Measurement of a fluid parameter in a pressure support system
First Claim
1. A pressure support system comprising:
- a motor having a plurality of phase windings;
a switching element operatively coupled to the plurality of phase windings to selectively supply electrical power from a power source to the plurality of phase windings;
a blower coupled to the motor, wherein rotation of the blower by the motor elevates a pressure of fluid at an outlet of the blower;
a patient circuit coupled to the outlet of the blower and adapted to communicate the pressurized fluid with an airway of a patient;
rotational speed controlling means for maintaining a rotational speed of the motor at a set rotational speed corresponding to a selected pressure for the fluid in the patient circuit, wherein the rotational speed of the motor is maintained at the set rotational speed based on a first signal that controls actuation of the switching element; and
fluid parameter monitoring means for monitoring a parameter associated with a flow of fluid in the patient circuit based on the first signal produced by the rotational speed controlling means.
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Accused Products
Abstract
A pressure support system has a motor, a switching element that supplies power to motor windings, and a blower coupled to the motor. Rotation of the blower elevates a pressure of fluid in a patient circuit coupled to an outlet of the blower. A rotational speed controller maintains the motor at a set rotational speed corresponding to a selected pressure for the fluid in the patient circuit. The rotational speed of the motor is maintained by a switching signal provided by a rotational speed controller to the switching element to control the actuation of the switching element. A fluid parameter monitoring portion monitors a parameter associated with the flow of fluid in the patient circuit, such as the magnitude, direction, or volume, based on a characteristic, such as duty cycle, of the switching signal, or based on a characteristic of a control signal that is used to generate the switching signal.
74 Citations
26 Claims
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1. A pressure support system comprising:
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a motor having a plurality of phase windings; a switching element operatively coupled to the plurality of phase windings to selectively supply electrical power from a power source to the plurality of phase windings; a blower coupled to the motor, wherein rotation of the blower by the motor elevates a pressure of fluid at an outlet of the blower; a patient circuit coupled to the outlet of the blower and adapted to communicate the pressurized fluid with an airway of a patient; rotational speed controlling means for maintaining a rotational speed of the motor at a set rotational speed corresponding to a selected pressure for the fluid in the patient circuit, wherein the rotational speed of the motor is maintained at the set rotational speed based on a first signal that controls actuation of the switching element; and fluid parameter monitoring means for monitoring a parameter associated with a flow of fluid in the patient circuit based on the first signal produced by the rotational speed controlling means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A pressure support system comprising:
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a motor having a plurality of phase windings; a switching element operatively coupled to the plurality of phase winding and adapted to selectively supply electrical power from a power source to the phase windings of the motor; tachometer sensing means for measuring a rotational speed of the motor and for outputting a tachometer signal indicative thereof; a blower coupled to the motor, wherein rotation of the blower by the motor elevates a pressure of fluid at an outlet of the blower; a patient circuit coupled to the outlet of the blower and adapted to communicated the pressurized fluid with an airway of a patient; processing means for comparing the tachometer signal to a reference motor speed signal corresponding to a selected pressure for the fluid in the patient circuit and for producing a rotational speed error signal based on a result of the comparison; a speed controller circuit operatively coupled to the processing means such that the speed controller circuit produces a control signal having a characteristic that varies based on the rotational speed error signal, so that the motor operates at a set rotational speed that corresponds to the selected pressure for the fluid in the patient circuit, and wherein the control signal controls actuation of the switching element; and fluid parameter monitoring means for monitoring a parameter associated with a flow of fluid in the patient circuit based on the characteristic of the control signal. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A pressure support system comprising:
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a motor having a plurality of phase windings; a switching element operatively coupled to the plurality of phase winding and adapted to selectively supply electrical power from a power source to the phase windings of the motor; tachometer sensing means for measuring a rotational speed of the motor and for outputting a tachometer signal indicative thereof; a blower coupled to the motor, wherein rotation of the blower by the motor elevates a pressure of fluid at an outlet of the blower; a patient circuit coupled to the outlet of the blower and adapted to communicated the pressurized fluid with an airway of a patient; processing means for comparing the tachometer signal to a reference motor speed signal corresponding to a selected pressure for the fluid in the patient circuit and for producing a rotational speed error signal based on a result of the comparison; a speed controller circuit operatively coupled to the processing means such that the speed controller circuit produces a control signal having a characteristic that varies based on the rotational speed error signal; a commutator circuit that outputs a drive signal based on the reference motor speed signal; a chopping circuit that combines the control signal and the drive signal to produce a switching signal, wherein the switching signal is provided by to the switching element to control actuation of the switching element; and fluid parameter monitoring means for monitoring a parameter associated with a flow of fluid in the patient circuit based on the characteristic of the switching signal. - View Dependent Claims (23, 24, 25, 26)
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Specification