A comparative analysis of different approaches to target differentiation and localization using infrared sensors

Cataloged from PDF version of article.This study compares the performances of various techniques for the differentiation and localization of commonly encountered features in indoor environments, such as planes, corners, edges, and cylinders, possibly with different surface properties, using simple infrared sensors. The intensity measurements obtained from such sensors are highly dependent on the location, geometry, and surface properties of the reflecting feature in a way that cannot be represented by a simple analytical relationship, therefore complicating the localization and differentiation process. The techniques considered include rule-based, template-based, and neural network-based target differentiation, parametric surface differentiation, and statistical pattern recognition techniques such as parametric density estimation, various linear and quadratic classifiers, mixture of normals, kernel estimator, k-nearest neighbor, artificial neural network, and support vector machine classi- fiers. The geometrical properties of the targets are more distinctive than their surface properties, and surface recognition is the limiting factor in differentiation. Mixture of normals classifier with three components correctly differentiates three types of geometries with different surface properties, resulting in the best performance (100%) in geometry differentiation. For a set of six surfaces, we get a correct differentiation rate of 100% in parametric differentiation based on reflection modeling. The results demonstrate that simple infrared sensors, when coupled with appropriate processing, can be used to extract substantially more information than such devices are commonly employed for. The demonstrated system would find application in intelligent autonomous systems such as mobile robots whose task involves surveying an unknown environment made of different geometry and surface types. Industrial applications where different materials/surfaces must be identified and separated may also benefit from this approach.Aytaç, TayfunPh.D

Kızılötesi algılayıcılar ile ayırtedme ve konumlandırma

Cataloged from PDF version of article.Thesis (M.S.): Bilkent University, Department of Electrical and Electronic Engineering, İhsan Doğramacı Bilkent University, 2002.Includes bibliographical references (leaves 52-57).In this thesis different approaches for the differentiation and localization of targets using low cost infrared sensors are presented. The intensity readings obtained with such sensors are highly dependent on the location and properties of targets in a way which cannot be represented in a simple manner, making the differentiation and localization process difficult. We propose the use of angular intensity scans and present different approaches to process them. Using these approaches, targets of different geometrical shapes but identical surface properties targets of difffferent surface properties but identical geometry, and targets having both different geometrical shapes and surface properties are differentiated and localized in a position-invariant manner. Maximum correct differentiation rates of 97% 87% and 65% are respectively achieved in these cases, indicating that the geometrical properties of targets are more distinctive than their surface properties in the differentiation process. The different approaches are verified experimentally with target types of commonly encountered geometries in indoor environments and with surfaces of different reflection properties. The results indicate that simple infrared sensors, when coupled with appropriate processing, can be used to extract a significantly greater amount of information than they are commonly employed for.by Tayfun Aytaç.M.S

Is Robotic Complete Mesocolic Excision Feasible for Transverse Colon Cancer?

Introduction: Laparoscopic complete mesocolic excision (CME) for transverse colon cancer is technically challenging. Robotic technology has been developed to reduce technical limitations of laparoscopy. Yet, no data are available on the role of robotic approach for CME of transverse colon cancer. The aim of this study is to evaluate the feasibility and short-term outcomes of robotic CME in this subset of colon cancer. Methods: A retrospective review of a prospectively maintained database of 29 consecutive patients undergoing robotic CME for transverse colon adenocarcinoma between December 2014 and December 2017 was performed. Data on demographics, tumor characteristics, postoperative 30-day complications, and oncologic outcomes were analyzed. Results: There were 21 (72%) men and 8 women with a mean age of 62.915.6 years and a body mass index of 26.4 +/- 4.8kg/m(2). Of the 29 robotic CME procedures, 12 patients underwent extended right colectomy, 10 extended left colectomy, 6 subtotal colectomy, and 1 total colectomy. The mean operative time was 321.7 +/- 111.3 minutes and estimated blood loss was 106.9 +/- 110.9mL (median, 50; range, 10-400mL). The intra- and postoperative complication rates were 7% and 24%, respectively. There were no conversions. The mean time to first bowel movement was 3.5 +/- 1.3 and length of hospital stay was 7.1 +/- 3.0 days. All the resections were R0. The mean number of harvested lymph nodes in extended and subtotal/total colectomy procedures was 36.6 +/- 13.1 and 71.0 +/- 30.3, respectively. The rate of mesocolic plane surgery was 79%. There were no statistically significant differences between the mesocolic and the intramesocolic/muscularis propria plane resections with respect to clinical characteristics, operative outcomes, and pathology results (P>.05). Conclusions: Robotic CME for transverse colon cancer is feasible and can be a procedure of choice to achieve a good surgical quality

Surgery for Intestinal Crohn's Disease: Results of a multidisciplinary approach

Objectives: Crohn's disease is a chronic inflammatory bowel disease that requires lifelong multidisciplinary management. Seventy percent of patients affected by Crohn's disease will require at least one surgical procedure over their lifetime. The aim of this retrospective study was to present our series of patients suffering from Crohn's disease who were scheduled for surgery by a multidisciplinary team

Totally laparoscopic and totally robotic surgery in patients with left‐sided colonic diverticulitis

Background Introduction of the da Vinci Xi system has facilitated the use of robotics in colorectal surgery. Nevertheless, data on the outcomes of robotic surgery for the treatment of colonic diverticulitis have remained scarce. Methods Patient demographics, clinical characteristics, and perioperative outcomes of the patients undergoing totally robotic with the da Vinci Xi system or laparoscopic surgery for left-sided colonic diverticulitis (LCD) were compared. Results Laparoscopic and robotic groups included 22 and 20 patients, respectively. There were no significant differences between the two groups in terms of patient demographics, clinical characteristics, operative time, and postoperative complications. There were three conversions in the laparoscopy group and no conversion in the robotic group (P = 0.23). Conversion to open surgery was associated with postoperative morbidity (P = 0.02). Conclusion Robotic surgery is an applicable alternative for the treatment of LCD. Robotic approach may potentially lower the risk of operative morbidity by reducing the requirement of conversion

Totally laparoscopic and totally robotic surgery in patients with left-sided colonic diverticulitis

Background Introduction of the da Vinci Xi system has facilitated the use of robotics in colorectal surgery. Nevertheless, data on the outcomes of robotic surgery for the treatment of colonic diverticulitis have remained scarce. Methods Patient demographics, clinical characteristics, and perioperative outcomes of the patients undergoing totally robotic with the da Vinci Xi system or laparoscopic surgery for left-sided colonic diverticulitis (LCD) were compared. Results Laparoscopic and robotic groups included 22 and 20 patients, respectively. There were no significant differences between the two groups in terms of patient demographics, clinical characteristics, operative time, and postoperative complications. There were three conversions in the laparoscopy group and no conversion in the robotic group (P = 0.23). Conversion to open surgery was associated with postoperative morbidity (P = 0.02). Conclusion Robotic surgery is an applicable alternative for the treatment of LCD. Robotic approach may potentially lower the risk of operative morbidity by reducing the requirement of conversion