Augmented Reality to Improve Surgical Workflow in Minimally Invasive Transforaminal Lumbar Interbody Fusion – A Feasibility Study With Case Series

Objective Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is a highly reproducible procedure for the fusion of spinal segments. We recently introduced the concept of “total navigation” to improve workflow and eliminate fluoroscopy. Image-guided surgery incorporating augmented reality (AR) may further facilitate workflow. In this study, we developed and evaluated a protocol to integrate AR into the workflow of MIS-TLIF. Methods A case series of 10 patients was the basis for the evaluation of a protocol to facilitate tubular MIS-TLIF by the application of AR. Surgical TLIF landmarks were marked on a preoperative computed tomography (CT)-scan using dedicated software. This marked CT scan was fused intraoperatively with the low-dose navigation CT scan using elastic image fusion, and the markers were transferred to the intraoperative scan. Our experience with this workflow and the surgical outcomes were collected. Results Our AR protocol was safely implemented in all cases. The TLIF landmarks could be preoperatively planned and transferred to the intraoperative imaging. Of the 10 cases, 1 case had additionally a synovial cyst resection and in 2 cases an additional bony decompression was performed due to central stenosis. The average procedure time was 160.6±31.9 minutes. The AR implementation added 1.72±0.37 minutes to the overall procedure time. No complications occurred. Conclusion Our findings support the idea that total navigation with AR may further facilitate the workflow, especially in cases with more complex anatomy and for teaching and training purposes. More work is needed to simplify the software and make AR integration more user-friendly

The effects of forest degradation on arboreal primates within Sikundur, the Gunung Leuser Ecosystem, Northern Sumatra

Abstract of a paper given at the 87th Annual Meeting of the American Association of Physical Anthropologists held at Austin, Texas, 11-14 April 201

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum

High-flow nasal cannula therapy for hypoxemic respiratory failure in patients with COVID-19.

INTRODUCTION: High-flow nasal cannula (HFNC) therapy in patients with hypoxemic respiratory failure due to COVID-19 is poorly understood and remains controversial. METHODS: We evaluated a large cohort of patients with COVID-19-related hypoxemic respiratory failure at the temporary COVID-19 hospital in Mexico City. The primary outcome was the success rate of HFNC to prevent the progression to invasive mechanical ventilation (IMV). We also evaluated the risk factors associated with HFNC success or failure. RESULTS: HFNC use effectively prevented IMV in 71.4% of patients [270 of 378 patients; 95% confidence interval (CI) 66.6-75.8%]. Factors that were significantly different at admission included age, the presence of hypertension, and the Charlson comorbidity index. Predictors of therapy failure (adjusted hazard ratio, 95% CI) included the comorbidity-age-lymphocyte count-lactate dehydrogenase (CALL) score at admission (1.27, 1.09-1.47; p < 0.01), Rox index at 1 hour (0.82, 0.7-0.96; p = 0.02), and no prior steroid treatment (0.34, 95% CI 0.19-0.62; p < 0.0001). Patients with HFNC success rarely required admission to the intensive care unit and had shorter lengths of hospital stay [19/270 (7.0%) and 15.0 (interquartile range, 11-20) days, respectively] than those who required IMV [104/108 (96.3%) and 26.5 (20-36) days, respectively]. CONCLUSION: Treating patients with HFNC at admission led to improvement in respiratory parameters in many patients with COVID-19