摘要:
Microfluidic devices may be fabricated from thermoplastics using, for example, hot embossing techniques. In some embodiments, the devices feature non-uniform surface modifications.
摘要:
Provided are methods and devices for formation and study of three-dimensional biological systems, including prokaryotic and eukaryotic cell migration, proliferation, and differentiation.
摘要:
Provided are methods and devices for formation and study of three-dimensional biological systems, including prokaryotic and eukaryotic cell migration, proliferation, and differentiation.
摘要:
A microfluidic device for more accurately modeling the in vitro environment in which cancer occurs is disclosed. The device comprises a surface defining one or more microfluidic channels that may further comprise one or more endothelial cells, a first three dimensional scaffold comprising one or more cancer cells that is spatially separated from the one or more microfluidic channels, and a second three dimensional scaffold comprising one or more stromal cells, at least a portion of which is interposed between the one or more microfluidic channels and the first three dimensional scaffold. The second three dimensional scaffold is in fluid communication with both the first three dimensional scaffold and the one or more microfluidic channels. The device can be used to assay anti-cancer agents, or as a system for modeling the growth, behavior, or metastasis and tumor formation of cancer cells.
摘要:
A bypass conduit and related methods include implanting a bypass in the heart between a heart chamber and an at least partially occluded artery to directly flow blood from the chamber to the artery. The bypass conduit is configured to have a higher resistance to blood flow in a first direction than in a second direction without any active flow control mechanism. The bypass conduit may have a first end defining a first opening and a second end defining a second opening and a wall extending between the two ends that defines a lumen extending between the two openings. The ends and the wall of the conduit are configured to have a higher resistance to blood flow in a first direction than in a second direction. A method of bypassing an at least partially occluded artery includes determining a resistance to blood flow of the artery at a location of an at least partial occlusion and selecting a conduit having a configuration based on the resistance to blood flow of the artery at the location of the at least partial occlusion. The method further includes implanting the conduit in a heart wall between the heart chamber and the artery downstream of the at least partial occlusion to directly flow blood between the chamber and the artery.
摘要:
A stent suitable for implantation in myocardial tissue to enhance perfusion therein may include a tubular member having first and second ends and a lumen. The first end of the stent may be configured to pierce myocardial tissue and the lumen may be configured to be placed in flow communication with a coronary vessel. The stent may further include a means for retaining the tubular member within the myocardial tissue. A method for implanting the stent may include positioning the first end of the stent at a desired implantation site and applying force to the second end of the stent to implant the stent within the myocardial tissue. The method may further include engaging the means for retaining with the myocardial tissue to retain the stent in position.
摘要:
A microfluidic device for more accurately modeling the in vitro environment in which cancer occurs is disclosed. The device comprises a surface defining one or more microfluidic channels that may further comprise one or more endothelial cells, a first three dimensional scaffold comprising one or more cancer cells that is spatially separated from the one or more microfluidic channels, and a second three dimensional scaffold comprising one or more stromal cells, at least a portion of which is interposed between the one or more microfluidic channels and the first three dimensional scaffold. The second three dimensional scaffold is in fluid communication with both the first three dimensional scaffold and the one or more microfluidic channels. The device can be used to assay anti-cancer agents, or as a system for modeling the growth, behavior, or metastasis and tumor formation of cancer cells.
摘要:
A method and apparatus for deriving a physiological description and clinically-useful data reboarding the cardiovascular system of an individual subject. The method includes obtaining a measurement sample associated with cardiovascular flow and utilizing a model, which may be distributed and/or non-linear to derive a description and data. The model generates and uses functions of source parameters and may, in an embodiment, match measurement samples against a library of stored predicted samples. A best-matching, predicted sample may then be associated with a measurement sample. An apparatus is provided which, according to an embodiment, includes an input for obtaining a measurement sample, a processor to derive the description and data, and an output. The apparatus may also include a digital storage medium to store a library of predicted samples.
摘要:
A tobacco smoke article holder for a testing machine and a method of mounting a tobacco smoke article in the holder to simulate the human smoking process including an inflatably lined flow-through conduit having a depth substantially equal to the average width of a human lip and a cross-section in liner-relaxed state approximating the cross-section of the tobacco smoke article to accommodate normal insertion depth of the tobacco smoke article.
摘要:
A method and apparatus for testing pressure applied to a smoking article is provided and is particularly useful in testing lip pressure applied to cigarettes. The system includes a pressure sensor adapted to be positioned on a predetermined portion of the smoking article that is to be subjected to external pressure. A pressure transducer is connected to the sensor. The output of the transducer responsive to the pressure applied to the smoking article and sensed by the sensor is displayed. Additionally, a method and apparatus for calibrating the pressure sensor is included. The calibration system includes a rigid enclosure and an elastomeric tube positioned in a recess in the enclosure and connected to a pressure regulator. The enclosure includes a recess conforming to the configuration of the smoking article with a pressure sensor mounted thereon and positioned so that the smoking article in the recess is in communication with the elastomeric tube so that when the tube is pressurized it exerts a measured contact stress on the smoking article and pressure sensor. Thus, the calibration can take place over a range of anticipated pressures.