Temporomandibular synovial fluid pressure response to altered mandibular positions

1990 ◽  
Vol 98 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Dennis M. Ward ◽  
Rolf G. Behrents ◽  
Jerold S. Goldberg
Keyword(s):  
Synovial Fluid ◽  
Fluid Pressure ◽  
Pressure Response

Computational Simulation of Synovial Fluid Kinematics of the Scapholunate Joint

2019 ◽  
Vol 24 (02) ◽  
pp. 169-174
Author(s):  
Yoke-Rung Wong ◽  
Sophie Sok Huei Tay ◽  
Ita Suzana Mat Jais ◽  
Hwa-Liang Leo ◽  
Chee-Fui Lieu ◽  
...  
Keyword(s):  
Synovial Fluid ◽  
Fluid Model ◽  
Computational Simulation ◽  
Fluid Pressure ◽  
Pressure Change ◽  
Carpal Bones ◽  
Ligament Injury ◽  
Maximum Pressure ◽  
Fluid Interface ◽  
Volume Method

Background: The interaction between wrist kinematics and synovial fluid pressure has yet to be studied. To our knowledge, this is the first study to determine the effect of scapholunate joint kinematics on synovial fluid pressure change using finite volume method. Methods: The carpal bones of a cadaveric hand were obtained from Computed Tomography (CT) scans. CT images of the carpal bones were segmented and reconstructed into 3D model. The 3D synovial fluid model between the scaphoid and lunate was constructed and then used for computational simulations. The kinematics data of scapholunate joint obtained from radioulnar deviation of the wrist was investigated. Results: It was found that the pressure in synovial fluid varied from -1.68 to 2.64 Pa with maximum pressure located at the scaphoid-fluid interface during the radial deviation. For ulnar deviation, the pressure increased gradually from the scaphoid-fluid interface towards the lunate-fluid interface (-1.37 to 0.37 Pa). Conclusions: This new computational model provides a basis for the study of pathomechanics of ligament injury with the inclusion of synovial fluid.

Fluid pressure response to undrained compression in saturated sedimentary rock

Geophysics ◽  
1986 ◽  
Vol 51 (4) ◽  
pp. 948-956 ◽  
Author(s):  
Douglas H. Green ◽  
Herbert F. Wang
Keyword(s):  
Pore Pressure ◽  
Effective Stress ◽  
Wave Attenuation ◽  
Fluid Pressure ◽  
Confining Pressure ◽  
Pressure Response ◽  
Additional Parameter ◽  
Seismic Wave Velocity ◽  
Specific Storage ◽  
Order Of Magnitude

The pore pressure response of saturated porous rock subjected to undrained compression at low effective stresses are investigated theoretically and experimentally. This behavior is quantified by the undrained pore pressure buildup coefficient, [Formula: see text] where [Formula: see text] is fluid pressure, [Formula: see text] is confining pressure, and [Formula: see text] is the mass of fluid per unit bulk volume. The measured values for B for three sandstones and a dolomite arc near 1.0 at zero effective stress and decrease with increasing effective stress. In one sandstone, B is 0.62 at 13 MPa effective stress. These results agree with the theories of Gassmann (1951) and Bishop (1966), which assume a locally homogeneous solid framework. The decrease of B with increasing effective stress is probably related to crack closure and to high‐compressibility materials within the rock framework. The more general theories of Biot (1955) and Brown and Korringa (1975) introduce an additional parameter, the unjacketed pore compressibility, which can be determined from induced pore pressure results. Values of B close to 1 imply that under appropriate conditions within the crust, zones of low effective pressure characterized by low seismic wave velocity and high wave attenuation could exist. Also, in confined aquifer‐reservoir systems at very low effective stress states, the calculated specific storage coefficient is an order of magnitude larger than if less overpressured conditions prevailed.

Analysis of the Pressure Response of Kick Control in MPD

2014 ◽  
Vol 997 ◽  
pp. 713-716
Author(s):  
Pu Liu ◽  
Hu Yin ◽  
Tian Xiang Wang ◽  
Meng Han Si
Keyword(s):  
Oil And Gas ◽  
Fluid Pressure ◽  
Pressure Response ◽  
Control Technology ◽  
Gas Well ◽  
Well Drilling ◽  
Well Control ◽  
Overflow Control ◽  
And Control ◽  
Conventional Drilling

With narrow Density Windows wells and high pressure oil and gas well drilling growing in number, the kick risks becoming increasingly prominent and higher requirements for well control technology being needed, the manage pressure drilling (MPD) technology is used more and more widely. The problems like how to effectively find gas overflowand how to effectively control the overflow in the MPD must be solved.Well must be shuted timely in conventional drilling when overflow happens.The special characteristics of overflow control equipment determines the diversity and effectiveness of its overflow monitoring means in MPD, and the overflow is found more effectively and timely than conventional drilling. Well control risk will increase sharply if kick cannot be timely and effectively identified and controled when overflow occurs. MPD can quickly adjust the wellhead back pressure and inhibit the formation fluid further invasion. Therefore, combining with MPD process and the fluid pressure parameters, the article establishs process of kick recognition and kick control, analyses of the process and analyzes and evaluates the pressure response in process of kick control.MPD can better control the bottom hole pressure in well control situation, ensuring drilling safety. The process of kick recognition and control is of great significance to promote the development and application of kick control technology in MPD.

Effects of intravenous nitroglycerin on the intracranial pressure and volume pressure response

1983 ◽  
Vol 58 (4) ◽  
pp. 562-565 ◽  
Author(s):  
Ghaleb A. Ghani ◽  
Yung Fong Sung ◽  
Michael S. Weinstein ◽  
George T. Tindall ◽  
Alan S. Fleischer
Keyword(s):  
Blood Pressure ◽  
Intracranial Pressure ◽  
Fluid Pressure ◽  
Pressure Response ◽  
Mean Blood Pressure ◽  
Intravenous Nitroglycerin ◽  
Content Type ◽  
Ventricular Fluid Pressure ◽  
The Mean ◽  
Fine Print

✓ Ventricular fluid pressure (VFP) and volume-pressure response were measured during nitroglycerin (NTG) infusion in nine patients anesthetized with N2O and fentanyl. The patients' ventilation was controlled, and PaCO2 was kept at 32 ± 4 mm Hg. When an infusion of 0.01% NTG was given intravenously to decrease the mean blood pressure to 95.1%, 84.7%, and 78.2% of control, the VFP increased from control levels of 9.94 ± 2.14 mm Hg to 12.89 ± 2.25, 15.6 ± 2.85, and 14.43 ± 3.45 mm Hg, respectively. The volume-pressure response showed a significant increase when blood pressure decreased to 84.7% and 78.2% of control. These results suggest that intravenous NTG caused an increase in the intracranial pressure and a decrease in the intracranial compliance.

scholarly journals Influence of Synovial Fluid Pressure on Biphasic Lubrication Property in Articular Cartilage

2018 ◽  
Vol 13 (3) ◽  
pp. 172-177 ◽  
Author(s):  
Shoko Horibata ◽  
Seido Yarimitsu ◽  
Hiromichi Fujie
Keyword(s):  
Articular Cartilage ◽  
Synovial Fluid ◽  
Fluid Pressure

Lubrication of the Human Ankle Joint in Walking

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Miroslav Hlaváček
Keyword(s):  
Hyaluronic Acid ◽  
Synovial Fluid ◽  
Ankle Joint ◽  
Fluid Pressure ◽  
Fluid Viscosity ◽  
Fluid Filtration ◽  
Sliding Motion ◽  
Gel Layer ◽  
Human Ankle ◽  
The Matrix

Human ankle joint lubrication in walking is analyzed. A biphasic mixture model is considered for articular cartilage (ideal interstitial fluid and elastic porous matrix that is transversely isotropic and inhomogeneous throughout its thickness). Synovial fluid is considered Newtonian. Its viscosity is due to the macromolecules of hyaluronic acid that are too large to enter the matrix pores. Due to the fluid pressure gradient water and small solutes pass through the matrix pores and across the articular surface in both directions. The effect of the time varying concentration of hyaluronic acid or of the synovial fluid viscosity on the synovial film thickness distribution is small and neglected in the model. Periodic sliding motion of the articular surfaces and periodic loading of the joint as encountered in walking are included in the analysis. Synovial fluid serves as a fluid lubricant. The model shows that soon after the onset of walking the normal human ankle joint works in a mixed lubrication mode (a combination of boundary and fluid-film lubrications). A protective gel layer formed in the gap due to the synovial fluid filtration by cartilage may serve as a boundary lubricant. The synovial gel layer is not guaranteed in the osteoarthritic case, and the rough sliding surfaces may get repeatedly into an intimate contact and wear off due to the reciprocating sliding motion.

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