Soft Tissue Deformation Model Based on Marquardt Algorithm and Enrichment Function

In order to solve the problem of high computing cost and low simulation accuracy caused by discontinuity of incision in traditional meshless model,this paper proposes a soft tissue deformation model based on the Marquardt algorithm and enrichment function.The model is based on the element-free Galerkin method,in which Kelvin viscoelastic model and adjustment function are integrated.Marquardt algorithm is applied to fit the relation between force and displacement caused by surface deformation,and the enrichment function is applied to deal with the discontinuity in the meshless method.To verify the validity of the model,the Sensable Phantom Omni force tactile interactive device is used to simulate the deformations of stomach and heart.Experimental results show that the proposed model improves the real-time performance and accuracy of soft tissue deformation simulation,which provides a new perspective for the application of the meshless method in virtual surgery.

A Soft Tissue Acupuncture Model Based on Mass-Spring Force Ne

In the simulation of acupuncture manipulation,it is necessary to accurately capture the information of acupuncture points and particles around them.Therefore,a soft tissue modeling method that can accurately track model particles is needed.In this paper,a soft tissue acupuncture model based on the mass-spring force net is designed.MSM is used as the auxiliary model and the SHF model is combined.SHF is used to establish a three-layer soft tissue model of skin,fat,and muscle,and a layer of the MSM based force network is covered on the surface of soft tissue to realize the complementary advantages and disadvantages of spherical harmonic function and MSM.In addition,a springback algorithm is designed to simulate the springback phenomenon of soft tissue skin during acupuncture.The evaluation results show that the soft tissue acupuncture modeling method based on mass-spring force net can effectively simulate the springback phenomenon of soft tissue surface during acupuncture surgery,and has good comprehensive performance in the application of virtual acupuncture surgery simulation.

A Three-Stage Cutting Simulation System Based on Mass-Spring Model

The cutting simulation of soft tissue is important in virtual surgery.It includes three major challenges in computation:Soft tissue simulation,collision detection,and handling,as well as soft tissue models.In order to address the earlier challenges,we propose a virtual cutting system based on the mass-spring model.In this system,MSM is utilized to simulate the soft tissue model.Residual stress is introduced to the model for simulating the shrinking effect of soft tissue in cutting.Second,a cylinder-based collision detection method is used to supervise the collision between surgical tools and soft tissue.Third,we simulate the cutting operation with a three-stage cutting method with swept volume,B´ezier curve,and an algorithm named shortest distance nodes matching method.In order to verify the system performance,we carry out three validation experiments on the proposed system:Cutting accuracy experiment,collision detection validation,and practical cutting evaluation.Experiments indicate that our system can well perform the shrinking effect of soft tissue in cutting.The system has fast and accurate collision detection.Moreover,the system can reconstruct smooth incisions vividly.

Modified Advanced Life Support in Obstetrics course: Feasibility, trainee satisfaction, and sustainability potential

Objective:The main objective of this initiative was to present evaluation results from an inno-vative adaptation of the Advanced Life Support in Obstetrics(ALSO)training course.We modified the traditional ALSO curriculum in our institution by adding hands-on training in laceration repairs and simulation scenarios on acute maternity care.Methods:The modified ALSO provider course was designed to enhance cognitive and proce-dural skills of health care professionals in managing obstetric emergencies.Forty-nine participants attended this course and completed a posttraining survey.Descriptive statistics were used to de-scribe the participant-reported assessment scores for the ALSO course on three domains(subject knowledge,organization and clarity,and teaching effectiveness)for each of 12 course topics.Results:Evaluation of the results showed a high rate of trainee satisfaction as evidenced by the mean assessment scores across all topics ranging from 4.80 to 4.98(out of 5.00).All trainees said they would refer others to the course.Our modified ALSO course effectively addressed the important needs of primary care physicians involved in maternity care,especially in underserved communities where specialized obstetric care is not readily available.Both simulation scenarios and workshops using simulated human tissue provide a better foundation before formal training.Conclusion:Given the changing legal and regulatory climate,we expect that learning to treat complex obstetric situations on the job will become increasingly risky.With this in mind,both simulation scenarios and workshops using simulated human tissue will provide a better foundation before formal training.