scholarly journals A novel six-legged walking machine tool for in-situ operations

2020 ◽  
Vol 15 (3) ◽  
pp. 351-364
Author(s):  
Jimu Liu ◽  
Yuan Tian ◽  
Feng Gao
Keyword(s):  
Machine Tool ◽  
Motion Planning ◽  
Kinematic Model ◽  
The Body ◽  
Body Motion ◽  
Walking Distance ◽  
Walking Machine ◽  
Planning Scheme ◽  
Increasing Demand

Abstract The manufacture and maintenance of large parts in ships, trains, aircrafts, and so on create an increasing demand for mobile machine tools to perform in-situ operations. However, few mobile robots can accommodate the complex environment of industrial plants while performing machining tasks. This study proposes a novel six-legged walking machine tool consisting of a legged mobile robot and a portable parallel kinematic machine tool. The kinematic model of the entire system is presented, and the workspace of different components, including a leg, the body, and the head, is analyzed. A hierarchical motion planning scheme is proposed to take advantage of the large workspace of the legged mobile platform and the high precision of the parallel machine tool. The repeatability of the head motion, body motion, and walking distance is evaluated through experiments, which is 0.11, 1.0, and 3.4 mm, respectively. Finally, an application scenario is shown in which the walking machine tool steps successfully over a 250 mm-high obstacle and drills a hole in an aluminum plate. The experiments prove the rationality of the hierarchical motion planning scheme and demonstrate the extensive potential of the walking machine tool for in-situ operations on large parts.

scholarly journals Physics of martial arts: Incorporation of angular momentum to model body motion and strikes

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255670
Author(s):  
Alexis Merk ◽  
Andrew Resnick
Keyword(s):  
Angular Momentum ◽  
Classroom Environment ◽  
Martial Arts ◽  
Kinematic Model ◽  
Time Lapse ◽  
The Body ◽  
Body Motion ◽  
Deformable Solid ◽  
Mechanics Model ◽  
Improved Model

We develop a physics-based kinematic model of martial arts movements incorporating rotation and angular momentum, extending prior analyses. Here, our approach is designed for a classroom environment; we begin with a warm-up exercise introducing counter-intuitive aspects of rotational motion before proceeding to a set of model collision problems that are applied to martial arts movements. Finally, we develop a deformable solid-body mechanics model of a martial arts practitioner suitable for an intermediate mechanics course. We provide evidence for our improved model based on calculations from biomechanical data obtained from prior reports as well as time-lapse images of several different kicks. In addition to incorporating angular motion, our model explicitly makes reference to friction between foot and ground as an action-reaction pair, showing that this interaction provides the motive force/torque for nearly all martial arts movements. Moment-of-inertia tensors are developed to describe kicking movements and show that kicks aimed high, towards the head, transfer more momentum to the target than kicks aimed lower, e.g. towards the body.

Design and Analysis of a Smart Rehabilitation Walker With Passive Pelvic Mechanism

2020 ◽  
Vol 12 (3) ◽  
Author(s):  
Jiancheng (Charles) Ji ◽  
Shuai Guo ◽  
Fengfeng (Jeff) Xi ◽  
Leigang Zhang
Keyword(s):  
Degrees Of Freedom ◽  
Force Feedback ◽  
Kinematic Model ◽  
The Body ◽  
Community Based ◽  
Community Based Rehabilitation ◽  
Left And Right ◽  
Increasing Demand ◽  
Limb Rehabilitation ◽  
Motion Intention

Abstract In response to the ever-increasing demand of community-based rehabilitation, a novel smart rehab walker iReGo is designed to facilitate the lower limb rehabilitation training based on motion intention recognition. The proposed walker provides a number of passive degrees-of-freedom (DoFs) to the pelvis that are used to smooth the hip rotations in such a way that the natural gait is not significantly affected, meanwhile, three actuated DoFs are actively controlled to assist patients with mobility disabilities. The walker first identifies the user’s motion intention from the interaction forces in both left and right sides of the pelvis and then uses the kinematic model to generate appropriate driving velocities to support the body weight and improve mobility. In this paper, workspace, dexterity, and the force field of the walker are analyzed based on the system Jacobian. Simulation and experiments with healthy subjects are carried out to verify the effectiveness and tip-over stability. These results demonstrate that the walker has sufficient workspace for pelvic motions, satisfactory dexterity, and near-linear force feedback within the prescribed workspace, and that the walker is easily controlled to ensure normal gait.

Use of Gait-Kinematics in Sensor-Based Gait Monitoring: A Feasibility Study

2013 ◽  
Vol 81 (4) ◽  
Author(s):  
Yohannes Ketema ◽  
Demoz Gebre-Egziabher ◽  
Michael Schwartz ◽  
Chris Matthews ◽  
Ryan Kirker
Keyword(s):  
Kinematic Model ◽  
Human Locomotion ◽  
The Body ◽  
Step Size ◽  
Gait Patterns ◽  
Gait Kinematics ◽  
Key Points ◽  
Gait Monitoring

A concept for fusing information from the kinematics describing human locomotion with body-fixed sensors for the purpose of in situ gait monitoring is studied. This is done by using an individual's gait patterns (as captured by a simplified kinematic model) with acceleration measurements made at key points on the body. The gait patterns are expressed as nominal relations between shank, thigh, and stance leg angles during normal walking. It is shown how the use of known gait patterns reduces the required number of sensors attached to the body that are required for a sensor-based monitoring of gait. The feasibility of the approach is demonstrated using a single acceleration measurement at the ankle to estimate limb angles and step size in situ. Such gait monitoring may be used for the evaluations of a subject's overall quality of gait through the determination of flexions at the knees and hip. In addition, step sizes, distance walked, and speed can be estimated. Apart from gait analysis, the method can be used for remotely monitoring the safety of individuals to the extent this can be done through consideration of the state of gait.

Scaffolds for Drug Delivery in Tissue Engineering

2008 ◽  
Vol 1 (2) ◽  
pp. 113-123 ◽  
Author(s):  
Vikas V. Gaikwad ◽  
Abasaheb B. Patil ◽  
Madhuri V. Gaikwad
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Heart Diseases ◽  
Cartilage Regeneration ◽  
Tissue Growth ◽  
The Body ◽  
Patient Specific ◽  
In Situ Gel ◽  
Heart Muscle Cells

Scaffolds are used for drug delivery in tissue engineering as this system is a highly porous structure to allow tissue growth.  Although several tissues in the body can regenerate, other tissue such as heart muscles and nerves lack regeneration in adults. However, these can be regenerated by supplying the cells generated using tissue engineering from outside. For instance, in many heart diseases, there is need for heart valve transplantation and unfortunately, within 10 years of initial valve replacement, 50–60% of patients will experience prosthesis associated problems requiring reoperation. This could be avoided by transplantation of heart muscle cells that can regenerate. Delivery of these cells to the respective tissues is not an easy task and this could be done with the help of scaffolds. In situ gel forming scaffolds can also be used for the bone and cartilage regeneration. They can be injected anywhere and can take the shape of a tissue defect, avoiding the need for patient specific scaffold prefabrication and they also have other advantages. Scaffolds are prepared by biodegradable material that result in minimal immune and inflammatory response. Some of the very important issues regarding scaffolds as drug delivery systems is reviewed in this article.

Critical analysis and unique management of Gridhrasi w.s.r. to Sciatica - A Case Report

2018 ◽  
Vol 3 (4) ◽  
Author(s):  
Dr. Rangarajan B. ◽  
Dr. Muralidhara .
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Case Report ◽  
Total Population ◽  
The Body ◽  
Walking Distance ◽  
Common Symptom ◽  
Low Back ◽  
Short Term ◽  
Lower Back

Gridhrasi (Sciatica) is a disorder in which low back pain is found, that spreads through the hip, to the back of the thigh and down the inside of the leg. Mechanical low back pain (LBP) remains the second most common symptom related reason for seeing a physician. 85% of total population will experience an episode of mechanical LBP at some point during their lifetime. Fortunately, the LBP resolves for the vast majority within 2-4 weeks. There are many causes for low back pain, however true sciatica is a symptom of inflammation or compression of the sciatica nerve. The sciatica nerve carries impulses between nerve roots in the lower back and the muscles and nerve of the buttocks, thighs and lower legs. Compression of a nerve root often occurs as a result of damage to one of the discs between the vertebrae. In some cases, sciatic pain radiate from other nerves in the body. This is called referred pain. Pain associated with sciatica often is severe, sharp and shooting. It may be accompanied by other symptom, such as numbness, tingling, weakness and sensitivity to touch. There is only conservative treatment giving short term relief in pain or surgical intervention with side effect. But these are not successful and therefore those who are suffering from this are always in search of result oriented remedy. Walking distance and SLR test were taken for assessment parameter, VAS score was adopted for pain. Before treatment patient was not able to walk even 4 to 5 steps due to severe pain, was brought on stretcher and his SLR was 30° of right side. After 22 days of treatment he was able to walk up to 500 meters without any difficulty, SLR was changed to 60° and patient had got 80 % relief in pain. This case report showed that Ayurvedic protocol is potent and safe in the treatment of Gridhrasi.

Chaos in body–vortex interactions

2010 ◽  
Vol 466 (2119) ◽  
pp. 1871-1891 ◽  
Author(s):  
Johan Roenby ◽  
Hassan Aref
Keyword(s):  
Body Shape ◽  
Mass Density ◽  
Relative Equilibrium ◽  
Large Body ◽  
Point Vortex ◽  
Cylindrical Body ◽  
The Body ◽  
Body Motion ◽  
Single Vortex ◽  
Vortex Interactions

The model of body–vortex interactions, where the fluid flow is planar, ideal and unbounded, and the vortex is a point vortex, is studied. The body may have a constant circulation around it. The governing equations for the general case of a freely moving body of arbitrary shape and mass density and an arbitrary number of point vortices are presented. The case of a body and a single vortex is then investigated numerically in detail. In this paper, the body is a homogeneous, elliptical cylinder. For large body–vortex separations, the system behaves much like a vortex pair regardless of body shape. The case of a circle is integrable. As the body is made slightly elliptic, a chaotic region grows from an unstable relative equilibrium of the circle-vortex case. The case of a cylindrical body of any shape moving in fluid otherwise at rest is also integrable. A second transition to chaos arises from the limit between rocking and tumbling motion of the body known in this case. In both instances, the chaos may be detected both in the body motion and in the vortex motion. The effect of increasing body mass at a fixed body shape is to damp the chaos.

scholarly journals Ferromagnetic soft catheter robots for minimally invasive bioprinting

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Cheng Zhou ◽  
Youzhou Yang ◽  
Jiaxin Wang ◽  
Qingyang Wu ◽  
Zhuozhi Gu ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
The Body ◽  
Magnetic Actuation ◽  
Internal Organs ◽  
Planar Surfaces ◽  
Reinforced Polymer ◽  
Direct Fabrication ◽  
Digitally Controlled

AbstractIn vivo bioprinting has recently emerged as a direct fabrication technique to create artificial tissues and medical devices on target sites within the body, enabling advanced clinical strategies. However, existing in vivo bioprinting methods are often limited to applications near the skin or require open surgery for printing on internal organs. Here, we report a ferromagnetic soft catheter robot (FSCR) system capable of in situ computer-controlled bioprinting in a minimally invasive manner based on magnetic actuation. The FSCR is designed by dispersing ferromagnetic particles in a fiber-reinforced polymer matrix. This design results in stable ink extrusion and allows for printing various materials with different rheological properties and functionalities. A superimposed magnetic field drives the FSCR to achieve digitally controlled printing with high accuracy. We demonstrate printing multiple patterns on planar surfaces, and considering the non-planar surface of natural organs, we then develop an in situ printing strategy for curved surfaces and demonstrate minimally invasive in vivo bioprinting of hydrogels in a rat model. Our catheter robot will permit intelligent and minimally invasive bio-fabrication.

Mammary-type Myofibroblastoma with Leiomyomatous Differentiation: A Rare Variant with Potential Pitfalls

2021 ◽  
pp. 106689692110313
Author(s):  
Alexander M. Strait ◽  
Julia A. Bridge ◽  
Anthony J. Iafrate ◽  
Marilyn M. Li ◽  
Feng Xu ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Transcriptome Sequencing ◽  
Smooth Muscle Actin ◽  
The Body ◽  
Muscle Actin ◽  
Mature Adipose Tissue ◽  
Spindle Cells ◽  
Whole Transcriptome Sequencing ◽  
Whole Transcriptome

Myofibroblastoma is a rare, benign stromal tumor with a diverse morphologic spectrum. Mammary-type myofibroblastoma (MTMF) is the extra-mammary counterpart of this neoplasm and its occurrence throughout the body has become increasingly recognized. Similar morphologic variations of MTMF have now been described which mirror those seen in the breast. We describe a case of intra-abdominal MTMF composed of short fascicles of eosinophilic spindle cells admixed with mature adipose tissue. The spindle cells stained diffusely positive for CD34, desmin, smooth muscle actin, and h-caldesmon by immunohistochemistry. Concurrent loss of RB1 (13q14) and 13q34 loci were confirmed by fluorescence in situ hybridization whereas anchored multiplex PCR and whole transcriptome sequencing did not reveal any pathognomonic fusions suggesting an alternative diagnosis. To the best of our knowledge this is the first documented case of leiomyomatous variant of MTMF.

A real-time motion planning scheme for collaborative robots using HRI-based cost function

2021 ◽  
Vol 8 (1) ◽  
pp. 42
Author(s):  
Khawaja Fahad Iqbal ◽  
Akira Kanazawa ◽  
Silvia Romana Ottaviani ◽  
Jun Kinugawa ◽  
Kazuhiro Kosuge
Keyword(s):  
Motion Planning ◽  
Cost Function ◽  
Real Time ◽  
Collaborative Robots ◽  
Time Motion ◽  
Planning Scheme

scholarly journals Self-rechargeable cardiac pacemaker system with triboelectric nanogenerators

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hanjun Ryu ◽  
Hyun-moon Park ◽  
Moo-Kang Kim ◽  
Bosung Kim ◽  
Hyoun Seok Myoung ◽  
...  
Keyword(s):  
Medical Devices ◽  
Mechanical Energy ◽  
Cardiac Pacemaker ◽  
Operation Time ◽  
Lithium Ion ◽  
The Body ◽  
Body Motion ◽  
Triboelectric Nanogenerator ◽  
Implantable Medical Devices ◽  
Energy Harvesters

AbstractSelf-powered implantable devices have the potential to extend device operation time inside the body and reduce the necessity for high-risk repeated surgery. Without the technological innovation of in vivo energy harvesters driven by biomechanical energy, energy harvesters are insufficient and inconvenient to power titanium-packaged implantable medical devices. Here, we report on a commercial coin battery-sized high-performance inertia-driven triboelectric nanogenerator (I-TENG) based on body motion and gravity. We demonstrate that the enclosed five-stacked I-TENG converts mechanical energy into electricity at 4.9 μW/cm3 (root-mean-square output). In a preclinical test, we show that the device successfully harvests energy using real-time output voltage data monitored via Bluetooth and demonstrate the ability to charge a lithium-ion battery. Furthermore, we successfully integrate a cardiac pacemaker with the I-TENG, and confirm the ventricle pacing and sensing operation mode of the self-rechargeable cardiac pacemaker system. This proof-of-concept device may lead to the development of new self-rechargeable implantable medical devices.

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