Abstract: Disclosed herein are designs for improved inflatable structures for use during minimally invasive cardiovascular procedures. These inflatable structures facilitate the perfusion of blood through an anatomical structure, such as a heart valve, during the cardiovascular procedure. The inflatable structures are formed of a plurality of balloons arranged radially around a central location. The plurality of balloons form a lumen through which blood flows. Each balloon of the plurality is shaped or configured to stabilize the adjacent balloons, limiting their movement relative to each other. For example, some embodiments can feature balloons with a keystone shape that limits movement of the balloons inward toward the lumen. Some implementations can also include a support coil running through the lumen. The support coil holds enables the lumen to be open to perfusion even in the early stages of balloon inflation.

Abstract: A rapid monitoring and discrimination method for drought conditions in summer maize based on chlorophyll content includes: 1) Obtaining multi-spectral imagery through UAV multi-payload low-altitude remote sensing technology and measuring chlorophyll content on the ground. Additionally, calculating vegetation indices including Normalized Difference Vegetation Index (NDVI), Soil-Adjusted Vegetation Index (SAVI), and Renormalized Difference Vegetation Index (RENDVI). 2) Selecting vegetation indices and constructing regression equations with measured chlorophyll content during different growth stages. The regression equation with the highest correlation for each growth stage is chosen as the optimal model equation for that particular stage. 3) Using the optimal model equations to retrieve chlorophyll content for each period and determining thresholds for chlorophyll content across different drought levels through calibration.

Abstract: Disclosed herein are designs for improved inflatable structures for use during minimally invasive cardiovascular procedures. These inflatable structures facilitate the perfusion of blood through an anatomical structure, such as a heart valve, during the cardiovascular procedure. The inflatable structures are formed of a plurality of balloons arranged radially around a central location. The plurality of balloons form a lumen through which blood flows. Each balloon of the plurality is shaped or configured to stabilize the adjacent balloons, limiting their movement relative to each other. For example, some embodiments can feature balloons with a keystone shape that limits movement of the balloons inward toward the lumen. Some implementations can also include a support coil running through the lumen. The support coil holds enables the lumen to be open to perfusion even in the early stages of balloon inflation.

Abstract: A rapid monitoring and discrimination method for drought conditions in summer maize based on chlorophyll content includes: 1) Obtaining multi-spectral imagery through UAV multi-payload low-altitude remote sensing technology and measuring chlorophyll content on the ground. Additionally, calculating vegetation indices including Normalized Difference Vegetation Index (NDVI), Soil-Adjusted Vegetation Index (SAVI), and Renormalized Difference Vegetation Index (RENDVI). 2) Selecting vegetation indices and constructing regression equations with measured chlorophyll content during different growth stages. The regression equation with the highest correlation for each growth stage is chosen as the optimal model equation for that particular stage. 3) Using the optimal model equations to retrieve chlorophyll content for each period and determining thresholds for chlorophyll content across different drought levels through calibration.

Abstract: A cleaning roller is mountable to a cleaning robot. The cleaning roller includes a sheath comprising a shell, an outer diameter of the shell tapering from a first end portion of the sheath and a second end portion of the sheath toward a center of the roller. The cleaning roller further includes a core including a central portion interlocked with the sheath to rotationally couple the core to the sheath and inhibit relative translation of the sheath and the core along an axis of rotation. An inner surface of the sheath and an outer surface of the core define an air gap therebetween, the air gap extending from the central portion of the core longitudinally along the axis of rotation toward the first end portion or the second end portion.

Abstract: A delivery sheath includes an outer tubular layer and an initially folded inner tubular layer. When an implant passes therethrough, the outer tubular layer expands and the inner tubular layer unfolds into an expanded lumen diameter. The sheath may also include selectively placed longitudinal support rods that mediate friction between the inner and outer tubular layers to facilitate easy expansion, thereby reducing the push force needed to advance the implant through the sheath's lumen.

Abstract: A delivery sheath includes an outer tubular layer and an initially folded inner tubular layer. When an implant passes therethrough, the outer tubular layer expands and the inner tubular layer unfolds into an expanded lumen diameter. The sheath may also include selectively placed longitudinal support rods that mediate friction between the inner and outer tubular layers to facilitate easy expansion, thereby reducing the push force needed to advance the implant through the sheath's lumen.

Abstract: Disclosed herein are expandable introducer sheaths and methods of making and using the same. The sheaths minimize trauma to a patient's vasculature by allowing for temporary expansion of a portion of the sheath to accommodate passage of a delivery system for a cardiovascular device, then return to a non-expanded state after the passage of the device. The sheath includes an elongated annular member having longitudinally extending channels that facilitate the sheath's temporary expansion. The channels are positioned in such a way that, upon expansion, they enable the movement of protruding contact surfaces toward the inner and outer surfaces of the annular member, reducing friction between the surface and the passing device. Some embodiments of the expandable sheath include an elastic outer layer that pushes the protruding contact surfaces back towards their original positions after the passage of the device.

Abstract: A vibration frequency adjustment system, comprising a vibratable component (102), at least one counterweight (401, 402), at least one drive device (407, 408), and a controller (307). The vibratable component (102) is configured to be connected to a vibration source (101). The vibration source (101) has an operating frequency range, and the vibratable component (102) has a natural vibration frequency. The at least one counterweight (401, 402) is configured to be movable along the vibratable component (102). The at least one drive device (407, 408) is configured to enable the at least one counterweight (401, 402) to be maintained at or moved to various counterweighting positions (421, 422, 423) on the vibratable component (102). The controller (307) is communicatively connected to the at least one drive device (407, 408). The vibration frequency adjustment system is used for a variable-frequency screw unit so as to reduce the vibration of an exhaust pipe.

Abstract: Inflatable devices are disclosed including a surface which has a network of polymer chains and is configured to be inflatable into a therapeutically or diagnostically useful shape, and at least one ultrashort laser pulse-formed modification in the surface. The network can, for example, include a network morphology that is substantially unchanged by modification with the ultrashort pulse laser. Ultrashort laser pulses can be laser pulses equal to or less than 1000 picoseconds in duration. Advantageously, the etching process uses a relatively low-heat laser to avoid significant heating of surrounding polymers while modifying the surface (and other structures) of the device. The process is configured so that the polymer chain morphology adjacent the modification is substantially unaffected by the low-heat laser. The resulting inflatable device has customized surface features while still retaining substantially homogenous polymer network morphology.

Abstract: A cleaning roller is mountable to a cleaning robot. The cleaning roller includes a sheath comprising a shell, an outer diameter of the shell tapering from a first end portion of the sheath and a second end portion of the sheath toward a center of the roller. The cleaning roller further includes a core including a central portion interlocked with the sheath to rotationally couple the core to the sheath and inhibit relative translation of the sheath and the core along an axis of rotation. An inner surface of the sheath and an outer surface of the core define an air gap therebetween, the air gap extending from the central portion of the core longitudinally along the axis of rotation toward the first end portion or the second end portion.

Abstract: An expandable delivery sheath includes an elastic outer tubular layer and an inner tubular layer. The inner tubular layer includes a thick wall portion integrally connected to a thin wall portion. The thin wall portion can include longitudinal reinforcing members/rods that facilitate unfolding during the passage of the implant, thus decreasing the push force and increasing the consistency of the push force. The inner tubular layer can have a non-expanded or folded condition wherein the thin wall portion folds onto an outer surface of the thick wall portion under urging of the elastic outer tubular layer. When an implant passes therethrough, the outer tubular layer stretches and the inner tubular layer unfolds into an expanded lumen diameter. Once the implant passes, the outer tubular layer again urges the inner tubular layer into the non-expanded condition with the sheath reassuming its smaller profile.

Abstract: A clock circuit comprises an oscillator circuit and a power-on reset circuit, the oscillator circuit comprises a current generating module and a loop oscillation module connected together; the current generating module is used for outputting a control current to the loop oscillation module; the loop oscillation module is used for outputting an oscillation signal with a set frequency under action of the control current; and the power-on reset circuit is connected to the loop oscillation module and is used for providing an enabling control signal to the loop oscillation module after a power supply is powered on to the power-on reset circuit and the oscillator circuit.

Abstract: An implantable prosthetic valve assembly, according to one embodiment, comprises a frame assembly including a plurality of struts and a prosthetic valve secured inside the frame assembly by one or more sutures. At least one of the plurality of spaced struts contains a recess that accepts a portion of the one or more sutures.

Abstract: Disclosed herein are expandable introducer sheaths and methods of making and using the same. The sheaths minimize trauma to a patient's vasculature by allowing for temporary expansion of a portion of the sheath to accommodate passage of a delivery system for a cardiovascular device, then return to a non-expanded state after the passage of the device. The sheath includes an elongated annular member having longitudinally extending channels that facilitate the sheath's temporary expansion. The channels are positioned in such a way that, upon expansion, they enable the movement of protruding contact surfaces toward the inner and outer surfaces of the annular member, reducing friction between the surface and the passing device. Some embodiments of the expandable sheath include an elastic outer layer that pushes the protruding contact surfaces back towards their original positions after the passage of the device.

Abstract: Inflatable devices are disclosed including a surface which has a network of polymer chains and is configured to be inflatable into a therapeutically or diagnostically useful shape, and at least one ultrashort laser pulse-formed modification in the surface. The network can, for example, include a network morphology that is substantially unchanged by modification with the ultrashort pulse laser. Ultrashort laser pulses can be laser pulses equal to or less than 1000 picoseconds in duration. Advantageously, the etching process uses a relatively low-heat laser to avoid significant heating of surrounding polymers while modifying the surface (and other structures) of the device. The process is configured so that the polymer chain morphology adjacent the modification is substantially unaffected by the low-heat laser. The resulting inflatable device has customized surface features while still retaining substantially homogenous polymer network morphology.

Abstract: An expandable delivery sheath includes an elastic outer tubular layer and an inner tubular layer. The inner tubular layer include a thick wall portion integrally connected to a thin wall portion. The thin wall portion can include longitudinal reinforcing members/rods that facilitate unfolding during the passage of the implant, thus decreasing the push force and increasing the consistency of the push force. The inner tubular layer can have a non-expanded or folded condition wherein the thin wall portion folds onto an outer surface of the thick wall portion under urging of the elastic outer tubular layer. When an implant passes therethrough, the outer tubular layer stretches and the inner tubular layer unfolds into an expanded lumen diameter. Once the implant passes, the outer tubular layer again urges the inner tubular layer into the non-expanded condition with the sheath reassuming its smaller profile.

Abstract: An implantable prosthetic valve assembly, according to one embodiment, comprises a frame assembly including a plurality of struts and a prosthetic valve secured inside the frame assembly by sutures. At least one of the plurality of spaced struts contains at least one hole that passes from one side of the at least one strut to another side of the at least one strut and a recess disposed around the hole.

Abstract: The present invention provides a clock circuit comprises an oscillator circuit and a power-on reset circuit, the oscillator circuit comprises a current generating module and a loop oscillation module connected together; the current generating module is used for outputting a control current to the loop oscillation module; the loop oscillation module is used for outputting an oscillation signal with a set frequency under action of the control current; and the power-on reset circuit is used for providing an enabling control signal to the loop oscillation module after a power supply is powered on; the power-on reset circuit is connected to the loop oscillation module.