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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A mixed reality framework for surgical navigation: approach and preliminary results

Murlidaran, Shravan 23 April 2019 (has links)
The overarching purpose of this research is to understand whether Mixed Reality can enhance a surgeon’s manipulations skills during minimally invasive procedures. Minimally-invasive surgery (MIS) utilizes small cuts in the skin - or sometimes natural orifices - to deploy instruments inside a patient’s body, while a live video feed of the surgical site is provided by an endoscopic camera and displayed on a screen. MIS is associated with many benefits: small scars, less pain and shorter hospitalization time as compared to traditional open surgery. However, these benefits come at a cost: because surgeons have to work by looking at a monitor, and not down on their own hands, MIS disrupts their eye-hand coordination and makes even simple surgical maneuvers challenging to perform. In this study, we wish to use Mixed Reality technology to superimpose anatomical models over the surgical site and explore if it can be used to mitigate this problem.
2

Pediatric Minimally Invasive Surgerytric: A Bibliometric Study on 30 Years of Research Activity

Shu, Boshen, Fen, Xiaoyan, Martynov, , Illya, Lacher, Martin, Mayer, Steffi 27 February 2024 (has links)
Background: Pediatric minimally invasive surgery (MIS) is a standard technique worldwide. We aimed to analyze the research activity in this field. Methods: Articles on pediatric MIS (1991–2020) were analyzed from the Web of Science ™ for the total number of publications, citations, journals, and impact factors (IF). Of these, the 50 most cited publications were evaluated in detail and classified according to the level of evidence (i.e., study design) and topic (i.e., surgical procedure). Results: In total, 4464 publications and 53,111 citations from 684 journals on pediatric MIS were identified. The 50 most cited papers were published from 32 institutions in the USA/Canada (n = 28), Europe (n = 19 ), and Asia (n = 3) in 12 journals. Four authors (USA/Europe) contributed to 26% of the 50 most cited papers as first/senior author. Hot topics were laparoscopic pyeloplasty (n = 9), inguinal hernia repair (n = 7), appendectomy, and pyloromyotomy (n = 4 each). The majority of publications were retrospective studies (n = 33) and case reports (n = 6) (IF 5.2 ± 3.2; impact index 16.5 ± 6.4; citations 125 ± 39.4). They were cited as often as articles with high evidence levels (meta-analyses, n = 2; randomized controlled trials, n = 7; prospective studies, n = 2) (IF 12.9 ± 22.5; impact index 14.0 ± 6.5; citations 125 ± 34.7; p > 0.05). Conclusions: Publications on laparoscopic pyeloplasty, inguinal hernia repair, appendectomy, and pyloromyotomy are cited most often in pediatric MIS. However, the relevant number of studies with strong evidence for the advantages of MIS in pediatric surgery is missing
3

DETERMINATION OF EFFECTIVE TRAINING METHODS TO LEARN A LAPAROSCOPIC CAMERA NAVIGATION TASK UNDER STRESSFUL ENVIRONMENTS

Vasudevan, Devnath 13 February 2012 (has links)
Stress in surgical environment is generally very high and can result in performance degradation increasing patient risk .Current Training systems for learning minimally invasive surgical skills do not consider the component of stress in their training model. In this study the focus was on developing alternative training models that would allow the learner to effectively perform minimally invasive skill under stress. Two alternate training methods: 1) Training under stress until high performance levels and 2) training until high performance and low cognitive load are achieved were considered for this study. The control group consisted of training under no stress and until high performance levels are achieved. Stressful environments for this study were simulated using physiologic stressors. The effectiveness of the training was evaluated by a comparative analysis of the different performance measures across the groups. We determined that training until automation as the most effective method to perform effectively under stress.
4

An Augmented Virtuality Navigation System for Arthroscopic Knee Surgery

Li, John 30 November 2010 (has links)
Arthroscopic knee surgery can be challenging because there is no intuitive relationship between the arthroscopic image, shown on a screen above the patient, and the camera in the surgeon's hand. As a result, arthroscopic surgeons require extensive training and experience. This thesis describes a computer system to help improve target acquisition in arthroscopy by visualizing the location and alignment of an arthroscope using augmented virtuality. A 3D computer model of the patient's joint (from CT) is shown, along with a model of the tracked arthroscopic probe and the projection of the camera image onto the virtual joint. We performed a user study to determine the effectiveness of this navigated display; the study showed that for novice residents, the navigated display improved target acquisition. However, residents with at least two years of experience performed worse. For surgeons, no effect on performance was found. / Thesis (Master, Computing) -- Queen's University, 2010-11-25 23:29:46.526
5

Semi-Robotic Knee Arthroscopy System with Braking Mechanism

Hua, Thai 01 January 2023 (has links) (PDF)
To alleviate the poor ergonomics which surgeons suffer during knee arthroscopy, a semi-robotic device with braking mechanism is created for intraoperative assistance. A slitted ball joint assembly is developed to transmit the clamping force to the arthroscope inside. Ball deformation and stress at various angles to the vertical and clamping forces is recorded through Abaqus Finite Element Analysis (FEA). Contact forces between the scope and inner surfaces of the ball is also computed in FEA at different clamping forces. The von Mises stress occurring in the ball joint is under the yield stress limit for polyethylene, and there is noticeable force preventing the scope from sliding along the ball through-hole under clamping. A prototype of this device is constructed for proof-of-concept.
6

Local infiltration analgesia in knee arthroplasty

Essving, Per January 2012 (has links)
Local infiltration analgesia (LIA) is a new technique for postoperative pain management following knee arthroplasty. LIA involves a long-acting local anesthetic (ropivacaine), a non-steroid anti-inflammatory drug (ketorolac) and epinephrine infiltrated into the knee joint during surgery and injected postoperatively via a catheter. In the first two studies, LIA was compared with placebo in unicompartmental (I) and total (II) knee arthroplasty. Postoperative pain levels, morphine consumption and the incidence of side effects were lower in the LIA groups. In addition, we found a shorter length of hospital stay in the LIA group following unicompartmental knee arthroplasty compared with placebo (I), while the time to home readiness was shorter in the LIA group following total knee arthroplasty (II). In this study, we found that the unbound venous blood concentration of ropivacaine was below systemic toxic blood concentrations in a sub-group of patients. In the third study, LIA was compared with intrathecal morphine for postoperative pain relief following total knee arthroplasty (III). Pain scores and morphine consumption were lower, length of hospital stay was shorter and patient satisfaction was higher in the LIA group. In the final study, we investigated the effect of minimally invasive surgery (MIS) compared with conventional surgery in unicompartmental knee arthroplasty (IV). Both groups received LIA. We found no statistically significant differences in postoperative pain, morphine consumption, knee function, home readiness, hospital stay or patient satisfaction. In conclusion, LIA provided better postoperative pain relief and earlier mobilization than placebo, both in unicompartmental and total knee arthroplasty. When compared to intrathecal morphine, LIA also resulted in improved postoperative pain relief and earlier mobilization. Minimally invasive surgery did not improve outcomes after unicompartmental knee arthroplasty, when both groups received LIA.
7

AUTOMATIC PERFORMANCE LEVEL ASSESSMENT IN MINIMALLY INVASIVE SURGERY USING COORDINATED SENSORS AND COMPOSITE METRICS

Taha Abu Snaineh, Sami 01 January 2013 (has links)
Skills assessment in Minimally Invasive Surgery (MIS) has been a challenge for training centers for a long time. The emerging maturity of camera-based systems has the potential to transform problems into solutions in many different areas, including MIS. The current evaluation techniques for assessing the performance of surgeons and trainees are direct observation, global assessments, and checklists. These techniques are mostly subjective and can, therefore, involve a margin of bias. The current automated approaches are all implemented using mechanical or electromagnetic sensors, which suffer limitations and influence the surgeon’s motion. Thus, evaluating the skills of the MIS surgeons and trainees objectively has become an increasing concern. In this work, we integrate and coordinate multiple camera sensors to assess the performance of MIS trainees and surgeons. This study aims at developing an objective data-driven assessment that takes advantage of multiple coordinated sensors. The technical framework for the study is a synchronized network of sensors that captures large sets of measures from the training environment. The measures are then, processed to produce a reliable set of individual and composed metrics, coordinated in time, that suggest patterns of skill development. The sensors are non-invasive, real-time, and coordinated over many cues such as, eye movement, external shots of body and instruments, and internal shots of the operative field. The platform is validated by a case study of 17 subjects and 70 sessions. The results show that the platform output is highly accurate and reliable in detecting patterns of skills development and predicting the skill level of the trainees.
8

Augmented Reality for Spatial Perception in the Computer Assisted Surgical Trainer

Wagner, Adam, Wagner, Adam January 2017 (has links)
Traditional laparoscopic surgery continues to require significant training on the part of the surgeon before entering the operating room. Augmented Reality (AR) has been investigated for use in visual guidance in training and during surgery, but little work is available investigating the effectiveness of AR techniques in providing the user better awareness of depth and space. In this work we propose several 2D AR overlays for visual guidance in training for laparoscopic surgery, with the goal of aiding the user's perception of depth and space in that limiting environment. A pilot study of 30 subjects (22 male and 8 female) was performed with results showing the effect of the various overlays on subject performance of a path following task in the Computer Assisted Surgical Trainer (CAST-III) system developed in the Model Based Design Lab. Deviation, economy of movement, and completion time are considered as metrics. Providing a reference indicator for the nearest point on the optimal path is found to result in significant reduction (p < 0.05) in subject deviation from the path. The data also indicates a reduction in subject deviation along the depth axis and total path length with overlays designed to provide depth information. Avenues for further investigation are presented.
9

Minimally invasive approach for percutaneous CentriMag right ventricular assist device support using a single PROTEKDuo Cannula

Kazui, Toshinobu, Tran, Phat L., Echeverria, Angela, Jerman, Catherine F., Iwanski, Jessika, Kim, Samuel S., Smith, Richard G., Khalpey, Zain I. 04 August 2016 (has links)
Background: Right ventricular failure is a serious complication after left ventricular assist device placement. Case Presentation: A 70-year-old male in decompensated heart failure with right ventricular failure after the placement of a left ventricular assist device. A single dual-lumen PROTEKDuo cannula was inserted percutaneously via the internal jugular vein to draw blood from the right atrium and return into the pulmonary artery using the CentriMag system, by passing the failing ventricle. The patient was successfully weaned from right ventricular assist device. Conclusions: In comparison to two-cannula conventional procedures, this right ventrivular assist device system improves patient rehabilitation and minimizes blood loss and risk of infection, while shortening procedure time and improving clinical outcomes in right ventricular failure.
10

Passive Resonant Coil Based Fast Registration And Tracking System For Real-Time Mri-Guided Minimally Invasive Surgery

Ma, Yunzhao 30 May 2013 (has links)
"This thesis presents a single-slice based fast stereotactic registration and tracking technique along with a corresponding modular system for guiding robotic mechanism or interventional instrument to perform needle-based interventions under live MRI guidance. The system can provide tracking of full 6 degree-of-freedom (DOF) in stereotactic interventional surgery based upon a single, rapidly acquired cross-sectional image. The whole system is constructed with a modular data transmission software framework and mechanical structure so that it supports remote supervision and manipulation between a 3D Matlab tracking user interface (UI) and an existing MRI robot controller by using the OpenIGTLink network communication protocol. It provides better closed-loop control by implementing a feedback output interface to the MRI-guided robot. A new compact fiducial frame design is presented, and the fiducial is wrapped with a passive resonant coil. The coil resonates at the Larmor frequency for 3T MRI to enhance signal strength and enable for rapid imaging. The fiducial can be attached near the distal end of the robot and coaxially with a needle so as to visualize target tissue and track the surgical tool synchronously. The MRI-compatible design of fiducial frame, robust tracking algorithm and modular interface allow this tracking system to be conveniently used on different robots or devices and in different size of MRI bores. Several iterations of the tracking fiducial and passive resonant coils were constructed and evaluated in a Phillips Achieva 3T MRI. To assess accuracy and robustness of the tracking algorithm, 25 groups of images with different poses were successively scanned along specific sequence in and MRI experiment. The translational RMS error along depth is 0.271mm with standard deviation of 0.277mm for totally 100 samples. The overall angular RMS error is less than 0.426 degree with standard deviation of 0.526 degree for totally 150 samples. The passive resonant coils were shown to significantly increase signal intensity in the fiducial relative to the surroundings and provide for rapid imaging with low flip angles. "

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