System for determining pumping mechanism position while limiting volume of fluid pumped
First Claim
1. A system for determining the position of a drive member, the drive member moving in a plurality of movement increments over a complete rotation, the drive member connected to a pumping mechanism such that as the drive member turns through the plurality of movement increments over the complete rotation, the pumping mechanism correspondingly pumps volume increments of fluid, at least some of the volume increments varying in quantity from other volume increments, the system comprising:
- a disk coupled to the drive member for rotation therewith, the disk having a plurality of spaced-apart markers, the number of markers being less than the plurality of movement increments of the drive member, the positions of the markers on the disk selected such that the markers are located on the disk in known positions that correspond to particular volume increments pumped by the pumping mechanism and the spacing between the markers selected so that known volume totals are pumped by the pumping mechanism between said markers with the markers being located closer together to correspond to higher pumped volume increments and the markers being located farther apart to correspond to lower pumped volume increments;
a sensor located to sense the markers of the disk as the drive member rotates and to produce marker signals upon sensing the markers; and
a processor that provides control signals to cause the drive member to turn sequentially through the plurality of movement increments, the processor receiving the marker signals from the sensor and counting the movement increments of the drive member between receipt of marker signals to calculate the position of the drive member based on the receipt of marker signals and the number of movement increments counted.
13 Assignments
0 Petitions
Accused Products
Abstract
A drive member of a peristaltic pumping mechanism includes a disk that rotates with the drive member and has two transparent sectors and two opaque sectors alternating with the transparent sectors. As a stepper motor rotates the drive member to pump fluid, a single optical sensor senses the disk and provides signals indicative of whether a transparent sector or opaque sector is being detected. A processor counts the number of motor steps in the detected transparent or opaque sector and based on the number of counted steps in a type of sector detected or the number of steps counted when a state change to the other type of sector occurs, determines the motor position. In another aspect, the position disk is integrally formed as a single piece with the cams and cam shaft of a pumping mechanism.
60 Citations
14 Claims
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1. A system for determining the position of a drive member, the drive member moving in a plurality of movement increments over a complete rotation, the drive member connected to a pumping mechanism such that as the drive member turns through the plurality of movement increments over the complete rotation, the pumping mechanism correspondingly pumps volume increments of fluid, at least some of the volume increments varying in quantity from other volume increments, the system comprising:
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a disk coupled to the drive member for rotation therewith, the disk having a plurality of spaced-apart markers, the number of markers being less than the plurality of movement increments of the drive member, the positions of the markers on the disk selected such that the markers are located on the disk in known positions that correspond to particular volume increments pumped by the pumping mechanism and the spacing between the markers selected so that known volume totals are pumped by the pumping mechanism between said markers with the markers being located closer together to correspond to higher pumped volume increments and the markers being located farther apart to correspond to lower pumped volume increments; a sensor located to sense the markers of the disk as the drive member rotates and to produce marker signals upon sensing the markers; and a processor that provides control signals to cause the drive member to turn sequentially through the plurality of movement increments, the processor receiving the marker signals from the sensor and counting the movement increments of the drive member between receipt of marker signals to calculate the position of the drive member based on the receipt of marker signals and the number of movement increments counted. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A system for determining the position of a drive member of an infusion pump, the drive member being driven by a stepper motor rotating the drive member, the drive member moving in a plurality of movement increments over a complete rotation, the drive member connected to a pumping mechanism such that as the drive member turns through the plurality of movement increments over a complete rotation, the pumping mechanism correspondingly pumps volume increments of fluid, at least some of the volume increments varying in quantity from other volume increments, the system comprising:
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a disk coupled to the drive member for rotation therewith, the disk having a plurality of first sectors and a plurality of second sectors alternating with the first sectors, the number of sectors being less than the plurality of movement increments of the drive member, the positions of the sectors on the disk selected such that the sectors are located on the disk in known positions that correspond to particular volume increments pumped by the pumping mechanism and the sizes of the sectors selected so that known volume totals are pumped by the pumping mechanism during each sector with the sectors being smaller to correspond to higher pumped volume increments and the sectors being larger to correspond to lower pumped volume increments wherein the positions and sizes of the sectors are selected so that locating the position of the drive member from any position on the disk results in pumping of a reduced volume of fluid by the pumping mechanism; a sensor located to sense the sectors as the drive member rotates and to produce a first position signal at each movement increment corresponding to a first sector and a second position signal at each movement increment corresponding to a second sector; and a processor that provides control signals to cause the motor to turn the drive member sequentially through the plurality of movement increments, and to receive multiple position signals from the sensor and to count the movement increments turned while receiving first and second position signals and to calculate the position of the drive member based on the number and type of movement increments counted. - View Dependent Claims (9, 10, 11, 12)
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13. A system for determining the position of a drive member of an infusion pump, the drive member being driven by a stepper motor rotating the drive member, the drive member moving in a plurality of movement increments over a complete rotation, the drive member connected to a pumping mechanism such that as the drive member turns through the plurality of movement increments over a complete rotation, the pumping mechanism correspondingly pumps volume increments of fluid, at least some of the volume increments varying in quantity from other volume increments, the system comprising:
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a disk coupled to the drive member for rotation therewith, the disk having a plurality of opaque sectors and a plurality of transparent sectors alternating with the opaque sectors, the number of sectors being less than the plurality of movement increments of the drive member, the positions of the sectors on the disk selected such that the sectors are located on the disk in known positions that correspond to particular volume increments pumped by the pumping mechanism and the sizes of the sectors are selected so that known volume totals are pumped by the pumping mechanism during each sector with the sectors being smaller to correspond to higher pumped volume increments and the sectors being larger to correspond to lower pumped volume increments wherein the positions and sizes of the sectors are selected so that locating the position of the drive member from any position on the disk results in pumping of a reduced volume of fluid by the pumping mechanism; an optical sensor located to sense the sectors as the drive member rotates and to produce a first position signal at each movement increment corresponding to an opaque sector and a second position signal at each movement increment corresponding to a transparent sector; and a processor that provides control signals to cause the motor to turn the drive member sequentially through the plurality of movement increments, and to receive position signals from the sensor and to count the movement increments turned while receiving the first and second position signals to determine the position of the drive member thereby. - View Dependent Claims (14)
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Specification