64 results about "Wall stress" patented technology

A system delivers cardiac pacing therapy and chemical and/or biological therapy to modulate myocardial tissue growth in a heart after myocardial infarction (MI). The system includes an agent delivery device to release one or more agents to an MI region to modulate myocardial tissue growth in that region, and a cardiac rhythm management (CRM) device to deliver pacing pulses to enhance the effects of the one or more agents by altering myocardial wall stress and cardiac workload. In one embodiment, the system is an implantable system including an implantable agent delivery device and an implantable CRM device.

The device and method for reducing heart wall stress. The device can be one which reduces wall stress throughout the cardiac cycle or only a portion of the cardiac cycle. The device can be configured to begin to engage, to reduce wall stress during diastolic filling, or begin to engage to reduce wall stress during systolic contraction. Furthermore, the device can be configured to include at least two elements, one of which engages full cycle and the other which engages only during a portion of the cardiac cycle.

A system delivers combined ventricular assist device (VAD) therapy and chemical and/or biological therapy to modulate myocardial tissue growth in a heart after myocardial infarction (MI). The system includes an agent delivery device to release one or more agents to an MI region to modulate myocardial tissue growth in that region, and a VAD to enhance the effects of the one or more agents by reducing myocardial wall stress and the overall cardiac workload. In one embodiment, the system is an implantable system including an implantable agent delivery device and an implantable VAD for long-term use in a patient.

An apparatus and method for assessing myocardial wall stress is disclosed. The method may be used in conjunction with electro-stimulatory therapy for preventing or reversing ventricular remodeling. In such therapy, one or more stimulatory pulses are delivered to the heart such that a stressed region of the myocardium is pre-excited relative to other regions, thereby subjecting the stressed region to a lessened preload and afterload during systole. The unloading of the stressed myocardium over time effects reversal of undesirable ventricular remodeling.

Devices and methods for treatment of a failing heart by reducing the heart wall stress. The device can be one which reduces wall stress throughout the cardiac cycle or only a portion of the cardiac cycle.

Cardiomyopathy may be treated by distributing space-occupying agent within the myocardium in a pattern about one or more chambers of the heart, such that the space-modifying agent integrates into and thickens at least part of the cardiac wall about the chamber so as globally to reduce wall stress and stabilize or even reduce chamber size. Some patterns also cause a beneficial global reshaping of the chamber. These changes occur quickly and are sustainable, and have a rapid and sustainable therapeutic effect on cardiac function. Over time the relief of wall stress reduces oxygen consumption and promotes healing. Moreover, various long-term therapeutic effects may be realized depending on the properties of the space-occupying agent, including combinations with other therapeutic materials. Specific cardiac conditions treatable by these systems and methods include, for example, dilated cardiomyopathy (with or without overt aneurismal formations), congestive heart failure, and ventricular arrhythmias. Patterns of distribution of space-occupying agent within the myocardium for global resizing may also be used or augmented to treat localized conditions such as myocardial infarctions, overt aneurysm of the ventricular wall as typically forms in response to large transmural myocardial infarctions, and mitral regurgitation due to a noncompliant mitral valve. These techniques may also be used to treat localized conditions that may not yet have progressed to cardiomyopathy.

Method and apparatus are disclosed for treating congestive heart failure. The method includes relieving wall stress on a diseased heart by an amount to decrease a rate of myocardial cell loss. Further, the method includes pharmacologically encouraging a myocardial cell gain. Cell gain may be encouraged by cell replication, cell recruitment or inhibition of cell death. Further embodiments of the method include a passive cardiac constraint selected to reduce wall stress on the heart. An apparatus of the present invention includes a passive cardiac constraint and a pharmacological agent to encourage cell gain.

A technique that improves large-eddy simulation consists in replacing the instantaneous sub-grid scale eddy-viscosity (such as the dynamic Smagorinsky model eddy-viscosity) in the near-wall region with an eddy-viscosity computed from Reynolds Averaged Navier-Stokes eddy-viscosity and corrected dynamically using the resolved turbulent stress. The near-wall eddy-viscosity formulation is applied either with a wall stress model on coarse grids that do not resolve the wall or with wall-resolved grids coarsened in the wall-parallel directions. Reynolds averaged Navier-Stokes eddy-viscosity is computed either from a look-up table or from a simultaneous solution of a Reynolds Averaged Navier-Stokes turbulence model.

The invention relates to a device and a method for detecting coal seam gas pressure and coal wall stress. The detection device comprises a pressure detector and a stress detector which penetrate the rock layer to be positioned in a drilled hole on a coal wall and an analog-to-digital converter, a monolithic processor and a display which are arranged outside the drilled hole on the coal wall, and the detection method comprises the following steps: a hole is drilled on a coal seam, the pressure detector and the stress detector are transported inside the drilled hole and respectively used for detecting the gas pressure inside the coal seam and the coal wall stress, wherein, the pressure detector transforms the detected information into a standard current signal, the stress detector transforms the detected information into a voltage signal for amplification, and the current signal and the voltage signal are transmitted to the outside of the drilled hole through wires, and are transformed into digital signals through the analog-to-digital converter; and after program operation and processing of the monolithic processor, the numerical values of the coal seam gas pressure and the coal wall stress can be displayed on the display screen. Therefore, not only the measurement time of the coal seam gas pressure can be greatly shortened, but also the technical requirements for hole sealing are lowered, and the cost is saved.

The invention discloses a self-propelled diameter-variable stress rosette pasting device used for geostress measuring and relates to the technical field of surveying of geological and mineral energy resources and geotechnical engineering. The self-propelled diameter-variable stress rosette pasting device comprises an orientor, an automatic climbing system, a colloid storing and extruding mechanism, a stress rosette fixing and pasting mechanism and a drive-by-wire operator controlling the automatic climbing system, and the orientor, the automatic climbing system, the colloid storing and extruding mechanism and the stress rosette fixing and pasting mechanism are connected sequentially. By the self-propelled diameter-variable stress rosette pasting device, functions of mounting-in-place and pasting of strain gauges in the process of geostress testing through a hole wall stress relieving method can be realized, the problems that a strain meter is complex in mounting process and low in success rate, testing depth is limited by length of a mounting guide rod and the like when a conventional hollow inclusion method is adopted for geostress measuring are solved effectively, application range of the hole wall stress relieving method for geostress measuring is expanded, and testing efficiency is improved. The self-propelled diameter-variable stress rosette pasting device has the advantages of low testing cost, convenience in carrying, simplicity and convenience in on-site operation and the like.

The invention discloses a supercharging effect force-considering hole-wall collapsing pressure calculation method, and belongs to the field of oil drilling. The method comprises the following steps of: obtaining a stratum parameter and a drilling fluid density from geological information, logging information and drilling information of a selected area; obtaining a mud cake penetration rate from drilling fluid penetration experiment information of the selected area; obtaining a rock mechanical parameter from rock mechanical experiment information and the logging information of the selected area; obtaining a supercharging effect force coefficient according to the stratum parameter, the drilling fluid density and the mud cake penetration rate; and substituting the rock mechanical parameter, the stratum parameter and the supercharging effect force coefficient into a hole-wall collapsing pressure model to obtain hole-wall collapsing pressure. According to the method, the hole-wall stress features under drilling fluid environment can be reflected more really, and basis is provided or the selection of reasonable drilling fluid density in the drilling process.

The invention belongs to the technical field of mining, and particularly relates to a sublevel-open-stoping-method pressure-relief stoping method for a high-dipping medium-thick ore body. The method achieves pressure-relief type stoping by means of the steps that a cut parvis is formed through blasting in groups, and then the ore body is divided into three subsections in the vertical direction of the ore body; the ore body is divided into a plurality of stopes in each subsection, and each stope is divided into I-VI rows of grouped concentrated blasting subareas to conduct blasting in groups; broken ores are formed after blasting is conducted, a route for transmitting hanging wall stress to heading wall through the ore body is cut off, and pressure-relief grooves in stair shapes are formed in the vertical direction of the ore body. In addition, through multi-group concentrated blasting, a hole-by-hole millisecond blasting detonation technology is adopted, disturbance and damage to rock mass caused by multi-group blasting of traditional operation are reduced, the blasting efficiency is enhanced, the stope room stoping period is shortened, and the ore production efficiency is enhanced.

The invention provides a deep foundation pit enclosure wall stress deformation quick calculating method in consideration of wall soil coupling; and the method fully considers a coupling relation of wall soil deformation in the foundation pit excavation unloading process, and has the advantages of high calculating efficiency, more accordance with actual conditions and the like. The method comprisesthe following steps: (1) an elastic foundation beam model is built (an elastic beam is adopted to simulate a ground continuous wall, a spring unit is adopted to simulate a support, a soil spring unitis adopted to simulate in-pit soil, and the soil pressure adopts a non-limit soil pressure model), and related calculating parameters are determined; (2) the after-wall soil pressure distribution iscalculated (the supposed wall deformation is firstly calculated as zero); (3) a stress balance equation of the ground continuous wall is calculated to obtain corresponding wall deformation; (4) wall deformation errors calculated by two times are judged to restrain to a set value; and if requirements are not met, the steps (2) to (4) are repeated until the errors are restrained to the set value toobtain a final wall deformation value; and (5) the wall bending moment and shearing force and the after-wall soil pressure distribution are calculated based on the wall deformation value.

The invention provides a stress peak detection method through a laser shock peening hole wall. The stress peak detection method comprises the following steps that a finite element model of the laser shock peening hole is established; simulation calculation is performed; a laser loading curve is determined according to the laser shock process parameters; a shock trajectory path is set; a simulation calculation module is started; hole opening finite element simulation is started; laser shock peening simulation is performed on the acting area of laser shock, and then hole opening simulation is performed on the shock center area; the laser shock process parameters are changed and the steps are repeated; a relation curve between the residual stress and the hole wall stress peak of the hole wall surface theory is drawn; the sample is prepared, and laser shock peening processing and hole opening are performed on the sample; the surface residual stress of the hole of the sample is measured for statistical analysis; and the actual residual stress peak of the hole wall is estimated. The surface residual stress near the hole angle can be measured according to the relation curve between the laser shock peening surface residual stress near the hole angle and the hole wall stress peak.

The present invention relates to a pressure regulation type children pigeon breast appliance. The pressure regulation type children pigeon breast appliance is provided with a chest orthopedic stand, a fixing strap, a pressure fixing plate, a pressure monitoring gauge, fixing tying belts, tying belt fixing buttons and fixing shoulder straps, wherein two ends of the fixing strap are connected with the fixing tying belts, two ends of the chest orthopedic stand are connected with the tying belt fixing buttons, the tying belt fixing buttons coordinate with the fixing tying belts, the fixing shoulder straps are connected between the chest orthopedic stand and the fixing strap, inner sides of both the chest orthopedic stand and the fixing strap are provided with liners, the pressure monitoring gauge is disposed at an outer side face of the chest orthopedic stand, the pressure fixing plate is disposed at the inner side face of the chest orthopedic stand, and a thin film pressure sensor is disposed on the inner surface of the pressure fixing plate. The pressure regulation type children pigeon breast appliance has the advantages that the orthopedic pressure can be displayed and is adjustable, chest wall stressed situations can be monitored, the chest wall pressure degree can be conveniently adjusted, and tissue injuries caused by excessive pressure are prevented.