Pressure (occlusion) sensor
First Claim
1. A system for detecting an impediment to a fluid flow through an intravenous line, comprising:
- (a) a pump chassis;
(b) a pump in fluid communication with the intravenous line and mountable within the pump chassis to receive a driving force, said pump including a proximal port, a distal port, and an elastomeric membrane overlying a fluid path through the fluid pump adjacent the proximal port and distal port;
(c) a proximal pressure sensor mounted on the pump chassis and including a member that is coupled to the elastomeric membrane adjacent to the proximal port of the pump and responsive to a deflection and force exerted by the elastomeric membrane due to a proximal fluid pressure within the pump, producing a proximal pressure signal indicative thereof;
(d) a distal pressure sensor mounted on the pump chassis and including a member that is coupled to the elastomeric membrane adjacent to the distal port of the pump and responsive to a deflection and force exerted by the elastomeric membrane due to a distal fluid pressure within the pump, producing a distal pressure signal indicative thereof; and
(e) a controller that is electrically coupled to the proximal pressure sensor and the distal pressure sensor to receive the proximal and distal pressure signals, said controller employing the proximal pressure signal to determine a baseline proximal pressure and an absolute proximal pressure, and employing the distal pressure signal to determine a baseline distal pressure and an absolute distal pressure, and determining whether an impediment to fluid flow through the intravenous line has occurred as a function of the baseline proximal pressure, the baseline distal pressure, the absolute proximal pressure, and the absolute distal pressure.
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Accused Products
Abstract
A system and a method for detecting the presence of an occlusion in an intravenous (IV) line supplying a medicinal liquid to a patient. Two pressure occlusion sensors are employed to produce a value for the proximal and distal pressures within an IV pumping cassette that is disposed in the fluid path of the IV line. Each pressure occlusion sensor includes a strain gauge connected to a leaf spring that is fixed at one end within a pump chassis and a rod that is disposed transverse to the leaf spring. Each rod has one end that responds to the force of a portion of an elastomeric membrane inside the pumping cassette and another end that contacts a free end of the leaf spring. When a leaf spring is flexed by the movement of a rod, the strain gauge mounted on the leaf spring produces a differential voltage that corresponds to a fluid pressure within the pumping cassette. The distal pressure occlusion sensor automatically opens a flow stop on the pumping cassette when the pumping cassette is inserted into the pump chassis. The outputs from the distal and proximal pressure sensors are sampled at least once per second to ensure that maximum pressure values are not exceeded and that a pressure sensor failure is immediately detected.
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Citations
33 Claims
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1. A system for detecting an impediment to a fluid flow through an intravenous line, comprising:
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(a) a pump chassis; (b) a pump in fluid communication with the intravenous line and mountable within the pump chassis to receive a driving force, said pump including a proximal port, a distal port, and an elastomeric membrane overlying a fluid path through the fluid pump adjacent the proximal port and distal port; (c) a proximal pressure sensor mounted on the pump chassis and including a member that is coupled to the elastomeric membrane adjacent to the proximal port of the pump and responsive to a deflection and force exerted by the elastomeric membrane due to a proximal fluid pressure within the pump, producing a proximal pressure signal indicative thereof; (d) a distal pressure sensor mounted on the pump chassis and including a member that is coupled to the elastomeric membrane adjacent to the distal port of the pump and responsive to a deflection and force exerted by the elastomeric membrane due to a distal fluid pressure within the pump, producing a distal pressure signal indicative thereof; and (e) a controller that is electrically coupled to the proximal pressure sensor and the distal pressure sensor to receive the proximal and distal pressure signals, said controller employing the proximal pressure signal to determine a baseline proximal pressure and an absolute proximal pressure, and employing the distal pressure signal to determine a baseline distal pressure and an absolute distal pressure, and determining whether an impediment to fluid flow through the intravenous line has occurred as a function of the baseline proximal pressure, the baseline distal pressure, the absolute proximal pressure, and the absolute distal pressure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for detecting an impediment to fluid flow through an intravenous line in which is disposed a pump for infusing a medicinal fluid into a patient, comprising the steps of:
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(a) sensing a fluid pressure in the pump, producing a fluid pressure signal; (b) sampling the fluid pressure signal a plurality of time, when the pump is at a predefined point in a pumping cycle, producing samples; (c) determining a baseline pressure; (d) detecting that an impediment to fluid flow has occurred as a function of the baseline pressure and a threshold value; and (e) providing an alarm to alert a user if the impediment to fluid flow is detected. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. An occlusion detector disposed in a pump that infuses a medicinal fluid into a patient through an intravenous line, for determining if an impediment to fluid flow through the intravenous line has occurred, comprising:
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(a) a beam that is cantilever mounted to the pump, so that a free end of the beam is able to flex in response to a force applied to the free end of the beam; (b) a strain gauge mounted on the beam so as to sense a deflection of the beam; (c) an elongate rod disposed within an orifice formed within the pump and movable in a direction aligned with a longitudinal axis of the rod, one end of the rod contacting the free end of the beam, an opposite end of the rod having a force corresponding to a fluid pressure within the intravenous line applied thereto, in the direction of the longitudinal axis of the rod, said force causing the beam to deflect and thus causing the strain gauge to produce a signal indicative of the fluid pressure; (d) an alarm indicative of an impediment to fluid flow through the intravenous line; and (e) a controller coupled to the strain gauge to receive the signal, said controller sampling the signal to produce samples and to determine a baseline pressure while the pump is operating, and as a function of the baseline pressure, determining a relative pressure, said controller detecting an impediment to the fluid flow through the intravenous line as a function of the relative pressure and causing the alarm to be activated to alert a user of the impediment to the fluid flow. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32)
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33. A system for detecting an impediment to a fluid flow through an intravenous line, comprising:
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(a) a pump chassis; (b) a pump in fluid communication with the intravenous line and mountable within the pump chassis to receive a driving force, said pump including a proximal port, a distal port, an elastomeric membrane overlying a fluid path through the fluid pump adjacent the proximal port and distal port, and a flow stop that is in contact with the elastomeric membrane adjacent to the distal port, said flow stop being movable between a stop position in which it applies a force to the elastomeric membrane that closes off fluid flow through the pump and a sensing position in which it transmits force produced by a distal pressure within the pump and thus, indicative of the distal pressure; (c) a proximal pressure sensor mounted on the pump chassis and including a member that is coupled to the elastomeric membrane adjacent to the proximal port of the pump and responsive to a deflection and force exerted by the elastomeric membrane due to a proximal fluid pressure within the pump, producing a proximal pressure signal indicative thereof; (d) a distal pressure sensor mounted on the pump chassis and coupled to the flow stop to respond to the force transmitted by the flow stop from the elastomeric membrane, producing a distal pressure signal indicative thereof; and (e) a controller that is electrically coupled to the proximal pressure sensor and the distal pressure sensor to receive the proximal and distal pressure signals, said controller employing the proximal pressure signal to determine a proximal fluid pressure, and employing the distal pressure signal to determine a distal fluid pressure, and determining whether an impediment to fluid flow through the intravenous line has occurred as a function of the proximal fluid pressure, and of the distal fluid pressure.
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Specification