Abstract: Described are methods for monitoring of stresses and other material properties. These methods use measurements of effective electrical properties, such as magnetic permeability and electrical conductivity, to infer the state of the test material, such as the stress, temperature, or overload condition. The sensors, which can be single element sensors or sensor arrays, can be used to periodically inspect selected locations, mounted to the test material, or scanned over the test material to generate two-dimensional images of the material properties. Magnetic field or eddy current based inductive and giant magnetoresistive sensors may be used on magnetizable and/or conducting materials, while capacitive sensors can be used for dielectric materials. Methods are also described for the use of state-sensitive layers to determine the state of materials of interest. These methods allow the weight of articles, such as aircraft, to be determined.

Abstract: Apparatus and methods are described for the improved throughput and increased reliability for inspection of critical surfaces on aircraft engine disks. Eddy current sensor arrays allow two-dimensional images to be generated for detection of cracks in regions with fretting damage. Background variations due to fretting damage and stress variations are also accommodated. These arrays are combined with instrumentation that permits parallel data acquisition for each sensing element and rapid inspection rates. Inflatable support structures behind the sensor array improve sensor durability and reduce fixturing requirements for the inspection.

Abstract: Methods are described for the use of conformable eddy-current sensors and sensor arrays for characterizing residual stresses and applied loads in materials. In addition, for magnetizable materials such as steels, these methods can be used to determine carbide content and to inspect for grinding burn damage. The sensor arrays can be mounted inside or scanned across the inner surface of test articles and hollow fasteners to monitor stress distributions. A technique for placing eddy-current coils around magnetizable fasteners for load distribution monitoring is also disclosed.

Abstract: Pressurized elastic support structures or balloons are used to press flexible sensors against the surface a material under test. Rigid support elements can also be incorporated into the inspection devices to maintain the basic shape of the inspection structure and to facilitate positioning of the sensors near the test material surface. The rigid supports can have the approximate shape of the test material surface or the pressurization of one or more balloons can be used to conform the sensor to the shape of the test material surface.

Abstract: A thrombus filter configured for placement in within a blood vessel lumen defined by a blood vessel wall. Methods and devices for selectively removing the thrombus filter when the presence of a filter in the vascular system is no longer desired. The thrombus filter includes a first strand formation, a second strand formation, and a joined portion.

Abstract: A thrombus filter configured for placement in within a blood vessel lumen defined by a blood vessel wall. Methods and devices for selectively removing the thrombus filter when the presence of a filter in the vascular system is no longer desired. The thrombus filter includes a first strand formation, a second strand formation, and a joined portion.

Abstract: A system for controlling delivery of a physiological fluid internally to a patient from a balloon catheter. The system includes a controller, an inflation-fluid pressurizer for maintaining inflation fluid in an inflation-fluid conduit under pressure, and a physiological-fluid pressurizer for maintaining physiological fluid in a physiological-fluid conduit under pressure. The inflation-fluid pressurizer is connected to receive signals from the controller to cycle pressure in the inflation-fluid conduit between a balloon inflating pressure and a balloon deflating pressure. The physiological-fluid pressurizer is connected to receive signals from the controller to cycle pressure in the physiological-fluid conduit between a fluid delivery pressure and a resting pressure. The controller is programmed to synchronize signals to the inflation-fluid pressurizer with signals to the physiological-fluid pressurizer.

Abstract: A thrombus filter configured for placement in within a blood vessel lumen defined by a blood vessel wall. Methods and devices for selectively removing the thrombus filter when the presence of a filter in the vascular system is no longer desired. The thrombus filter includes a first strand formation, a second strand formation, and a joined portion.

Abstract: A thrombus filter configured for placement in within a blood vessel lumen defined by a blood vessel wall. Methods and devices for selectively removing the thrombus filter when the presence of a filter in the vascular system is no longer desired. The thrombus filter includes a first strand formation, a second strand formation, and a joined portion.

Abstract: A medical device for delivering a drug internally to a patient's body. The medical device includes a catheter with a catheter shaft and a balloon attached to a distal end of the catheter shaft and a flexible, thin-walled sheath extending over the balloon. The sheath includes a balloon-enveloping portion having an inner diameter sized to fit closely around the balloon and a collar distal to, and having an inner diameter slightly smaller than the inner diameter of the balloon-enveloping portion. The collar terminates in an opening, and a tab extends distally from a wall of the sheath.