9 research outputs found
Recommended from our members
Fast Surgical Simulation to Improve Mitral Valve Repair
Mitral valve repair, the preferred method of treating mitral regurgitation, is a demanding surgical procedure consisting of the resection and approximation of valve tissue. Operating on an arrested heart, the clinician is forced to predict closed valve shape and the effect of surgical modifications. The valve's complex morphology makes this a difficult task, and as a result, the procedure is underperformed by less experienced surgeons in lieu of the simpler, less effective valve replacement.Engineering and Applied Science
Recommended from our members
Fast Interactive Simulations of Mitral Valve Repair
Engineering and Applied Science
Should I Stop or Should I Go: Early Stopping with Heterogeneous Populations
Randomized experiments often need to be stopped prematurely due to the
treatment having an unintended harmful effect. Existing methods that determine
when to stop an experiment early are typically applied to the data in aggregate
and do not account for treatment effect heterogeneity. In this paper, we study
the early stopping of experiments for harm on heterogeneous populations. We
first establish that current methods often fail to stop experiments when the
treatment harms a minority group of participants. We then use causal machine
learning to develop CLASH, the first broadly-applicable method for
heterogeneous early stopping. We demonstrate CLASH's performance on simulated
and real data and show that it yields effective early stopping for both
clinical trials and A/B tests.Comment: NeurIPS 2023 (spotlight
Recommended from our members
On the design of an interactive, patient-specific surgical simulator for mitral valve repair
Surgical repair of the mitral valve is a difficult procedure that is often avoided in favor of less effective valve replacement because of the associated technical challenges facing non-expert surgeons. In the interest of increasing the rate of valve repair, an accurate, interactive surgical simulator for mitral valve repair was developed. With a haptic interface, users can interact with a mechanical model during simulation to aid in the development of a surgical plan and then virtually implement the procedure to assess its efficacy. Sub-millimeter accuracy was achieved in a validation study, and the system was successfully used by a cardiac surgeon to repair three virtual pathological valves.Engineering and Applied Science
Fully-Automated Analysis of Body Composition from CT in Cancer Patients Using Convolutional Neural Networks
The amounts of muscle and fat in a person's body, known as body composition,
are correlated with cancer risks, cancer survival, and cardiovascular risk. The
current gold standard for measuring body composition requires time-consuming
manual segmentation of CT images by an expert reader. In this work, we describe
a two-step process to fully automate the analysis of CT body composition using
a DenseNet to select the CT slice and U-Net to perform segmentation. We train
and test our methods on independent cohorts. Our results show Dice scores
(0.95-0.98) and correlation coefficients (R=0.99) that are favorable compared
to human readers. These results suggest that fully automated body composition
analysis is feasible, which could enable both clinical use and large-scale
population studies
Recommended from our members
Patient-Specific Mitral Leaflet Segmentation from 4D Ultrasound
Segmenting the mitral valve during closure and throughout a cardiac cycle from four dimensional ultrasound (4DUS) is important for creation and validation of mechanical models and for improved visualization and understanding of mitral valve behavior. Current methods of segmenting the valve from 4DUS either require extensive user interaction and initialization, do not maintain the valve geometry across a cardiac cycle, or are incapable of producing a detailed coaptation line and surface. We present a method of segmenting the mitral valve annulus and leaflets from 4DUS such that a detailed, patient-specific annulus and leaflets are tracked throughout mitral valve closure, resulting in a detailed coaptation region. The method requires only the selection of two frames from a sequence indicating the start and end of valve closure and a single point near a closed valve. The annulus and leaflets are first found through direct segmentation in the appropriate frames and then by tracking the known geometry to the remaining frames. We compared the automatically segmented meshes to expert manual tracings for both a normal and diseased mitral valve, and found an average difference of 0.59 ± 0.49mm, which is on the order of the spatial resolution of the ultrasound volumes (0.5–1.0mm/voxel).Engineering and Applied Science