Fluid flow sensor, method and system
First Claim
1. A flow sensor comprising:
- a light emitter placed at a first end of a housing;
a light detector placed at a second end of the housing;
the housing defining a flow path in which a fluid moves in a general direction from one of the first and second ends of the housing to the other of the first and second ends of the housing; and
a diaphragm member placed in the flow path between the emitter and the detector, the diaphragm member opening upon flow through the flow path such that light from the emitter is detected by the detector, the diaphragm 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 placed at a first end of a housing; a light detector placed at a second end of the housing; the housing defining a flow path in which a fluid moves in a general direction from one of the first and second ends of the housing to the other of the first and second ends of the housing; and a diaphragm member placed in the flow path between the emitter and the detector, the diaphragm member opening upon flow through the flow path such that light from the emitter is detected by the detector, the diaphragm 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 diaphragm member placed in a flow path within a housing, the housing having first and second ends and configured such that the flow path extends in a general direction from the first end to the second end, the diaphragm member including a stationary portion and an openable portion; an emitter located at one of the first and second ends; a receiver located at the other of the first and second ends; a first output state caused via operation of the emitter and receiver 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 via operation of the emitter and receiver 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 emitter, a receiver, and a member having an openable portion, the member placed in and held around its perimeter by a housing, the openable portion residing within the perimeter of the member, the housing defining a flow path in fluid communication with the valve; 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 diaphragm member located in a fluid flow path resides in a first position, the diaphragm member and fluid flow path located within a housing, the housing having first and second ends and configured such that the fluid flow path extends in a general direction from the first end to the second end; locating a source at one of the first and second ends; locating a receiver at the other of the first and second ends; 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 diaphragm member to move to a second positions, changing a level of communication between the source and receiver. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36, 37, 38)
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Specification