Abstract: A membrane for use in an implantable glucose sensor including at least one crosslinked substantially hydrophobic polymer and at least one crosslinked substantially hydrophilic polymer; wherein the first and second polymers are different polymers and substantially form an interpenetrating polymer network, semi-interpenetrating polymer network, polymer blend, or copolymer. The membranes are generally characterized by providing a permeability ratio of oxygen to glucose of about 1 to about 1000 in units of (mg/dl glucose) per (mmHg oxygen). Three methods of making membranes from hydrophobic and hydrophilic monomers formed into polymer networks are provided, wherein according to at least two of the methods, the monomers may be substantially immiscible with one another.

Abstract: A membrane for use in an implantable glucose sensor including at least one crosslinked substantially hydrophobic polymer and at least one crosslinked substantially hydrophilic polymer; wherein the first and second polymers are different polymers and substantially form an interpenetrating polymer network, semi- interpenetrating polymer network, polymer blend, or copolymer. The membranes are generally characterized by providing a permeability ratio of oxygen to glucose of about 1 to about 1000 in units of (mg/dl glucose) per (mmHg oxygen). Three methods of making membranes from hydrophobic and hydrophilic monomers formed into polymer networks are provided, wherein according to at least two of the methods, the monomers may be substantially immiscible with one another.

Abstract: An improved analog front end and methods for increasing the power efficiency of duplex signals on a transmission line are disclosed. The improved analog front end bifurcates a hybrid into a fixed portion and an adaptive portion. The adaptive portion combines a biquad and a summer to produce a filter transfer function suited to compensate for transmission line irregularities. A method for configuring a local transceiver to minimize power requirements at a remote transmitter is disclosed. Broadly the method entails, applying a transmit signal to a front end in the absence of a remote signal; optimizing the transmit signal power; recording the reflected transmit signal; applying an adaptive filter in response to transmission line irregularities; and controllably adjusting the adaptive filter to minimize the amplitude of the reflected version of the transmit signal in the receive path. A method for recovering a remotely generated signal is also disclosed.

Abstract: An improved line driver and method for increasing the power efficiency, signal accuracy, and stability of a transmit signal on a transmission line are disclosed. The improved line driver uses a negative feedback control loop, thereby enhancing operational stability and suppressing both amplifier imperfections and discrete component manufacturing variances. Furthermore, when the improved line driver output stage is integrated with a hybrid, the composite circuit provides a power efficient full duplex solution for line driver applications. In a preferred embodiment, the improved line driver may comprise an active line termination control loop with current sense feedback, a first amplifier, and a second amplifier. The present invention can also be viewed as providing a method for increasing the stability, power efficiency, and accuracy of a line driver in a duplex transmission system.

Abstract: The present invention relates to a shoe sole that includes a polyamide in the form of powder or microfibers admixed with a thermoplastic base material to improve the strength, durability, abrasion resistance, and other desirable physical properties of the shoe sole. Suitable thermoplastic base materials include rubber, polyurethane or ethylene vinyl acetate. The polyamide microfibers are randomly and nonuniformly oriented to reinforce the shoe sole in all directions.

Abstract: Microarrays are made from sections of a molded block having many channels. These channels, which are formed by casting and/or embedding a rod in a moldable solid, are used to immobilize biological and chemical binding components after rod removal. The microarrays can be used in general biological assays, clinical evaluations and chemical library analyses.

Abstract: A system and method for filter tuning are presented. The system comprises means for adjusting the components of a filter by coarse adjustments such that the filter is set with an initial cutoff frequency of adequate accuracy to satisfy the requirements of the filter application, and means for adjusting the components of the filter by fine adjustments such that the filter is set to maintain the accuracy of the initial cutoff frequency in response to cutoff frequency drift. The method comprises the steps of adjusting the components of a filter by coarse adjustments such that the filter is set with an initial cutoff frequency of adequate accuracy to satisfy the requirements of the filter application, and adjusting the components of the filter by fine adjustments such that the filter is set to maintain the accuracy of the initial cutoff frequency in response to cutoff frequency drift.

Abstract: A continuous-time smoothing filter circuit and method for implementing the same are disclosed. The circuit may be implemented as a cascade of two sections. The first section may comprise two programmable 3rd order low-pass filters, each filter having a low Q value complex pole pair, as well as, a negative real pole. The second section may comprise an output stage amplifier having a low output impedance in order to drive external loads. Each of the 3rd order low-pass filters may be under programmable control to select and coarsely tune the cut-off frequency for each of the two filters. In its broadest terms, the method of the present invention can be described as: processing a digital to analog converter generated output signal with a first 3rd order low-pass filter; processing a first output signal provided by the first 3rd order low-pass filter with a second 3rd order low-pass filter; and processing a second output signal provided by the second 3rd order low-pass filter with a low-output impedance amplifier.

Abstract: The present invention relates to a shoe sole that includes a polyamide in the form of powder or microfibers admixed with a thermoplastic base material to improve the strength, durability, abrasion resistance, and other desirable physical properties of the shoe sole. Suitable thermoplastic base materials include rubber, polyurethane or ethylene vinyl acetate. The polyamide microfibers are randomly and nonuniformly oriented to reinforce the shoe sole in all directions.

Abstract: Cement compositions including initiation systems containing at least one peroxide or amine which has a higher molecular weight than the heretofore-employed peroxide BPO and amine DMpT, respectively. In particular, derivatives of peroxides and amines bearing large substituents relative to BPO and DMpT and polymeric peroxides and amines are suitably employed in the reaction mixture. Through the use of these initiator systems in which one or more of the components has reduced mobility relative to the materials employed in the conventional mixtures, it is possible to control the exothermicity and the peak temperature of the polymerization, while nonetheless achieving timely and adequate polymerization of the material. Concurrently, the choice of components for use in the initiation system advantageously results in a reduction in the generation of waste products and in the potential toxicity of the composition.

Abstract: An intraocular lens of the type having a plurality of legs which enter the lens in the anterior or posterior chamber by tangential contact between eye tissue and a region on each leg, wherein the region is composed of a compressible material. Also disclosed are homogeneous lenses in which the legs are colored.

Abstract: Disclosed are a novel monomer, and oxygen-permeable copolymers made therefrom, as well as contact lenses made from said copolymers, wherein the novel monomer has the formula: ##STR1##

Abstract: An intraocular lens of the type having a plurality of legs which center the lens in the anterior or posterior chamber by tangential contact between eye tissue and a region on each leg, wherein the region is composed of a compressible material. Also disclosed are homogeneous lenses in which the legs are colored.

Abstract: Compounds of the general formula ##STR1## wherein n, R.sub.1, R.sub.2 and X are defined herein, are effective inhibitors of polymerization of vinylic monomers, particularly acrylic monomers. The inhibitors are easily, efficiently, and thoroughly removed from solution with the monomer by contact with charcoal.

Abstract: The present invention relates to a method of modifying a surface of a soft contact lens to make the lens resistant to soiling. The method comprises initiating a reaction between the unhydrated lens surface containing carboxylic acid or alcohol moieties and agents capable of reacting with carboxylic acid or alcohol moieties in order to produce a surface which then either has a hydrophobic coating, a nonionic hydrophilic coating or is charged.

Abstract: An interpenetrating network polymer is obtained by mixing hydrophilic monomer vinyl pyrrolidone and hydrophobic monomer (5-alkylene-m-dioxanyl) acrylic ester in the presence of at least two crosslinking agents and, optionally, hydroxyalkyl acrylic ester and catalysts and causing polymerization to occur. Contact lenses made from the polymer have high tensile strength and can absorb a high degree of water.

Abstract: This disclosure describes the treatment of cellulose acetate butyrate contact lenses which are rendered hydrophilic by contacting said lenses with a treating agent which increases the hydrophilicity of said lenses. The treating agent is ammoniacal salt, alkali-metal hydroxide, strong mineral acid, benzene sulfonic acid, alkali metal borohydride or organometallic compound.

Abstract: This invention relates to a method for preparing globular, hydrophilic copolymers which have reticulated internal structures and are suitable for gas and gel chromatography. The method comprises polymerization by suspension polymerization methods of hydrophilic and hydrophilic monomers in aqueous medium in the presence of a component which prevents transfer of the hydrophilic monomer into the aqueous medium and the solubility of the aqueous medium in the monomeric phase.

Abstract: This invention relates to a method for preparing globular, hydrophilic copolymers which have reticulated internal structures and are suitable for gas and gel chromatography. The method comprises polymerization by suspension polymerization methods of hydrophilic and hydrophilic monomers in aqueous medium in the presence of a component which prevents transfer of the hydrophilic monomer into the aqueous medium and the solubility of the aqueous medium in the monomeric phase.

Abstract: There is disclosed a hydrophilic gel suitable for exposure to repeated long-term contact with live tissues or mucous membranes and consisting of macromolecules obtained by polymerizing a mixture of at least two copolymerizable units and a crosslinking agent. The mixture consists of from 52 to 99.5 parts by weight of N,N-diethylacrylamide, 43 to 0.1 parts by weight of a member selected from the group consisting of N,N-dialkyl acrylamide, N-alkyl methacrylamide, nitriles of acrylic and methacrylic acids and from 5 to 0.4 parts by of a divinylic monomer selected from the group consisting of diesters of acrylic acid and methacrylic acid, and methylene or ethylene-bis-methacrylamide or acrylamide.