Origami inspired design for capsule endoscope to retrograde using intestinal peristalsis

Capsule endoscopy has gained a lot of attention in the medical field in the recent past as an effective way of investigating unusual symptoms experienced in places such as esophagus, stomach, small intestine and colon. However, motion control of the capsule endoscope is challenging and often requires a power source and miniature actuators. To address these issues, we present a novel origami inspired structure as an attachment to the capsule endoscope. The proposed origami structure utilizes the wave generated by peristalsis of the intestine to move it forward and backward. When the origami structure is folded, the capsule endoscope is propelled forward by intestinal peristalsis. When the origami structure is unfolded, the intestinal peristalsis squeezes the origami structure to drive the capsule endoscope to move in the opposite direction. Therefore, folding and unfolding of the proposed origami structure would allow to control the movement direction of the capsule endoscope. In this paper, we present the design, simulations and experimental validation of the proposed origami structure

Local Universe as a benchmark to stellar populations in the epoch of reionisation

Large scale structure and cosmolog

Investigation of the agricultural resources in Sri Lanka

The author has identified the following significant results. Several in-house capabilities were developed. The facilities to prepare color composites of excellent quality were developed, using bulk B/W 70 mm transparencies or 1:1,000,000 positive transparencies. These color composites were studied through optical devices on light tables. A zoom transfer scope was also added, enabling direct transfer of LANDSAT composite data on to base maps

Identification of Haptic Based Guiding Using Hard Reins

This paper presents identifications of human-human interaction in which one person with limited auditory and visual perception of the environment (a follower) is guided by an agent with full perceptual capabilities (a guider) via a hard rein along a given path. We investigate several identifications of the interaction between the guider and the follower such as computational models that map states of the follower to actions of the guider and the computational basis of the guider to modulate the force on the rein in response to the trust level of the follower. Based on experimental identification systems on human demonstrations show that the guider and the follower experience learning for an optimal stable state-dependent novel 3rd and 2nd order auto-regressive predictive and reactive control policies respectively. By modeling the follower's dynamics using a time varying virtual damped inertial system, we found that the coefficient of virtual damping is most appropriate to explain the trust level of the follower at any given time. Moreover, we present the stability of the extracted guiding policy when it was implemented on a planar 1-DoF robotic arm. Our findings provide a theoretical basis to design advanced human-robot interaction algorithms applicable to a variety of situations where a human requires the assistance of a robot to perceive the environment

Significance of the compliance of the joints on the dynamic slip resistance of a bioinspired hoof

Robust mechanisms for slip resistance are an open challenge in legged locomotion. Animals such as goats show impressive ability to resist slippage on cliffs. It is not fully known what attributes in their body determine this ability. Studying the slip resistance dynamics of the goat may offer insight toward the biologically inspired design of robotic hooves. This article tests how the embodiment of the hoof contributes to solving the problem of slip resistance. We ran numerical simulations and experiments using a passive robotic goat hoof for different compliance levels of its three joints. We established that compliant yaw and pitch and stiff roll can increase the energy required to slide the hoof by ≈ 20% compared to the baseline (stiff hoof). Compliant roll and pitch allow the robotic hoof to adapt to the irregularities of the terrain. This produces an antilock braking system-like behavior of the robotic hoof for slip resistance. Therefore, the pastern and coffin joints have a substantial effect on the slip resistance of the robotic hoof, while the fetlock joint has the lowest contribution. These shed insights into how robotic hooves can be used to autonomously improve slip resistance

A State-Dependent Damping Method to Reduce Collision Force and Its Variability

This paper investigates the effect of biologically inspired angle-dependent damping profile in a robotic joint primarily on the magnitude and the variability of the peak collision force. Joints such as the knee that experience collision forces are known to have an angle-dependent damping profile. In this paper, we have quantified and compared three damping profiles. Our numerical and experimental results show that the proposed hyperbolic angle-dependent damping profile can minimize both the magnitude and the variability of the peak collision force(average magnitude and variability reduction of 26% and 47% compared to the peak constant damping profile). Very often, the variability of the force across the collision between the robot and the environment cause uncertainty about the state variables of the robotic joint. We show that by increasing the slope of the proposed hyperbolic angle-dependent damping profile, we can also reduce the variability and the magnitude of post-collision peak displacement and peak velocity compared to those of constant damping profile. This was achieved while reducing the mean root square of power consumed by the robotic joint

Newly Discovered Bright z~9-10 Galaxies and Improved Constraints on Their Prevalence Using the Full CANDELS Area

We report the results of an expanded search for z~9-10 candidates over the ~883 arcmin^2 CANDELS+ERS fields. This study adds 147 arcmin^2 to the search area we consider over the CANDELS COSMOS, UDS, and EGS fields, while expanding our selection to include sources with bluer J_{125}-H_{160} colors than our previous J_{125}-H_{160}>0.5 mag selection. In searching for new z~9-10 candidates, we make full use of all available HST, Spitzer/IRAC, and ground-based imaging data. As a result of our expanded search and use of broader color criteria, 3 new candidate z~9-10 galaxies are identified. We also find again the z=8.683 source previously confirmed by Zitrin+2015. This brings our sample of probable z~9-11 galaxy candidates over the CANDELS+ERS fields to 19 sources in total, equivalent to 1 candidate per 47 arcmin^2 (1 per 10 WFC3/IR fields). To be comprehensive, we also discuss 28 mostly lower likelihood z~9-10 candidates, including some sources that seem to be reliably at z>8 using the HST+IRAC data alone, but which the ground-based data show are much more likely at z<4. One case example is a bright z~9.4 candidate COS910-8 which seems instead to be at z~2. Based on this expanded sample, we obtain a more robust LF at z~9 and improved constraints on the volume density of bright z~9 and z~10 galaxies. Our improved z~9-10 results again reinforce previous findings for strong evolution in the UV LF at z>8, with a factor of ~10 evolution seen in the luminosity density from z~10 to z~8.Comment: 22 pages, 12 figures, 6 tables, accepted for publication in the Astrophysical Journa

Granular jamming based controllable organ design for abdominal palpation

Medical manikins play an essential role in the training process of physicians. Currently, most available simulators for abdominal palpation training do not contain controllable organs for dynamic simulations. In this paper, we present a soft robotics controllable liver that can simulate various liver diseases and symptoms for effective and realistic palpation training. The tumors in the liver model are designed based on granular jamming with positive pressure, which converts the fluid-like impalpable particles to a solid-like tumor state by applying low positive pressure on the membrane. Through inflation, the tumor size, liver stiffness, and liver size can be controlled from normal liver state to various abnormalities including enlarged liver, cirrhotic liver, and multiple cancerous and malignant tumors. Mechanical tests have been conducted in the study to evaluate the liver design and the role of positive pressure granular jamming in tumor simulations

Palpation force modulation strategies to identify hard regions in soft tissue organs

This work was supported by EPSRC MOTION grant (grant number EP/N03211X/1), National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy’s and St Thomas’ NHS Foundation Trust and King’s College London and Vattikuti Foundation

Probing the ISM of Heiiλ1640 emitters at z = 2-4 via MUSE

Large scale structure and cosmolog