IP Library Granted Patent US 12,390,103
Granted Patent B2
US 12,390,103 · App. 18/037,596 · Granted Aug 19, 2025

Estimation device, estimation method, and estimation program

Inventors: Jumpei Yamashita (Musashino, JP); Hidetaka Koya (Musashino, JP); Akira Kataoka (Musashino, JP)
Assignee: Nippon Telegraph and Telephone Corporation
A61B3/112
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Quick Facts
Patent No.
US 12,390,103
App. No.
18/037,596
Granted
Aug 19, 2025
Kind
B2
Abstract

An estimation device includes processing circuitry configured to acquire a pupil diameter of a subject whose work performance is to be estimated at a time of work and a luminance of a gaze target of the subject, calculate a variation amount of the pupil diameter of the subject from time-series data of the pupil diameter of the subject, determine whether or not the luminance of the gaze target of the subject is equal to or higher than a predetermined value, and determine that a correlation between a magnitude of the variation amount of the pupil diameter of the subject and a deterioration in the work performance of the subject is low in a case where it is determined that the luminance of the gaze target of the subject is equal to or higher than a predetermined threshold.

Claims (28)

1. An estimation device comprising:

processing circuitry configured to:

acquire a pupil diameter of a subject whose work performance is to be estimated at a time of work and a luminance of a gaze target of the subject;

calculate a variation amount of the pupil diameter of the subject from time-series data of the pupil diameter of the subject;

determine whether or not the luminance of the gaze target of the subject is equal to or higher than a predetermined value; and

determine that a correlation between a magnitude of the variation amount of the pupil diameter of the subject and a deterioration in the work performance of the subject is low in a case where it is determined that the luminance of the gaze target of the subject is equal to or higher than a predetermined threshold, determine that the correlation between the magnitude of the variation amount of the pupil diameter of the subject and the deterioration in the work performance of the subject is high in a case where it is determined that the luminance of the gaze target of the subject is lower than the predetermined threshold, and estimate the work performance of the subject based on a result of the determination and the variation amount of the pupil diameter of the subject.

2. The estimation device according to claim 1 , wherein

the processing circuitry is further configured to estimate that the work performance of the subject is higher as the variation amount of the pupil diameter of the subject is larger in a case where it is determined that the luminance of the gaze target is equal to or higher than the predetermined threshold, and estimate that the work performance of the subject is lower as the variation amount of the pupil diameter of the subject is larger in a case where it is determined that the luminance of the gaze target is lower than the predetermined threshold.

3. The estimation device according to claim 1 , wherein

the processing circuitry is further configured to estimate that the work performance of the subject is lower as the variation amount of the pupil diameter of the subject is smaller in a case where it is determined that the luminance of the gaze target is equal to or higher than the predetermined threshold, and estimate that the work performance of the subject is higher as the variation amount of the pupil diameter of the subject is smaller in a case where it is determined that the luminance of the gaze target is lower than the predetermined threshold.

4. The estimation device according to claim 1 , wherein

the processing circuitry is further configured to exclude, from the time-series data of the pupil diameter of the subject, time-series data of the pupil diameter in a period in which a value of the pupil diameter is equal to or smaller than a predetermined threshold among the time-series data of the pupil diameter of the subject, and calculate the variation amount of the pupil diameter of the subject from the time-series data obtained by the exclusion.

5. The estimation device according to claim 1 , wherein

the processing circuitry is further configured to smooth the time-series data of the pupil diameter of the subject by use of a low-pass filter or a moving average to calculate the variation amount of the pupil diameter of the subject.

6. The estimation device according to claim 1 , wherein

the processing circuitry is further configured to obtain first-order differential values of the time-series data of the pupil diameter of the subject, takes take absolute values of the first-order differential values of the time-series data, calculate an average value of the absolute values of the first-order differential values of the time-series data, and calculate the variation amount of the pupil diameter of the subject by use of the calculated average value.

7. The estimation device according to claim 1 , wherein

the processing circuitry is further configured to set a value obtained by logarithmically transforming the calculated variation amount of the pupil diameter of the subject as the variation amount of the pupil diameter of the subject.

8. An estimation method executed by an estimation device, the estimation method comprising:

acquiring a pupil diameter of a subject whose work performance is to be estimated at a time of work and a luminance of a gaze target of the subject;

calculating a variation amount of the pupil diameter of the subject from time-series data of the pupil diameter of the subject;

determining whether or not the luminance of the gaze target of the subject is equal to or higher than a predetermined value; and

determining that a correlation between a magnitude of the variation amount of the pupil diameter of the subject and a deterioration in the work performance of the subject is low in a case where it is determined that the luminance of the gaze target of the subject is equal to or higher than a predetermined threshold, determining that the correlation between the magnitude of the variation amount of the pupil diameter of the subject and the deterioration in the work performance of the subject is high in a case where it is determined that the luminance of the gaze target of the subject is lower than the predetermined threshold, and estimating the work performance of the subject based on a result of the determination and the variation amount of the pupil diameter of the subject.

9. A non-transitory computer-readable recording medium storing therein an estimation program that causes a computer to execute a process comprising:

acquiring a pupil diameter of a subject whose work performance is to be estimated at a time of work and a luminance of a gaze target of the subject;

calculating a variation amount of the pupil diameter of the subject from time-series data of the pupil diameter of the subject;

determining whether or not the luminance of the gaze target of the subject is equal to or higher than a predetermined value; and

determining that a correlation between a magnitude of the variation amount of the pupil diameter of the subject and a deterioration in the work performance of the subject is low in a case where it is determined that the luminance of the gaze target of the subject is equal to or higher than a predetermined threshold, determining that the correlation between the magnitude of the variation amount of the pupil diameter of the subject and the deterioration in the work performance of the subject is high in a case where it is determined that the luminance of the gaze target of the subject is lower than the predetermined threshold, and estimating the work performance of the subject based on a result of the determination and the variation amount of the pupil diameter of the subject.

Assignments (2)
CHANGE OF NAME Recorded Dec 5, 2025
From: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
To: NTT, INC.
Reel/Frame 073861/0410 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 18, 2023
From: YAMASHITA, JUMPEI; KOYA, HIDETAKA; KATAOKA, AKIRA
To: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Reel/Frame 063681/0206 →
Continuity (1)
Related Publication 20230404393A1 · Dec 21, 2023
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