73 research outputs found

    Learning to See Forces: Surgical Force Prediction with RGB-Point Cloud Temporal Convolutional Networks

    Full text link
    Robotic surgery has been proven to offer clear advantages during surgical procedures, however, one of the major limitations is obtaining haptic feedback. Since it is often challenging to devise a hardware solution with accurate force feedback, we propose the use of "visual cues" to infer forces from tissue deformation. Endoscopic video is a passive sensor that is freely available, in the sense that any minimally-invasive procedure already utilizes it. To this end, we employ deep learning to infer forces from video as an attractive low-cost and accurate alternative to typically complex and expensive hardware solutions. First, we demonstrate our approach in a phantom setting using the da Vinci Surgical System affixed with an OptoForce sensor. Second, we then validate our method on an ex vivo liver organ. Our method results in a mean absolute error of 0.814 N in the ex vivo study, suggesting that it may be a promising alternative to hardware based surgical force feedback in endoscopic procedures.Comment: MICCAI 2018 workshop, CARE(Computer Assisted and Robotic Endoscopy

    A development of assistant surgical robot system based on surgical-operation-by-wire and hands-on-throttle-and-stick

    Get PDF
    BACKGROUND: Robot-assisted laparoscopic surgery offers several advantages compared with open surgery and conventional minimally invasive surgery. However, one issue that needs to be resolved is a collision between the robot arm and the assistant instrument. This is mostly caused by miscommunication between the surgeon and the assistant. To resolve this limitation, an assistant surgical robot system that can be simultaneously manipulated via a wireless controller is proposed to allow the surgeon to control the assistant instrument. METHODS: The system comprises two novel master interfaces (NMIs), a surgical instrument with a gripper actuated by a micromotor, and 6-axis robot arm. Two NMIs are attached to master tool manipulators of da Vinci research kit (dVRK) to control the proposed system simultaneously with patient side manipulators of dVRK. The developments of the surgical instrument and NMI are based on surgical-operation-by-wire concept and hands-on-throttle-and-stick concept from the earlier research, respectively. Tests for checking the accuracy, latency, and power consumption of the NMI are performed. The gripping force, reaction time, and durability are assessed to validate the surgical instrument. The workspace is calculated for estimating the clinical applicability. A simple peg task using the fundamentals of laparoscopic surgery board and an in vitro test are executed with three novice volunteers. RESULTS: The NMI was operated for 185 min and reflected the surgeon’s decision successfully with a mean latency of 132 ms. The gripping force of the surgical instrument was comparable to that of conventional systems and was consistent even after 1000 times of gripping motion. The reaction time was 0.4 s. The workspace was calculated to be 8397.4 cm(3). Recruited volunteers were able to execute the simple peg task within the cut-off time and successfully performed the in vitro test without any collision. CONCLUSIONS: Various experiments were conducted and it is verified that the proposed assistant surgical robot system enables collision-free and simultaneous operation of the dVRK’s robot arm and the proposed assistant robot arm. The workspace is appropriate for the performance of various kinds of surgeries. Therefore, the proposed system is expected to provide higher safety and effectiveness for the current surgical robot system

    Understanding Gen-Z College Student Needs Regarding Social Media Apps through a Case Study on Bondit, a Social Media App for College Students

    No full text
    Gen-Z college students are the first generation of college students that did not experience a world without the internet (Chillakuri, 2020). They have access to social media platforms to connect with peers, and they have access to multiple websites that their college provides in terms of campus resources. Despite the wealth of resources that they enjoy, the college retention rate of Gen-Z students is lower compared to previous generations due to poor mental health (Selingo, 2018). Existing research attributes this phenomenon to a lack of sense of belonging (Thomas et al., 2020) that is induced by existing popular social media platforms, such as Instagram (Knight-McCord et al., 2016), and the absence of features specifically designed to promote that feeling amongst college peers. College is not merely a place for accumulating knowledge, but to meet and socialize with peers, and to inspire creations that could resolve some of humanity’s biggest challenges. How might we help Gen-Z college students better bond with college peers through social media so that they can have a more positive college experience? This study aims to learn the needs of Gen-Z college students and identify social media app features that could promote college bonding through using Bondit, a new social media app for college student bonding, as a case study. This research also contributes with functional requirements and design recommendations for social media platforms that aim to create better college bonding experiences for Gen-Z college students.S.M

    LiDAR Localization using reflective properties in harsh environment that interfere with LiDAR sensing

    No full text
    LiDAR localization is an essential technology for autonomous robots. By positioning, the robot can determine its location and drive toward a mission point. This paper presents a novel localization method to overcome the limitations of lidar sensor data in harsh environments that interfere with lidar sensing, such as an environment in which haze is scattered or surrounded by glass structures. Unlike the existing method that uses the geometrical features of lidar sensor data, in this paper, we propose a feature that is characteristically expressed even in the harsh environment above by utilizing the reflective feature of lidar, and localization method using this feature is also proposed.1

    Ultra-Thin ReS2 Nanosheets Grown on Carbon Black for Advanced Lithium-Ion Battery Anodes

    Get PDF
    ReS2 nanosheetsaregrownonthesurfaceofcarbonblack(CB)viaanefficienthydrothermal method. We confirmed the ultra-thin ReS2 nanosheets with≈1–4 layers on the surface of the CB (ReS2@CB) by using analytical techniques of field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM). The ReS2@CB nanocomposite showed high specific capacities of 760, 667, 600, 525, and 473 mAh/g at the current densities of 0.1 (0.23 C), 0.2 (0.46 C), 0.3 (0.7 C), 0.5 (1.15 C) and 1.0 A/g (2.3 C), respectively, in conjunction with its excellent cycling performance (432 mAh/g at 2.3 C; 91.4% capacity retention) after 100 cycles. Such LIB performance is greatly higher than pure CB and ReS2 powder samples. These results could be due to the following reasons: (1) the low-cost CB serves as a supporter enabling the formation of ≈1–4 layered nanosheets of ReS2, thus avoiding its agglomeration; (2) the CB enhances the electrical conductivity of the ReS2@CB nanocomposite; (3) the ultra-thin (1–4 layers) ReS2 nanosheets with imperfect structure can function as increasing the number of active sites for reaction of Li+ ions with electrolytes. The outstanding performance and unique structural characteristics of the ReS2@CB anodes make them promising candidates for the ever-increasing development of advanced LIBs. © 2019 by the authors. © 2019 by the authors

    In situ fabrication of a graphene-coated three-dimensional nickel oxide anode for high-capacity lithium-ion batteries

    No full text
    The high theoretical specific capacity of nickel oxide (NiO) makes it attractive as a high-efficiency electrode material for electrochemical energy storage. However, its application is limited due to its inferior electrochemical performance and complicated electrode fabrication process. Here, we developed an in situ fabrication of a graphene-coated, three-dimensional (3D) NiO-Ni structure by simple chemical vapor deposition (CVD). We synthesized NiO layers on Ni foam through a thermal oxidation process; subsequently, we grew graphene layers directly on the surface of NiO after a hydrogen-assisted reduction process. The uniform graphene coating renders high electrical conductivity, structural flexibility and high elastic modulus at atomic thickness. The graphene-coated 3D NiO-Ni structure delivered a high areal density of ∼23 mg cm-2. It also exhibits a high areal capacity of 1.2 mA h cm-2 at 0.1 mA cm-2 for its Li-ion battery performance. The high capacity is attributed to the high surface area of the 3D structure and the unique properties of the graphene layers on the NiO anode. Since the entire process is carried out in one CVD system, the fabrication of such a graphene-coated 3D NiO-Ni anode is simple and scalable for practical applications. © 2018 The Royal Society of Chemistry1

    Optical fiber-driven low-energy electron gun for time-resolved streak diffraction

    No full text
    The wave guiding feature of the optical fibre optical fibres is specifically exploited to construct a novel type of electron gun to realize single-shot low-energy electron diffraction experiments with the sub-picosecond resolution for studying irreversible samples

    Optical fiber-driven low-energy electron gun for time-resolved streak diffraction

    Get PDF
    The wave guiding feature of the optical fibre optical fibres is specifically exploited to construct a novel type of electron gun to realize single-shot low-energy electron diffraction experiments with the sub-picosecond resolution for studying irreversible samples

    Tomato and Watermelon Production with Mulches and Automatic Drip Irrigation in North Dakota

    No full text
    In North Dakota, agriculture contributes a large sector of the state’s economy, but vegetable production is limited due to the state’s climate condition. Inadequate soil moisture and low soil temperature are the two major factors prohibiting quality produce and high-yield vegetable production. In this study, a soil-water potential, sensor-based drip irrigation system was developed, designed, and installed to evaluate its application on tomato and watermelon productions in a two-year field experiment in 2019 and 2020. The experimental treatments were drip irrigation and no irrigation under three mulches: black plastic, clear plastic, and landscape fabric mulches. Irrigation was scheduled at 8:00 am for watermelon and 9:00 a.m. for tomato, with the ability for each irrigation event to be bypassed based on the soil moisture conditions. Due to rainfall differences in the two years, irrigation was barely needed in 2019, but in 2020, drip irrigation was applied frequently. On average, for the two-years’ field experiment, the highest yield for tomatoes was obtained from drip irrigation under black plastic drip irrigation treatment with 40.24 Mg ha−1 in 2020, whereas the highest yield for watermelon was from drip irrigation under clear plastic mulch with 165.55 Mg ha−1 in 2020. The effect of mulch, irrigation, and combined practices were analyzed based on the average fruit weight and diameter, electrical conductivity (EC), pH, and sugar content of the samples. The results showed that for watermelon, the average weight and diameter were significantly heavier and higher with irrigation treatments, but the EC and the pH values were significantly higher with mulch treatments. For tomatoes, the average weight, diameter, pH, and sugar content were all significantly higher with mulch treatment, but the EC was higher with irrigation treatment

    Diborylmethyl Group as a Transformable Building Block for the Diversification of Nitrogen-Containing Molecules

    No full text
    © 2022 Wiley-VCH GmbH.The development of new approaches to installing diverse carbon fragments to a nitrogen atom has attracted considerable attention in chemical science. While numerous strategies have been devised to forge C(sp3)−N bonds, one conceptually powerful and straightforward approach is to insert a transformable sp3-carbon unit onto a nitrogen atom for modular diversification. Here we describe the successful synthesis of halo-diborylmethanes and their applications to the preparation of nitrogen-substituted diborylmethanes through their homologative coupling with a variety of nitrogen nucleophiles including biologically relevant molecules. This process exhibits a remarkably broad substrate scope, and the usefulness of the obtained compounds is demonstrated by the modular diversification of the diborylmethyl group to access various nitrogen-containing molecules.11Nsciescopu
    corecore