13 research outputs found

    Motion Planning for a Climbing Robot with Stochastic Grasps

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    Motion planning for a multi-limbed climbing robot must consider the robot's posture, joint torques, and how it uses contact forces to interact with its environment. This paper focuses on motion planning for a robot that uses nontraditional locomotion to explore unpredictable environments such as martian caves. Our robotic concept, ReachBot, uses extendable and retractable booms as limbs to achieve a large reachable workspace while climbing. Each extendable boom is capped by a microspine gripper designed for grasping rocky surfaces. ReachBot leverages its large workspace to navigate around obstacles, over crevasses, and through challenging terrain. Our planning approach must be versatile to accommodate variable terrain features and robust to mitigate risks from the stochastic nature of grasping with spines. In this paper, we introduce a graph traversal algorithm to select a discrete sequence of grasps based on available terrain features suitable for grasping. This discrete plan is complemented by a decoupled motion planner that considers the alternating phases of body movement and end-effector movement, using a combination of sampling-based planning and sequential convex programming to optimize individual phases. We use our motion planner to plan a trajectory across a simulated 2D cave environment with at least 95% probability of success and demonstrate improved robustness over a baseline trajectory. Finally, we verify our motion planning algorithm through experimentation on a 2D planar prototype.Comment: 7 pages, 7 figure

    Review Article Halitosis: Much beyond oral malodor

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    Oral malodor one of the most common complaints with which patients approaches us thinking it can be detrimental to his self-image and confidence. Even though majority of oral malodor is of oral origin, there are multiple other systemic causes that have to be addressed while we diagnose and treat this condition. Most of these patients look up to oral care physicians for expert advice, it is critical for us to have the knowledge base and communication techniques to provide quality clinical assessment and implement effective intervention programs. This article reviews the various causes and the diagnostic modalities which will help us treat this multifaceted condition. Key words: Halitosis, Oral malodor, Systemic diseases, Diagnosis The word halitosis is derived from the Latin word halitus, which means exhalation. Halitosis is a term used to refer to offensive or bad breath. Fetor ex ore, fetor oris and stomatodysodia (dysodia in Greek refers to stench) are other terms that have been used in literature to describe halitosis. Halitosis is a general term used to describe an offensive odor emanating fro

    Lightening dark dental radiograph

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    Abstract Radiograph should be of diagnostic quality for proper diagnosis. Dark radiographs are most commonly encountered faults in dental radiography which renders the radiograph useless. Such faulty radiograph requires a retake of the radiograph which causes unnecessary exposure to the patient and waste of precious time. Hence, a simple method is required which could salvage a dark radiograph. This article describes various methods used for lightening a dark radiograph along with a simple method like scraping the emulsion

    An implemntation mechanism for design patterns

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    Chronic bilateral dislocation of temporomandibular joint

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    Dislocation of the condyle of the mandible is a common condition that may occur in an acute or chronic form. It is characterised by inability to close the mouth with or without pain. Dislocation has to be differentiated from subluxation which is a self reducible condition. Dislocation can occur in any direction with anterior dislocation being the commonest one. Various predisposing factors have been associated with dislocation like muscle fatigue and spasm, the defect in the bony surface like shallow articular eminence, and laxity of the capsular ligament. People with defect in collagen synthesis like Ehler Danlos syndrome, Marfan syndrome are said to be genetically predisposed to this condition. Various treatment modalities have been used ranging from conservative techniques to surgical methods. Acute dislocations can be reduced manually or with conservative approach and recurrent and chronic cases can be reduced by surgical intervention. Though the dislocation in our case was 4 months a simple manual reduction proved to be successful. We believe that manual reduction can be attempted as first line of treatment prior to surgical intervention

    Detection of human papilloma virus in potentially malignant and malignant lesions of the oral cavity and a study of associated risk factors

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    Background: Squamous cell carcinoma of the head and neck is the 6 th most frequently occurring cancer worldwide, with over 400,000 cases projected annually. Multiple factors such as tobacco, alcohol, irradiation, virus, and chronic irritants are involved in the development of oral squamous cell carcinomas (OSCCs). The most important risk factors are chronic exposure to tobacco and alcohol. Although the evidence that implicates virus is increasing, particularly (human papillomavirus [HPV]), in the carcinogenesis process, the role of virus is not well established. Aim and Objective: This study is designed to assess the presence of HPV in potentially malignant and malignant lesions of the oral cavity as well as to correlate the presence of HPV with addictive habits and histopathological grading of the disease. Materials and Methods: Biopsy samples of OSCC and potentially malignant lesions were obtained and 3, 5 μm thickness sections were cut using a microtome. The sections were collected using a sterile brush and transferred to an Eppendorf tube. DNA extraction and polymerase chain reaction for the detection of HPV were done. Results and Conclusion: The association between histopathological grading and presence of HPV was assessed using Chi-square test and the values thus obtained were found to be statistically significant. HPV was more predominantly seen in well-differentiated carcinomas and moderately differentiated carcinomas as compared to poorly differentiated carcinomas

    Case Note Mucoepidermoid carcinoma: "A Mimicker"?

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    Abstract Neoplasms of the sublingual salivary glands are very rare and comprise only between 0.5% and 1% of all epithelial salivary tumors and approximately 1.5% of all carcinomas of the major salivary glands. Mucoepidermoid carcinomas were fi rst described by Masson and Berger in 1924. This paper reports a case of well differentiated mucoepidermoid carcinoma in the fl oor of the mouth which clinically and cytologically mimicked the tumour of perineural invasion,adenoid cystic carcinoma

    Genetic association of solute carrier transporter gene variants with metformin response

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    Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by elevated blood glucose levels and is influenced by both genetic and environmental factors. It is treated with various classes of oral antidiabetic drugs, however, response to treatment is highly variable with patients failing to achieve adequate glycemic control. Treatment response variability has been associated with single nucleotide polymorphisms (SNPs) which influence the pharma-cokinetics and pharmacodynamics of drug(s). The aim of this study was to evaluate the genetic association of 17 SNPs and the response to metformin therapy in patients diagnosed with diabetes from the indigenous Nguni population of South Africa. One hundred and forty indigenous African patients diagnosed with T2DM were recruited and genotyped using the MassARRAY® system. Therapeutic response of patients was ascertained by a change in Hb A1c. Two SNPs (rs1801282 and rs6265) were monomorphic. All other variants were within the Hardy-Weinberg equilibrium (HWE). The T allele of the SLC variant rs316009 [odds ratio (OR) = 0.25, 95% confidence interval (95% CI) = 0.01-0.09, p value = 0.044] and the CT genotype of the PCK1 variant rs4810083 (OR = 2.80, 95% CI = 1.01-7.79, p value = 0.049) were associated with an improved response to treatment after adjustment. No association was observed with post Bonferroni correction. Moreover, this study provides important additional data regarding possible associations between genetic variants and metformin therapy outcomes. In addition, this is one of the first studies providing genetic data from the understudied indigenous sub-Saharan African populations
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