Dual mode negative pressure source operation for provision of negative pressure wound therapy
AssigneeT.J.Smith and Nephew, Limited
InventorsBen Alan Askem, David Michael Elder
Life of this patent
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Abstract
A negative pressure source can be fluidically connected to the wound dressing, the wound dressing can be positioned to cover at least a portion of the wound, and the negative pressure source can be controlled to supply negative pressure to the wound via the fluid flow path. An actuator of the negative pressure source can be controlled to operate in a dual mode by transitioning between a proportional-integral (PI) control or proportional-integral-derivative (PID) control and a pulsed control. Stalling of the actuator can be prevented, and therapy can be provided without interruptions.
Claims26
A negative pressure wound therapy device comprising:
- a source of negative pressure connected via a fluid flow path to a wound covered by a wound dressing, the source of negative pressure configured to supply negative pressure to the wound via the fluid flow path;
- a pressure sensor configured to measure pressure in the fluid flow path;
- and
- a controller configured to control the source of negative pressure, the controller further configured to:
- determine a pressure difference between a negative pressure setpoint corresponding to desired negative pressure at the wound and pressure measured by the pressure sensor;
- in response to determining that the pressure difference does not satisfy a flow threshold indicative of a low flow in the fluid flow path, apply to an actuator of the source of negative pressure a first drive signal determined based on the pressure difference, the application of the first drive signal causing reduction of the pressure difference;
- and
- in response to determining that the pressure difference satisfies the flow threshold, apply a second drive signal to the actuator, the second drive signal causing the actuator to be activated for a first period of time and deactivated for a second period of time subsequent to the first period of time.
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A negative pressure wound therapy device comprising:
- a source of negative pressure connected via a fluid flow path to a wound covered by a wound dressing, the source of negative pressure configured to supply negative pressure to the wound via the fluid flow path;
- a pressure sensor configured to measure pressure in the fluid flow path;
- and
- a controller configured to control the source of negative pressure, the controller further configured to:
- responsive to a determination that a pressure difference between a desired level of negative pressure at the wound and pressure measured by the pressure sensor does not satisfy a stall threshold of a motor of the source of negative pressure, actuate the motor according to a proportional integral (PI) control or proportional integral derivative (PID) control;
- and
- responsive to a determination that the pressure difference satisfies the stall threshold of the motor, actuate the motor according to a pulsed control.
A negative pressure wound therapy device comprising:
- a source of negative pressure connected via a fluid flow path to a wound covered by a wound dressing, the source of negative pressure configured to supply negative pressure to the wound via the fluid flow path;
- a pressure sensor configured to measure pressure in the fluid flow path;
- and
- a controller configured to control the source of negative pressure, the controller further configured to:
- apply a first drive signal to an actuator of the source of negative pressure to cause the source of negative pressure to supply negative pressure to the wound via the fluid flow path;
- monitor negative pressure at the wound using the pressure sensor;
- adjust the first drive signal applied to the actuator based on a difference between the monitored negative pressure and a negative pressure setpoint;
- and
- responsive to a determination that a flow in the fluid flow path satisfies a flow threshold indicative of a low flow, apply a second drive signal different from the first drive signal to the actuator wherein application of the second drive signal causes the actuator to continue operating to establish or maintain the negative pressure setpoint at the wound.
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Dependencies are inferred from the claim text.