摘要:
Devices, systems and methods are provided for stabilizing and grasping tissues such as valve leaflets, assessing the grasp of these tissues, approximating and fixating the tissues, and assessing the fixation of the tissues to treat cardiac valve regurgitation, particularly mitral valve regurgitation.
摘要:
Disclosed are methods, systems, and devices for the endovascular repair of cardiac valves, particularly the atrioventricular valves which inhibit back flow of blood from a heart ventricle during contraction. The procedures described herein can be performed with interventional tools, guides and supporting catheters and other equipment introduced to the heart chambers from the patient's arterial or venous vasculature remote from the heart. The interventional tools and other equipment may be introduced percutaneously or may be introduced via a surgical cut down, and then advanced from the remote access site through the vasculature until they reach the heart.
摘要:
Devices, systems and methods are provided for tissue approximation and repair at treatment sites. In particular, fixation devices are provided comprising a pair of elements each having a first end, a free end opposite the first end, and an engagement surface therebetween for engaging the tissue, the first ends being moveable between an open position wherein the free ends are spaced apart and a closed position wherein the free ends are closer together with the engagement surfaces generally facing each other. The fixation devices also include a locking mechanism coupled to the elements for locking the elements in place. The devices, systems and methods of the invention will find use in a variety of therapeutic procedures, including endovascular, minimally-invasive, and open surgical procedures, and can be used in various anatomical regions, including the abdomen, thorax, cardiovascular system, heart, intestinal tract, stomach, urinary tract, bladder, lung, and other organs, vessels, and tissues. The invention is particularly useful in those procedures requiring minimally-invasive or endovascular access to remote tissue locations, where the instruments utilized must negotiate long, narrow, and tortuous pathways to the treatment site.
摘要:
An active electronic device has drain and source electrodes that make ohmic conduct with a layer of a semiconductor. The semiconductor layer may be a thin layer of an organic or amorphous semiconductor. The drain and source electrodes are on a first face of the layer of semiconductor at locations that are spaced apart on either side of a channel. The device has a gate electrode on a second face of the layer of semiconductor adjacent to the channel. The gate electrode makes a Schottky contact with the semiconductor to produce a depletion region in the channel. The gate electrode may encapsulate the channel so that the channel is protected from contact with oxygen, water molecules or other materials in the environment. In some embodiments, the device has an additional gate electrode separated from the semiconductor layer by an insulating layer. Such embodiments combine features of OFETs and MESFETs.
摘要:
An active electronic device has drain and source electrodes that make ohmic conduct with a layer of a semiconductor. The semiconductor layer may be a thin layer of an organic or amorphous semiconductor. The drain and source electrodes are on a first face of the layer of semiconductor at locations that are spaced apart on either side of a channel. The device has a gate electrode on a second face of the layer of semiconductor adjacent to the channel. The gate electrode makes a Schottky contact with the semiconductor to produce a depletion region in the channel. The gate electrode may encapsulate the channel so that the channel is protected from contact with oxygen, water molecules or other materials in the environment. In some embodiments, the device has an additional gate electrode separated from the semiconductor layer by an insulating layer. Such embodiments combine features of OFETs and MESFETs.
摘要:
A storage system is provided that includes a plurality of storage devices and a data structure, accessible to the storage system, that includes a plurality of records corresponding to a plurality of network devices that are coupled to the storage system. Each record includes configuration data that identifies each of the plurality of storage devices to which data access by a respective one of the plurality of network devices is authorized. Each record may further include visibility data that identifies whether certain types of non-data access, such as requests for general information relating to a respective storage device, by a respective one of the plurality of network devices is permitted, even though data access to the respective storage device by the respective one of the plurality of network devices is not authorized.
摘要:
A method for driving an actuator. The method includes applying an electrical potential across an electrostrictive material relative to a counterelectrode disposed within an electrolyte, thereby creating a double layer potential across a region of enhanced ionic concentration. A current flowing between the electorostrictive material and the counterelectrode is measured. A portion of the applied potential appearing across the electrolyte and counterelectrode is calculated and subtracted from the applied potential to obtain an estimated double layer potential. The applied electrical potential is adjusted to obtain a specified double layer potential.
摘要:
The synthesis of thiophene based conducting polymer molecular actuators, exhibiting electrically triggered molecular conformational transitions is reported. Actuation is believed to be the result of conformational rearrangement of the polymer backbone at the molecular level, not simply ion intercalation in the bulk polymer chain upon electrochemical activation. Molecular actuation results from π-π stacking of thiophene oligomers upon oxidation, producing a reversible molecular displacement that leads to surprising material properties, such as electrically controllable porosity and large strains. The existence of active molecular conformational changes is supported by in situ electrochemical data. Single molecule techniques have been used to characterize the molecular actuators.
摘要:
A method of manufacturing a polymer transistor having a controllable gap is provided in an embodiment. In the embodiment, a conducting tip is positioned proximate to a conducting surface so as to form a gap, an electrochemical medium is introduced in contact with the conducting tip and the conducting surface, and an electrical potential is applied across the electrochemical medium so as to deposit a conductive polymer that electrically bridges the formed gap. In another embodiment, a counter electrode is provided in the electrochemical solution, facilitating processing in which the electrochemical potential at the conducting tip and at the conducting surface are the same and there is a return path for electrical current through the counter electrode. Repositioning of the tip during and after polymer deposition provides, in a further embodiment, adds additional capability with respect to gap control and polymer properties.
摘要:
A simple, inexpensive storage container for newspapers and the like is described for attachment to an apartment door or the like, such that papers can be inserted from the top but cannot be removed until the door is opened so as to expose an open side of the container. The container is secured in tamper proof manner by adhesive or simple slot and screw means.