Abstract: Adjusting the popping pressure of a surgically-implanted shunt valve of the type having one or more elements adapted to move under the influence of a magnetic field, by positioning an adjustment device in proximity to the implanted valve but external to the body, providing the adjustment device with a plurality of electromagnets, selectively energizing the electromagnets through a sequence of steps in which different ones of the electromagnets are energized at successive steps, selecting the sequence of energization and the orientation and strength of the electromagnets so that the elements in the implanted device are caused to move in response to the sequence of energization to thereby adjust the popping pressure.

Abstract: A stepping motor isolated physically from electrical power sources and powered by the influence of a magnetic field applied from outside the apparatus, the stepping motor including a rotor and one or more stator elements, the stator elements being composed of magnetically soft and permeable material shaped and positioned with respect to the rotor so that when magnetized under the influence of the external field the stator elements strengthen and orient the magnetic field in their vicinities so as to cause movement of the rotor.

Abstract: A technique for transmitting from within the body information concerning an internal parameter (e.g., a measurement of a physiopathological parameter or a parameter generated by an implanted pacemaker), without physical connections to the implanted device, without an externally applied or internally generated electromagnetic field, and without implantation of radioactive material. The implanted device generates a magnetic field having an orientation influenced by changes in the internal parameter. The field is generated by one or more permanent magnets in the implanted device. The orientation of the field is detected externally using a viewer that provides a display indicative of the orientation. The display may provide an image of the magnetic field (e.g., a compass needle or magnetometer) that aligns itself with the field in a known manner. The magnetic field can be generated by a rotatable element on which are carried one or more permanent magnets (e.g.

Abstract: A surgically-implantable shunt valve in which the popping pressure is adjusted in finite increments by application of an external magnetic field.

Abstract: A surgically-implantable shunt valve for venting cerebrospinal fluid in the treatment of hydrocephalus and for shunting other body fluids, the valve having a flexible diaphragm mounted within a non-metallic housing, a plate mounted on the flexible diaphragm, the plate having a circular aperture and the diaphragm having an opening aligned with the aperture, the diaphragm being generally coplanar with the plate, the diaphragm and plate dividing the housing into inlet and outlet chambers that communicate through the aperture, the inlet and outlet chambers being generally free of blind cavities so as to inhibit collection of debris, the valve having a valve element (such as a spherical ball) residing on the inlet side of the aperture, the valve element being biased against the circular periphery of the aperture to keep it closed until the cerebrospinal fluid pressure in the inlet chamber exceeds a preselected popping pressure, and the valve having a screw for making external adjustments to the popping pressure.

Abstract: In a surgically implantable shunt system for venting cerebrospinal fluid in the treatment of hydrocephaly, a valve and the method of testing it are disclosed. The valve comprises an elongate hollow valve body into which a flat plate tightly fits, partitioning the valve body into an outlet and an inlet chamber. The flat plate has a circular aperture connecting the chambers and upon which rests a spherical ball of diameter larger than the aperture. A flat spring biases the ball against the circular periphery of the aperture creating a circular seal and providing a precisely defined back pressure, low hysteresis and low susceptibility to bridging by debris. Testing for leakage is accomplished by illuminating with light of a suitable frequency the aperture with ball seated and detecting any light transmitted therethrough.

Abstract: In a surgically implantable shunt system for venting cerebrospinal fluid in the treatment of hydrocephaly, a valve and the method of testing it are disclosed. The valve comprises an elongate hollow valve body into which a flat plate tightly fits, partitioning the valve body into an outlet and an inlet chamber. The flat plate has a circular aperture connecting the chambers and upon which rests a spherical ball of diameter larger than the aperture. A flat spring biases the ball against the circular periphery of the aperture creating a circular seal and providing a precisely defined back pressure, low hysteresis and low susceptiblity to bridging by debris. Testing for leakage is accomplished by illuminating with light of a suitable frequency the aperture with ball seated and detecting any light transmitted therethrough.

Abstract: Disclosed is an apparatus for reproducing patterns on flocked material. The pattern to be reproduced is scanned as a sequence of lines. For each line, the reflected light intensity is measured as a function of the position along the scanned line. This information is then used to control an air jet for selectively deflecting from the perpendicular the flocking fibers thereby to reproduce the desired pattern.

Abstract: In the method of treating ascites disclosed herein, an intraperitoneal inlet tube is connected to an implanted jugular catheter through a valving unit including a pair of one-way valve units which are connected in series through a flexible intermediate chamber to another pair of one-way valve units. The flexible chamber is surgically secured near the surface of the patient's abdomen or chest, preferably over the sternum, so that, by manual pressure, the patient can periodically deform the conduit thereby to effect pumping of the ascites fluid.

Abstract: The servo valve disclosed herein is rendered essentially insensitive to changes in pressure across the valving element by providing spring biasing of the valving element which is controlled by a diaphragm exposed to the inlet and outlet pressures. In a particular embodiment, the diaphragm is spring biased and the spring rates for the diaphragm and the valve element are selected in such proportion that the change in biasing force on the valve element exactly compensates for any change in inlet pressure. Therefore, the valve remains closed for any inlet pressure, unless the bias on the spring rates is unbalanced by a signal coming from a sensor.

Abstract: In the implantable pressure sensor disclosed herein, a radio-opaque liquid is contained within a resiliently compressible vessel of a silicone rubber, the volume of liquid actually contained within the vessel being then variable as a function of the pressure or force applied to the vessel. The silicone rubber is rendered impervious to the radio-opaque liquid by a treatment which involves expandng and saturating the cured silicone rubber with a mixture of a hydrocarbon solvent such as heptane containing a dissolved wax such as beeswax. The solvent expands and saturates the silicone rubber, carrying beeswax into the silicone rubber. When the solvent evaporates, the beeswax is then trapped within the interstices of the silicone rubber, under tension.