BLOOD FLOW MEASURING APPARATUS AND BRAIN ACTIVITY MEASURING APPARATUS USING THE SAME

• US 20090270745A1
• Filed: 07/08/2009
• Published: 10/29/2009
• Est. Priority Date: 02/14/2008
• Status: Active Grant

• Current Assignee: Cyberdyne Inc.
• Original Assignee: University of Tsukuba
• Inventors: SANKAI, Yoshiyuki
• Granted Patent: US 8,945,018 B2
• Time in Patent Office: Days
• US Class Current: 600/504
• CPC Class Codes: A61B 5/0042 for the brain
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/4064 Evaluating the brain A61B5/031, A61B5/369, A61B5/14553 take precedence
• CPC Class Codes: A61B 5/6814 Head

Abstract

A blood flow measuring apparatus includes a sensor unit including a light emitter configured to emit light onto a measurement area and a light receiver configured to receive the light transmitted through the measurement area; at least one more light receiver configured to receive the light transmitted through the measurement area; and a control part configured to measure a blood flow state of the measurement area according to signals outputted by the light receivers. The light emitted by the light emitter is received by the light receivers arranged at different distances from the light emitter and the light receivers output the signals responsive to the received light. The control part measures the blood flow state of the measurement area by performing an arithmetic process to cancel a component of oxygen saturation in the blood, said component being included in the signals outputted by the light receivers.

Claims

1. A blood flow measuring apparatus comprising:

a sensor unit including a light emitting part configured to emit light onto a measurement area and a light receiving part configured to receive the light transmitted through the measurement area;

at least one more light receiving part configured to receive the light transmitted through the measurement area; and

a control part configured to measure a blood flow state of the measurement area according to signals outputted by the light receiving parts,

wherein the light emitted by the light emitting part is received by the light receiving parts arranged at different distances from the light emitting part and the light receiving parts output the signals responsive to the received light; and

the control part measures the blood flow state of the measurement area by performing an arithmetic process to cancel a component of oxygen saturation in the blood, said component being included in the signals outputted by the light receiving parts.

2. The blood flow measuring apparatus as claimed in claim 1, wherein the light emitting part emits first light having a wavelength that is hardly influenced in an optical characteristic by the oxygen saturation in the blood and second light having a wavelength that is influenced in an optical characteristic by the oxygen saturation in the blood.

3. The blood flow measuring apparatus as claimed in claim 2, wherein the control part compares first amounts of transmitted light of the first light received by the light receiving parts and second amounts of transmitted light of the second light received by the light receiving parts to measure the blood flow state of the measurement area.

4. The blood flow measuring apparatus as claimed in claim 3, wherein the control part measures the blood flow state of the measurement area according to measurement data responsive to the first and second amounts of the transmitted light, said measurement data being outputted by the light receiving parts.

5. The blood flow measuring apparatus as claimed in claim 1, wherein the sensor unit includes an optical path separating member configured to have different refraction indexes with respect to light that proceeds from the light emitting part to the measurement area and light that proceeds from the measurement area to the light receiving part that is included in the sensor unit;

and the light emitting part emits the light and said light receiving part included in the sensor unit receives the light through the optical path separating member.

6. A brain activity measuring apparatus comprising the blood flow measuring apparatus as claimed in claim 1, wherein a blood flow of a brain is measured by using the blood flow measuring apparatus and an activity state of the brain is measured according to a result of the measurement performed by the blood flow measuring apparatus.

7. A brain activity measuring apparatus comprising the blood flow measuring apparatus as claimed in claim 2, wherein a blood flow of a brain is measured by using the blood flow measuring apparatus and an activity state of the brain is measured according to a result of the measurement performed by the blood flow measuring apparatus.

8. The brain activity measuring apparatus as claimed in claim 7, wherein a plurality of sensor units including said sensor unit are provided at different positions, each having an identical configuration to said sensor unit;

said at least one more light receiving part is included as a light receiving part of a different sensor unit from said sensor unit among the plurality of sensor units; and

the control part makes a light emitting part of one of the sensor units emit the first light and the second light, detects amounts of transmitted light of the first and second light received by light receiving parts of at least two of said sensor units that are separated at different distances from said one sensor unit, and measures the brain activity state of the measurement area according to measurement data responsive to the amounts of the transmitted light of the first light and the second light, said measurement data being outputted by the at least two of said light receiving parts.

9. The brain activity measuring apparatus as claimed in claim 8, wherein the control part sequentially makes the light emitting parts of all the sensor units emit the first light and the second light, detects an intensity of the light received by light receiving parts of at least two sensor units which are separated at different distances from the sensor unit which emits light, and measures the brain activity state of the measurement area according to measurement data responsive to the amounts of transmitted light of the first light and the second light, said measurement data being outputted by the at least two of said light receiving parts.

10. The brain activity measuring apparatus as claimed in claim 6, wherein the sensor unit includes a brain wave measuring electrode configured to measure a brain wave.

11. The brain activity measuring apparatus as claimed in claim 10, wherein the brain wave measuring electrode is formed over a leading end surface and a side surface of the optical path separating member.