95146 results about "Piston" patented technology

A piston-type infusion pump is provided having an improved method of occlusion detection. The infusion pump includes processing circuitry for controlling the drive mechanism to infuse medication to a patient, including a sensor to track the position of the syringe plunger, thereby metering the amount of medication dispensed to the patient. The processing circuitry also includes a force sensor for providing signals indicative of the presence of occlusions along the infusion path. The operation of the drive mechanism causes delivery of medication to the patient. The infusion pump is constructed to be watertight.

A pump system for an infusion system includes a linear drive (36, 36′) which minimizes the space occupied by the pump components in a portable housing (10, 10′). A motor (34) and a motor drive shaft (42) are arranged in parallel with, and adjacent to a syringe (14, 14′) and lead screw (94, 94′). A gear box (54) connects the drive shaft and lead screw to transfer rotational movements between them. A piston driving member, such as a cone (116) or drive nut (116′) converts the rotational movement of the lead screw into linear motion of a syringe piston (24). Sensors (150, 152) detect when the piston or cone is in a “home” position and in an “end” position, respectively. Optionally, a proximity sensor (170) is used to ensure that the cone and the piston (24) are abutting during dispensing. Alternatively, a clamping member (350) selectively clamps the lead screw (94′) against linear motion in at least a dispensing direction.

A vial adapter having a needle-free valve, a sharpened cannula used to perforate a vial's rubber stopper, and a circular array of claws of different lengths to engage vial closures of different diameters. The array of claws includes a first set of claws each having a first length extending inwardly from the periphery of the housing of the adapter and a second set of claws alternating with the first set of claws and each having a longer length. The second set of claws are mounted so that they deflect and plastically deform out of the way in the case where the adapter is engaged with a vial that exceeds a predetermined size. The housing includes a shroud that is at least as long as the sharpened cannula to protect medical personnel who use the adapter from inadvertent punctures. The needle-free valve includes a resiliently deformable piston element with a naturally open bore. The interior of the piston provides a fluid flow path through the adapter. In one embodiment, the first set of claws of the adapter may be used with a vial closure of at approximately 20 mm in diameter and the second set of claws may be used with a vial closure of approximately 13 to 17 mm in diameter.

An indirect gas operating system for an M4 type automatic or semi-automatic firearm. The indirect gas operating system has a gas block having a cylinder. The gas block is fitted to a barrel assembly having a bore with the cylinder in communication with the bore. A piston having a piston end and a striking end has the piston end fitted to the cylinder. A bolt assembly having a striking surface is provided. When a cartridge is fired, gas displaces the piston end and causes the striking end to strike the striking surface displacing the bolt assembly. The cylinder and the piston are together removable as an assembly from the firearm without removal of the gas block.

An improved pump, reservoir and reservoir piston are provided for controlled delivery of fluids. A motor is operably coupled to a drive member, such as a drive screw, which is adapted to advance a plunger slide in response to operation of the motor. The plunger slide is removably coupled to the piston. A method, system, and an article of manufacture for automatically detecting an occlusion in a medication infusion pump is provided. The electrical current to an infusion pump is measured. Based on measurements of one or more variables, the infusion pump detects whether there is an occlusion in the system. The methods of detecting occlusions may be dynamic.