摘要:
The present invention relates to a system for obtaining strain corresponding to an object's deformation by radially-tagged magnetic resonance imaging (MRI). The system acquires at least a ring-shaped crown region of Fourier domain (k-space) data for at least two sequential images of a radially-tagged object at different phases of deformation of the radially-tagged object. A first image represents a primary state of the radially-tagged object and a second image represents a secondary state of the radially-tagged object. Additionally, the images include radial tag lines. The first and second images are reconstructed as a reconstructed primary-state image and a reconstructed secondary-state image. The images are reconstructed as weighted by circumferential density of the radial tag lines, such that they are “tag line density-weighted” reconstructed images. Circumferential strain of the radially-tagged object is determined by comparing the two images.
摘要:
A method and apparatus that enables the production of micron-scale free-standing bubbles made of liquids containing surfactants are provided. The method and apparatus of the invention overcomes the limitations of conventional bubble forming techniques by using a controlled cavitation process in a liquid media.
摘要:
A method of fabricating optical energy collection and conversion devices using carbon nanotubes (CNTs), and a method of anchoring CNT's into thin polymeric layers is disclosed. The basic method comprises an initial act of surrounding a plurality of substantially aligned nanostructures within at least one fluid layer of substantially uniform thickness such that a first end of the plurality of nanostructures protrudes from the fluid layer. Next, the fluid layer is altered to form an anchoring layer, thereby fastening the nanostructures within the primary anchoring layer with the first ends of the nanostructures protruding from a first surface of the primary anchoring layer. Finally, a portion of the anchoring layer is selectively removed such that a second end of the nanostructures is exposed and protrudes from the anchoring layer. The resulting product is an optically absorbent composite material having aligned nanostructures protruding from both sides of an anchoring layer.
摘要:
Apparatus and methods for root canal treatments are provided. In some embodiments, an aiming element may be used to position a high-velocity liquid jet near a desired location in the tooth. Embodiments of the aiming element may include an interrupter that deflects or impedes the liquid jet when it is not desirable for the jet to propagate from the aiming element. Embodiments of the aiming element may include an elongated member that permits passage of the liquid jet through a channel. The elongated member may include one or more openings, for example, on sides and/or ends of the member. Some root canal cleaning techniques include one or more applications of the liquid jet followed by application of a disinfectant such as, for example, an aqueous solution of sodium hypochlorite.
摘要:
A method for forming a cardiovascular structure in culture is provided. The method includes applying mechanical force to a cell population in culture such that a cardiovascular structure is formed. In some embodiments, the mechanical force is produced in culture medium by a pulsatile liquid flow with a retrograde component. The cell population can include stem cells or differentiated cells, or combinations of both. In particular embodiments, a cardiovascular valve is formed. Scaffolds for the support and growth of the cell population, and bioreactors including the scaffolds, are also provided.
摘要:
In various embodiments of a method for filling root canal spaces, the root canal spaces are cleaned and irrigated, for example, by any suitable endodontic procedure, and the irrigating liquid is not removed from the canal spaces prior to filling. In some embodiments, a hydrophobic filler material is introduced into the root canal spaces while they are filled with liquid. As the canal spaces are filled, the hydrophobic filler material displaces the liquid and drives it out of the canal spaces, towards the crown of the tooth, where it can be removed. The hydrophobic filler material may comprise magnetically responsive particles having a hydrophobic surface coating that are compacted into the root canal spaces by application of a magnetic force field. In other embodiments, hydrophilic filler material in a flowable phase is introduced into the canal spaces where it partly displaces and partly absorbs the irrigating liquid before solidifying.
摘要:
The present invention relates to a system for three-dimensional (3-D) acoustic imaging of a scattering structure using information from a two-dimensional (2-D) image. The system uses a characterized sensor array to emit a signal from the sensor array into an object of interest to generate at least one 2-D representation of the object of interest. The 2-D representation comprises a plurality of x and y coordinate pairs and at least one candidate scattering structure. The candidate scattering structure comprises a shape defined by at least one pair of x and y coordinates. The candidate scattering structure shape is restricted to at least one pair of x and y coordinates. The pair of x and y coordinates of the candidate scattering structure shape are then compared with a first coordinate-dependent response function to assign an x, y, and z position of a scattering structure in 3-D space.
摘要:
A shunt system for use in a human body that is formed from a length of tube that is configured as a pump. The length of tube may be configured as a hydroimpedance pomp, whose surfaces are pressed to pump fluid in the specified direction and way. The length of tube that forms the pump may be connected to shunt inlet and outlet parts, and may also include a valve that is adjustable to prevent back draining of fluid.
摘要:
An extracardiac pumping system and method for using it supplement the circulation of blood, including the cardiac output, in a patient without any component thereof being connected to the patient's heart. A battery powered pump may be implanted subcutaneously and attached to an inflow conduit fluidly coupled to a patient's femoral artery via a subcutaneous anastomosis connection. The pump draws blood from the inflow conduit and discharges it through an outflow conduit fluidly coupled to a second peripheral artery via another subcutaneous anastomosis connection. The battery may be charged extracorporeally and the pump may be operated in either a continuous or pulsatile fashion in synchronization with the patient's heart. The conduits can be housed in a multi-lumen catheter and a reservoir may be provided which fluidly communicates with the inflow conduits. An additional feature may keep blood traveling extracorporeally within the system at or near body temperature. The system is capable of adjusting outflow from the pump to optimize the mixing of red blood cells in the aorta and thereby enhance oxygen delivery to tissues by minimizing blood cell concentration in the center of the aorta.
摘要:
A device and method for three-dimensional (3-D) imaging using a defocusing technique is disclosed. The device comprises a lens, a plurality of spatially-biased apertures obstructing the lens, a sensor operable for capturing light transmitted from an object through the lens and the plurality of spatially-biased apertures, and a processor communicatively connected with the sensor for processing the sensor information and producing a 3-D image of the object. The spatially-biased apertures may differ in shape, size, and/or distance from the optical axis.