Fully Immersive Virtual Reality for Skull-base Surgery: Surgical Training and Beyond

Purpose: A virtual reality (VR) system, where surgeons can practice procedures on virtual anatomies, is a scalable and cost-effective alternative to cadaveric training. The fully digitized virtual surgeries can also be used to assess the surgeon's skills using measurements that are otherwise hard to collect in reality. Thus, we present the Fully Immersive Virtual Reality System (FIVRS) for skull-base surgery, which combines surgical simulation software with a high-fidelity hardware setup. Methods: FIVRS allows surgeons to follow normal clinical workflows inside the VR environment. FIVRS uses advanced rendering designs and drilling algorithms for realistic bone ablation. A head-mounted display with ergonomics similar to that of surgical microscopes is used to improve immersiveness. Extensive multi-modal data is recorded for post-analysis, including eye gaze, motion, force, and video of the surgery. A user-friendly interface is also designed to ease the learning curve of using FIVRS. Results: We present results from a user study involving surgeons with various levels of expertise. The preliminary data recorded by FIVRS differentiates between participants with different levels of expertise, promising future research on automatic skill assessment. Furthermore, informal feedback from the study participants about the system's intuitiveness and immersiveness was positive. Conclusion: We present FIVRS, a fully immersive VR system for skull-base surgery. FIVRS features a realistic software simulation coupled with modern hardware for improved realism. The system is completely open-source and provides feature-rich data in an industry-standard format.Comment: IPCAI/IJCARS 202

Improving Surgical Situational Awareness with Signed Distance Field: A Pilot Study in Virtual Reality

The introduction of image-guided surgical navigation (IGSN) has greatly benefited technically demanding surgical procedures by providing real-time support and guidance to the surgeon during surgery. \hi{To develop effective IGSN, a careful selection of the surgical information and the medium to present this information to the surgeon is needed. However, this is not a trivial task due to the broad array of available options.} To address this problem, we have developed an open-source library that facilitates the development of multimodal navigation systems in a wide range of surgical procedures relying on medical imaging data. To provide guidance, our system calculates the minimum distance between the surgical instrument and the anatomy and then presents this information to the user through different mechanisms. The real-time performance of our approach is achieved by calculating Signed Distance Fields at initialization from segmented anatomical volumes. Using this framework, we developed a multimodal surgical navigation system to help surgeons navigate anatomical variability in a skull base surgery simulation environment. Three different feedback modalities were explored: visual, auditory, and haptic. To evaluate the proposed system, a pilot user study was conducted in which four clinicians performed mastoidectomy procedures with and without guidance. Each condition was assessed using objective performance and subjective workload metrics. This pilot user study showed improvements in procedural safety without additional time or workload. These results demonstrate our pipeline's successful use case in the context of mastoidectomy.Comment: First two authors contributed equally. 6 page

Twin-S: A Digital Twin for Skull-base Surgery

Purpose: Digital twins are virtual interactive models of the real world, exhibiting identical behavior and properties. In surgical applications, computational analysis from digital twins can be used, for example, to enhance situational awareness. Methods: We present a digital twin framework for skull-base surgeries, named Twin-S, which can be integrated within various image-guided interventions seamlessly. Twin-S combines high-precision optical tracking and real-time simulation. We rely on rigorous calibration routines to ensure that the digital twin representation precisely mimics all real-world processes. Twin-S models and tracks the critical components of skull-base surgery, including the surgical tool, patient anatomy, and surgical camera. Significantly, Twin-S updates and reflects real-world drilling of the anatomical model in frame rate. Results: We extensively evaluate the accuracy of Twin-S, which achieves an average 1.39 mm error during the drilling process. We further illustrate how segmentation masks derived from the continuously updated digital twin can augment the surgical microscope view in a mixed reality setting, where bone requiring ablation is highlighted to provide surgeons additional situational awareness. Conclusion: We present Twin-S, a digital twin environment for skull-base surgery. Twin-S tracks and updates the virtual model in real-time given measurements from modern tracking technologies. Future research on complementing optical tracking with higher-precision vision-based approaches may further increase the accuracy of Twin-S

PVDF-Based Piezoelectric Microphone for Sound Detection Inside the Cochlea: Toward Totally Implantable Cochlear Implants

We report the fabrication and characterization of a prototype polyvinylidene fluoride polymer-based implantable microphone for detecting sound inside gerbil and human cochleae. With the current configuration and amplification, the signal-to-noise ratios were sufficiently high for normally occurring sound pressures and frequencies (ear canal pressures >50–60 dB SPL and 0.1–10 kHz), though 10 to 20 dB poorer than for some hearing aid microphones. These results demonstrate the feasibility of the prototype devices as implantable microphones for the development of totally implantable cochlear implants. For patients, this will improve sound reception by utilizing the outer ear and will improve the use of cochlear implants

Intensive medical student involvement in short-term surgical trips provides safe and effective patient care: a case review

<p>Abstract</p> <p>Background</p> <p>The hierarchical nature of medical education has been thought necessary for the safe care of patients. In this setting, medical students in particular have limited opportunities for experiential learning. We report on a student-faculty collaboration that has successfully operated an annual, short-term surgical intervention in Haiti for the last three years. Medical students were responsible for logistics and were overseen by faculty members for patient care. Substantial planning with local partners ensured that trip activities supplemented existing surgical services. A case review was performed hypothesizing that such trips could provide effective surgical care while also providing a suitable educational experience.</p> <p>Findings</p> <p>Over three week-long trips, 64 cases were performed without any reported complications, and no immediate perioperative morbidity or mortality. A plurality of cases were complex urological procedures that required surgical skills that were locally unavailable (43%). Surgical productivity was twice that of comparable peer institutions in the region. Student roles in patient care were greatly expanded in comparison to those at U.S. academic medical centers and appropriate supervision was maintained.</p> <p>Discussion</p> <p>This demonstration project suggests that a properly designed surgical trip model can effectively balance the surgical needs of the community with an opportunity to expose young trainees to a clinical and cross-cultural experience rarely provided at this early stage of medical education. Few formalized programs currently exist although the experience above suggests the rewarding potential for broad-based adoption.</p

Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas

Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN

Chicken thigh microvascular training model improves resident surgical skills

Objectives: Microsurgical techniques are essential for vessel anastomosis in free flap reconstructive surgery. However, teaching these skills intraoperatively is difficult. The chicken thigh microvascular model is a high‐fidelity model that has been previously validated to differentiate between skill levels of surgeons. This study aims to determine if this model objectively improves microsurgical skills. Study Design Validation study Methods: Thirteen residents were given a tutorial on microvascular anastomosis and asked to perform anastomoses on the microvascular model. Anastomoses were video‐recorded and the time required for trainees to complete the first stitch of their first anastomosis was compared to the time required for the first stitch of their last anastomosis. Comparison of first and last stitch times was completed using a paired student t‐test. All participants completed a survey regarding their experience with the simulator. Results: There was a statistically significant decrease between the time required for the first stitch (235 s, 95%CI 198–272 s) compared to last stitch (120 s, 95%CI 92–149 s), and an average 48.7% (115 s) decrease in time (p < 0.001). Junior (PGY 2/3) and senior (PGY 4/5) residents had similar decreases in time, 49.1% and 48.21%, respectively. One hundred percent of residents felt they improved during the session and 92% of residents agreed or strongly agreed that their final stitch was better than their last stitch. All residents agreed or strongly agreed that the simulation is realistic, effective in teaching the procedure, and would translate to improved intraoperative performance. Conclusions: The chicken thigh model demonstrates objective improvements in resident microvascular surgical skills. Level of Evidence N

Chicken thigh microvascular training model improves resident surgical skills

Objectives: Microsurgical techniques are essential for vessel anastomosis in free flap reconstructive surgery. However, teaching these skills intraoperatively is difficult. The chicken thigh microvascular model is a high‐fidelity model that has been previously validated to differentiate between skill levels of surgeons. This study aims to determine if this model objectively improves microsurgical skills. Study Design Validation study Methods: Thirteen residents were given a tutorial on microvascular anastomosis and asked to perform anastomoses on the microvascular model. Anastomoses were video‐recorded and the time required for trainees to complete the first stitch of their first anastomosis was compared to the time required for the first stitch of their last anastomosis. Comparison of first and last stitch times was completed using a paired student t‐test. All participants completed a survey regarding their experience with the simulator. Results: There was a statistically significant decrease between the time required for the first stitch (235 s, 95%CI 198–272 s) compared to last stitch (120 s, 95%CI 92–149 s), and an average 48.7% (115 s) decrease in time (p < 0.001). Junior (PGY 2/3) and senior (PGY 4/5) residents had similar decreases in time, 49.1% and 48.21%, respectively. One hundred percent of residents felt they improved during the session and 92% of residents agreed or strongly agreed that their final stitch was better than their last stitch. All residents agreed or strongly agreed that the simulation is realistic, effective in teaching the procedure, and would translate to improved intraoperative performance. Conclusions: The chicken thigh model demonstrates objective improvements in resident microvascular surgical skills. Level of Evidence N