1062results about How to "Reduce shear force" patented technology

A cardiopulmonary bypass system utilizing membrane-based reciprocating positive displacement blood pumps (“pod pumps”). In one aspect, the pod pumps are constructed to provide reduced shear forces on the blood being pumped. In another aspect blood flow through the pod pumps can be controlled by a controller using information from pressure sensors in the control chamber of the pod pumps. In another aspect, the pod pumps are included on a disposable unit that can be received and held by a receptacle means on a base unit, the base unit also providing pressurized control fluid to the pod pumps on the disposable unit through the receptacle means.

A vascular closure device comprising a retrievable sheath-delivered contractible, clip device with structural radial or terminal members with terminal and non-terminal hooks that engage the vessel wall. Unlike other vascular closure clips, this device is delivered on the outside rather than the inside of sheath. Closure of the tissue opening can be effected by the feet of the clip engaging the puncture, aperture, or wound edges and memory characteristics of the device cause a contraction of the members, bringing the members into apposition and the wound edges together, permitting immediate vascular closure and healing of the blood vessel. The device can be delivered and recovered by an intravascular sheath.

The invention discloses an exciting device for testing dynamic property of an MEMS microstructure or micro-device and belongs to a minitype mechanical electronic system. A structure of the device comprises that: a microstructure to be tested is arranged on a crossed spring strip of the top part; the crossed spring strip is arranged on the top part of a sleeve by a bolt; piezoelectric ceramics, an upper connecting block, a steel ball, a lower connecting block and a pressure sensor are arranged inside the sleeve; the bottom of the piezoelectric ceramics is fixed on the upper connecting block; the top part is contacted with the crossed spring strip to change the thickness of an adjustable washer; the piezoelectric ceramics is pressed by the crossed spring strip; the pressure sensor is arranged on a base plate; and the base plate and the sleeve are connected by a bolt. The exciting device has the advantages that in normal environment the device can carry out excitation on the MEMS microstructure, can remove shearing force produced in the using process of the piezoelectric ceramics and effectively prolong the service life of the piezoelectric ceramics through exertion of certain pretightening force on the piezoelectric ceramics at the same time; and the device can measure the output force of the piezoelectric ceramics by the pressure sensor, thereby conveniently seeking a frequency response function of the microstructure and obtaining dynamic property parameters of the microstructure.

A hemodialysis and vascular access system comprises a subcutaneous composite PTFE silastic arteriovenous fistula having an indwelling silastic venous end which is inserted percutaneously into a vein and a PTFE arterial end which is anastomosed to an artery. Access to a blood stream within the system is gained by direct puncture of needle(s) into a needle receiving site having a tubular passage within a metal or plastic frame and a silicone upper surface through which needle(s) are inserted. In an alternate embodiment of the invention, percutaneous access to a blood stream may be gained by placing needles directly into the system (i.e. into the PTFE arterial end). The invention also proposes an additional embodiment having an arterialized indwelling venous catheter where blood flows from an artery through a tube and a port into an arterial reservoir and is returned to a vein via a port and a venous outlet tube distinct and distant from the area where the blood from the artery enters the arterial reservoir. The site where blood is returned to the vein is not directly fixed to the venous wall but is free floating within the vein. This system provides a hemodialysis and venous access graft which has superior longevity and performance, is easier to implant and is much more user friendly.

A method of servicing a wellbore in a subterranean formation comprising preparing a composition comprising a base fluid, a thixotropic viscosifier, a gellable composition and a bridging material, applying a shear force to the composition such that the composition viscosity decreases, introducing the composition into a lost circulation zone in the subterranean formation, wherein the lost circulation zone comprises cavities greater than about 200 microns in diameter, decreasing the shear force applied to the composition, and allowing the composition to set in the lost circulation zone. A method of servicing a wellbore in a subterranean formation comprising placing a first stream comprising a dilute solution of a metal acrylate into a lost circulation zone in the subterranean formation, placing a second stream comprising an activator into the lost circulation zone, and forming a lost circulation material upon contacting of the metal acrylate and the activator, wherein the lost circulation material forms in from about 0 to about 60 minutes.

A device, system and method for axenically culturing and harvesting cells and/or tissues, including bioreactors and fermentors. The device is preferably disposable but nevertheless may be used continuously for a plurality of consecutive culturing/harvesting cycles prior to disposal of same. This invention also relates to batteries of such devices which may be used for large-scale production of cells and tissues. According to preferred embodiments of the present invention, the present invention is adapted for use with plant cell culture.

Methods and systems for applying nanowires and electrical devices to surfaces are described. In a first aspect, at least one nanowire is provided proximate to an electrode pair. An electric field is generated by electrodes of the electrode pair to associate the at least one nanowire with the electrodes. The electrode pair is aligned with a region of the destination surface. The at least one nanowire is deposited from the electrode pair to the region. In another aspect, a plurality of electrical devices is provided proximate to an electrode pair. An electric field is generated by electrodes of the electrode pair to associate an electrical device of the plurality of electrical devices with the electrodes. The electrode pair is aligned with a region of the destination surface. The electrical device is deposited from the electrode pair to the region.

Engineered particles are provided may be used for the delivery of a bioactive agent to the respiratory tract of a patient. The particles may be used in the form of dry powders or in the form of stabilized dispersions comprising a nonaqueous continuous phase. In particularly preferred embodiments the particles may be used in conjunction with an inhalation device such as a dry powder inhaler, metered dose inhaler or a nebulizer.

The invention provides a compact axial-flow magnetic-levitation artificial heart pump, in particular to an artificial heart pump characterized in that two permanent magnet bearings and a mix of radial magnetic bearing suspension, and the radial magnetic bearing and a permanent magnet motor share a stator and a rotor. The compact axial-flow magnetic-levitation artificial heart pump has the structure that the compact axial-flow magnetic-levitation artificial heart pump comprises a stator assembly, a rotor assembly, a front guidance impeller and a rear guidance impeller; a taper-shaped or axial permanent magnet bearing is respectively formed by a first permanent magnet (9) and a right permanent magnet ring (14) as well as a second permanent magnet (19) and a left permanent magnet ring (18) to realize the purpose that the rotor axially supports in a suspension mode; a torque coil (5) and a suspension coil (7) are respectively wound on a motor stator (6); and with a certain decoupling control algorithm, the motor stator not only generates torque force but also generates radial suspension support force. In the compact axial-flow magnetic-levitation artificial heart pump, the rotor is supported by permanent magnetic force and electromagnetic force, and the compact axial-flow magnetic-levitation artificial heart pump has the advantages of small damage on blood, less radiation, compact structure and the like, is easy to transplant, is suitable for patients suffering from cardiac function failure, heart diseases and the like and can be used for ventricular assisting for a long time or a short time.

A cylindrical punch member equipped at the leading end thereof with a hole-punching blade is movably supported on a base frame in a hole-punching direction. A drive means is equipped that applies thrusting force to the punch member; a cam follower member disposed between the base frame and punch member engages a cam means disposed at either the base frame or punch member. An oblique cam surface inclined at a predetermined angle with regard to a hole-punching direction is equipped in cam means to give rotational drive force around an axis of rotation to the punch member that is moved in the hole-punching direction by the drive means. This configuration causes each of a plurality of cylindrical punch members to rotate around their axes of rotation when moved in a hole-punching direction by drive means thereby punching a hole in a sheet with a reduced shear force; the centrifugal force of that punch member rotation causing paper cutting debris to be scattered evenly under the punch member.

A piezoelectric micromotor for moving a moveable element comprising: a vibrator in the shape of a rectangular parallelepiped formed from a plurality of thin layers of piezoelectric material having first and second identical relatively large rectangular face surfaces defined by long and short edge surfaces wherein the layers are aligned one on top of the other and have their face surfaces bonded together; electrodes on surfaces of the layers; a contact region located on one or more edge surfaces of the layers, urged against the body; and at least one electrical power supply that electrifies electrodes to excite vibrations in the vibrator and thereby in the contact region that impart motion to the body.

A tile and tiled display system having at least two adjacent tiles each having a display screen with display pixels which are picture elements, whereby for coloured displays each pixel is comprised of a plurality light emitting or light modulating elements. Each of the tiles has at least one first substrate of a first material and at least one first layer of a second material fixed to the first substrate where the thickness of the at least one first layer is less than the thickness of the first substrate; the coefficient of thermal expansion of the first substrate is less than the coefficient of thermal expansion of the at least one first layer and the distance between the at least two tiles is less than the size of a pixel on the display screen. The first substrates of adjacent tiles can be brought in mechanical contact.

Provided is an angular ball bearing capable of controlling the whirling of a retainer at the time of high speed rotation.The retainer 21 of the synthetic resin is installed between an outer ring 1 and an inner ring 11, and the balls 31 are accommodated in a pocket 23 formed in the retainer 21. The pocket 23 is made to be cylindrical and a conical guide face 26 is formed at the end of inner diameter side of the back and front part of the retainer circumference direction of its cylindrical inner face 24. A curvature radius at the end of a large diameter of this conical guide face 26 is made larger than that of the cylindrical guide face 24 and a contact point of the balls 31 to the conical guide face 26 is prevented not to displace largely toward the diameter at the time of high speed rotation and then the whirling of the retainer 21 is controlled.

The invention relates to a multifunctional biological solid fermentation tank. The main body structure of the fermentation tank is a horizontal propeller, and spiral auger propeller blades are installed below the tank bottom. An auger is directly communicated with steam for sterilizing form the bottom of the tank and communicated with air for cooling, a spray tube on the upper part of the tank body sprays bacterial liquid for inoculation and can also spray water mist for humidity regulation, and thus, uniform inoculation and humidity control can be realized. The unique tank body horizontal type propeller and the auger coordination system below the tank body are utilized, and the circular flowing and the thorough mixing of a solid material in the tank body during fermentation are realized by controlling the rotating speed and the rotating direction; stirring nonuniformity caused by using a motor to rotate forwards or backwards repeatedly is avoided, automatic material discharge can be realized after fermentation, and material discharge is clean and complete. The operations of sterilization, cooling, inoculation, fermentation, temperature control, humidity control, ventilation, vacuum drying and the like required by solid fermentation can all be completed in the biological solid fermentation tank. The biological solid fermentation tank has the advantages of hardly no bacterial contamination, small occupied space, high automation degree, labor saving, investment saving and the like.

The invention relates to a hollow short implant of a dental implant, which comprises an one-stage structure and a two-stage structure, wherein the one-stage implant part is connected with an abutment part into a whole; the two-stage structure comprises an implant, a bridge adapter ring and a central bolt; peripheral cylinder spirochaeta of the implant part is divided into three stages, saw-tooth double thread in the main part of the implant can bear heavier load; the hollow structural design of the implant part keeps live bone column with a base and blood supply so as to enhance the supporting strength of the bone and the implant; a self-tapping socket can make bone tissue of the internal and external of the implant grow through and heal; a platform transfer design allows the epithelial cuff of the gum around the implant more reliable to avoid bone resorption caused by micro moving and micro leakage. The short hollow implant realizes combination of the internal and external bone, increases the combination area and supporting strength for a short or a long term, can be implanted rapidly with high strength, better retention in the early stage, high success rate in a long term, and solves the problem that the upper and lower jaws abrase the dental area in the conventional oral implant technology.