摘要:
An electromechanical/solid-state AC relay has an electromechanical winding coil that moves an armature to force mechanical contacts to open or close. Electrical arcing across the mechanical contacts that occur as the contacts are opening or closing can damage and severely reduce the lifetime of the relay. Contact arcing is prevented by pulsing a triac on for a short period of time just before and after the mechanical contacts make or break contact. The triac limits the voltage difference across the mechanical contacts to less than one volt to prevent arcing. The triac is turned off after the mechanical contacts finish moving, reducing the heating and average power through the triac. A zero-sampling circuit that detects when the AC input voltage switches across 0 volts and activates a control integrated circuit to switch on the triac during zero-crossings to minimize power surges.
摘要:
An electromechanical/solid-state AC relay has an electromechanical winding coil that moves an armature to force mechanical contacts to open or close. Electrical arcing across the mechanical contacts that occur as the contacts are opening or closing can damage and severely reduce the lifetime of the relay. Contact arcing is prevented by pulsing a triac on for a short period of time just before and after the mechanical contacts make or break contact. The triac limits the voltage difference across the mechanical contacts to less than one volt to prevent arcing. The triac is turned off after the mechanical contacts finish moving, reducing the heating and average power through the triac. A zero-sampling circuit that detects when the AC input voltage switches across 0 volts and activates a control integrated circuit to switch on the triac during zero-crossings to minimize power surges.
摘要:
A reduced-pressure system for treating tissue, such as damaged subcutaneous tissue, includes a shaped dressing bolster for placing on the patient's epidermis and substantially sized to overlay the damaged subcutaneous tissue. The system further includes a sealing subsystem for providing a fluid seal over the shaped dressing bolster and a portion of the patient's epidermis, and a reduced-pressure subsystem for delivering a reduced pressure to the sealing subsystem. The reduced-pressure system may develop a force, which may include a vertical force that is realized at tissue site deeper than the epidermis or a closing force directed towards the incision. The shaped dressing bolster is shaped to evenly distribute the force. Other methods and systems are included.
摘要:
Silicone hydrogel contact lenses are formed from the reaction product of a polymerizable composition comprising at least one acrylate-containing siloxane monomer, at least one hydrophilic vinyl-containing monomer, and at least one vinyl-containing cross-linking agent, wherein the polymerizable composition has a molar ratio of total amount of hydrophilic vinyl-containing monomer to total amount of acrylate-containing siloxane monomer of from 5:1 to 30:1, respectively. The silicone hydrogel contact lenses have good manufacturing processability, can be manufactured without the use of alcohol solvents, and have excellent surface wettability.
摘要:
Silicone hydrogel contact lenses that are derived from a polymerizable composition including a first siloxane monomer represented by formula (3): wherein m of formula (3) represents one integer from 3 to 10, n of formula (3) represents one integer from 1 to 10, R1 of formula (3) is an alkyl group having from 1 to 4 carbon atoms, and each R2 of formula (3) is independently either a hydrogen atom or a methyl group; and at least one vinyl ether-containing cross-linking agent are described. Batches of silicone hydrogel contact lenses and methods of making silicone hydrogel contact lenses are also described. In one example, the batches of silicone hydrogel contact lenses are dimensionally stable, and the method of making is a method of making dimensionally stable silicone hydrogel contact lenses.
摘要:
Silicone hydrogel contact lenses that are derived from a polymerizable composition including a first siloxane monomer represented by formula (3): wherein m of formula (3) represents one integer from 3 to 10, n of formula (3) represents one integer from 1 to 10, R1 of formula (3) is an alkyl group having from 1 to 4 carbon atoms, and each R2 of formula (3) is independently either a hydrogen atom or a methyl group; and at least one vinyl ether-containing cross-linking agent are described. Batches of silicone hydrogel contact lenses and methods of making silicone hydrogel contact lenses are also described. In one example, the batches of silicone hydrogel contact lenses are dimensionally stable, and the method of making is a method of making dimensionally stable silicone hydrogel contact lenses.
摘要:
Ophthalmic lens molds include first and second mold members sized and adapted to be assembled, for example interference fitted, together to define a lens-shaped cavity therebetween. At least one of the mold members includes a polar polymeric material and has a flexural modulus less than 3800 MPa.
摘要:
A dressing assembly for use with a reduced pressure treatment system, the dressing assembly develops a directed force under reduced pressure. The directed force may be a radial force or a closing force. The dressing assembly includes a shaped dressing bolster having a shaped extremity that is operable to evenly deliver the radial force and to distribute reduced pressure. Numerous shapes may be used for the shaped extremity. The dressing assembly may further include an over-drape to assist in creating a seal over the shaped dressing bolster and against a portion of a patient's epidermis.
摘要:
The present invention relates to the fabrication of multichannel nerve conduits for use in the repair of nerve injury. In particular, the invention relates to collagen multichannel nerve conduits which are suitable for use in repair of peripheral nerves.
摘要:
Contact lens molds and methods of producing soft cast-molded contact lens products are provided. The methods include placing a soft hydrophilic contact lens-forming composition in a cavity formed between a first mold member and a second mold member, subjecting the composition in the cavity to conditions effective to form a contact lens product from the composition, and repeating the placing and subjecting steps a plurality of times, thereby producing a plurality of soft contact lens products. At least the first mold members, and advantageously all of the first and second mold members, are injection-molded with a nucleated thermoplastic polyolefin resin having a melt flow rate in a range of 10 g/10 min to about 40 g/10 min.