A catheter is disclosed which is simple to use, avoids the problems with prior catheters, which is fail-safe and fool-proof and one by which the patient cannot injure himself. The catheter comprises a flexible inner tubular member forming a flow duct, snuggly and slidably disposed in an outer tubular member, and having a rounded expansion tip at its inner end comprised of a plurality of prongs biased outwardly and operable to expand and open on inward movement of the inner tubular member in the outer tubular member to a position where the prongs are beyond the inner end of the outer member and to retract on movement of the inner tubular member outwardly in the outer tubular member to a position where at least a portion of the prongs are within the outer tubular member. The outer end of the inner tubular member extends outwardly sufficiently for this movement and has a circumferentially and outwardly extending shoulder adjacent its outer end to engage and secure an end of a resilient drain tube to the inner tubular member. Detents, preferably axially spaced, circumferentially extending mating rings and grooves, are disposed on the inner and outer tubular members which releasably lock them in a position where the prongs are expanded and in a position where the prongs are retracted. Drain holes are provided in the outer and inner tubular members and are arranged to register when the inner tubular member is locked in a position where the prongs are expanded. An outwardly facing circumferential shoulder is provided on the expansion tip and intermediate the prongs which limit outward movement of the inner tubular member in the outer tubular member. Preferably, the prongs are formed by longitudinally extending slits in the expansion tip and a portion of the inner tubular member adjacent thereto. Other features and details are disclosed throughout.
The present invention comprises an apparatus and a method for harvesting veins. The apparatus includes an elongate member, a set of prongs disposed at the end of the member, a light carrying system for positioning the apparatus, and a triggering mechanism for opening and closing the prongs such that a vein can be dissected from surrounding tissue with minimal intrusiveness and minimal chance of damaging the surrounding tissue. Once the vein has been separated from the surrounding tissue by the apparatus, a vein dissector having an inflatable cover at the end is placed around the vein from the posterior and inflated and deflated to gently dissect the vein.
A series of medical instruments can be made with the use of shape memory tube with a transformation temperature that is above or below the ambient temperature. In the first case, the material behaves with the shape memory effect and in the second case the behavior is superelastic. The wall of the tube has been provided with a plurality of slots in specific places, often near or at the distal end of the instrument, and in specific arrangements which allow local variations in diameter, shape, and/or length. These variations can either be caused by the memory effect during temperature change or by superelastic behavior during change of the mechanical influences on the memory metal by the surrounding material.
A sampling catheter having an outer tube of resilient material with a normally closed distal end and an inner flexible tube which is longer than the outer tube and which is normally held in retracted position with respect to the distal end of the outer tube by means of a loop of the inner tube which is fastened to the outer tube. The assembled catheter is disposed in a sealed package with the inner tube in such retracted position.
A device for positioning an endotracheal tube when the tube is inserted into the trachea of a patient for lung inflation uses the patient's carina as a reference point against which the endotracheal tube is positioned. The positioning device consists of an elongate, flexible member with at least three flexible filaments at its distal end which assume a compressed tripodal configuration when inserted through the endotracheal tube. When the distal end of the positioning device emerges from the distal end of the endotracheal tube, the flexible elements spring out into a tripodal-shaped structure. As the positioning device is advanced further, the apex of the tripodal-shaped structure engages the carina. At this point the positioning device provides a reference line for correctly locating the distal end of the endotracheal tube with respect to the carina. Since the dimensions of the positioning device and the endotracheal tube are known, the location of the distal end of the tube with respect to the carina can be indirectly derived by observing the position of the tube with respect to the positioning device. The relative measurement is provided by calibration marks at the proximal end of the positioning device. Once the endotracheal tube is correctly positioned in the trachea, the positioning device can be withdrawn. The tripodal-shaped structure is compressed when the distal end of the positioning device enters the distal end of the endotracheal tube lumen. The positioning device is then removed to allow ventilation of the patient through the endotracheal tube.
A gastrostomy-jejunal feeding tube comprises a gastrostomy tube having an enlarged resiliently, collapsible retainer element on the distal end thereof and a jejunal feeding tube which is removably received in the gastrostomy tube in a manner which allows fluids to pass through the gastrostomy tube despite the presence of the jejunal feeding tube therein. The gastrostomy-jejunal feeding tube is adapted to be installed in a patient so that the gastrostomy tube extends through the stomach wall, fascia and skin for draining fluids from the stomach and so that the jejunal feeding tube extends into the jejunum area of the intestines for feeding and medicating the patient. Since the jejunal feeding tube is removable from the gastrostomy tube it can be replaced without surgery, and since the retainer element is resiliently collapsible, it can be pulled outwardly through the stomach wall to allow the gastrostomy tube to be removed from the patient without surgery.
