CONTROL CIRCUIT AND METHOD FOR NEGATIVE PRESSURE WOUND TREATMENT APPARATUS
First Claim
1. A negative pressure wound therapy apparatus comprising:
- a wound dressing;
a fluid collection container;
a vacuum pump comprising a pump motor;
one or more tubes configured to at least channel a flow of fluid between said wound dressing, said fluid collection canister, and said pump;
a pressure sensor configured to measure a pressure in one or more of said one or more tubes and to generate a pressure sensor voltage reflecting pressure in one or more of said one or more tubes;
a control circuit for controlling the pressure in said one or more tubes without using a processor, the control circuit comprising;
a pressure controller for controlling the pump motor, the pressure controller comprising;
a difference circuit configured to;
receive the pressure sensor voltage from the pressure sensor;
receive a desired pressure voltage from a user; and
provide a difference signal comprising an amplified difference between the desired pressure voltage and the pressure sensor voltage, wherein the difference circuit provides proportional control; and
a pulse width modulator configured to generate a motor control signal responsive to the difference signal, the motor control signal configured to control a speed of the pump motor; and
a stall controller for preventing stalling of the pump motor, the stall controller comprising;
a comparison circuit configured to generate an override signal based at least in part on the difference signal and at least one reference signal, the override signal configured to prevent stalling of the pump motor; and
stall logic configured to output a combined control signal based at least in part on the override signal and the motor control signal, the combined control signal configured to control the pressure in said one or more tubes without stalling the pump motor.
2 Assignments
0 Petitions
Accused Products
Abstract
A negative pressure wound therapy apparatus can include a wound dressing, a fluid collection container, a vacuum pump comprising a pump motor, and tubing. Additionally, the apparatus can include a pressure sensor that measures a pressure in the tubing. One or more tubes can channel a fluid between the wound dressing, the fluid collection canister, and the pump. In addition, first and second control circuits can be provided for controlling the pump motor without using a processor. The first control circuit can generate a difference signal between a desired pressure input and a pressure sensor input, and can further generate a motor control signal responsive to the difference signal. Moreover, a second control circuit can provide an override signal based at least in part on the difference signal and at least one reference signal. The override signal beneficially overrides the motor control signal to prevent the pump motor from stalling.
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Citations
25 Claims
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1. A negative pressure wound therapy apparatus comprising:
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a wound dressing; a fluid collection container; a vacuum pump comprising a pump motor; one or more tubes configured to at least channel a flow of fluid between said wound dressing, said fluid collection canister, and said pump; a pressure sensor configured to measure a pressure in one or more of said one or more tubes and to generate a pressure sensor voltage reflecting pressure in one or more of said one or more tubes; a control circuit for controlling the pressure in said one or more tubes without using a processor, the control circuit comprising; a pressure controller for controlling the pump motor, the pressure controller comprising; a difference circuit configured to; receive the pressure sensor voltage from the pressure sensor; receive a desired pressure voltage from a user; and provide a difference signal comprising an amplified difference between the desired pressure voltage and the pressure sensor voltage, wherein the difference circuit provides proportional control; and a pulse width modulator configured to generate a motor control signal responsive to the difference signal, the motor control signal configured to control a speed of the pump motor; and a stall controller for preventing stalling of the pump motor, the stall controller comprising; a comparison circuit configured to generate an override signal based at least in part on the difference signal and at least one reference signal, the override signal configured to prevent stalling of the pump motor; and stall logic configured to output a combined control signal based at least in part on the override signal and the motor control signal, the combined control signal configured to control the pressure in said one or more tubes without stalling the pump motor. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A negative pressure wound therapy apparatus comprising:
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a wound dressing; a fluid collection container; a vacuum pump comprising a pump motor; one or more tubes configured to at least channel a flow of fluid between said wound dressing, said fluid collection canister, and said pump; a pressure sensor configured to measure a pressure in one or more of said one or more tubes and to generate a pressure sensor signal; a first control circuit for controlling the pump motor without using a processor, the first control circuit configured to; generate a difference signal comprising a difference between a desired pressure input and the pressure sensor signal; and generate a motor control signal responsive to the difference signal, the motor control signal configured to control a speed of the pump motor; and a second control circuit for providing, without using a processor, an override signal based at least in part on the difference signal and at least one reference signal, the override signal configured to override the motor control signal and thereby prevent the pump motor from stalling. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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16. A method of controlling a pump for negative pressure wound therapy, the method comprising:
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providing a wound dressing, a fluid collection container, a vacuum pump, one or more tubes configured to at least channel a flow of fluid between said wound dressing, said fluid collection canister, and said pump, and a pressure sensor configured to measure a pressure in one or more of said one or more tubes and to generate an output signal; providing a motor control signal without using a processor, said providing the motor control signal comprising; receiving the output signal from said pressure sensor; providing a difference signal comprising a difference between a desired pressure input and the output signal from said pressure sensor; generating a motor control signal responsive to the difference signal, the motor control signal configured to control the pump motor; and preventing stalling of the pump motor without using a processor, said preventing stalling of the pump motor comprising; generating an override signal based at least in part on the difference signal and at least one reference signal; and preventing the pump motor from stalling by using the override signal to override the motor control signal. - View Dependent Claims (17, 18, 19, 20, 21)
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22. A method for treating a wound, comprising the steps of:
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providing a wound dressing, a fluid collection container, a vacuum pump, one or more tubes configured to at least channel a flow of fluid between said wound dressing, said fluid collection container, and said vacuum pump, and a pressure sensor configured to measure a pressure in one or more of said one or more tubes; controlling a pump motor to provide a negative pressure to said wound dressing without using a processor, said controlling the pump motor comprising; receiving a pressure sensor input from the pressure sensor, the pressure sensor input reflecting pressure in one or more of said one or more tubes; outputting a motor control signal responsive to the pressure sensor input and a desired pressure input, the motor control signal configured to control a speed of the pump motor; and outputting an override signal based at least in part on the pressure sensor input and the desired pressure input, the override signal configured to override the motor control signal in order to prevent the pump motor from stalling. - View Dependent Claims (23)
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24. An apparatus for detecting high air flow in a negative pressure wound therapy system, comprising:
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a wound dressing; a fluid collection container; a vacuum pump; one or more tubes configured to at least channel a flow of fluid between said wound dressing, said fluid collection canister, and said pump; a first pressure sensor configured to measure a pressure in one or more of said one or more tubes at a first location and to generate a first output signal; a second pressure sensor configured to measure a pressure in said tubing at a second location apart from said first location and to generate a second output signal; a difference circuit configured to provide a difference signal reflecting a difference between the first and second output signals; a comparison circuit configured to provide a comparison signal based at least in part on the difference signal and a threshold signal; and an alarm circuit configured to produce an alarm responsive to the comparison signal, the alarm reflecting a high flow condition. - View Dependent Claims (25)
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Specification