Temperature monitoring and control for negative pressure wound therapy systems
A negative pressure wound therapy can include a negative pressure source configured to provide negative pressure to a wound of a patient covered by a wound dressing, first sensor and second sensors configured to measure temperature of the negative pressure system, electronic control circuitry configured to control operation of the negative pressure source responsive to temperature measured by the first sensor, and a programmable controller configured to control operation of the negative pressure source responsive to temperature measured by the second sensor, the controller configured to control operation of the negative pressure source independently of the electronic control circuitry.
1 . A negative pressure wound therapy system comprising:
a negative pressure source configured to provide negative pressure to a wound of a patient covered by a wound dressing;
a first sensor configured to measure a temperature of at least a first portion of the negative pressure wound therapy system;
a second sensor configured to measure a temperature of at least one of the patient or at least a second portion of the negative pressure wound therapy system;
a non-programmable electronic control circuitry configured to deactivate the negative pressure source responsive to a determination that the temperature measured by the first sensor satisfies a first temperature threshold indicative of unsafe operation, the non-programmable electronic control circuitry comprising an analog comparator configured to output the determination that the temperature measured by the first sensor satisfies the first temperature threshold, and the analog comparator accepting as a first input the temperature measured by the first sensor and as a second input the first temperature threshold; and
a programmable controller configured to control operation of the negative pressure source responsive to temperature measured by the second sensor, the programmable controller configured to control operation of the negative pressure source independently of the non-programmable electronic control circuitry.
2 . The system of claim 1 , wherein the programmable controller is configured to reduce activity of the negative pressure source responsive to temperature measured by the second sensor satisfying a second temperature threshold that is lower than the first temperature threshold and not satisfying the first temperature threshold.
3 . The system of claim 2 , wherein reducing activity of the negative pressure source comprises lowering a duty cycle of the negative pressure source.
4 . The system of claim 1 , further comprising the wound dressing, wherein at least one of the negative pressure source, the first sensor, the second sensor, the non-programmable electronic control circuitry, or the programmable controller is at least partially supported by the wound dressing.
5 . The system of claim 1 , wherein the temperature measured by the first sensor is indicative of a temperature of the negative pressure source.
6 . The system of claim 1 , wherein the non-programmable electronic control circuitry is configured to deactivate the negative pressure source responsive to a determination that the temperature measured by the first sensor satisfies the first temperature threshold.
7 . The system of claim 1 , wherein the analog comparator is configured to operate in a presence of noise as a result of at least one of: one or more inputs of the analog comparator being filtered or a feedback being provided between the first or second input of the analog comparator and an output of the analog comparator.
8 . The system of claim 7 , wherein the feedback comprises a resistor positioned between a non-inverting input of the analog comparator and the output of the analog comparator.
9 . The system of claim 1 , further comprising a power source configured to provide power at least to the negative pressure source and a boost converter configured to increase power provided by the power source and provide the increased power to the negative pressure source, and wherein the first sensor is further configured to measure temperature of the boost converter.
10 . The system of claim 9 , wherein the first sensor is positioned proximal to the boost converter.
11 . The system of claim 1 , wherein the second sensor comprises a pair of sensors, and wherein the programmable controller is configured to determine a temperature of at least one of the negative pressure source or another component of the negative pressure wound therapy system based on a difference between measurements of first and second sensors of the pair of sensors.
12 . The system of claim 11 , wherein the first and second sensors of the pair of sensors are configured to measure pressure and temperature.
13 . The system of claim 11 , wherein the first sensor of the pair of sensors is positioned at an inlet of the negative pressure source and the second sensor of the pair of sensors is positioned at an exhaust of the negative pressure source.
14 . The system of claim 1 , wherein the programmable controller is configured to control operation of the negative pressure source responsive to temperature measured by the second sensor by at least one of:
deactivating the negative pressure source responsive to the temperature measured by the second sensor satisfying the first temperature threshold;
reducing activity of the negative pressure source responsive to the temperature measured by the second sensor satisfying a second temperature threshold lower than the first temperature threshold and not satisfying the first temperature threshold; or
taking no action responsive to the temperature measured by the second sensor not satisfying the second temperature threshold.
15 . The system of claim 14 , wherein reducing the activity of the negative pressure source comprises reducing a duty cycle of the negative pressure source.
16 . The system of claim 1 , wherein the programmable controller is further configured to disable activation of the negative pressure source responsive to a determination that the temperature measured by at least one of the first sensor or the second sensor satisfies the first temperature threshold indicative of unsafe operation.
17 . The system of claim 1 , further comprising a switch configured to permit activation of the negative pressure source, and wherein the switch is configured to be deactivated responsive to a determination that the temperature measured by at least one of the first sensor or the second sensor satisfies the first temperature threshold.
18 . The system of claim 1 , wherein the second sensor is configured to measure temperature of the patient, and wherein the programmable controller is configured to deactivate the negative pressure source responsive to a determination that the temperature measured by the second sensor satisfies a second temperature threshold indicative of high patient temperature.
19 . The system of claim 1 , wherein the programmable controller is configured to execute instructions to control operation of the negative pressure source responsive to temperature measured by the second sensor.
20 . The system of claim 1 , wherein the non-programmable electronic control circuitry comprises only analog circuitry configured solely to allow or disallow provision of negative pressure to the wound.
21 . The system of claim 1 , wherein the programmable controller is further configured to determine that the first sensor or the second sensor is malfunctioning based on a determination that output of one of the first sensor or second sensor but not the other indicates that the first temperature threshold has been satisfied.