Graphical User Interface for Evidential Reasoning Models

The Capri system is an evidential reasoning system based on the belief function calculus to support automated reasoning and decision making in uncertain environments. Example domains of application include, medical diagnosis, as well as identifying biological biomarkers. The purpose of this project is to build a Python web-based and app-based Graphical User Interface (GUI), called PyGrapher, that facilitates building graphical evidential reasoning models. The graphical models built using PyGrapher will then be converted to a form that is suitable for input to the Capri system. The PyGrapher system provides an intuitive means to build and manipulate evidential reasoning models as graphs that can be readily manipulated as the user desires. PyGrapher was built in a very user friendly manner and special care was taken to make sure that the interface highlights relevant errors to the user at the earliest occurrence

Graph Based System for Evidential Reasoning

In the modern data driven world, graph editing tools have become very essential as they provide means to understand, visualize and manipulate complex relationships between various datasets. They have especially played a crucial role in the space of evidential reasoning, where it has made a significant impact in the decision making process by developers, analysts and researchers to understand and represent the connection in the data. Existing tools fail to handle huge amounts of data efficiently and also don’t have the features required to handle tasks related to evidential reasoning.To address these gaps, we developed Pygrapher Web UI tool. We developed it using technologies such as Vis.js, React, JSX and CSS. This tool is designed to provide the users an easy and interactive interface which can help them create complex graphs by manipulating the nodes and edges of the graph. The tool provides both robustness as well as is much more efficient in handling large amounts of data. The Data Management Layer of the Pygrapher, is supported by a reliable File System, that ensures that the data is handled securely. Future developments of PyGrapher will focus on integration with external systems and incorporation of a query language. These enhancements will be based on the user feedback and evaluations of the tool.We will ensure that PyGrapher continues to evolve and meet the changing demands in the field of Evidential Reasoning

EVA: Laparoscopic instrument tracking based on endoscopic video analysis for psychomotor skills assessment

INTRODUCTION: The EVA (Endoscopic Video Analysis) tracking system a new tracking system for extracting motions of laparoscopic instruments based on non-obtrusive video tracking was developed. The feasibility of using EVA in laparoscopic settings has been tested in a box trainer setup. METHODS: EVA makes use of an algorithm that employs information of the laparoscopic instrument's shaft edges in the image, the instrument's insertion point, and the camera's optical centre to track the 3D position of the instrument tip. A validation study of EVA comprised a comparison of the measurements achieved with EVA and the TrEndo tracking system. To this end, 42 participants (16 novices, 22 residents, and 4 experts) were asked to perform a peg transfer task in a box trainer. Ten motion-based metrics were used to assess their performance. RESULTS: Construct validation of the EVA has been obtained for seven motion-based metrics. Concurrent validation revealed that there is a strong correlation between the results obtained by EVA and the TrEndo for metrics such as path length (p=0,97), average speed (p=0,94) or economy of volume (p=0,85), proving the viability of EVA. CONCLUSIONS: EVA has been successfully used in the training setup showing potential of endoscopic video analysis to assess laparoscopic psychomotor skills. The results encourage further implementation of video tracking in training setups and in image guided surgery

Sub-lunar Tap Yielding eXplorer (STYX) & Surface Telemetry Operations and Next-generation Excavation System (STONES)

The NASA RASC-AL Moon to Mars competition challenges student teams to develop a lightweight, durable, and hands-off method for extracting water from Martian/lunar subsurface ice layers while mapping soil density profiles. Future interplanetary expeditions are dependent on the availability of clean water and this project aims to accomplish this task. The challenge description enumerates several criteria to be met for successful designs. For further information, the STYX & STONES team conducted research on Cal Poly’s competition project from last year to consider the areas for redesign. As such, the team has utilized the background research from relevant patents and journal articles to consider brainstorming potentially viable solutions. Based on these solutions for each subsystem, the team converged the ideas using a series of decision matrices into a final design direction. In addition to reviewing the STYX design, several new considerations were made for the scope of this project. Primarily, this year’s team focused on developing a prototype that has the capability of operating in an extraterrestrial environment and thoroughly fulfilling the requirements posed by NASA. To visualize the requirements, the team created a list of customer needs, a House of Quality diagram, and an engineering specifications table. Additionally, the STYX & STONES team discussed the design process it plans to follow including major project milestones. Specifically, the team plans to excel in collecting more than five quarts of water autonomously while successfully identifying the overburden layers – tasks that previous teams have struggled with. The team’s design direction includes two main components: a masonry drill bit and an auger- heater probe hybrid tool. The masonry drill bit will create a hole in the overburden using the force from a rotary hammer. The heater probe tool will then be moved to align with the hole and be driven into the loosened overburden using the force of a small gear motor. The heater probe will then melt ice using a hot waterjet and deliver water via a peristaltic pump and a two-stage filtration system. To verify the design, the team completed a multitude of analyses and tests for each subsystem and the prototype as a whole. Through drilling tests, the team found that the rotary hammer and masonry bit can easily cut through all overburden layers while keeping weight on bit (WOB) below 150N. Similarly, the load cells attached to the drill carriage were tested and proven to be accurate at recording WOB data and providing feedback to the controller to monitor WOB. Furthermore, the load cells proved successful at recording accurate WOB data that can be analyzed to determine overburden composition. The pumping system was also tested and was capable of effectively moving water through all filters and delivering fluid to the waterjet. More tests were completed to verify the heater probe tool; these tests included controlling heater temperature, melting ice, expelling water through the waterjet, and removing loose material from the hole. To verify the design requirements, the team has completed analysis pertaining to each subsystem including the drill, heater probe, frame, and control systems. The team is confident in the drilling design based on testing and vibrations analysis. In the same manner, the team verified that the 12V peristaltic pump will have enough pressure head rise based on analysis and prototype testing. Using the prototype heater probe as a reference, the team fully characterized the heat transfer parameters of the final design and is confident the auger will be effective considering surrounding debris. Finally, the team tested the water jet design using 120oF water which provided optimistic results that the water jet will significantly expand the melt radius per hole. As a next step, the team will be testing the mechanical and controls systems simultaneously using manufactured parts. The following report details the subsystems and relevant information

OPTICAL-BASED TACTILE SENSORS FOR MINIMALLY INVASIVE SURGERIES: DESIGN, MODELING, FABRICATION AND VALIDATION

Loss of tactile perception is the most challenging limitation of state-of-the-art technology for minimally invasive surgery. In conventional open surgery, surgeons rely on their tactile sensation to perceive the tissue type, anatomical landmarks, and instrument-tissue interaction in the patient’s body. To compensate for the loss of tactile feedback in minimally invasive surgery, researchers have proposed various tactile sensors based on electrical and optical sensing principles. Optical-based sensors have shown the most compatibility with the functional and physical requirements of minimally invasive surgery applications. However, the proposed tactile sensors in the literature are typically bulky, expensive, cumbersome to integrate with surgical instruments and show nonlinearity in interaction with biological tissues. In this doctoral study, different optical tactile sensing principles were proposed, modeled, validated and various tactile sensors were fabricated, and experimentally studied to address the limitations of the state-of-the-art. The present thesis first provides a critical review of the proposed tactile sensors in the literature with a comparison of their advantages and limitations for surgical applications. Afterward, it compiles the results of the design, modeling, and validation of a hybrid optical-piezoresistive sensor, a distributed Bragg reflecting sensor, and two sensors based on the variable bending radius light intensity modulation principle. The performance of each sensor was verified experimentally for the required criteria of accuracy, resolution, range, repeatability, and hysteresis. Also, a novel image-based intensity estimation technique was proposed and its applicability for being used in surgical applications was verified experimentally. In the end, concluding remarks and recommendations for future studies are provided

Risk factors, repair techniques and short term subjective outcome of obstetrics anal sphincter injuries at Chris Hani Baragwanath academic hospital

Faculty of Health sciences School of medicine Submitted in the partial fulfilment of the requirements for the degree of: Master of Medicine in Obstetrics and Gynaecology at Wits University Johannesburg, 2016Background Obstetric anal sphincter injuries (OASIS) complicates vaginal deliveries in 1-4% of patients globally. Risk factors include: Primiparity, increased birth weight > 4000g, assisted deliveries and precipitous labour amongst others. Aims and objectives To evaluate risk factors, describe repair methods at Chris Hani Baragwanath Academic Hospital (CHBAH) and assess outcomes post repair. Methods This was a prospective cohort study where 60 patients over the age of 18 with 3rd and 4th degree tears were recruited. Exclusion criteria: 1st, 2nd degree tear. Data was collected from medical files after repair. Women were interviewed telephonically at 6 and 12 weeks postpartum. Results The incidence of OASIS at CHBAH was 0.5%. Seventy-three percent of the study population were primigravids. End to end repair technique was popular amongst the surgeons (41.6%). Leakage of gas was the most common complaint of the patients reached at the follow up interview. Conclusion The low incidence of OASIS at CHBAH is similar to other studies. Primiparity was the leading risk factor in this study. Most of the patients were asymptomatic at follow up. Of those that were symptomatic, symptoms improved with time.MT201

Mastering Endo-Laparoscopic and Thoracoscopic Surgery

This is an open access book. The book focuses mainly on the surgical technique, OR setup, equipments and devices necessary in minimally invasive surgery (MIS). It serves as a compendium of endolaparoscopic surgical procedures. It is an official publication of the Endoscopic and Laparoscopic Surgeons of Asia (ELSA). The book includes various sections covering basic skills set, devices, equipments, OR setup, procedures by area. Each chapter cover introduction, indications and contraindications, pre-operative patient’s assessment and preparation, OT setup (instrumentation required, patient’s position, etc.), step by step description of surgical procedures, management of complications, post-operative care. It includes original illustrations for better understanding and visualization of specific procedures. The book serves as a practical guide for surgical residents, surgical trainees, surgical fellows, junior surgeons, surgical consultants and anyone interested in MIS. It covers most of the basic and advanced laparoscopic and thoracoscopic surgery procedures meeting the curriculum and examination requirements of the residents

Mastering Endo-Laparoscopic and Thoracoscopic Surgery

This is an open access book. The book focuses mainly on the surgical technique, OR setup, equipments and devices necessary in minimally invasive surgery (MIS). It serves as a compendium of endolaparoscopic surgical procedures. It is an official publication of the Endoscopic and Laparoscopic Surgeons of Asia (ELSA). The book includes various sections covering basic skills set, devices, equipments, OR setup, procedures by area. Each chapter cover introduction, indications and contraindications, pre-operative patient’s assessment and preparation, OT setup (instrumentation required, patient’s position, etc.), step by step description of surgical procedures, management of complications, post-operative care. It includes original illustrations for better understanding and visualization of specific procedures. The book serves as a practical guide for surgical residents, surgical trainees, surgical fellows, junior surgeons, surgical consultants and anyone interested in MIS. It covers most of the basic and advanced laparoscopic and thoracoscopic surgery procedures meeting the curriculum and examination requirements of the residents