Showing papers on "Paddle published in 2021"

Underwater Walking Mechanism of Underwater Amphibious Robot Using Hinged Multi-modal Paddle

Abstract: This study proposes an underwater walking mechanism for an underwater amphibious robot that is propelled by a degree of freedom flapping foil system. To implement stable walking in water, we proposed a distinctive hinged multi-modal paddle and developed an underwater amphibious robot. For the proposed paddle, forward walking model is proposed regarding both the ground contact and hydrodynamic forces in each walking phase: the stance and swing phases. Then, we generalized dynamic equations of motion for the amphibious robot based on the forward walking model. The proposed mechanism and robot were evaluated through thrust and forward walking tests in an indoor water tank. The results of the forward walking test exhibited a highly accurate trajectory of legged locomotion compared to the model-based simulation results. Moreover, field tests on gravel and soft terrains of a seabed, revealed that the proposed system allowed the amphibious robot to walk qualitatively.

Long-Term Changes in Thecal Sac Compression and Decreased Cerebrospinal Fluid Space Following Paddle Lead Spinal Cord Stimulation at T9: A Long-Term Follow-Up via Three-Dimensional Myelographic Computed Tomography.

Abstract: OBJECTIVES To investigate the long-term changes in thecal sac compression following T9 paddle lead spinal cord stimulation (SCS) using three-dimensional myelographic computed tomography (CT). MATERIALS AND METHODS Seventeen patients with five-column paddle lead SCS at T9 underwent three-dimensional myelographic CT scans preoperatively, immediately after surgery, and after an average of 11 months. The cross-sectional areas of thecal sac and spinal cord and the widths of anterior and posterior CSF spaces were repeatedly measured and compared. The contact angle of the lead with long-term pain relief was assessed. RESULTS The cross-sectional areas of thecal sac and spinal cord decreased significantly after lead placement (30.47 ± 9.21% and 4.71 ± 9.84%, respectively). Even after 11 months, a significant reduction was found with the preoperative values (17.97 ± 12.32% and 2.88 ± 7.09%). The widths of anterior and posterior CSF spaces decreased significantly after surgery (43.53 ± 13.17% and 57.13 ± 13.17%, respectively) and the severe decrease persisted long-term (29.13 ± 21.54% and 50.99 ± 16.07%). The average pain relief was 42.27 ± 17.50% with no correlation between the rate of reduction in cross-sectional areas of thecal sac and the widths of CSF spaces. CONCLUSIONS Significant early reduction and late partial restoration occurred in the thecal sac and spinal cord and the width of the anterior and posterior CSF spaces in the T9 5-column paddle lead SCS. Thecal sac compromise was expected to some extent after paddle lead implantation, but the degree is significant, and the cross-sectional area of the spinal cord as well as the thecal sac is affected. Fortunately, these anatomical changes did not cause any clinical problems except for intercostal root irritation. The shape and flat contours of the five-column paddle leads clearly affected the results.

Design, Modeling and Performance Evaluation of Mobile Robot Based on Eccentric Paddle Mechanism

Abstract: In order to improve climbing performance of the robot in complex environments, the wheeled-legged mechanism is gradually being widely used. In this paper, we use computer-aided modeling technology to design a 2-DOF ePaddle-based robot of high step-climbing capacity. Climbing strategies of the robot under the circle-wheeled (CW) mode and active-paddle-legged (APL) mode are carried out. We discuss determinants for success in climbing by establishing the climbing posture models. Simulation results processed with MATLAB tools reveal that paddle’s motion can significantly improve the climbing performance to avoid slipping. The experimental results verify the robot is capable of climbing over 300mm obstacle APL modes, which is 2.14 times the wheel radius.

Preoperative Thoracic Spine Magnetic Resonance Imaging for Spinal Cord Stimulation: Should Such a Recommendation Be an Absolute Requirement?

Abstract: Objective Current published guidelines recommend advanced imaging, specifically, thoracic magnetic resonance imaging (MRI), prior to implantation of epidural paddle spinal cord stimulator (SCS) leads. Preoperative imaging may affect surgical approach to minimize risk of complications. We aimed to assess the impact of preoperative thoracic MRI on surgical planning in a large series of surgical paddle SCS lead placements in a real-world setting. Materials and methods This is a retrospective study of a prospectively maintained data base of 160 patients treated by SCS with awake thoracic surgical paddle lead placement in a single academic functional neurosurgery center from 2013 to 2021. All patients had a thoracic MRI prior to implantation. Abnormal MRI findings were reviewed to determine their potential impact on the safety of surgical paddle lead placement. A minor impact was defined as anatomical areas to avoid with paddle lead placement. Major impacts included significant deviations from standard approach to electrode placement. Results None of the 160 patients had signs or symptoms referable to thoracic spine pathology prior to lead implant. Sixty-seven had abnormal thoracic MRI findings, and 36 had abnormal MRI findings that impacted surgical planning. Thirty-one patients had MRI findings with minor impact. Five patients (more than 3%) had findings with major impact. Conclusions This is the largest case series assessing the impact of preoperative thoracic MRI on surgical planning for patients undergoing paddle SCS placement. Twenty-two percent of patients had MRI findings that impacted surgical planning with 3% requiring additional surgical decompression for safe paddle lead placement. Without advanced imaging to inform surgical planning, unnecessary risk may have been placed on these patients. Although such imaging has been recommended by consensus committees in published guidelines, our study is the first to present a large institutional experience of real-world data that demonstrates its importance.

Artificial muscle actuators

Abstract: A hinge-type actuator device in accordance with the present disclosure may include a first and second paddle, a first and second artificial muscle actuator segment, and a plurality of contacts, where the first and second artificial muscle actuator segments are actuated via the contacts, actuation of the first artificial muscle actuator segment causes the first and second paddle to open the hinge-type actuator, and actuation of the second artificial muscle actuator segment causes the first and second paddle to close the hinge-type actuator.

Lead frame, package structure and method for manufacturing the same

Abstract: A lead frame includes a die paddle, a plurality of leads, at least one connector and a bonding layer. The leads surround the die paddle. Each of the leads includes an inner lead portion adjacent to and spaced apart from the die paddle and an outer lead portion opposite to the inner lead portion. The connector is connected to the die paddle and the inner lead portions of the leads. The bonding layer is disposed on a lower surface of the die paddle and a lower surface of each of the outer lead portions.

Glass crushing apparatus

Abstract: An apparatus 10 for crushing glass comprises an enclosed impact chamber 14, a rotating paddle 16 within the enclosed chamber, an electric motor 30 for rotating the paddle, a delivery chute 20 having an upper end 21 for receiving glass bottles and a lower end (22, fig 4) in communication with the impact chamber, and a collection chamber (70) provided below and in communication with the impact chamber. The impact chamber includes an inclined impact surface 18 extending below the lower end of the delivery chute. The paddle rotates about a horizontal axis opposite and parallel to the impact surface, and has at least two paddle arms 26, each travel downwards when closest to the impact surface. Each paddle arm has a chamfered impact tip (28, fig 9) at its end, with a clearance between the impact tip and impact surface of between 15 and 50 mm. The apparatus may be provided with a lid 40 at the upper end of the chute, the lid being connected to the electric motor so that it switches on when the lid is raised. The apparatus creates glass cullet of an appropriate size for storage, transport and recycling.

Marine multi-gear paddle hanging machine

Abstract: The invention relates to the technical field of paddle hanging machines, and discloses a marine multi-gear paddle hanging machine. The machine comprises a fixed plate; a rhombic inserting column is fixedly connected to the middle of the lower surface of the fixed plate, circular inserting columns are fixedly connected to the front side and the rear side of the lower surface of the fixed plate, andmounting bolts are arranged on the front side and the rear side of the upper surface of the fixed plate; a first L-shaped supporting plate is fixedly connected to the middle of the upper surface of the fixed plate, and an auxiliary reinforcing device is arranged on the right side of the upper surface of the first L-shaped supporting plate. According to the multi-gear paddle hanging machine for the ship, through cooperative use of the fixed plate, the rhombic inserting columns, the circular inserting columns and the mounting bolts, fixed mounting of the fixed plate is achieved, mounting of themulti-gear paddle hanging machine mounting base is achieved, rapid mounting of the multi-gear paddle hanging machine is achieved, and the mounting speed of the multi-gear paddle hanging machine is increased; the multi-gear paddle hanging machine is convenient for a user to use, saves a large amount of mounting time, improves the working efficiency, and improves the practicability of the multi-gear paddle hanging machine.

Tray attachment for saws

Abstract: An apparatus can include a first material support member and a second material support member each configured to removably attach to a tile tray. The material support members can define a linear saw blade slot through which a saw blade extends while cutting a planar material. The apparatus also can include a first paddle and a second paddle each configured to interpose a respective portion of the planar material between the respective paddle and a respective one of the material support members. Each of the paddles further can be configured to engage the respective material support member using an alignment pin that fixes a position of the paddle relative to the position of the respective material support member.

Paddle for propulsion of watercraft

Abstract: A paddle for watercraft has a shaft to which blades are attached at opposite ends. The blades may be mounted directly to the shaft or via drop cranks. The shaft is suspended on handles oriented transversely to the shaft's longitudinal axis. The handles are capable of pivoting motion relative to the shaft as well as rotational motion about their respective longitudinal axes.

Method of automatically extracting energy from flowing liquid and device using the same

Abstract: A method of automatically extracting energy from flowing liquid and a device using the same are disclosed. The device includes a paddle rod and a swing device. The paddle rod includes two paddles to bear a pushing force of flowing liquid. When the paddle rod is swung, one of the two paddle enters water and the other paddle leaves from water surface. When the paddle in the water bears a pushing force of flowing liquid to drive a rotary body to swing, the paddle rod moves upwardly and leaves the water surface, and the other paddle enters water to bear the pushing force, and after the rotary body is driven to swing reversely, the paddle rod moves upwardly and leaves water surface, and at the same time the paddle enters the water to bear the pushing force, to drive the rotary body to swing reversely.

System and method for ligament balancing using robotically held device

Abstract: A device for ligament balancing includes a mount at a first end of the device and a head portion at a second end of the device, the head portion having a substantially planar surface, a first paddle, and a second paddle, wherein the first and second paddle are rotatable about a first longitudinal axis and a second longitudinal axis, respectively, relative to the substantially planar surface. The device further includes a stem extending from the head portion and a shaft extending between the stem and the mount. The mount includes a coupling portion configured to couple the device to a robotic device such that movement of the device is controlled by the robotic device.

Heated paddle hairbrush

Abstract: A heated paddle hairbrush includes a novel bristle arrangement which establishes a large surface area for contacting the length of hair during grooming while also creating a serpentinous path through which the length of hair must traverse thereby enhancing the grooming effect on the hair.

High Performance Across Two Atari Paddle Games Using the Same Perceptual Control Architecture Without Training

Abstract: Deep reinforcement learning (DRL) requires large samples and a long training time to operate optimally. Yet humans rarely require long periods training to perform well on novel tasks, such as computer games, once they are provided with an accurate program of instructions. We used perceptual control theory (PCT) to construct a simple closed-loop model which requires no training samples and training time within a video game study using the Arcade Learning Environment (ALE). The model was programmed to parse inputs from the environment into hierarchically organised perceptual signals, and it computed a dynamic error signal by subtracting the incoming signal for each perceptual variable from a reference signal to drive output signals to reduce this error. We tested the same model across two different Atari paddle games Breakout and Pong to achieve performance at least as high as DRL paradigms, and close to good human performance. Our study shows that perceptual control models, based on simple assumptions, can perform well without learning. We conclude by specifying a parsimonious role of learning that may be more similar to psychological functioning.

Mammography machine compression paddle movement andobserver performance analysis

Abstract: Full field digital mammography (FFDM) was introduced into the United Kingdom (UK) as a replacement for screen-film mammography (SFM) in 2005. Since then, individual breast screening centres have begun to report blurred images through local audits. Blurring was probably present in SFM as well, however the improvement in contrast resolution in FFDM may have made it more apparent. The sources of blurring include improper imaging techniques, patient movement caused by breathing and heart motion,the viscoelastic motion of the breast, and paddle motion. This thesis aims to test the hypothesis that paddle motion might cause image blur. It investigates whether blurring can be detected visually on technical review monitors and reporting grade monitors. The thesis presents a method to minimise paddle motion during X-ray exposure. Six papers have been published. Two of these (papers 1 and 2) investigated paddle displacement using linear potentiometers. Three investigated the influence of paddle motion on image quality. Paper 3 investigated whether paddle motion can cause image blur; paper 4 determined the minimum amount of simulated motion required for the visual detection of blurring; and paper 5 evaluated the practitioner’s ability to identify blurring on monitors with different resolutions (2.3 MP and 5 MP). The final research paper (paper 6) investigated a way to reduce paddle displacement settling time; this involved the use of a closed-loop control system. Results: In papers 1 and 2 paddle displacement followed a bi-exponential function with a settling time of approximately 40 s. The use of average paddle displacement to estimate the amount of paddle motion would underestimate the worst case of the three different runs of the experiment. The estimated paddle motion would be greatly reduced if the time of exposure is delayed from 5 to 10 s. In paper 3 all metal ball bearings shown increased in diameters and the range of magnification varied from 1.04 to 1.21. T-test results shown that there was a significant difference (p < 0.05) in the ball bearing diameters between the intensity thresholding and the edge detection methods for all paddle/ compression force combinations. The ball bearing diameters calculated by the intensity thresholding method had higher variability than the edge detection method. In paper 4 the soft-edged mask method best represented the physical process that caused the blurring effect and was chosen as the standard simulation approach for motion blurring. The ratio between the vertical paddle motion and the horizontal breast motion estimated by the mathematical model is approximately 1:0.3. In paper 5 the angular size calculation shown that for a viewing distance of 75 cm the screen resolution for 5 MP and 12 MP monitors was better than the observer eyes' resolution. For a viewing distance of 30 cm the observer eyes' resolution was better than the screen resolution for 2.3 MP, 5 MP and 12 MP monitors. Among all three monitors, image displayed on the 12 MP monitor has the lowest loss in image quality after interpolation. In paper 6 the simulation results shown that force overshoot is possible for position control system. Force overshoot occurred almost instantaneously for step input and its magnitude is about 10 times larger than the ramp input. Force overshoot and steadystate error can be eliminated by the use of force control system. Conclusion: The magnitude of calculated paddle motion is much lower than the minimum amount of simulated motion required for the visual detection of blurring. Mathematical models have shown that vertical paddle motion caused a smaller horizontal breast displacement when compressed. Therefore, there is no sufficient evidence to support the hypothesis that paddle motion is a cause of image blurring in FFDM.

Flywheel and paddle assembly for a chipping or shredding apparatus, and an apparatus incorporating same

Abstract: A flywheel and paddle assembly for a chipping or shredding apparatus, including a wood chipper, a brush chipper, and a leaf shredder. The assembly has a flywheel attached coaxially to a drive shaft. The flywheel has at least one aperture extending from the front side to the back side, and carries at least one knife adjacent to the at least one aperture. The knife presents a knife edge on the front side of the flywheel. A paddle is rotatably mounted coaxially to the drive shaft adjacent to the back side of the flywheel. The paddle is configured to rotate on the drive shaft independently of the flywheel. A chipping or shredding apparatus incorporating the aforesaid flywheel and paddle assembly is also disclosed.

External defibrillator apparatus with self-contained piezoelectric power source

Abstract: An external defibrillator apparatus (10, 74) operates to deliver electrical shocks to the heart muscles of a patient using a self-contained piezoelectric power source. The apparatus has a body (12) which includes a handle portion (26) in fixed operative connection with disposed paddle portions (14, 16). Each paddle portion includes a respective electrode (22, 24). Manual movement of a trigger (28, 78) is operative to cause circuitry (32, 82) which includes a piezoelectric crystal (34) to develop sufficient electrical potential between the electrodes to deliver the electrical shocks to the heart muscles through external contact with the patient's chest.