Fluid delivery system and method
First Claim
1. A fluid delivery system having a fluid-handling unit comprising:
- a tube adapted for receiving a fluid from a fluid source, the tube comprising a freestanding tube portion through which the fluid flows;
means for vibrating the freestanding tube portion of the tube at a resonant frequency thereof that varies with the density of the fluid flowing therethrough, the Coriolis effect causing the freestanding tube portion to twist while being vibrated at resonance, the freestanding tube portion exhibiting a degree of twist that varies with the mass flow rate of the fluid flowing therethrough;
means for sensing movement of the freestanding tube portion of the tube, the movement-sensing means producing a first output signal based on the resonant frequency of the freestanding tube portion and a second output signal based on the degree of twist of the freestanding tube portion;
means for setting a range for the first output signal corresponding to a range for the density of the fluid; and
means for stopping flow of the fluid through the fluid handling unit in response to the first output signal from the movement-sensing means, wherein the flow-stopping means, the movement-sensing means, and the range-setting means cooperate to stop the flow of the fluid through the fluid handling unit if the density of the fluid is outside the range therefor set with the range-setting means.
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Accused Products
Abstract
A fluid delivery system capable of delivering a precise amount of fluid and monitor certain properties of the fluid so that the correct fluid is safely delivered to its intended destination. The system makes use of a flow sensor comprising a freestanding tube portion vibrated at a resonant frequency, wherein the resonant frequency corresponds to the density of the fluid flowing through the tube portion and the tube portion exhibits a degree of twist that varies with the mass flow rate of the fluid flowing therethrough. Movement of the tube portion is then sensed to produce a first output signal corresponding to the fluid density and a second output signal corresponding to the mass flow rate. The system is also equipped to measure elapsed time and to stop fluid flow in response to either of the first and second output signals.
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Citations
30 Claims
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1. A fluid delivery system having a fluid-handling unit comprising:
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a tube adapted for receiving a fluid from a fluid source, the tube comprising a freestanding tube portion through which the fluid flows;
means for vibrating the freestanding tube portion of the tube at a resonant frequency thereof that varies with the density of the fluid flowing therethrough, the Coriolis effect causing the freestanding tube portion to twist while being vibrated at resonance, the freestanding tube portion exhibiting a degree of twist that varies with the mass flow rate of the fluid flowing therethrough;
means for sensing movement of the freestanding tube portion of the tube, the movement-sensing means producing a first output signal based on the resonant frequency of the freestanding tube portion and a second output signal based on the degree of twist of the freestanding tube portion;
means for setting a range for the first output signal corresponding to a range for the density of the fluid; and
means for stopping flow of the fluid through the fluid handling unit in response to the first output signal from the movement-sensing means, wherein the flow-stopping means, the movement-sensing means, and the range-setting means cooperate to stop the flow of the fluid through the fluid handling unit if the density of the fluid is outside the range therefor set with the range-setting means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An infusion system comprising:
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a first flow sensor that receives a first fluid from a first fluid source and delivers the first fluid to a tube attached to a human subject, the first flow sensor comprising a first freestanding tube portion through which the first fluid flows, first means for vibrating the first freestanding tube portion at a resonant frequency thereof that varies with the density of the first fluid flowing therethrough, first means for sensing movement of the first freestanding tube portion, the first movement-sensing means producing a first output signal based on the resonant frequency of the first freestanding tube portion and a second output signal based on the degree of twist of the first freestanding tube portion, the Coriolis effect causing the first freestanding tube portion to twist while being vibrated at resonance, the first freestanding tube portion exhibiting a degree of twist that varies with the mass flow rate of the first fluid flowing therethrough;
a plurality of second flow sensors arranged in fluidic parallel, the second flow sensors delivering at least a second fluid from at least a second fluid source to the tube, each of the second flow sensors comprising a second freestanding tube portion through which the second fluid flows, second means for vibrating the second freestanding tube portion at a resonant frequency thereof that varies with the density of the second fluid flowing therethrough, second means for sensing movement of the second freestanding tube portion, the second movement-sensing means producing a first output signal based on the resonant frequency of the second freestanding tube portion and a second output signal based on the degree of twist of the second freestanding tube portion, the Coriolis effect causing the second freestanding tube portion to twist while being vibrated at resonance, the second freestanding tube portion exhibiting a degree of twist that varies with the mass flow rate of the second fluid flowing therethrough;
means for measuring elapsed time during which the first and second fluids have flowed through the first and second flow sensors; and
means for stopping flow of the first and second fluids through the first and second flow sensors, respectively, in response to either of the first and second output signals from the first and second movement-sensing means, wherein the flow-stopping means is operable to stop the flow of the second fluid if, based on the elapsed time determined by the time-measuring means and the second output signal of the second movement-sensing means, a specified amount of the second fluid has passed through any one or more of the second flow sensors. - View Dependent Claims (13, 14, 15, 16)
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17. A fluid delivery method comprising the steps of:
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flowing a fluid through a freestanding tube portion;
vibrating the freestanding tube portion at a resonant frequency thereof that varies with the density of the fluid flowing therethrough, the Coriolis effect causing the freestanding tube portion to twist while being vibrated at resonance, the freestanding tube portion exhibiting a degree of twist that varies with the mass flow rate of the fluid flowing therethrough;
sensing movement of the freestanding tube portion and producing a first output signal based on the resonant frequency of the freestanding tube portion and a second output signal based on the degree of twist of the freestanding tube portion;
measuring elapsed time during which the fluid has flowed through the freestanding tube portion; and
stopping flow of the fluid through the freestanding tube portion in response to either of the first and second output signals, wherein flow of the fluid is stopped if, based on the elapsed time and the second output signal, a specified amount of the fluid has passed through the freestanding tube portion. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25)
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26. An infusion method comprising the steps of:
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flowing a first fluid from a first fluid source through a first flow sensor to a tube attached to a human subject, the first flow sensor comprising a first freestanding tube portion through which the first fluid flows, first means for vibrating the first freestanding tube portion at a resonant frequency thereof that varies with the density of the first fluid flowing therethrough, first means for sensing movement of the first freestanding tube portion, the first movement-sensing means producing a first output signal based on the resonant frequency of the first freestanding tube portion and a second output signal based on the degree of twist of the first freestanding tube portion, the Coriolis effect causing the first freestanding tube portion to twist while being vibrated at resonance, the first freestanding tube portion exhibiting a degree of twist that vanes with the mass flow rate of the first fluid flowing therethrough;
flowing a second fluid from a second fluid source through a second flow sensor to the tube, the second flow sensor comprising a second freestanding tube portion through which the second fluid flows, second means for vibrating the second freestanding tube portion at a resonant frequency thereof that varies with the density of the second fluid flowing therethrough, second means for sensing movement of the second freestanding tube portion, the second movement-sensing means producing a first output signal based on the resonant frequency of the second freestanding tube portion and a second output signal based on the degree of twist of the second freestanding tube portion, the Coriolis effect causing the second freestanding tube portion to twist while being vibrated at resonance, the second freestanding tube portion exhibiting a degree of twist that varies with the mass flow rate of the second fluid flowing therethrough;
measuring elapsed time during which the first and second fluids have flowed through the first and second flow sensors, respectively; and
stopping flow of the first and second fluids through the first and second flow sensors, respectively, in response to either of the first and second output signals from the first and second movement-sensing means, wherein the flow of the second fluid is stopped if, based on the elapsed time determined by the time-measuring means and the second output signal of the second movement-sensing means, a specified amount of the second fluid has passed through the second flow sensor. - View Dependent Claims (27, 28, 29, 30)
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Specification