Patents Assigned to Medical Research Associates, Ltd. #2
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Patent number: 4613640Abstract: Compositions, including hydrocarbon elastomeric block copolymers, such as styrene-ethylene-butylene-styrene and styrene-butadiene-styrene with mineral oil and essentially linear (i.e. non-cross-linked) polysiloxanes are made transparent by using polysiloxanes which are miscible with mineral oil. A preferred polysiloxane is polymethyloctyl siloxane. Transparent films, bags, tubes and other articles, especially useful in medical applications, such as catheters, blood tubes and blood bags, can be processed from the compositions.Type: GrantFiled: November 13, 1985Date of Patent: September 23, 1986Assignee: Medical Research Associates, Ltd. #2Inventors: Richard J. Deisler, Eugene P. Goldberg
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Patent number: 4578413Abstract: This invention provides tubings formed of a polymeric composition comprising a thermoplastic elastomeric hydrocarbon black copolymer and a polysiloxane having a kinematic viscosity of 20 to 10.sup.6 centistokes at room temperature, the polysiloxane constituting from about 0.1 to 12 percent by weight of the composition. The tubings can be used in medical applications.Type: GrantFiled: December 21, 1983Date of Patent: March 25, 1986Assignee: Medical Research Associates, Ltd. #2Inventor: Robert E. Sterling
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Patent number: 4559671Abstract: A sterile handle cover is disclosed for covering a lamp handle of a surgical lamp to provide a sterile surface for adjustment of the lamp by an operator. The handle cover comprises a grip portion defined by a first and a second end. An end wall is integrally attached proximate the first end of the grip portion to form a hollow container open at the second end. A protector is connected to the second end of the grip portion and extends radially outwardly for protecting the hand of the operator from contacting portions of the surgical lamp proximate the lamp handle. A plurality of ribs are disposed in the grip portion for frictionally engaging the lamp handle of the surgical lamp to maintain the position of the handle cover thereon.Type: GrantFiled: May 2, 1984Date of Patent: December 24, 1985Assignee: Medical Research Associates Ltd. #2Inventors: Winston A. Andrews, Larry Carpenter
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Patent number: 4552914Abstract: A composition of matter composed of a thermoplastic elastomeric hydrocarbon block copolymer having 0.1 to 8 percent polysiloxane, or silicone oil, uniformly distributed throughout. The composition exhibits improved surface, elasticity, and tensile strength characteristics as well as superior processibility. The block copolymer may take the form of styrene-ethylene-butylene-styrene in which the styrene blocks have a molecular weight of 5,000 to 40,000 and the ethylene-butylene block has a molecular weight of 20,000 to 500,000. Uniformly dispersed mineral oil may constitute 10 to 60 percent of the composition's total weight which may also include less than 45 percent polypropylene. Combining the copolymer with the silicone oil occurs under the influence of a pressure of 1,500 to 2,500 p.s.i. such as provided by extrusion blending. The resulting elastomeric composition may extrude in sheets as thin as 0.015, 0.010, or even 0.005 inch, which a puller may thin even further.Type: GrantFiled: December 4, 1984Date of Patent: November 12, 1985Assignee: Medical Research Associates, Ltd. #2Inventor: Robert E. Sterling
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Patent number: 4550727Abstract: An electrosurgical generator, having particular utility in surgical procedures on human joints, is provided with an output impedance in the range of 600 to 2,500 Ohms in order to efficiently transfer energy to the high impedance joint. The relatively high output impedance permits much lower power settings to be empolyed than are required by conventional electrosurgical generators so that little or no damage results in surrounding tissue. In the preferred embodiment, the output impedance range is 900 to 1,400 Ohms and is provided by an isolation transformer in which the turns ratio is selected to obtain the desired generator output impedance across the transformer secondary winding.Type: GrantFiled: July 8, 1983Date of Patent: November 5, 1985Assignee: Medical Research Associates, Ltd. #2Inventor: Frederick W. Rexroth
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Patent number: 4481323Abstract: This invention provides a composition of matter composed of a substantially uniform mixture of a thermoplastic elastomeric hydrocarbon black copolymer and 0.1 to 12 percent by weight of the composition of a polysiloxane. The composition exhibits improved surface, elasticity, and tensile strength characteristics as well as superior processibility. The block copolymer may comprise blocks of styrene-ethylene-butylene-styrene in which the styrene blocks have a molecular weight of 5,000 to 40,000 and the ethylene-butylene block has a molecular weight of 20,000 to 500,000. Mineral oil and polypropylene are preferably dispersed in the composition. Combining the copolymer with the polysiloxane typically occurs under the influence of a pressure of 1,500 to 2,500 p.s.i. or above, such as provided by extrusion blending. The resulting elastomeric composition may be extruded into sheets as thin as 0.015, 0.010, or even 0.005 inch, which a puller may thin even further.Type: GrantFiled: May 21, 1981Date of Patent: November 6, 1984Assignee: Medical Research Associates, Ltd. #2Inventor: Robert E. Sterling
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Patent number: 4378801Abstract: A fixed high frequency oscillator, variable frequency divider, and low frequency timer are provided to produce a high frequency output pulse group which is terminated at different intervals by both the variable frequency divider and the timer. The characteristics of the frequency divider may be varied to produce a number of modes of generator operation, all of which utilize a single high frequency output. The generator includes apparatus for producing a voltage spike as one of the pulses of each output group with a crest ratio of at least 3:1 in the cut command group and at least 14:1 in the fulgurate mode. The spike reionizes the current path through tissue without excessive tissue destruction due to wasted power and is minimized in dessicate mode where reionization arcing is undesirable. A pair of opto-isolated hand-held switches allow the user to select continuously between two preset modes of operation without risking shock.Type: GrantFiled: December 10, 1980Date of Patent: April 5, 1983Assignee: Medical Research Associates Ltd. #2Inventor: Roger L. Oosten
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Patent number: 4318409Abstract: A fixed high frequency oscillator, variable frequency divider, and low frequency timer are provided to produce a high frequency output pulse group which is terminated at different intervals by both the variable frequency divider and the timer. The characteristics of the frequency divider may be varied to produce a number of modes of generator operation, all of which utilize a single high frequency output. The generator includes circuitry for producing a voltage spike as one of the pulses of each output group with a ratio of peak power to RMS power of at least 10:1 in the cut command group and at least 19:1 in the coagulate command group. The spike reionizes the current path through tissue without excessive tissue destruction due to wasted power. A pair of opto-isolated hand-held switches allow the user to select continuously between two preset modes of operation without risking shock.Type: GrantFiled: December 17, 1979Date of Patent: March 9, 1982Assignee: Medical Research Associates, Ltd. #2Inventor: Roger L. Oosten