IP Library › Granted Patent US 12,721,560
Granted Patent B2
US 12,721,560 · App. 18/407,924 · Granted Sep 1, 2026

Circadian rhythm-based training data correction for drowsiness detection systems and applications

Inventors: Yuzhuo Ren (Sunnyvale, CA); Niranjan Avadhanam (Saratoga, CA); Varsha Hedau (Sunnyvale, CA); Zhengmin Zhang (Santa Clara, CA); Shelly Goel (Irving, TX)
Assignee: NVIDIA Corporation
A61B5/18A61B5/162A61B5/163A61B5/372A61B5/4857A61B5/6893A61B5/7267B60W60/00G06V10/774G06V20/597B60W2540/229
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 12,721,560
App. No.
18/407,924
Granted
Sep 1, 2026
Kind
B2
Abstract

In various examples, circadian rhythm-based data augmentation for drowsiness detection systems and applications are provided. Embodiments described herein may produce an estimated circadian rhythm for a test subject and/or vehicle driver or other machine operator or occupant, and use the pattern of that circadian rhythm to correct, confirm, calibrate, or otherwise augment drowsiness assessments derived from video image data. The position of a person in the context of their process C circadian cycle may be used as indication of their level of drowsiness. An estimated process C circadian cycle may be used to generate more accurate ground truth training data for training machine learning models, and may be used by real-time, in-vehicle drowsiness detection systems that infer driver drowsiness levels based on captured images. In various embodiments, a circadian rhythm drowsiness estimate may be used to correct, calibrate, augment, and/or replace a drowsiness score predicted by a machine learning model.

Claims (78)

1 . One or more processors comprising one or more processing units to:

receive a first ground truth image sequence representing visual characteristics of a test subject in the first ground truth image sequence during a testing period, the first ground truth image sequence comprising one or more drowsiness labels indicating a drowsiness of the test subject;

correlate a position on a circadian rhythm process to a time of the testing period;

apply one or more drowsiness corrections to the one or more drowsiness labels based at least on an alertness value corresponding to the position on the circadian rhythm process, to generate a second ground truth image sequence; and

train a machine learning model to infer a drowsiness level based on the second ground truth image sequence.

2 . The one or more processors of claim 1 , wherein the one or more processing units are further to:

determine the alertness value corresponding to the position on the circadian rhythm process based at least on a time of day and sensor data representing sleep information measured from the test subject.

3 . The one or more processors of claim 1 , wherein the one or more processing units are further to:

determine the alertness value corresponding to the position on the circadian rhythm process based at least on a time of day and sleep information based at least on responses to questions to the test subject.

4 . The one or more processors of claim 1 , wherein the one or more processing units are further to:

compute the one or more drowsiness corrections based at least on the alertness value corresponding to the position on the circadian rhythm process and time-on-task data associated with a task performed by the test subject during the testing period.

5 . The one or more processors of claim 1 , wherein the one or more processing units are further to:

compute the one or more drowsiness corrections based at least on the alertness value corresponding to the position on the circadian rhythm process and one or more alertness test measurements captured from the test subject during the testing period.

6 . The one or more processors of claim 5 , wherein the one or more alertness test measurements comprise at least one of an electroencephalogram (EEG) test and a mean reaction time (MRT) measurement.

7 . The one or more processors of claim 1 , wherein the first ground truth image sequence captures visual characteristics of the test subject performing one or more psychomotor vigilance tests (PVTs) over a course of the testing period.

8 . The one or more processors of claim 1 , wherein one or more drowsiness labels of the second ground truth image sequence comprise a score based at least on a Karolinska Sleepiness Scale (KSS).

9 . The one or more processors of claim 1 , wherein visual characteristics of the test subject in the first ground truth image sequence comprise at least one of an eye blink rate, an eye blink velocity, an eye blink amplitude, a time of eye closure, a head pose, an eye gaze direction, and a pattern of yawning behavior.

10 . The one or more processors of claim 1 , wherein the circadian rhythm process corresponds to a circadian rhythm process C curve.

11 . The one or more processors of claim 1 , wherein the one or more processors are comprised in at least one of:

a control system for an autonomous or semi-autonomous machine;

a perception system for an autonomous or semi-autonomous machine;

a system for performing simulation operations;

a system for performing digital twin operations;

a system for performing light transport simulation;

a system for performing collaborative content creation for three-dimensional assets;

a system for performing deep learning operations;

a system for performing remote operations;

a system for performing real-time streaming;

a system for generating or presenting one or more of augmented reality content, virtual reality content, or mixed reality content;

a system implemented using an edge device;

a system implemented using a robot;

a system for performing conversational AI operations;

a system implementing one or more language models;

a system implementing one or more large language models (LLMs);

a system for generating synthetic data;

a system for generating synthetic data using AI;

a system incorporating one or more virtual machines (VMs);

a system implemented at least partially in a data center; or

a system implemented at least partially using cloud computing resources.

12 . A system comprising:

one or more processing units to:

determine a drowsiness score estimate for a test subject during a testing period based at least on correlating a circadian rhythm process to the test subject at a time of the testing period;

apply one or more drowsiness corrections based at least on the drowsiness score estimate to a first ground truth image sequence representing visual characteristics of the test subject during the testing period to generate a second ground truth image sequence, the one or more drowsiness corrections correcting one or more drowsiness labels of the first ground truth image sequence; and

train a machine learning model using the second ground truth image sequence to infer a drowsiness level.

13 . The system of claim 12 , wherein the one or more processing units are further to:

determine the drowsiness score estimate based at least on a circadian rhythm process C curve.

14 . The system of claim 12 , wherein visual characteristics of the test subject in the first ground truth image sequence comprise at least one of an eye blink rate, an eye blink velocity, an eye blink amplitude, a time of eye closure, a head pose, an eye gaze direction, and a pattern of yawning behavior.

15 . The system of claim 12 , wherein the one or more processing units are further to:

determine the drowsiness score estimate based at least on an alertness value corresponding to a position on the circadian rhythm process, the position determined based at least on a time of day and sensor data representing sleep information measured from the test subject.

16 . The system of claim 12 , wherein the one or more processing units are further to:

determine the drowsiness score estimate based at least on an alertness value corresponding to a position on the circadian rhythm process, the position determined based at least on a time of day and sleep information based at least on responses to questions to the test subject.

17 . The system of claim 12 , wherein the one or more processing units are further to:

compute the one or more drowsiness corrections based at least on an alertness value corresponding to a position on the circadian rhythm process and time-on-task data associated with a task performed by the test subject during the testing period.

18 . The system of claim 12 , wherein the one or more processing units are further to:

compute the one or more drowsiness corrections based at least on an alertness value corresponding to a position on the circadian rhythm process and one or more alertness test measurements captured from the test subject during the testing period.

19 . The system of claim 12 , wherein the one or more processing units are comprised in at least one of:

a control system for an autonomous or semi-autonomous machine;

a perception system for an autonomous or semi-autonomous machine;

a system for performing simulation operations;

a system for performing digital twin operations;

a system for performing light transport simulation;

a system for performing collaborative content creation for three-dimensional assets;

a system for performing deep learning operations;

a system for performing remote operations;

a system for performing real-time streaming;

a system for generating or presenting one or more of augmented reality content, virtual reality content, or mixed reality content;

a system implemented using an edge device;

a system implemented using a robot;

a system for performing conversational AI operations;

a system implementing one or more language models;

a system implementing one or more large language models (LLMs);

a system for generating synthetic data;

a system for generating synthetic data using AI;

a system incorporating one or more virtual machines (VMs);

a system implemented at least partially in a data center; or

a system implemented at least partially using cloud computing resources.

20 . A method comprising:

generating a second ground truth image sequence from a first ground truth image sequence by applying one or more drowsiness corrections to one or more labels of the first ground truth image sequence, the one or more drowsiness corrections determined using a drowsiness score estimate for a test subject during a testing period associated with the first ground truth image sequence, the drowsiness score estimate based at least on correlating a circadian rhythm process to the test subject at a time of the testing period.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 15, 2025
From: REN, YUZHUO; AVADHANAM, NIRANJAN; HEDAU, VARSHA; ZHANG, ZHENGMIN; GOEL, SHELLY
To: NVIDIA CORPORATION
Reel/Frame 069883/0590 →
Continuity (1)
Related Publication 20250221647A1 · Jul 10, 2025
References Cited (33)
US 10235859B1 · Hiles · 2019 [cited by applicant]
US 10885698B2 · Muthler et al. · 2021 [cited by applicant]
US 20100079294A1 · Rai · 2010 [cited by examiner]
US 20100090839A1 · Omi · 2010 [cited by applicant]
US 20120133515A1 · Palshof · 2012 [cited by applicant]
US 20140046546A1 · Kollegger et al. · 2014 [cited by applicant]
US 20160071393A1 · Kaplan et al. · 2016 [cited by applicant]
US 20170313190A1 · Shimada · 2017 [cited by examiner]
US 20190216391A1 · Kenyon · 2019 [cited by examiner]
US 20200317211A1 · Stiller et al. · 2020 [cited by applicant]
US 20220375590A1 · Kinnunen · 2022 [cited by examiner]
US 20230245474A1 · Shinozaki · 2023 [cited by examiner]
US 20240199061A1 · Reifman · 2024 [cited by applicant]
DE 102015122245A1 · 2017 [cited by applicant]
WO 2017102614A1 · 2017 [cited by applicant]
WO WO2023218546A1 · 2023 [cited by examiner]
Ghoddoosian et al., “A Realistic Dataset and Baseline Temporal Model for Early Drowsiness Detection”, 2019 IEEE/CVF Conference on Computer Vision and Pattern Recognition Workshops (CVPRW), Long Beach, CA, USA, 2019, pp.… [cited by examiner]
Perkins et al., “Challenges of Driver Drowsiness Prediction: The Remaining Steps to Implementation”, in IEEE Transactions on Intelligent Vehicles, vol. 8, No. 2, pp. 1319-1338, Feb. 2023 (Year: 2023). [cited by examiner]
Riani et al., “Towards Classifying Human Circadian Rhythm Using Multiple Modalities,” 2021 9th International Conference on Affective Computing and Intelligent Interaction (ACII), Nara, Japan, 2021, pp. 1-8 (Year: 2021). [cited by examiner]
Shraddha et al., “Driver Drowsiness Detection System Using Artificial Intelligence”, 2023 International Conference on Computing, Communication, and Intelligent Systems (ICCCIS), pp. 1183-1188 (Year: 2023). [cited by examiner]
Reddy et al., “Effective Model of Detecting Driver's Drowsiness”, Proceedings of the 5th International Conference on Smart Systems and Inventive Technology (ICSSIT 2023), pp. 1405-1408 (Year: 2023). [cited by examiner]
“Taxonomy and Definitions for Terms Related to Driving Automation Systems for On-Road Motor Vehicles”, National Highway Traffic Safety Administration (NHTSA), A Division of the US Department of Transportation, and the S… [cited by applicant]
“Taxonomy and Definitions for Terms Related to Driving Automation Systems for On-Road Motor Vehicles”, National Highway Traffic Safety Administration (NHTSA), A Division of the US Department of Transportation, and the S… [cited by applicant]
'ISO 26262, “Road vehicle—Functional safety,” International standard for functional safety of electronic system, Retrieved from Internet URL: https://en.wikipedia.org/wiki/ISO_26262, accessed on Sep. 13, 2021, 8 pages. [cited by applicant]
“Circadian Rhythms Promote Wakefulness”, Centers for Disease Control and Prevention, Retrieved on Apr. 1, 2020, 1 page. [cited by applicant]
“Circadian Rhythms”, National Institute of General Medical Sciences, Oct. 2020, 3 pages. [cited by applicant]
De Naurois et al., “Detection and Prediction of Driver Drowsiness Using Artificial Neural Network Models”, Accident Analysis & Prevention, vol. 126, May 2019, pp. 95-104. [cited by applicant]
Ghoddoosian et al., “A Realistic Dataset and Baseline Temporal Model for Early Drowsiness Detection”, 2019 IEEE/CVF Conference on Computer Vision and Pattern Recognition Workshops (CVPRW), 2019, 10 pages. [cited by applicant]
IEC 61508, “Functional Safety of Electrical/Electronic/Programmable Electronic Safety-related Systems,” Retrieved from Internet URL: https://en.wikipedia.org/wiki/IEC_61508, accessed on Apr. 1, 2022, 7 pages. [cited by applicant]
Massoz et al., “The ULg Multimodality Drowsiness Database (called Drozy) and Examples of Use”, 2016 IEEE Winter Conference on Applications of Computer Vision (WACV), May 2016, 7 pages. [cited by applicant]
Shahid et al., “Karolinska Sleepiness Scale”, Stop, That and One Hundred Other Sleep Scales, 2012, pp. 209-210. [cited by applicant]
Non-Final Office Action received for U.S. Appl. No. 18/408,336, mailed on Jan. 23, 2026, 16 pages. [cited by applicant]
Notice of Allowance received for U.S. Appl. No. 18/408,336, mailed on May 26, 2026, 8 pages. [cited by applicant]