US 11,864,831 B2
Visual field test device, method of controlling same, and visual field test program
Satoshi Inoue, Tokyo (JP); Shinji Kimura, Tokyo (JP); and Kenzo Yamanaka, Tokyo (JP)
Assigned to CREWT MEDICAL SYSTEMS, INC., Tokyo (JP)
Appl. No. 16/982,755
Filed by CREWT MEDICAL SYSTEMS, INC., Tokyo (JP)
PCT Filed Mar. 6, 2019, PCT No. PCT/JP2019/008928
§ 371(c)(1), (2) Date Sep. 21, 2020,
PCT Pub. No. WO2019/181517, PCT Pub. Date Sep. 26, 2019.
Claims priority of application No. 2018-051554 (JP), filed on Mar. 19, 2018.
Prior Publication US 2021/0007598 A1, Jan. 14, 2021
Int. Cl. A61B 3/024 (2006.01); G16H 10/60 (2018.01); G16H 50/20 (2018.01); G06N 7/01 (2023.01)
CPC A61B 3/024 (2013.01) [G06N 7/01 (2023.01); G16H 10/60 (2018.01); G16H 50/20 (2018.01)] 12 Claims
OG exemplary drawing
 
1. A visual field test device comprising:
a first probability density function acquisition unit configured to perform a step (1) of obtaining a probability density function f(x1) for a result value x1 obtained in a first visual field test, the probability density function f(x1) being a probability density function under at least two conditions regarding a test subject from among the number of years since a last test, an age, test coordinates, a history of illness, an illness name, an disease stage, an estimated threshold used in a past visual field test, and an indicator of a reliability of a past visual field test result;
a stimulation threshold determination unit configured to perform a step (2) of setting a stimulation threshold t1 to a value in a range of x1 in the probability density function f(x1);
a test result acquisition unit configured to perform a step (3) of obtaining a test result indicating whether or not a result greater than or equal to t1 was obtained in the first visual field test;
a second probability density function acquisition unit configured to perform a step (4) of, if a test result greater than or equal to t1 is obtained, obtaining a probability density function f(x2) by removing probability density values that are less than t1 from the probability density function f(x1), and if a test result greater than or equal to t1 is not obtained, obtaining the probability density function f(x2) by removing probability density values that are greater than or equal to t1 from the probability density function f(x1); and
a determination unit configured to perform a step (5) of determining whether or not a standard deviation σ of the probability density function f(x2) has fallen below a predetermined value,
wherein if the determination unit determines that the standard deviation σ has fallen below the predetermined value, a value of x2 having a highest probability density in the probability density function f(x2) is deemed to be a test value, and testing is ended, and
if the determination unit determines that the standard deviation σ has not fallen below the predetermined value, the first visual field test is replaced with a second visual field test, x2 is replaced with x3, x1 is replaced with x2, the stimulation threshold t1 is replaced with a stimulation threshold t2, and the second probability density function acquiring step is replaced with a third probability density function acquiring step, and the stimulation threshold determination unit, the test result acquisition unit, the second probability density function acquisition unit, and the determination unit repeat the steps (2), (3), (4), and (5) until the standard deviation σ of a probability density function f(x3) obtained by removing probability density values according to a test result has fallen below the predetermined value.