# US 11,896,465 B2 · Negative pressure wound therapy device activation and control

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- Number: US 11,896,465 B2
- Document ID: US11896465B2
- Status: Granted
- Kind: B2
- Application number: 17/406,564
- Filed: 2021-08-19
- Published: 2021-12-09
- Granted: 2024-02-13
- Earliest claimed: 2016-05-03
- Assignees: Smith & Nephew, Inc.
- Applicants: Smith & Nephew PLC
- Inventors: Ben Alan Askem; Victoria Beadle; John Philip Gowans; Mark Hesketh; Allan Kenneth Frazer Grugeon Hunt; William Kelbie; Damyn Musgrave; Joseph William Robinson
- Web page: https://patentgrep.com/patent/US11896465B2

## CPC

- A61F 13/05: specially adapted for use with sub-pressure or over-pressure therapy, wound drainage or wound irrigation, e.g. for use with negative-pressure wound therapy [NPWT]
- A61F 13/00063: {comprising medicaments or additives, e.g. odor control, PH control, debriding, antimicrobic (drug delivery dressings A61K9/70; chemical aspect of the additives A61L15/00)}
- A61M 1/74: {Suction control (underwater drainage A61M1/61)}
- A61M 1/96: {Suction control thereof}
- A61M 1/962: {having pumping means on the suction site, e.g. miniature pump on dressing or dressing capable of exerting suction}
- A61M 1/964: {having venting means on or near the dressing}
- A61M 1/982: {with means for detecting level of collected exudate}
- A61M 2205/13: with means for the detection of operative contact with patient, e.g. lip sensor
- A61M 2205/502: User interfaces, e.g. screens or keyboards
- A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C)
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}

## Abstract

Embodiments of negative pressure wound therapy systems and methods are disclosed. In one embodiment, an apparatus includes a wound dressing, negative pressure source, user interface, sensor, and control circuitry. The user interface can receive an activation input. The sensor can detect whether the wound dressing is positioned over a wound. The control circuitry can cause supply of negative pressure in response to receipt of the activation input and a determination that the sensor detects that the wound dressing is positioned over the wound. In addition, the control circuitry can prevent supply of negative pressure in response to a determination that the sensor does not detect that the wound dressing is positioned over the wound.

## Claims

### Claim 1

An apparatus for applying negative pressure to a wound, the apparatus comprising:
a wound dressing configured to be placed over a wound of a patient;
a negative pressure source configured to provide negative pressure to the wound via a fluid flow path connecting the negative pressure source to the wound dressing;
a user interface configured to receive an activation input;
a first sensor integrated with the wound dressing, the first sensor configured to detect whether the wound dressing is positioned over the wound; and
a control circuitry electrically coupled to the user interface and the first sensor, the control circuitry programmed to:
cause supply of negative pressure with the negative pressure source in response to receipt of the activation input by the user interface and a determination that the first sensor detects that the wound dressing is positioned over the wound, and
prevent supply of negative pressure with the negative pressure source in response to a determination that the first sensor does not detect that the wound dressing is positioned over the wound.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the control circuitry is further programmed to:
start a timer in response to receipt of the activation input by the user interface and the determination that the first sensor detects that the wound dressing is positioned over the wound; and
prevent supply of negative pressure with the negative pressure source in response to expiration of the timer.

### Claim 3 (depends on 2)

The apparatus of claim 2, wherein the control circuitry is further programmed to not start the timer in response to the determination that the first sensor does not detect that the wound dressing is positioned over the wound.

### Claim 4 (depends on 2)

The apparatus of claim 2, wherein the timer expires after between 5 days and 20 days.

### Claim 5 (depends on 2)

The apparatus of claim 2, further comprising a power source configured to supply power to one or more of the negative pressure source or the control circuitry, the control circuitry being further programmed to increase an amount of power supplied by the power source in response to expiration of the timer.

### Claim 6 (depends on 1)

The apparatus of claim 1, wherein the control circuitry is programmed to prevent supply of negative pressure with the negative pressure source by one or more of: deactivation of operation of the negative pressure source, opening of a vent positioned in the fluid flow path, or closing of a valve positioned in the fluid flow path.

### Claim 7 (depends on 1)

The apparatus of claim 1, wherein the control circuitry is programmed to:
cause supply of negative pressure with the negative pressure source in response to receipt of the activation input by the user interface and the determination that the first sensor detects that the wound dressing is positioned over the wound for a period of time, and
prevent supply of negative pressure with the negative pressure source in response to the determination that the first sensor detects that the wound dressing is positioned over the wound for less than the period of time.

### Claim 8 (depends on 1)

The apparatus of claim 1, wherein the first sensor comprises one or more of a capacitive sensor, an impedance sensor, an optical sensor, a piezoresistive sensor, a piezoelectric sensor, an elastoresistive sensor, or an electrochemical sensor.

### Claim 9 (depends on 1)

The apparatus of claim 1, further comprising:
a second sensor configured to monitor pressure in the fluid flow path, and
a third sensor configured to monitor pressure outside the wound dressing,
wherein the control circuitry is further programmed to control supply of negative pressure with the negative pressure source according at least to a comparison of the pressure monitored by the second sensor and the pressure monitored by the third sensor.

### Claim 10 (depends on 9)

The apparatus of claim 9, wherein the control circuitry is further programmed to:
determine a magnitude of a difference between the pressure monitored by the second sensor and the pressure monitored by the third sensor;
prevent supply of negative pressure with the negative pressure source in response to a determination that the magnitude satisfies a deactivation threshold; and
cause supply of negative pressure with the negative pressure source in response to a determination that the magnitude satisfies an activation threshold, the deactivation threshold being different from the activation threshold.

### Claim 11 (depends on 9)

The apparatus of claim 9, wherein the control circuitry is further programmed to vary a sampling rate at which the pressure monitored by the second sensor and the pressure monitored by the third sensor are sampled.

### Claim 12 (depends on 9)

The apparatus of claim 9, wherein the control circuitry is further programmed to enter a sleep mode in which the control circuitry does not sample the pressure monitored by the second sensor and the pressure monitored by the third sensor until the control circuitry leaves the sleep mode.

### Claim 13 (depends on 1)

The apparatus of claim 1, wherein the control circuitry is programmed to enter a sleep mode in response to the determination that the first sensor does not detect that the wound dressing is positioned over the wound.

### Claim 14 (depends on 1)

The apparatus of claim 1, wherein the control circuitry is programmed to enter a sleep mode while the negative pressure source supplies negative pressure.

### Claim 15

A method of operating a negative pressure wound therapy apparatus, the method comprising:
receiving an activation input with a user interface;
at a first time, determining that a first sensor detects that a wound dressing is positioned over a wound;
in response to receiving the activation input and determining that the first sensor detects that the wound dressing is positioned over the wound, supplying negative pressure with a negative pressure source to the wound via a fluid flow path connecting the negative pressure source to the wound dressing;
at a second time, determining that the first sensor does not detect that the wound dressing is positioned over a wound; and
in response to determining that the first sensor does not detect that the wound dressing is positioned over the wound, preventing supply of negative pressure with the negative pressure source to the wound,
wherein the method is performed under control of a control circuitry of the negative pressure wound therapy apparatus.

### Claim 16 (depends on 15)

The method of claim 15, further comprising:
starting a timer in response to receiving the activation input with the user interface and determining that the first sensor detects that the wound dressing is positioned over the wound; and
preventing supply of negative pressure with the negative pressure source to the wound in response to expiration of the timer.

### Claim 17 (depends on 15)

The method of claim 15, wherein the activation input is indicative of an element of the user interface being depressed for a period of time, the period of time being between 0.5 seconds and 5 seconds.

### Claim 18 (depends on 15)

The method of claim 15, further comprising determining whether the first sensor detects that the wound dressing in response to receiving the activation input with the user interface.

### Claim 19 (depends on 15)

The method of claim 15, wherein said supplying negative pressure with the negative pressure source is controlled according at least to a comparison of a pressure monitored by a second sensor and a pressure monitored by a third sensor, the second sensor monitoring the pressure in the fluid flow path, and the third sensor monitoring the pressure outside the wound dressing.

### Claim 20 (depends on 15)

The method of claim 15, further comprising:
sampling a pressure monitored by a second sensor and a pressure monitored by a third sensor, the second sensor monitoring the pressure in the fluid flow path, and the third sensor monitoring the pressure outside the wound dressing; and
varying a sampling rate at which the pressure monitored by the second sensor and the pressure monitored by the third sensor are sampled according to one or more of: (i) an amount of energy stored in a power source used to power the negative pressure source or the control circuitry or (ii) whether the negative pressure source is supplying negative pressure.