Assessment Of Neural Function

• US 20080108908A1
• Filed: 11/29/2004
• Published: 05/08/2008
• Est. Priority Date: 11/28/2003
• Status: Active Grant

• Current Assignee: KONAN MEDICAL USA, INC.
• Original Assignee: Australian National University
• Inventors: James, Andrew, Maddess, Ted
• Granted Patent: US 8,583,223 B2
• Time in Patent Office: Days
• US Class Current: 600/544
• CPC Class Codes: A61B 3/024 for determining the visual field, e.g. perimeter types
• CPC Class Codes: A61B 5/378 Visual stimuli

Abstract

Assessment of one of the sensory nervous systems of a human subject using patterns of null and non-null stimuli. Parts of the visual system for example, are presented with two simultaneous sequences of stimuli. Each sequence is varied over time between a null stimulus and one or more less frequent non-null stimuli. The variation of each sequence is also controlled so that neighbouring parts of the sensory system are less likely to receive simultaneous non-null stimuli. The stimuli are therefore sparse both in time and in some other aspect, typically a spatial dimension. One or more responses of the subject are measured and weight functions are determined for assessment of the sensory system.

Claims

1. A method of assessing a sensory nervous system of a subject, including:

simultaneously presenting two or more parts of the sensory system with respective sequences of stimuli,

varying each sequence over time between a null stimulus and one or more less frequent non-null stimuli,

controlling the variation of each sequence so that neighbouring parts of the sensory system are less likely to receive simultaneous non-null stimuli,

measuring one or more simultaneous responses by the subject to the sequences of stimuli, and

determining weight functions from the responses for assessment of the sensory system.

2. A method according to claim 1 wherein the non-null stimuli appear in each sequence at a rate of about 0.25 to 25 per second.

3. A method according to claim 1 wherein the probability of neighbouring parts in the sensory system having simultaneous non-null stimuli is zero.

4. A method according to claim 1 wherein the sensory system is a visual system and multiple parts of a retina are presented with stimuli.

5. A method according to claim 1 wherein the sensory system is a visual system and the sequences includes either binocular or dichoptic stimuli.

6. A method according to claim 1 wherein the sensory system is an aural or tactile system and the ears or skin are presented with stimuli.

7. A method according to claim 1 wherein the parts of the sensory system are in the retina, the ears, the skin, or in the brain of the subject.

8. A method according to claim 1 wherein the stimuli are selected from a range of signals such as light or sound frequency, or pressure.

9. A method according to claim 1 wherein the parts of the sensory system receiving stimuli form a region divided into classes and only one of the classes has a non-zero probability of receiving stimuli at any time.

10. A method according to claim 1 wherein the responses are nonlinear and the weight functions are Wiener or Volterra kernels.

11. Apparatus for assessing a sensory nervous system of a subject, including:

a stimulator that simultaneously presents two or more parts of the sensory system with respective sequences of stimuli,

a monitor that measures one or more simultaneous responses by the subject to the sequences of stimuli, and

a processor that varies each sequence over time between a null stimulus and one or more less probable non-null stimuli,

controls the variation of each sequence so that neighbouring parts of the sensory system are less likely to receive simultaneous non-null stimuli, and

determines weight functions from the responses for assessment of the sensory system.

12. Apparatus according to claim 11 wherein the sensory system is a visual, aural or tactile system and the stimulator presents optical patterns to the eyes, ears or skin of the subject.

13. Apparatus according to claim 11 wherein the monitor measures responses to the stimuli by way of electrode potentials on the head of the subject.