Patents Assigned to Medical Research Associates, Ltd. #2
  • Patent number: 4613640
    Abstract: 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: Grant
    Filed: November 13, 1985
    Date of Patent: September 23, 1986
    Assignee: Medical Research Associates, Ltd. #2
    Inventors: Richard J. Deisler, Eugene P. Goldberg
  • Patent number: 4578413
    Abstract: 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: Grant
    Filed: December 21, 1983
    Date of Patent: March 25, 1986
    Assignee: Medical Research Associates, Ltd. #2
    Inventor: Robert E. Sterling
  • Patent number: 4559671
    Abstract: 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: Grant
    Filed: May 2, 1984
    Date of Patent: December 24, 1985
    Assignee: Medical Research Associates Ltd. #2
    Inventors: Winston A. Andrews, Larry Carpenter
  • Patent number: 4552914
    Abstract: 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: Grant
    Filed: December 4, 1984
    Date of Patent: November 12, 1985
    Assignee: Medical Research Associates, Ltd. #2
    Inventor: Robert E. Sterling
  • Patent number: 4550727
    Abstract: 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: Grant
    Filed: July 8, 1983
    Date of Patent: November 5, 1985
    Assignee: Medical Research Associates, Ltd. #2
    Inventor: Frederick W. Rexroth
  • Patent number: 4481323
    Abstract: 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: Grant
    Filed: May 21, 1981
    Date of Patent: November 6, 1984
    Assignee: Medical Research Associates, Ltd. #2
    Inventor: Robert E. Sterling
  • Patent number: 4378801
    Abstract: 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: Grant
    Filed: December 10, 1980
    Date of Patent: April 5, 1983
    Assignee: Medical Research Associates Ltd. #2
    Inventor: Roger L. Oosten
  • Patent number: 4318409
    Abstract: 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: Grant
    Filed: December 17, 1979
    Date of Patent: March 9, 1982
    Assignee: Medical Research Associates, Ltd. #2
    Inventor: Roger L. Oosten