these factors when planning fNIRS studies. Conclusions extracted from fNIRS data will only be robust if appropriate methodology and analysis in accordance with the research question under investigation are employed. In order to address these issues and facilitate the quality control process, a taxonomy of factors influencing fNIRS data have been established. For each factor, a detailed description is provided and previous solutions are reviewed. Finally, a series of evidence-based recommendations are made with the aim of improving consistency and quality of fNIRS research.

Laparoscopic Skills Suffer on The First Shift of Sequential Night Shifts : Program Directors Beware and Residents Prepare

Objective:Research evaluating fatigue-induced skills decline has focused on acute sleep deprivation rather than the effects of circadian desynchronization associated with multiple shifts. As a result, the number of consecutive night shifts that residents can safely be on duty without detrimental effects to their technical skills remains unknown. A prospective observational cohort study was conducted to assess the impact of 7 successive night shifts on the technical surgical performance of junior residents. Methods:The interventional strategy included training 21 residents from surgery and allied disciplines on a virtual reality surgical simulator, towards the achievement of preset benchmark scores, followed by 294 technical skills assessments conducted over 1764 manpower night shift hours. Primary outcomes comprised serial technical skills assessments on 2 tasks of a virtual reality surgical simulator. Secondary outcomes included assessments of introspective fatigue, duration of sleep, and prospective recordings of activity (number of “calls” received, steps walked, and patients evaluated). Results:Maximal deterioration in performance was observed following the first night shift. Residents took significantly longer to complete the first (P = 0.002) and second tasks (P = 0.005) compared with baseline. They also committed significantly greater numbers of errors (P = 0.025) on the first task assessed. Improved performance was observed across subsequent shifts towards baseline levels. Conclusions:Newly acquired technical surgical skills deteriorate maximally after the first night shift, emphasizing the importance of adequate preparation for night rotas. Performance improvements across successive shifts may be due to ongoing learning or adaptation to chronic fatigue. Further research should focus on assessments of both technical procedural skills and cognitive abilities to determine the rotas that best minimize errors and maximize patient safety.

Validation of orthopaedic bench models for trauma surgery

The aim of this study was to validate the use of three models of fracture fixation in the assessment of technical skills. We recruited 21 subjects (six experts, seven intermediates, and eight novices) to perform three procedures: application of a dynamic compression plate on a cadaver porcine model, insertion of an unreamed tibial intramedullary nail, and application of a forearm external fixator, both on synthetic bone models. The primary outcome measures were the Objective Structural Assessment of technical skills global rating scale on video recordings of the procedures which were scored by two independent expert observers, and the hand movements of the surgeons which were analysed using the Imperial College Surgical Assessment Device. The video scores were significantly different for the three groups in all three procedures (p < 0.05), with excellent inter-rater reliability (alpha = 0.88). The novice and intermediate groups specifically were significantly different in their performance with dynamic compression plate and intramedullary nails (p < 0.05). Movement analysis distinguished between the three groups in the dynamic compression plate model, but a ceiling effect was demonstrated in the intramedullary nail and external fixator procedures, where intermediates and experts performed to comparable standards (p > 0.6). A total of 85% (18 of 21) of the subjects found the dynamic compression model and 57% (12 of 21) found all the models acceptable tools of assessment. This study has validated a low-cost, high-fidelity porcine dynamic compression plate model using video rating scores for skills assessment and movement analysis. It has also demonstrated that Synbone models for the application of and intramedullary nail and an external fixator are less sensitive and should be improved for further assessment of surgical skills in trauma. The availability of valid objective tools of assessment of surgical skills allows further studies into improving methods of training.

Smartphone breast applications – What's the evidence?

INTRODUCTION There are around 40,000 healthcare applications (apps) available for smartphones. Apps have been reviewed in many specialties. Breast cancer is the most common malignancy in females with almost 1.38 million new cases a year worldwide. Despite the high prevalence of breast disease, apps in this field have not been reviewed to date. We have evaluated apps relevant to breast disease with an emphasis on their evidence base (EB) and medical professional involvement (MPI). METHODS Searching the major app stores (apple iTunes, Google Play, BlackBerry World, Windows Phone) using the most common breast symptoms and diseases identified relevant apps. Extracted data for each app included target consumer, disease focus, app function, documentation of any EB, documentation of MPI in development, and potential safety concerns. RESULTS One-hundred-and-eighty-five apps were reviewed. The majority focused on breast cancer (n = 139, 75.1%). Educational (n = 94) and self-assessment tools (n = 30) were the most common functions demonstrated. EB and MPI was identified in 14.2% and 12.8% of apps respectively. Potential safety concerns were identified in 29 (15.7%) apps. CONCLUSIONS There is a lack of EB and MPI in the development of current breast apps. Safety concerns highlight the need for regulation, full authorship disclosure and clinical trials. A robust framework for identifying high quality applications is necessary. This will address the current barrier pertaining to a lack of consumer confidence in their use and further aid to promote their widespread implementation within healthcare.

The Neurocognitive Enhancement of Surgeons: An Ethical Perspective

Neurocognitive enhancement is a rapidly expanding scientific field. The vast ethical implications of this developing field for surgical practice have yet to be considered within the literature. This article outlines the reasons surgeons may, in the near future, consider using neurocognitive enhancement and addresses the resulting significant ethical implications of this. We do not seek to support or denounce the potential role of neurocognitive enhancement in surgeons, but to stimulate a debate, which, with ever-increasing levels of stimulant use in schools and colleges, and with a pharmaceutical industry driving the creation of new neuroactive products, has now become a necessity.

Endoscopic breast surgery: where are we now and what might the future hold for video-assisted breast surgery?

Endoscopic surgery has been extensively used for many surgical conditions and has gained acceptance as an alternative and less invasive approach to open surgery. However, minimal access endoscopic techniques have yet to be translated into mainstream clinical practice in breast surgery. More recently, technical innovations have made it feasible to conduct endoscopic breast cancer resection, with or without breast reconstruction, through wounds inconspicuously hidden in the axilla and periareolar region. Several clinical trials have now been conducted to demonstrate technical feasibility, assess safety and provide follow up data regarding oncological success of endoscopic breast surgery. This primary aim was to critically evaluate the literature in order to determine the oncological and cosmetic efficacy of endoscopic breast surgery. A systematic review was conducted using Medline, Ovid and Embase to identify original data from studies of endoscopic breast surgery. Initial results have demonstrated that endoscopic breast surgery is safe and technically feasible. Early data suggests that it is possible to achieve disease control with high rates of overall survival and low rates of local relapse recurrence and/or distant metastases. However, the absence of level I randomised clinical evidence currently precludes a recommendation that endoscopic breast cancer surgery is capable of achieving equivalent oncological outcomes to open surgery.