Infusion pump

摘要

An infusion pump has a primary finger with an inclined surface, which is obliquely inclined to an advancing and retracting direction, and a secondary finger with an inclined surface, which is slidable relative to the inclined surface of the primary finger. When the primary finger is advanced, the secondary finger is retracted in proportion to the variation (increasing) in an entire width of an infusion tube, and when the primary finger is retracted, the secondary finger is advanced in proportion the variation (decreasing) in the entire width of the infusion tube. This configuration can suppress the occurrence of any gap between a tip surface of the secondary finger and an outer peripheral surface of the infusion tube in the advancing and retracting process of the primary finger. Consequently, this prevents the infusion tube from meandering, and suppresses the reduction in the accuracy of the rate of infusion.

主权项

1. An infusion pump comprising a pump mechanism which presses an infusion tube to deliver an amount of infusion solution within the infusion tube,
wherein the pump mechanism comprises:
a primary finger capable of being advanced and retracted in an advancing and retracting direction relative to the infusion tube, the primary finger having a pair of tapered inclined surfaces opposingly inclined to the advancing and retracting direction, and the primary finger pressing the infusion tube when the primary finger is advanced;driving means which moves the primary finger in the advancing and retracting direction; anda pair of secondary fingers each capable of being advanced and retracted only in one direction orthogonal to the advancing and retracting direction of the primary finger, each of the pair of secondary fingers having an inclined surface arranged to contact and slidable relative to one of the tapered inclined surfaces of the primary finger, wherein when the primary finger is advanced and retracted, the tapered inclined surfaces of the primary finger and the inclined surfaces of the secondary fingers are arranged to slide in contact with each other, thereby causing the secondary fingers to move in conjunction with the movement of the primary finger in the directions orthogonal to the advancing and retracting direction of the primary finger, wherein, when the primary finger is advanced, the secondary fingers are retracted in proportion to a variation in an entire width of the infusion tube, and when the primary finger is retracted, the secondary fingers are advanced in proportion to the variation in the entire width of the infusion tube, and wherein, with an angle of inclination for the tapered inclined surfaces of the primary finger relative to a central axis being θ1, θ1 is set to satisfy θ1=tan−1 (π/4−½).