Safe and Robust Map Updating for Long-Term Operations in Dynamic Environments.

Ensuring safe and continuous autonomous navigation in long-term mobile robot applications is still challenging. To ensure a reliable representation of the current environment without the need for periodic remapping, updating the map is recommended. However, in the case of incorrect robot pose estimation, updating the map can lead to errors that prevent the robot's localisation and jeopardise map accuracy. In this paper, we propose a safe Lidar-based occupancy grid map-updating algorithm for dynamic environments, taking into account uncertainties in the estimation of the robot's pose. The proposed approach allows for robust long-term operations, as it can recover the robot's pose, even when it gets lost, to continue the map update process, providing a coherent map. Moreover, the approach is also robust to temporary changes in the map due to the presence of dynamic obstacles such as humans and other robots. Results highlighting map quality, localisation performance, and pose recovery, both in simulation and experiments, are reported.

Prognostic significance of right ventricle to pulmonary artery coupling in patients with mitral regurgitation treated with the MitraClip system.

OBJECTIVES: To evaluate the prognostic impact of baseline tricuspid annular plane systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) ratio, as an expression of the right ventricle-pulmonary artery (RV-PA) coupling, in patients with mitral regurgitation (MR) treated with the MitraClip. BACKGROUND: Impaired RV to PA coupling is considered a marker of RV dysfunction. METHODS: From February 2016 to February 2020, a total of 165 patients were evaluated and stratified in two groups according to a prespecified value of TAPSE/PASP ratio ≤ 0.36. RESULTS: The median patients' age was 79 (men: 62.4%). Sixty-three patients (38.1%) presented TAPSE/PASP ≤ 0.36 and were then compared with patients with TAPSE/PASP > 0.36. Functional MR etiology was more frequent in TAPSE/PASP ≤ 0.36 (71.4%; p = 0.046). Acute technical success was achieved in 92.7% of the population, without any significant difference between the two groups of study and with sustained results at 30-day (device success: 85.5%; procedural success: 84.8%). On multivariate Cox regression analysis, after correction for body mass index, chronic kidney disease and left ventricle ejection fraction ≥30% but <50%, TAPSE/PASP ≤ 0.36 remained a sustained predictor of mortality and hospitalization for heart failure at one year after MitraClip (hazard ratio: 3.87; 95% confidence interval: 1.83-8.22; p ≤ 0.001). Kaplan-Meier all-cause mortality and heart failure hospitalization rates at one year were consequently higher in patients with TAPSE/PASP ≤ 0.36 (39.4% vs. 14.8%; log-rank p ≤ 0.001). CONCLUSION: Baseline TAPSE/PASP ratio seems independently associated with all-cause mortality and heart failure hospitalization after MitraClip both in functional and degenerative MR.

Acute changes in mitral valve geometry after percutaneous valve repair with MitraClip XTR by three-dimensional echocardiography.

BACKGROUND: Mitral valve (MV) repair with MitraClip system is a safe treatment option for high-risk patients with significant mitral regurgitation (MR). We aimed to characterize, by three-dimensional echocardiography (3D-E), changes occurring in MV after implantation of third generation MitraClip XTR device, with specific reference to the underlying MR mechanism (functional vs degenerative, FMR vs DMR). METHODS: We prospectively enrolled 59 patients, who underwent intra-procedural 3D-E before and after device deployment. Three-D datasets were analyzed off-line, using a dedicated semiautomatic software, to obtain parametric quantification of mitral anatomy. RESULTS: Post-procedural MR of mild or lesser degree was achieved in 40 patients (68%), with no differences between FMR and DMR (p 0.9). After MitraClip XTR implantation, the FMR group experienced an immediate annular resizing, with reduction of antero-posterior diameter (p 0.024) and sphericity index (p 0.017), next to a recovery of physiological saddle-shape, defined by lower non-planar angle (p ≤0.001) and higher annulus height to commissural width ratio (p ≤0.001). On the opposite, the DMR group revealed a significant decrease of maximum annular velocity (p 0.027), addressing a mechanic effect of the device deployment. Finally, baseline anterior mitral leaflet angle was found as an independent predictor of acute procedural result (OR 6.7, [CI 1.01-44.33], p 0.049). CONCLUSIONS: MitraClip XTR implantation acts in restoring the original mitral geometry, with distinctive effects according to MR mechanism. Three-D parametric quantification of MV sheds new light on changes occurring in the valvular apparatus, and helps identifying possible new predictors of acute procedural success.

Delayed Anaerobic Threshold in Heart Failure Patients With Atrial Fibrillation.

PURPOSE: To assess whether atrial fibrillation (AF) in heart failure (HF) affects oxygen uptake at anaerobic threshold ((Equation is included in full-text article.)O2 AT) and heart rate (HR) kinetics. METHODS: A total of 15 patients with HF and AF and 18 with HF and sinus rhythm (SR) performed a maximal incremental and 2 constant workload cycle ergometer cardiopulmonary exercise tests (below and above AT, at 25% and 75% of maximal workload, respectively). At constant workload tests, kinetics of (Equation is included in full-text article.)O2 and HR were assessed by calculating time constant (τ). RESULTS: HF patients with AF showed a similar peak (Equation is included in full-text article.)O2 to those with SR (16.7 ± 4.5 mL/kg/min vs 16.6 ± 3.9 mL/kg/min). However, (Equation is included in full-text article.)O2 AT (11.3 ± 2.9 mL/kg/min vs 9.3 ± 2.8 mL/kg/min; P < .05), peak HR (149 ± 18.8 bpm vs 116.4 ± 20.4 bpm; P < .001), HR AT (125.3 ± 19.1 bpm vs 90.3 ± 15.5 bpm; P < .001), and HR increase during exercise were greater in HF patients with AF. Finally, τHR and τ(Equation is included in full-text article.)O2 below and above AT were not significantly different. CONCLUSIONS: In HF patients with AF, despite a similar peak (Equation is included in full-text article.)O2 compared with patients with HF and SR, (Equation is included in full-text article.)O2 AT is higher because of a higher HR and a greater HR increase during exercise. One postulated mechanism would be a greater cardiac output increase at the beginning of exercise in HF patients with AF. The delayed AT generates uncertainty about the meaning of a (Equation is included in full-text article.)O2 value at AT in HF patients with AF, because a higher AT is usually associated with better performance and a better prognosis.