RAPID MEASUREMENT OF VISUAL SENSITIVITY

• US 20150150444A1
• Filed: 05/09/2013
• Published: 06/04/2015
• Est. Priority Date: 05/09/2012
• Status: Active Grant

• Current Assignee: The Schepens Eye Research Institute Inc (Mass General Brigham, Inc.)
• Original Assignee: The Schepens Eye Research Institute Inc (Mass General Brigham, Inc.), Ohio State University
• Inventors: Bex, Peter, Dorr, Michael, Lesmes, Luis, Lu, Zhong-Lin
• Granted Patent: US 9,700,201 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 3/0025 characterised by electronic signal processing, e.g. eye models
• CPC Class Codes: A61B 3/022 for testing contrast sensitivity
• CPC Class Codes: A61B 3/032 Devices for presenting test symbols or characters, e.g. test chart projectors A61B3/036 takes precedence
• CPC Class Codes: A61B 3/06 for testing light sensitivity, e.g. adaptation; for testing colour vision

Abstract

Data is received characterizing a result of a first visual sensitivity test assessing capacity to detect spatial form across one or more different target sizes, and different contrasts. Using the received data, one or more first parameters defining a first estimated visual sensitivity for a first range of contrasts and a second range of spatial frequencies is determined. One or more second parameters defining a second estimated visual sensitivity for a third range of contrasts and a fourth range of spatial frequencies is determined using the one or more first parameters and a statistical inference by at least presenting a first visual stimulus, receiving a response, and determining a second visual stimulus based at least on the response and at least a rule. The one or more second parameters is provided. Related apparatus, systems, techniques and articles are also described.

Claims

1. A method comprising:

receiving data characterizing a result of a first visual sensitivity test assessing capacity to detect spatial form across one or more different target sizes, and different contrasts;

determining, using the received data, one or more first parameters defining a first estimated visual sensitivity for a first range of contrasts and a second range of spatial frequencies;

determining, using the one or more first parameters and a statistical inference, one or more second parameters defining a second estimated visual sensitivity for a third range of contrasts and a fourth range of spatial frequencies by at least presenting a first visual stimulus, receiving a response, and determining a second visual stimulus based at least on the response and at least a rule; and

providing the one or more second parameters.

2. The method of claim 1, wherein the first visual sensitivity test includes at least one of:

drawing a line on a spatial frequency image that indicates a transition between a visible contrast and an invisible contrast, the line characterizing a visual sensitivity;

or

indicating at least one of a presence or an absence of targets of differing spatial frequency.

3. The method of claim 1, wherein the first visual stimulus and second visual stimulus include one or more of:

a band-pass frequency stimulus, a band-pass frequency letter, and a localized windowed grating.

4. The method of claim 1, wherein each of the first visual stimulus and second visual stimulus includes a flickering and a band-pass filtered letter, wherein one or more of a temporal frequency of the flickering and a spatial frequency of the band-pass filtered letter varies between the first visual stimulus and the second visual stimulus.

5. The method of claim 1, wherein each of the first visual stimulus and the second visual stimulus comprise dynamic band-pass letter charts.

6. The method of claim 1, wherein the one or more first parameters include one or more of a peak sensitivity, a peak spatial frequency, low-frequency truncation, and a bandwidth.

7. The method of claim 1, wherein the first visual sensitivity test is performed using a mobile device.

8. The method of claim 7, wherein the determining the one or more second parameters further comprises:

providing instructions to view the first visual stimulus at a viewing distance, the vising distance determined by using a camera associated with the mobile device to measure a viewing distance;

wherein the determination of the one or more second parameters is based on the viewing distance.

9. The method of claim 1, further comprising:

assessing a visual function by at least using the one or more second parameters to compare visual sensitivity based on at least one or more of the following;

at different visual field locations, in different illumination conditions, in photopic and mesopic conditions, and at two or more levels of external illumination noise.

10. The method of claim 1, wherein the determining the one or more second parameters further comprises:

selecting the first visual stimulus based on at least previously determined parameters, the first visual stimulus being a band-pass frequency stimulus and the previously determined parameters characterizing a probability;

presenting the first visual stimulus using a display;

receiving a response relating to the first visual stimulus;

updating the probability based on at least a Bayes rule and a received response; and

iterating until a stopping criterion is satisfied.

11. The method of claim 1, wherein the providing comprises one or more of a transmitting, a displaying, a storing, and a computing of the one or more second parameters.

12. The method of claim 1, wherein the determining the one or more second parameters comprises:

iteratively presenting visual stimulus, receiving a response, and determining second visual stimulus for presenting using the response and at least the rule, the rule based on at least a Bayes rule.

13. The method of claim 1, wherein the one or more first parameters are used as a priori values for a Bayesian inference.

14. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following;

receive data characterizing a result of a first visual sensitivity test assessing capacity to detect spatial form across one or more different target sizes, and different contrasts

determine, using the received data, one or more first parameters defining a first estimated visual sensitivity for a first range of contrasts and a second range of spatial frequencies;

determine, using the one or more first parameters and a statistical inference, one or more second parameters defining a second estimated visual sensitivity for a third range of contrasts and a fourth range of spatial frequencies by at least presenting a first visual stimulus, receiving a response, and determining a second visual stimulus based at least on the response and at least a rule; and

provide the one or more second parameters.

15. The apparatus of claim 14, wherein, wherein the first visual sensitivity test includes at least one of:

drawing a line on a spatial frequency image that indicates a transition between visible and invisible contrast, the line characterizing a visual sensitivity;

or

indicating a presence or absence of targets of differing spatial frequency.

16. The apparatus of claim 14, wherein the first visual stimulus and second visual stimulus include one or more of:

a band-pass frequency stimulus, a band-pass frequency letter, and a localized windowed grating.

17. The apparatus of claim 14, wherein each of the first visual stimulus and second visual stimulus includes a flickering and a band-pass filtered letter, wherein one or more of a temporal frequency of the flickering and a spatial frequency of the band-pass filtered letter varies between the first visual stimulus and the second visual stimulus.

18. The apparatus of claim 14, wherein each of the first visual stimulus and the second visual stimulus comprise dynamic band-pass letter charts.

19. The apparatus of claim 14, wherein the one or more first parameters include a peak sensitivity, a peak spatial frequency, a low frequency truncation, and a bandwidth.

20. A non-transitory computer readable medium including computer code, which when executed by a computer processor provides operations comprising:

receiving data characterizing a result of a first visual sensitivity test assessing capacity to detect spatial form across one or more different target sizes, and different contrasts

determining, using the received data, one or more first parameters defining a first estimated visual sensitivity for a first range of contrasts and a second range of spatial frequencies;

determining, using the one or more first parameters and a statistical inference, one or more second parameters defining a second estimated visual sensitivity for a third range of contrasts and a fourth range of spatial frequencies by at least presenting a first visual stimulus, receiving a response, and determining a second visual stimulus based at least on the response and at least a rule; and

providing the one or more second parameters.

21. A method comprising:

receiving data characterizing a result of a first subjective visual sensitivity pre-test assessing capacity to detect spatial form across different contrasts;

determining, using the received data, one or more first parameters defining a first estimated visual contrast sensitivity function;

determining, using the one or more first parameters as a priori inputs to an iterative Bayesian inference, one or more second parameters defining a second estimated visual contrast function, the iterative Bayesian inference being performed by at least presenting a first visual stimulus, receiving a response, determining a second visual stimulus based at least on the response and at least Bayes rule, and iterating until a stopping condition is satisfied; and

providing the one or more second parameters.