IP Library › Granted Patent US 12,521,582
Granted Patent B2
US 12,521,582 · App. 18/578,544 · Granted Jan 13, 2026

Seal evaluation systems and methods for respiratory protection devices

Inventors: Wei Zhao (Wooodbury, MN); Wenbo Dong (Lakeville, MN); Yutao Gong (Woodbury, MN); Xuan Wang (Woodbury, MN); Francis T. Caruso (Hudson, WI)
Assignee: 3M Innovative Properties Company
A62B27/00G06T7/11G06T17/205A61M2016/0015G06T2207/10048
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Quick Facts
Patent No.
US 12,521,582
App. No.
18/578,544
Granted
Jan 13, 2026
Kind
B2
Abstract

A fit detection system for a respiratory protection device is presented that includes an infrared camera that captures an image sequence of a user wearing the respiratory protection device. The system also includes a temperature change detector that analyzes images in the image sequence and detects a temperature change profile of the respiratory protection device. The system also includes a communication component that communicates a fit indication based on the detected temperature change profile.

Claims (44)

1 . A fit detection system for a respiratory protection device, the system comprising:

an infrared camera that captures an image sequence of a user wearing the respiratory protection device;

a temperature change detector that analyzes images in the image sequence and detects a temperature change profile of the respiratory protection device; and

a communication component that communicates a fit indication based on the detected temperature change profile.

2 . The system of claim 1 , and further comprising:

a segmenter that analyzes the image sequence and generates segments for each image in the image sequence.

3 . The system of claim 2 , wherein, based on the segmented images, a 3D mesh generator generates a 3D mesh of the respiratory protection device.

4 . The system of claim 3 , wherein, based on the 3D mesh generator, a seal between the respiratory protection device and a face of the user is evaluated.

5 . The system of claim 1 , and further comprising an image identifier that identifies an inhale image, indicative of an inhale, and an exhale image, indicative of an exhale.

6 . The system of claim 1 , wherein the IR camera automatically captures the image sequence upon detecting the user in a field of view of the camera.

7 . The system of claim 1 , wherein the feature extractor detects a movement of the respiratory protection device in the image sequence.

8 . The system of claim 1 , wherein the communication component communicates the fit indication to a graphical user interface generator, and wherein the graphical user interface generator generates a graphical user interface that displays a fit indication.

9 . A method for checking a fit of a respiratory protection device, the method comprising:

capturing a sequence of infrared images of a wearer of the respiratory protection device;

isolating the respiratory protection device portion of the captured images;

detecting a temperature change profile of the respiratory protection device over time, from the captured images; and

based on the temperature change profile, determining a seal quality of the respiratory protection device.

10 . The method of claim 9 , and further comprising:

communicating the seal quality, using a communication component.

11 . The method of claim 9 , wherein isolating the respiratory protection device comprises:

segmenting a portion of the captured images containing the respiratory protection device; and

identifying a leak in a seal of the respiratory protection device based on the segmentation.

12 . The method of claim 11 , and further comprising:

generating a 3D mesh of the respiratory protection device; and

identifying a leak in a seal of the respiratory protection device based on the 3D mesh.

13 . The method of claim 11 , and further comprising overlaying a generated 3D mesh of the respiratory device with the segmented images of the respiratory protection device.

14 . The method of claim 9 , wherein detecting a temperature change profile further comprises:

identifying an inhale image in the sequence of infrared images;

identifying an exhale image in the sequence of infrared images; and

comparing a temperature difference in a pixel between the inhale image and the exhale image.

15 . The method of claim 9 , wherein the seal quality comprises a leak location and wherein the leak location is communicated to a graphical user interface generator which provides an indication of the leak location on a graphical user interface.

16 . The method of claim 9 , and further comprising the wearer activating an application on a computing device and, based on the activation, automatically completing the steps of capturing, isolating, detecting and determining.

17 . The method of claim 9 , wherein communicating comprises providing an alert that the seal quality is below a threshold.

18 . The method of claim 9 , wherein determining the seal quality comprises:

receiving an ambient temperature indication and;

wherein determining the seal quality comprises analyzing a database of temperature change profile data matching the ambient temperature indication.

19 . The method of claim 9 , wherein determining the seal quality comprises:

identifying a manufacturer and model of the RPD and;

wherein determining the seal quality comprises analyzing a database of temperature change profile data matching the identified RPD manufacturer and model.

20 . A touch free safety monitoring system comprising:

an IR camera with a field of view configured to, when an individual is detected within the field of view, capture a sequence of IR images of a face of the individual;

a temperature profile generator that, based on the images, generates a temperature profile of a respiratory protection device on the face of the individual;

a seal evaluator that, based on the temperature profile, evaluates a quality of a seal between the respiratory protection device and the face of the individual; and

a communication module that communicates the seal quality.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 21, 2024
From: ZHAO, WEI; DONG, WENBO; GONG, YUTAO; CARUSO, FRANCIS T.
To: 3M INNOVATIVE PROPERTIES COMPANY
Reel/Frame 067792/0426 →
Continuity (2)
Provisional Application 63203307 · Jul 16, 2021
Related Publication 20240293687A1 · Sep 5, 2024
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