Monolithic high performance miniature flow control unit
First Claim
1. A monolithic fluid flow control structure comprising:
- (a) a fluid channel extending through the fluid flow control structure between an inlet port and an outlet port, said inlet port being adapted to couple in fluid communication with a fluid reservoir from which fluid is supplied to the inlet port;
(b) a valve disposed in the fluid channel, upstream of the outlet port, said valve controlling fluid flow through the outlet port in response to a valve control signal applied to the valve;
(c) a first pressure sensor and a second pressure sensor, at least one of which is disposed within the fluid channel, between inlet port and the outlet port, said first and second pressure sensor producing first and second pressure signals that are employed in sensing fluid flow through said fluid flow control structure as a function of a differential pressure; and
(d) a bubble sensor that detects bubbles within the fluid channel.
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Accused Products
Abstract
A monolithic flow controller for controlling the rate at which a medicinal liquid is administered to a patient. The monolithic flow controller includes one or more virtual valves that, because of their relatively small opening size (less than 0.5 μm in diameter), only permit fluid to flow through the valve when a forward bias voltage is applied. If a reverse bias voltage or no voltage is applied, fluid flow through the opening is inhibited. The fluid rate through the device is monitored using two pressure sensors or a differential pressure sensor that determine the differential pressure along the flow path through the device or relative to the external ambient pressure. The flow through the device is equal to the product of the differential pressure and the conductance of the channel in the flow controller. A capacitive bubble sensor is optionally provided to detect bubbles in the medicinal liquid being administered to the patient. The flow controller can be made sufficiently small to be injected into a patient'"'"'s cardiovascular system or other portion of the patient'"'"'s body through a hypodermic syringe and needle, or it can be implanted in the patient'"'"'s body at a desired site. The medicinal liquid can be contained within an integral pressurized fluid reservoir, administered by gravity feed, or conveyed by a pump to an inlet port of the flow controller.
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Citations
20 Claims
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1. A monolithic fluid flow control structure comprising:
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(a) a fluid channel extending through the fluid flow control structure between an inlet port and an outlet port, said inlet port being adapted to couple in fluid communication with a fluid reservoir from which fluid is supplied to the inlet port;
(b) a valve disposed in the fluid channel, upstream of the outlet port, said valve controlling fluid flow through the outlet port in response to a valve control signal applied to the valve;
(c) a first pressure sensor and a second pressure sensor, at least one of which is disposed within the fluid channel, between inlet port and the outlet port, said first and second pressure sensor producing first and second pressure signals that are employed in sensing fluid flow through said fluid flow control structure as a function of a differential pressure; and
(d) a bubble sensor that detects bubbles within the fluid channel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A fluid flow control for controlling a flow of a medicinal fluid into a patient'"'"'s body, comprising:
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(a) a pair of slabs between which a fluid path is defined that extends between an inlet port and an outlet port, said inlet port being adapted to couple in fluid communication with a source of the medicinal fluid, to receive the medicinal fluid through the inlet port;
(b) flow sensing means for sensing a flow rate of the medicinal fluid along the fluid path as a function of a fluid pressure within the fluid path; and
(c) valve means for controlling a flow of the medicinal fluid through the fluid path in response to a fluid flow control signal, the valve means comprising a bias voltage applied to a plurality of orifices, each of the plurality of orifices having a cross-sectional area sufficiently small to prevent fluid flow through each of the plurality of orifices without the presence of a forward bias voltage, wherein the flow rate through the plurality of orifices is controlled by the magnitude and direction of the bias voltage applied. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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18. A fluid flow control structure comprising:
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(a) a fluid channel extending through the fluid flow control structure between an inlet port and an outlet port, said inlet port being adapted to couple in fluid communication with a fluid reservoir from which fluid is supplied to the inlet port;
(b) a valve for controlling fluid flow through the fluid channel as a function of a fluid pressure within the fluid channel, the valve comprising a bias voltage applied to a plurality of orifices, each of the plurality of orifices having a cross-sectional area sufficiently small to prevent fluid flow through each of the plurality of orifices without the presence of the bias voltage, wherein the flow rate through the plurality of orifices is controlled by the magnitude and direction of the bias voltage applied; and
(c) flow sensing structure for sensing a flow rate of the fluid in the fluid channel as a function of a fluid pressure within the fluid channel. - View Dependent Claims (19, 20)
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Specification