Head Pose Estimation and 3D Neural Surface Reconstruction via Monocular Camera in situ for Navigation and Safe Insertion into Natural Openings

As the significance of simulation in medical care and intervention continues to grow, it is anticipated that a simplified and low-cost platform can be set up to execute personalized diagnoses and treatments. 3D Slicer can not only perform medical image analysis and visualization but can also provide surgical navigation and surgical planning functions. In this paper, we have chosen 3D Slicer as our base platform and monocular cameras are used as sensors. Then, We used the neural radiance fields (NeRF) algorithm to complete the 3D model reconstruction of the human head. We compared the accuracy of the NeRF algorithm in generating 3D human head scenes and utilized the MarchingCube algorithm to generate corresponding 3D mesh models. The individual's head pose, obtained through single-camera vision, is transmitted in real-time to the scene created within 3D Slicer. The demonstrations presented in this paper include real-time synchronization of transformations between the human head model in the 3D Slicer scene and the detected head posture. Additionally, we tested a scene where a tool, marked with an ArUco Maker tracked by a single camera, synchronously points to the real-time transformation of the head posture. These demos indicate that our methodology can provide a feasible real-time simulation platform for nasopharyngeal swab collection or intubation.Comment: Accepted by ICBIR 202

PROTOPANAXADIOL SAPONINS IN THE CAUDEXES AND LEAVES OF PANAX NOTOGINSENG COULD BE THE MAIN CONSTITUENTS THAT CONTRIBUTE TO ITS ANTIDEPRESSANT EFFECTS

Objective: We previously found that total saponins, purified from the caudexes and leaves of Panax notoginseng (SCLPN), had antidepressant effects. In the present study, we investigated saponin monomers of SCLPN that may be the main constituents that contribute to the antidepressant effects of SCLPN. Methods: Three effective fractions of SCLPN, purified using a macroporous resin method, at doses of 50 and 100 mg/kg were tested in four different animal models of stress, including the learned helplessness test, tail suspension test, forced swim test, open field test, and reserpine-induced syndrome model. Using the same models of stress and the same doses, we then evaluated the antidepressant effects of four main and representative saponin monomers (ginsenosides Rd, Rb1 and Rg1 and notoginsenoside R1) in different effective fractions. We also examined the effects of Rd and Rb3 on monoamine neurotransmitter levels. To investigate the biotransformation of Rb1 and Rb3 orally administered in mice, Rb1 and Rb3 metabolites in blood and brain were determined by high-performance liquid chromatography. Results: Effective fraction A and C exerted greater antidepressant effects than fraction B in the behavioral tests and reserpine-induced syndrome model. Among the four saponin monomers, Rd had the strongest antidepressant effects, which improved depressive-like behavior in all four animal models of depression. We then found that Rb3 (50 and 100 mg/kg) and Rd (100 mg/kg) increased the levels of 5-hydroxytryptamine, dopamine, and norepinephrine, whereas 50 mg/kg Rd had no effect on the levels of these three neurotransmitters. Ginsenoside Rh2, C-K, and 20 (S)-protopanaxadiol saponins were detected in blood samples from mice that received Rb1 and Rb3, and protopanaxadiol saponins were found in the brain. Conclusion: The present results indicate that protopanaxadiol saponins in SCLPN have potential antidepressant-like effects

Evaluation of myocardial work in patients with hypertrophic cardiomyopathy and hypertensive left ventricular hypertrophy based on non-invasive pressure-strain loops

BackgroundThe capacity to distinguish hypertrophic cardiomyopathy (HCM) from hypertensive left ventricular hypertrophy (H-LVH) based on morphological features obtained by conventional echocardiography is limited. We investigated the global myocardial work of the left ventricle in two types of hypertrophies using the non-invasive myocardial work index (NMWI).MethodsConventional echocardiography was performed on 107 subjects with preserved left ventricular ejection fraction (LVEF ≥ 50%), who comprised patients with HCM (n = 40), H-LVH (n = 35), and healthy people with normal blood pressure and left ventricular structure (n = 32). Except for the conventional echocardiographic parameters, the left ventricular myocardial work parameters based on pressure-strain loops, including global myocardial work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE), were evaluated in three groups. Multivariate discriminant analysis and receiver operating characteristic (ROC) curve were used to evaluate the incremental value of NMWI for distinguishing HCM from H-LVH.ResultsCompared to the control group, GWI and GCW were significantly lower in HCM patients (P < 0.05), whereas GWI was significantly higher in H-LVH patients. GWW was higher and GWE was significantly decreased in both HCM and H-LVH patients than in the control group (P < 0.05). Multivariate discriminant analysis and ROC curve revealed that the inter-ventricular septum thickness (IVST)/left ventricular posterior wall thickness (LVPWT) and GCW were each able to distinguish HCM from H-LVH. The combination of IVST/LVPWT and GCW discriminated HCM and H-LVH with a higher predictive accuracy of 94.7%.ConclusionNMWI may provide additional information in evaluating the myocardial function in patients with HCM and H-LVH. Myocardial work combined with conventional echocardiography could improve the clinical diagnostic accuracy of distinguishing HCM and H-LVH

A Review on Tough Soft Composites at Different Length Scales

Soft composites are widely employed in industrial and biomedical fields, which often serve as load-bearing structural materials by virtue of a special combination of high strength, high toughness, and low flexural stiffness. Understanding the toughening mechanism of such composites is crucial for designing the next-generation soft materials. In this review, we give an overview of recent progress in soft composites, focusing on the design strategy, mechanical properties, toughening mechanisms, and relevant applications. Fundamental design strategies for soft composites that dissipate energy at different length scales are firstly described. By subsequently elucidating the synergistic effects of combining soft and hard phases, we show how a resulting composite can achieve unprecedented mechanical performance by optimizing the energy dissipation. Relevant toughening models are discussed to interpret the superior strength and fracture toughness of such soft composites. We also highlight relevant applications of these soft composites by taking advantage of their special mechanical responses

A Review on Tough Soft Composites at Different Length Scales

Soft composites are widely employed in industrial and biomedical fields, which often serve as load-bearing structural materials by virtue of a special combination of high strength, high toughness, and low flexural stiffness. Understanding the toughening mechanism of such composites is crucial for designing the next-generation soft materials. In this review, we give an overview of recent progress in soft composites, focusing on the design strategy, mechanical properties, toughening mechanisms, and relevant applications. Fundamental design strategies for soft composites that dissipate energy at different length scales are firstly described. By subsequently elucidating the synergistic effects of combining soft and hard phases, we show how a resulting composite can achieve unprecedented mechanical performance by optimizing the energy dissipation. Relevant toughening models are discussed to interpret the superior strength and fracture toughness of such soft composites. We also highlight relevant applications of these soft composites by taking advantage of their special mechanical responses.</jats:p