Elastic Shape-from-Template with Spatially Sparse Deforming Forces

2017 ◽  
Author(s):  
Abed Malti ◽  
Cedric Herzet
Keyword(s):  
Deforming Forces

A Technique for Measuring Absolute Toe Pressures: Evaluation of Pressure-Sensitive Film Techniques

Foot & Ankle ◽  
1992 ◽  
Vol 13 (4) ◽  
pp. 220-223 ◽  
Author(s):  
Alan S. Tuckman ◽  
Frederick W. Werner ◽  
Maria D. Fortino ◽  
Joseph A. Spadaro
Keyword(s):  
Soft Tissues ◽  
Flat Surface ◽  
Imaging System ◽  
Accurate Method ◽  
Total Force ◽  
Confined Space ◽  
Pressure Sensitive ◽  
Sensitive Film ◽  
Pressure Sensitive Film ◽  
Deforming Forces

Although a number of pathologies of the forefoot in ballet dancers on pointe have been described, pressures and deforming forces have not been adequately measured. To evaluate the possible use of pressure-sensitive film (PSF) in measuring the pressures on the external soft tissues in such a confined space as the dancer's toe shoe, it was tested and calibrated with 20 cadaver toes. Each cadaver toe was internally stabilized and loaded longitudinally against PSF on a flat surface. The resultant films were analyzed with a video imaging system and the pressures and total forces were determined. Results showed that the linearity of the PSF to pressure had a regression value of 0.98. By using two sensitivity ranges of films, the total force measured by the PSF was found to be within 10% of the known applied force on each toe. The PSF, therefore, may very well be a useful and accurate method of measuring external soft tissue pressures on the forefoot.

scholarly journals One-step Management of Severely Deformed, Long-Neglected Club Feet

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0046
Author(s):  
Michael Strauss ◽  
Isabella van Dalen
Keyword(s):  
Minimally Invasive ◽  
External Fixation ◽  
Soft Tissues ◽  
Operative Management ◽  
Wedge Osteotomy ◽  
Foot Deformities ◽  
Early Management ◽  
Tendon Transfers ◽  
One Stage ◽  
Deforming Forces

Category: Other Introduction/Purpose: Early management of the club foot using the Ponsetti technique has almost eliminated severe residual deformities from this problem. Unfortunately, in remote regions of the world patients may not have been afforded the benefits of this technique. The consequences are severely deformed, long-neglected foot deformities. Interventions to mitigate this problem have included talectomies, osteotomies, tendon transfers, gradual corrections using Ilizarov principles and as a last resort, transtibial amputations. All have undesirable features such as inadequate corrections with residual deformities, need for additional surgeries, intensive post-operative management and/or need for custom orthotics or prostheses. We propose a one-stage, single setting approach to this problem that fully realigns the foot and requires minimum of post-operative management. Methods: During a 2017 humanitarian mission to Vietnam, six patients with severely deformed, long-neglected club feet were managed at a remote orthopaedic rehabilitation facility using our one-stage, single surgery approach. The six-step procedure included: 1) Percutaneous tri-hemisections (Hoke) of the Achilles tendon, 2) Excision of lateral ulcers/bursas, 3) Minimally invasive releases of all constricting soft tissues structures, 4) Closing wedge osteotomy at apex of deformity, 5) Manual reduction to achieve plantigrade foot, and 6) Maintenance of correction with temporary spanning external fixation in five patients and percutaneous Steinmann pins in a four-year old patient. No tendon transfers were done. No tourniquets or perioperative antibiotics were used with these minimally invasive and percutaneous interventions. At six weeks, the external fixation was removed, walking casts were applied with minimal manipulations to optimally position the feet. At 12 weeks the casts were removed, patients allowed to use footwear of their choosing. Results: Follow-ups initially obtained weekly, then monthly through e-mails by a co-author fluent in Vietnamese were supplemented with photographs. Near-plantigrade feet axially aligned with the leg were obtained with all the initial corrections. By 48 hours pain was reported as minimal even though marked tension occurred across intact joint capsules in order to achieve the corrections. One skin, pin tract infection was reported that resolved once the pin was removed. Follow-up information at six months report that the corrections have been maintained with high satisfaction in all patients. Conclusion: Our innovative approach to deformed, neglected club feet is supported by appreciating the biomechanics of the problems. Dynamic deforming forces (tendons and muscles) must be released. Tendon transfers are inadequate to correct contractures. Bony deformities must be osteotomized. Viscoelasticity of ligaments and joint capsules deform with time and need not be released; corrections initially obtained using the fixators become permanent with time. Our experiences support the use of our approach for the patient population with which we dealt and suggest that earlier soft tissue releases of dynamic deforming forces be done in conjunction with the Ponsetti technique.

PUNCHING CUPS WITH BOTTOM FLANGE BY DIRECT EXTRUSION WITH COUNTER-PUNCH. METHODOLOGY FOR CALCULATING TECHNOLOGICAL PARAMETERS FREE EXTRUSION PROCESS

2020 ◽  
pp. 17-24 ◽  
Author(s):  
A. L. Vorontsov ◽  
I. A. Nikiforov
Keyword(s):  
Yield Stress ◽  
Extrusion Process ◽  
Maximum Pressure ◽  
Bottom Flange ◽  
Technological Parameters ◽  
Hardening Material ◽  
Direct Extrusion ◽  
Deformation Parameters ◽  
The Matrix ◽  
Deforming Forces

The methodology for calculating the energy and deformation parameters of the processes of free extrusion of glasses with a counter-punch is described. Extrusion of both non-hardening and hardening material is considered. In the latter case, accounting for the hardening of the extruded material is described in detail. The above formulas allow us to determine such important parameters of the stamping process as the total and specific deforming forces, maximum pressure on the matrix wall, and increase in yield stress.

Orthotic management of the lower limb in children with hereditary motor sensory neuropathy (HMSN)

2001 ◽  
Vol 25 (2) ◽  
pp. 139-143 ◽  
Author(s):  
F. Uygur ◽  
N. Bek ◽  
B. Kürklü ◽  
Ö. Yilmaz
Keyword(s):  
Natural History ◽  
Lower Limb ◽  
Sensory Neuropathy ◽  
Lower Limbs ◽  
Hereditary Motor ◽  
Paediatric Patients ◽  
Wide Range ◽  
History Of ◽  
Deforming Forces

The lower limbs of 55 paediatric patients, with the diagnosis of hereditary motor sensory neuropathy (HMSN) referred to the Orthotics and Biomechanics Department of Hacettepe University, were assessed for appropriate orthotic intervention. Since in the natural history of HMSN symptoms and complaints are variable there is a wide range of interventions possible. The biomechanics of deforming forces and the consequential incidence of deformities in these 55 children, its orthotic implications and the efficacy of orthotic applications are discussed in detail.

scholarly journals ALTERATIONS IN THE CYTOLOGIC DETAIL OF INTESTINAL SMOOTH MUSCLE CELLS IN VARIOUS STAGES OF CONTRACTION

1965 ◽  
Vol 27 (1) ◽  
pp. 199-213 ◽  
Author(s):  
Bernard P. Lane
Keyword(s):  
Smooth Muscle ◽  
Plasma Membrane ◽  
Fine Structure ◽  
Smooth Muscle Cells ◽  
Functional Organization ◽  
Intestinal Smooth Muscle ◽  
Small Areas ◽  
Different Diameters ◽  
Longitudinal Layer ◽  
Deforming Forces

The fine structure of the longitudinal layer of the tunica muscularis of the mouse jejunum was studied in various stages of mechanically stimulated contraction. The relaxed cell is long and narrow with smooth cytoplasmic and nuclear contours. As contraction progresses, the cell becomes ellipsoid and its borders exhibit invaginations at the points of myofilamentous attachment to the plasma membrane and vesicle-containing projections of the intervening membrane. These changes are interpreted as representing the deforming forces applied by the myofilaments to the plasma membrane. The nucleus of the contracted cell is shortened and widened, with convolution of its limiting membranes. This alteration, as well as progressive changes in the alignment of cytoplasmic organelles, is thought to be due to forces exerted on the internal structure of the cell by the contractile elements. The myofilaments form a network of oriented bundles during contraction. Aggregates of filaments of two different diameters are noted. The two sizes of filaments intermingle only in small areas of increased density. These dense areas increase in length and number during contraction. A model of the functional organization of the cell is proposed.

PUNCHING CUPS WITH BOTTOM FLANGE BY DIRECT EXTRUSION WITH COUNTER-PUNCH. METHODOLOGY FOR CALCULATING TECHNOLOGICAL PARAMETERS CRAMPED EXTRUSION PROCESS

2020 ◽  
pp. 2-9
Author(s):  
A. L. Vorontsov ◽  
I. A. Nikiforov
Keyword(s):  
Yield Stress ◽  
Extrusion Process ◽  
Maximum Pressure ◽  
Bottom Flange ◽  
Technological Parameters ◽  
Hardening Material ◽  
Direct Extrusion ◽  
Deformation Parameters ◽  
The Matrix ◽  
Deforming Forces

The method of calculating the energy and deformation parameters of the process of constrained extrusion of glasses with a counter-punch is described. Extrusion of both non-hardening and hardening material is considered. In the latter case, accounting for the hardening of the extruded material is described in detail. The above formulas allow us to determine such important parameters of the stamping process as the total and specific deforming forces, maximum pressure on the matrix wall, and increase in yield stress.

scholarly journals Complex Tibial Fractures: Tips and Tricks for Intramedullary Nail Fixation

2014 ◽  
Vol 5 ◽  
pp. CMTIM.S12264
Author(s):  
Michael Githens ◽  
Julius Bishop
Keyword(s):  
Surgical Technique ◽  
Intramedullary Nailing ◽  
Intramedullary Nail ◽  
Preoperative Planning ◽  
Tips And Tricks ◽  
Injured Limb ◽  
Tibia Fractures ◽  
Metaphyseal Fractures ◽  
Deforming Forces

Intramedullary nailing of metaphyseal and segmental tibia fractures can be technically challenging for a variety of reasons. Restoring length, alignment and rotation of the injured limb requires careful preoperative planning and meticulous attention to surgical technique, while avoiding common pitfalls. Understanding the deforming forces on the fracture segments and normal tibial osteology provides a background for recognizing the most common pitfalls when nailing these fractures. Many adjuncts for obtaining and maintaining fracture reduction while nailing have been described, including extended positioning, use of the femoral distractor, blocking screws, and provisional plating. We discuss these techniques as well as the role of intramedullary fixation for treating metaphyseal fractures with articular extension. The purpose of this paper is to describe the background and technique for a variety of operative tips and tricks to facilitate intramedullary nailing of metaphyseal and segmental tibia fractures.

scholarly journals Marcksl1 modulates endothelial cell mechanoresponse to haemodynamic forces to control blood vessel shape and size

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Igor Kondrychyn ◽  
Douglas J. Kelly ◽  
Núria Taberner Carretero ◽  
Akane Nomori ◽  
Kagayaki Kato ◽  
...  
Keyword(s):  
Blood Flow ◽  
Endothelial Cell ◽  
Actin Binding ◽  
Lumen Formation ◽  
Vessel Structure ◽  
Resolution Imaging ◽  
Deforming Forces ◽  
Balanced Network

Abstract The formation of vascular tubes is driven by extensive changes in endothelial cell (EC) shape. Here, we have identified a role of the actin-binding protein, Marcksl1, in modulating the mechanical properties of EC cortex to regulate cell shape and vessel structure during angiogenesis. Increasing and depleting Marcksl1 expression level in vivo results in an increase and decrease, respectively, in EC size and the diameter of microvessels. Furthermore, endothelial overexpression of Marcksl1 induces ectopic blebbing on both apical and basal membranes, during and after lumen formation, that is suppressed by reduced blood flow. High resolution imaging reveals that Marcksl1 promotes the formation of linear actin bundles and decreases actin density at the EC cortex. Our findings demonstrate that a balanced network of linear and branched actin at the EC cortex is essential in conferring cortical integrity to resist the deforming forces of blood flow to regulate vessel structure.

Surgery for Cerebral Palsy Part 3: Classification and Operative Procedures for Thumb Deformity

2001 ◽  
Vol 26 (5) ◽  
pp. 465-470 ◽  
Author(s):  
M. A. TONKIN ◽  
N. C. HATRICK ◽  
J. R. T. ECKERSLEY ◽  
G. COUZENS
Keyword(s):  
Cerebral Palsy ◽  
Functional Assessment ◽  
Assessment System ◽  
Operative Procedures ◽  
Accurate Assessment ◽  
Thumb Reconstruction ◽  
Deforming Forces

Spastic thumb deformity is the result of imbalance between intrinsic and extrinsic forces acting across unstable joints. This paper presents a classification of spastic thumb deformity based on the accurate assessment of the deforming forces, outlines methods for their correction and reviews the results of our surgery. Thumb reconstruction procedures were performed in 32 patients with 33 spastic thumb deformities. All patients were assessed pre- and postoperatively using the same functional assessment system which was performed by the same team. The thumb was maintained out of the palm in 29 patients and lateral pinch was established in 26 patients.

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