Creating a low-cost virtual reality surgical simulation to increase surgical oncology capacity and capability

Worldwide, more than 80% of people with cancer will require surgery during their disease course, but less than 25% have access to safe, affordable and timely surgery. Among the barriers to increasing surgical capacity are the time and costs required to train novices. Virtual reality (VR) surgical simulations can reduce the time required for novices to reach surgical proficiency, though their costs may exceed USD $100,000. The goal of this study was to determine if a low-cost system, using commercially available technology designed for in-home computer gaming, could be used to create a realistic VR surgical oncology simulation. Standard commercially available VR software and Oculus Rift hardware have been used to provide high-quality visuals and believable surgeon hand interactions. Near identical VR reproduction of an operating room using 1:1 scale matching of real-world elements, including equipment, instruments, supplies and sounds, maintaining frame rate greater than 60 fps to maintain visual fidelity has been created. Internal anatomy was designed as VR replica of human female pelvic anatomy, including organs, veins and other vessels, peritoneum and connective tissue. Internal anatomy was designed to run at 120 fps and to allow for a realistic abdominal radical hysterectomy simulation. Surgical hands were modelled to scale for those with large and small hands. Multiple hand positions were simulated using Oculus touch hardware. Reconstructing the virtual environment to simulate reality as accurately as possible was done to immerse users in the simulator so that they focus on learning and practise without distractions. Training modules were co-designed by experts in learning sciences, human behaviour, VR and gynaecologic oncology. We have successfully created a low-cost VR simulation to help prepare novice surgeons to perform a radical abdominal hysterectomy surgery procedure. The simulation can be used with commercially available computer gaming hardware that currently costs less than USD$1,500. Low-cost VR simulation has the potential to reduce the time and cost to train surgeons to perform surgical oncology procedures, as well as both improve and audit quality. If effective in real-world clinical trials, such simulations have relevance to multiple surgical procedures and applicability in both resource-limited and high-income settings

Photon-Phonon-assisted tunneling through a single-molecular quantum dot

Based on exactly mapping of a many-body electron-phonon interaction problem onto a one-body problem, we apply the well-established nonequilibrium Green function technique to solve the time-dependent phonon-assisted tunneling at low temperature through a single-molecular quantum dot connected to two leads, which is subject to a microwave irradiation field. It is found that in the presence of the electron-phonon interaction and the microwave irradiation field, the time-average transmission and the nonlinear differential conductance display additional peaks due to pure photon absorption or emission processes and photon-absorption-assisted phonon emission processes. The variation of the time-average current with frequency of the microwave irradiation field is also studied.Comment: 9 pages, 6 figures, submitted to Phys. Rev. B. accepted by Phys. Rev.

The Influence of Psychological Variables on Health-Related Quality of Life among HIV-Positive Individuals with a History of Intravenous Drug Use

OBJECTIVE: Intravenous drug use (IDU) remains a prominent pathway of HIV transmission in the United States, though little is know about modifiable factors influencing quality of life among IDUs. The goal of this study was to evaluate the influence of psychological variables (e.g., depression and anxiety) on health related quality of life among HIV-positive individuals with a history of IDU who were enrolled in outpatient treatment for opioid dependence. METHOD: 108 HIV-positive individuals with a history of IDU and participating in current outpatient treatment for opiate dependence who were screened for participation in a depression and adherence study reported sociodemographic data, depressive and anxiety symptoms and health-related quality of life (HRQoL; Multidimensional Health Assessment using the ACTG-SF 21). RESULTS: Multiple regression models controlling for disease stage and background characteristics identified significant negative relationships between General Health Perception and Functioning without Pain for anxiety and depression, and between Role Functioning and Physical Functioning for anxiety. CD4 cell count was significantly related to Physical Functioning only. CONCLUSIONS: Results indicate that distress (both depression and anxiety) contribute significantly to variation in HRQoL over and above the effects of disease variables. Effective depression and anxiety treatment may result in improved overall functioning