Modeling and simulation methods for RF MEMS VCOs

This work focusses on the modeling and the development of efficient coupled simulation techniques for MEMS based RF oscillators. High-level models for MEMS based varactors have been discussed and their accuracy issues are identified, based on comparisons with numerical simulations. A faster simulation approach based on the time-domain shooting method is proposed for computation of the steady state in MEMS based oscillators. Analysis, simulation and modeling techniques to characterize the effect of mechanical noise on the phase noise performance of these VCOs is presented

The interactive medical simulation toolkit (iMSTK): an open source platform for surgical simulation

Introduction: Human error is one of the leading causes of medical error. It is estimated that human error leads to between 250,000 and 440,000 deaths each year. Medical simulation has been shown to improve the skills and confidence of clinicians and reduce medical errors. Surgical simulation is critical for training surgeons in complicated procedures and can be particularly effective in skill retention.Methods: The interactive Medical Simulation Toolkit (iMSTK) is an open source platform with position-based dynamics, continuous collision detection, smooth particle hydrodynamics, integrated haptics, and compatibility with Unity and Unreal, among others. iMSTK provides a wide range of real-time simulation capabilities with a flexible open-source license (Apache 2.0) that encourages adoption across the research and commercial simulation communities. iMSTK uses extended position-based dynamics and an established collision and constraint implementations to model biological tissues and their interactions with medical tools and other tissues.Results: The platform demonstrates performance, that is, compatible with real-time simulation that incorporates both visualization and haptics. iMSTK has been used in a variety of virtual simulations, including for laparoscopic hiatal hernia surgery, laparoscopic cholecystectomy, osteotomy procedures, and kidney biopsy procedures.Discussion: iMSTK currently supports building simulations for a wide range of surgical scenarios. Future work includes expanding Unity support to make it easier to use and improving the speed of the computation to allow for larger scenes and finer meshes for larger surgical procedures

Identifying Opportunities for Virtual Reality Simulation in Surgical Education: A Review of the Proceedings from the Innovation, Design, and Emerging Alliances in Surgery (IDEAS) Conference: VR Surgery

To conduct a review of the state of virtual reality (VR) simulation technology, to identify areas of surgical education that have the greatest potential to benefit from it, and to identify challenges to implementation

Comparison of performance of virtual coupling schemes for haptic collaboration using real and emulated internet connections

Abstract — Networked haptic virtual environments (NHVEs) are those in which multiple users collaborate and experience force feedback at the same time. The robustness of such systems needs to be tested under various network conditions that closely mirror the Internet. Previously, we had proposed three virtual coupling schemes to maintain position coherency in a NHVE, which were tested using constant and then time-varying delays using the actual Internet through UDP packet reflectors. In this paper we present the results of comparing performance of the virtual coupling schemes for a time varying delay emulated using the popular network emulator NIST Net, with delay conditions that existed during our real Internet experiment to Italy. UDP was used for haptic data communication because of the high transmission rate requirements for NHVEs. Experiments were conducted for three fixed packet transmission rates of 1000, 500 and 100 Hz, and their performance compared using an independent-samples t-test to the data obtained using the Internet. Locally, the haptic update rate was maintained at 1000 Hz during the experiments. Our results show that the NIST Net was a suitable emulator for testing with lower packet transmission rates. At the transmission rate of 1000 Hz the performance of the virtual coupling schemes were significantly different from that of the actual Internet experiment. I