Fluid flow sensor, method and system
First Claim
1. A flow sensor comprising:
- a light emitter;
a light detector; and
a member placed in a flow path between the emitter and the detector, the member opening upon flow through the flow path such that light from the emitter is detected by the detector, the member closing upon a low pressure condition in the flow path such that not as much light from the emitter is detected by the detector.
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Accused Products
Abstract
A fluid flow sensor, a method of detecting flow/no flow and flow systems employing same are provided. In one embodiment, an infrared light emitting diode (“LED”), phototransistor, rigid housing and a flexible opaque diaphragm are used. The diaphragm opens upon a certain pressure and closes when that pressure is no longer present. The infrared LED is located at one end of a flow sensor, while the phototransistor is located at the opposite end. The flexible opaque diaphragm is located between the LED and the phototransistor. When flow is initiated, the diaphragm is pushed open allowing light from the infrared LED to pass through and be detected by the phototransistor. When flow is stopped, the diaphragm returns to the closed position and light no longer is allowed to pass through and therefore is not detected by the phototransistor.
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Citations
38 Claims
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1. A flow sensor comprising:
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a light emitter;
a light detector; and
a member placed in a flow path between the emitter and the detector, the member opening upon flow through the flow path such that light from the emitter is detected by the detector, the member closing upon a low pressure condition in the flow path such that not as much light from the emitter is detected by the detector. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A flow sensor comprising:
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a member placed in a flow path, the member including a stationary portion and an openable portion;
a first output state caused when the openable portion resides in a first position, the first output state indicative of a first flow state; and
a second output state caused when the openable portion resides in a second position, the second output state indicative of a second flow state. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A medical fluid system comprising:
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a valve operable to enable fluid to be delivered to a patient;
a sensor including an openable member placed in a flow path; and
a control scheme operable to signal an alarm based on whether the member resides in a first or a second position and an expected opened/closed state of the valve. - View Dependent Claims (25, 26, 27, 28)
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29. A flow sensing method comprising the steps of:
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establishing a first flow state when an openable portion of a member located in a fluid flow path resides in a first position; and
establishing a second fluid flow state when a force due to a flow of a fluid through the path causes the openable portion of the member to move to a second position. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36, 37, 38)
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Specification