Non-invasive blood analyzer

• US 5,974,338 A
• Filed: 04/15/1998
• Issued: 10/26/1999
• Est. Priority Date: 04/15/1997
• Status: Expired due to Term

• Current Assignee: Sysmex Corporation
• Original Assignee: Toa Medical Electronics Co., Ltd.
• Inventors: Kouchi, Yasuhiro, Asano, Kaoru
• Primary Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US09/060,080
• Time in Patent Office: 559 Days
• Field of Search: 600/310, 600/322, 600/323, 600/326, 600/473, 600/476, 356/39, 356/41
• US Class Current: 600/323
• CPC Class Codes: A61B 5/14535 for measuring haematocrit
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/14551 for measuring blood gases

Abstract

A non-invasive blood analyzer includes a light source unit for irradiating a portion of a living body, the portion including a blood vessel, and includes an image capturing unit for capturing an image of the irradiated portion. An analyzing unit is included for setting an analysis region in the captured image and analyzing a blood vessel portion in the set analysis region. The image capturing unit captures images of the irradiated portion of the living body a plurality of times and the analyzing unit specifies analysis regions including the same blood vessel portions with respect to the captured images. The analyzing unit determines these regions based upon a position of a feature in sequential images and calculates at least one of blood vessel width, blood component concentration and blood component concentration ratio with respect to the blood vessel portion in each specified analysis region.

Claims

1. A non-invasive blood analyzer comprising:

image capturing means for capturing an image of a portion of a living body irradiated by light, the portion including a blood vessel; and

analyzing means for extracting a position of a feature within a captured image of the living body to determine a specified analysis region,

wherein the image capturing means sequentially captures images of the irradiated portion of the living body a plurality of times, and the analyzing means compares an extracted position of the feature within a first captured image to an extracted position of the feature within a sequentially captured image to determine the specified analysis region, and calculates blood information from a blood vessel in the specified analysis region.

2. The non-invasive analyzer according to claim 1, further comprising a display unit, wherein the image capturing means captures images of the portion of the living body time-sequentially a plurality of times, and wherein results of calculations obtained from the captured images are displayable as a time-sequential change on the displaying unit.

3. The non-invasive blood analyzer according to claim 1, further comprising a light source for emitting a light beam having a wavelength where light absorption by oxyhemoglobin is substantially equal to light absorption by deoxyhemoglobin wherein the analyzing means calculates an image density distribution at a portion crossing the blood vessel with respect to each of the captured images and calculates blood vessel width based on the image density distribution.

4. The non-invasive blood analyzer according to claim 1, further comprising a light source for emitting two light beams, each light beam having a respective wavelength where light absorption by oxyhemoglobin is substantially equal to light absorption by deoxyhemoglobin, wherein the analyzing means calculates an image density distribution at a portion crossing the blood vessel in the analysis region of each of the images captured by using the light beams having the respective wavelengths and calculates a hemoglobin concentration or a hematocrit based on the image density distributions.

5. The non-invasive blood analyzer according to claim 1, further comprising a light source for emitting a light beam having a wavelength where light absorption by oxyhemoglobin is substantially equal to light absorption by deoxyhemoglobin and, a light beam having another wavelength where the light absorption by deoxyhemoglobin is sufficiently larger than the light absorption by oxyhemoglobin, wherein the analyzing means calculates a ratio of oxyhemoglobin concentration with respect to a concentration of total hemoglobin based on an image density distribution at a portion crossing the blood vessel in the analysis region of each image captured by using the light beams having the respective wavelengths.

6. The non-invasive analyzer according to claim 1, wherein the blood information calculated is one of a blood vessel width, a blood component concentration and a blood component concentration ratio.

7. The non-invasive analyzer according to claim 1, wherein the portion of the living body is a human finger and the feature of the living body is based on one of a contour of the finger, a contour of a joint portion and an arrangement pattern of blood vessels.

8. An analyzing unit for a non-invasive blood analyzer, comprising:

capturing means for sequentially capturing an image of an irradiated portion of a living body, including a blood vessel, a plurality of times;

extracting means for extracting morphological features of the living body from each of the sequentially captured images;

storing means for storing the extracted features;

comparing means for comparing the extracted features with each other;

analyzing means for specifying an analysis region based on the compared; and

calculating means for calculating blood information from a blood vessel in the specified analysis region.

9. The non-invasive blood analyzer according to claim 8, wherein the portion of the living body is a human finger and the feature of the living body is based on at least one of a contour of the finger, a contour of a joint portion and an arrangement pattern of blood vessels.

10. The analyzing unit according to claim 8, wherein the blood information calculated is one of a blood vessel width, a blood component concentration and a blood component concentration ratio.

11. A non-invasive blood analyzing method comprising the steps of:

irradiating a portion of the living body, the portion including a blood vessel;

capturing sequential images of the irradiated portion of the living body a plurality of times;

extracting morphological features of the portion of the living body from each of the sequentially captured images;

comparing the extracted features with each other;

specifying regions including the same blood vessel portions in the sequentially captured images based on the compared features; and

calculating at least one of blood vessel width, blood component concentration and blood component concentration ratio with respect to each specified analysis region.

12. A method of analyzing blood information, comprising the steps of:

capturing a first image of an irradiated portion of a living body;

setting an initial analysis region based on the first captured image;

determining a first position of a feature within the first captured image;

capturing a sequential image of said irradiated portion of the living body;

determining a second position of the feature within the sequentially captured image;

comparing the second position with the first position;

shifting the initial analysis region to a new analysis region, wherein the amount shifted is within a pre-determined range based on the compared positions; and

analyzing blood information within the new analysis region.

13. A method according to claim 12, wherein the step of determining a first position further comprises extracting a first position of a joint and storing coordinates of the first position of the joint.

14. A method according to claim 13, wherein the step of determining a second position further comprises extracting coordinates of a second position of the joint.

15. A method according to claim 14, wherein the step of comparing further comprises calculating horizontal and vertical position differences between coordinates of the first position and the second position of the joint.

16. A method according to claim 15, wherein the step of calculating differences further comprises comparing horizontal and vertical position differences within a pre-determined tolerance.

17. A method according to claim 16, further comprising the step of generating an error signal if the horizontal and vertical position differences are greater than said pre-determined tolerance.

18. A non-invasive blood analyzer comprising:

image capturing means for capturing an image of a portion of a living body irradiated by light, the portion including a blood vessel; and

analyzing means for analyzing the captured image,

wherein the image capturing means sequentially captures images of the irradiated portion of the living body a plurality of times, the analyzing means extracting features from the captured images, comparing the extracted features, specifying analysis regions including the same blood vessel portions in the captured images based on the comparison and calculating blood information values from the same portions in the captured images.

19. A non-invasive blood analyzer comprising:

image capturing means for capturing an image of a portion of a living body irradiated by light, the portion including a blood vessel;

analyzing means for analyzing the captured image; and

a display unit to display an analyzed result,

wherein the image capturing means sequentially captures images of the irradiated portion of the living body a plurality of times, the analyzing means calculating blood information values from the same blood vessel portions in the captured images, the display unit displaying the calculated blood information values in time series on a time coordinated system.

20. A non-invasive blood analyzer comprising:

a light source for irradiating a portion of a living body, the portion including a blood vessel;

image capturing means for capturing images of the irradiated portion of the living body, and

analyzing means for calculating blood information values from the same blood vessel portions in the captured images,

wherein the light source selectively emits first and second light beams, the first light beam having a wavelength where light absorption by oxyhemoglobin is substantially equal to light absorption by deoxyhemoglobin, the second light beam having a wavelength where the light absorption by deoxyhemoglobin is sufficiently larger than the light absorption by oxyhemoglobin, the image capturing means captures a set of images under the first and second light beams respectively, and the analyzing means specifies analysis regions including the same blood vessel portions in the set of images and calculates a ratio of oxyhemoglobin concentration with respect to a concentration of total hemoglobin based on an image density distribution at a portion crossing the same blood vessel in each image.

21. A non-invasive blood analyzer comprising:

a light source for irradiating a portion of a living body, the portion including a blood vessel;

image capturing means for capturing images of the irradiated portion of the living body, and

analyzing means for calculating blood information values from the same blood vessel portions in the captured images,

wherein the light source selectively emits first, second and third light beams, each of the first and second light beams having a respective wavelength where light absorption by oxyhemoglobin is substantially equal to light absorption by deoxyhemoglobin, the third light beam having a wavelength where the light absorption by deoxyhemoglobin is sufficiently larger than the light absorption by oxyhemoglobin, the image capturing means captures a set of images under the first, second and third light beams respectively, and the analyzing means specifies analysis regions including the same blood vessel portions in the set of images and calculates a hemoglobin concentration or a hematocrit based on an image density distribution at a portion crossing the same blood vessel in each of the images captured under the first and second beams, and a ratio of oxyhemoglobin concentration with respect to a concentration of total hemoglobin based on a image density distribution at a portion crossing the same blood vessel in each of the images captured under the first and third beams.