7,139 research outputs found
Patient experiences of swallowing exercises after head and neck cancer:A qualitative study examining barriers and facilitators using behaviour change theory
Poor patient adherence to swallowing exercises is commonly reported in the dysphagia literature on patients treated for head and neck cancer. Establishing the effectiveness of exercise interventions for this population may be undermined by patient non-adherence. The purpose of this study was to explore the barriers and facilitators to exercise adherence from a patient perspective, and to determine the best strategies to reduce the barriers and enhance the facilitators. In-depth interviews were conducted on thirteen patients. We used a behaviour change framework and model [Theoretical domains framework and COM-B (Capability-opportunity-motivation-behaviour) model] to inform our interview schedule and structure our results, using a content analysis approach. The most frequent barrier identified was psychological capability. This was highlighted by patient reports of not clearly understanding reasons for the exercises, forgetting to do the exercises and not having a system to keep track. Other barriers included feeling overwhelmed by information at a difficult time (lack of automatic motivation) and pain and fatigue (lack of physical capability). Main facilitators included having social support from family and friends, the desire to prevent negative consequences such as long-term tube feeding (reflective motivation), having the skills to do the exercises (physical capability), having a routine or trigger and receiving feedback on the outcome of doing exercises (automatic motivation). Linking these findings back to the theoretical model allows for a more systematic selection of theory-based strategies that may enhance the design of future swallowing exercise interventions for patients with head and neck cancer
Patient experiences of swallowing exercises after head and neck cancer:A qualitative study examining barriers and facilitators using behaviour change theory
Poor patient adherence to swallowing exercises is commonly reported in the dysphagia literature on patients treated for head and neck cancer. Establishing the effectiveness of exercise interventions for this population may be undermined by patient non-adherence. The purpose of this study was to explore the barriers and facilitators to exercise adherence from a patient perspective, and to determine the best strategies to reduce the barriers and enhance the facilitators. In-depth interviews were conducted on thirteen patients. We used a behaviour change framework and model [Theoretical domains framework and COM-B (Capability-opportunity-motivation-behaviour) model] to inform our interview schedule and structure our results, using a content analysis approach. The most frequent barrier identified was psychological capability. This was highlighted by patient reports of not clearly understanding reasons for the exercises, forgetting to do the exercises and not having a system to keep track. Other barriers included feeling overwhelmed by information at a difficult time (lack of automatic motivation) and pain and fatigue (lack of physical capability). Main facilitators included having social support from family and friends, the desire to prevent negative consequences such as long-term tube feeding (reflective motivation), having the skills to do the exercises (physical capability), having a routine or trigger and receiving feedback on the outcome of doing exercises (automatic motivation). Linking these findings back to the theoretical model allows for a more systematic selection of theory-based strategies that may enhance the design of future swallowing exercise interventions for patients with head and neck cancer
Pelphix: Surgical Phase Recognition from X-ray Images in Percutaneous Pelvic Fixation
Surgical phase recognition (SPR) is a crucial element in the digital
transformation of the modern operating theater. While SPR based on video
sources is well-established, incorporation of interventional X-ray sequences
has not yet been explored. This paper presents Pelphix, a first approach to SPR
for X-ray-guided percutaneous pelvic fracture fixation, which models the
procedure at four levels of granularity -- corridor, activity, view, and frame
value -- simulating the pelvic fracture fixation workflow as a Markov process
to provide fully annotated training data. Using added supervision from
detection of bony corridors, tools, and anatomy, we learn image representations
that are fed into a transformer model to regress surgical phases at the four
granularity levels. Our approach demonstrates the feasibility of X-ray-based
SPR, achieving an average accuracy of 93.8% on simulated sequences and 67.57%
in cadaver across all granularity levels, with up to 88% accuracy for the
target corridor in real data. This work constitutes the first step toward SPR
for the X-ray domain, establishing an approach to categorizing phases in
X-ray-guided surgery, simulating realistic image sequences to enable machine
learning model development, and demonstrating that this approach is feasible
for the analysis of real procedures. As X-ray-based SPR continues to mature, it
will benefit procedures in orthopedic surgery, angiography, and interventional
radiology by equipping intelligent surgical systems with situational awareness
in the operating room
Numerical and Experimental Investigation of Circulation in Short Cylinders
In preparation for an experimental study of magnetorotational instability
(MRI) in liquid metal, we explore Couette flows having height comparable to the
gap between cylinders, centrifugally stable rotation, and high Reynolds number.
Experiments in water are compared with numerical simulations. Simulations show
that endcaps corotating with the outer cylinder drive a strong poloidal
circulation that redistributes angular momentum. Predicted azimuthal flow
profiles agree well with experimental measurements. Spin-down times scale with
Reynolds number as expected for laminar Ekman circulation; extrapolation from
two-dimensional simulations at agrees remarkably well with
experiment at . This suggests that turbulence does not dominate
the effective viscosity. Further detailed numerical studies reveal a strong
radially inward flow near both endcaps. After turning vertically along the
inner cylinder, these flows converge at the midplane and depart the boundary in
a radial jet. To minimize this circulation in the MRI experiment, endcaps
consisting of multiple, differentially rotating rings are proposed. Simulations
predict that an adequate approximation to the ideal Couette profile can be
obtained with a few rings
Cystic lymphangioma of the lesser sac presenting as acute appendicitis: A case report
Intra-abdominal lymphangiomas usually present by 2 years of age and are uncommon in adults. Cystic lymphagiomas arising from the lesser sac are even more uncommon. We report an unusual case of a lesser sac cystic lymphangioma presenting as acute appendicitis. A 21 year old female was admitted with pyrexia, right iliac fossa tenderness and an elevated C-reactive protein (CRP). At laparotomy, a large fluid filled cystic lesion was observed occupying the right side of the abdominal cavity. The lesion was excised in its entirety and histological diagnosis confirmed lymphangioma. The patient remains well with no evidence of recurrence 1 year post resection
Association of Clinician Diagnostic Performance With Machine Learning-Based Decision Support Systems: A Systematic Review.
IMPORTANCE: An increasing number of machine learning (ML)-based clinical decision support systems (CDSSs) are described in the medical literature, but this research focuses almost entirely on comparing CDSS directly with clinicians (human vs computer). Little is known about the outcomes of these systems when used as adjuncts to human decision-making (human vs human with computer). OBJECTIVES: To conduct a systematic review to investigate the association between the interactive use of ML-based diagnostic CDSSs and clinician performance and to examine the extent of the CDSSs' human factors evaluation. EVIDENCE REVIEW: A search of MEDLINE, Embase, PsycINFO, and grey literature was conducted for the period between January 1, 2010, and May 31, 2019. Peer-reviewed studies published in English comparing human clinician performance with and without interactive use of an ML-based diagnostic CDSSs were included. All metrics used to assess human performance were considered as outcomes. The risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) and Risk of Bias in Non-Randomised Studies-Intervention (ROBINS-I). Narrative summaries were produced for the main outcomes. Given the heterogeneity of medical conditions, outcomes of interest, and evaluation metrics, no meta-analysis was performed. FINDINGS: A total of 8112 studies were initially retrieved and 5154 abstracts were screened; of these, 37 studies met the inclusion criteria. The median number of participating clinicians was 4 (interquartile range, 3-8). Of the 107 results that reported statistical significance, 54 (50%) were increased by the use of CDSSs, 4 (4%) were decreased, and 49 (46%) showed no change or an unclear change. In the subgroup of studies carried out in representative clinical settings, no association between the use of ML-based diagnostic CDSSs and improved clinician performance could be observed. Interobserver agreement was the commonly reported outcome whose change was the most strongly associated with CDSS use. Four studies (11%) reported on user feedback, and, in all but 1 case, clinicians decided to override at least some of the algorithms' recommendations. Twenty-eight studies (76%) were rated as having a high risk of bias in at least 1 of the 4 QUADAS-2 core domains, and 6 studies (16%) were considered to be at serious or critical risk of bias using ROBINS-I. CONCLUSIONS AND RELEVANCE: This systematic review found only sparse evidence that the use of ML-based CDSSs is associated with improved clinician diagnostic performance. Most studies had a low number of participants, were at high or unclear risk of bias, and showed little or no consideration for human factors. Caution should be exercised when estimating the current potential of ML to improve human diagnostic performance, and more comprehensive evaluation should be conducted before deploying ML-based CDSSs in clinical settings. The results highlight the importance of considering supported human decisions as end points rather than merely the stand-alone CDSSs outputs
Parametric Forcing of Waves with Non-Monotonic Dispersion Relation: Domain Structures in Ferrofluids?
Surface waves on ferrofluids exposed to a dc-magnetic field exhibit a
non-monotonic dispersion relation. The effect of a parametric driving on such
waves is studied within suitable coupled Ginzburg-Landau equations. Due to the
non-monotonicity the neutral curve for the excitation of standing waves can
have up to three minima. The stability of the waves with respect to long-wave
perturbations is determined a phase-diffusion equation. It shows that the
band of stable wave numbers can split up into two or three sub-bands. The
resulting competition between the wave numbers corresponding to the respective
sub-bands leads quite naturally to patterns consisting of multiple domains of
standing waves which differ in their wave number. The coarsening dynamics of
such domain structures is addressed.Comment: 23 pages, 6 postscript figures, composed using RevTeX. Submitted to
PR
The Hydrogen Epoch of Reionization Array Dish II: Characterization of Spectral Structure with Electromagnetic Simulations and its science Implications
We use time-domain electromagnetic simulations to determine the spectral
characteristics of the Hydrogen Epoch of Reionization Arrays (HERA) antenna.
These simulations are part of a multi-faceted campaign to determine the
effectiveness of the dish's design for obtaining a detection of redshifted 21
cm emission from the epoch of reionization. Our simulations show the existence
of reflections between HERA's suspended feed and its parabolic dish reflector
that fall below -40 dB at 150 ns and, for reasonable impedance matches, have a
negligible impact on HERA's ability to constrain EoR parameters. It follows
that despite the reflections they introduce, dishes are effective for
increasing the sensitivity of EoR experiments at relatively low cost. We find
that electromagnetic resonances in the HERA feed's cylindrical skirt, which is
intended to reduce cross coupling and beam ellipticity, introduces significant
power at large delays ( dB at 200 ns) which can lead to some loss of
measurable Fourier modes and a modest reduction in sensitivity. Even in the
presence of this structure, we find that the spectral response of the antenna
is sufficiently smooth for delay filtering to contain foreground emission at
line-of-sight wave numbers below Mpc, in
the region where the current PAPER experiment operates. Incorporating these
results into a Fisher Matrix analysis, we find that the spectral structure
observed in our simulations has only a small effect on the tight constraints
HERA can achieve on parameters associated with the astrophysics of
reionization.Comment: Accepted to ApJ, 18 pages, 17 Figures. Replacement matches accepted
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