Blood analyzing system

• US 5,296,194 A
• Filed: 01/23/1992
• Issued: 03/22/1994
• Est. Priority Date: 02/01/1991
• Status: Expired due to Fees

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Igarashi, Kenichi
• Primary Examiner(s): Housel, James C.
• Assistant Examiner(s): Snay, Jeffrey R.
• Application Number:
  US07/824,146
• Time in Patent Office: 789 Days
• Field of Search: 422/82.05, 422/100, 436/54, 73/864.11, 73/864.13, 73/864.16, 73/864.21, 250/231.13, 250/231.14, 250/229
• US Class Current: 422/82.05
• CPC Class Codes: B01L 3/0227 Details of motor drive means B01L3/0231, B01L3/0234 take precedence
• CPC Class Codes: G01N 21/78 producing a change of colour

Abstract

A blood analyzing system for analyzing the level of content of a component (such as glucose) of blood collected from a person or animal. In the blood analyzing system, a pipet unit includes a drop meter for measuring the volume of the blood sample actually dropped onto a test slide. Reacting to a reagent coated on the test slide, the blood sample changes its color, which is optically detected. A content calculating circuit calculates the level of content of the blood sample based on the received light signal. The content calculating circuit also corrects the calculated results according to the volume of the actually dropped blood sample.

Claims

1. A blood analyzing system for analyzing the level of content of a component of a blood sample dropped onto a test slide, comprising:

(a) a pipet unit for dropping the blood sample the blood sample having a predetermined desired dropped volume, said pipet unit including a pump having a cylinder and a piston;

(b) a stroke meter for measuring the stroke of said piston and for outputting a stroke signal indicating a measured volume of the dropped blood sample, said stroke meter provided in said pipet unit wherein said pipet unit includes a motor for generating power to reciprocate said piston in said cylinder, a gear coupled to a rotary shaft of said motor, and a piston actuator for converting rotary motion of an output shaft of said gear into a rectilinear motion to reciprocate said piston, said piston actuator including a rotor coupled to said output shaft of said gear, a feed screw whose one end is coupled to said piston, and a rotation preventing member for allowing only the reciprocation of said feed screw while preventing the rotation thereof, said rotor being threadably engaged with the other end of said feed screw, said rotor being rotated by said output shaft to reciprocate said screw, said stroke meter determining the volume of the dropped blood sample based on the rotative amount of said rotor, said stroke meter including a slit disc rotatable with said rotor, and a photointerrupter for emitting light from one side of said slit disc and receiving the light from another side of said slit disc, said slit disc and said photo-interrupter comprising a rotation detector for determining rotor rotation indicative of a stroke of said piston;

(c) a drop calculating circuit for receiving the stroke signal, calculating the volume of the dropped blood sample, and outputting a signal indicating the measured volume of the dropped blood sample;

(d) a light source for irradiating light to the test slide holding the dropped blood sample;

(e) an optical sensor for receiving the light reflected from the test slide and outputting a received light signal;

(f) a content calculating circuit for receiving the signal indicating the measured volume of the dropped blood sample, and determining the level of content of the component of the blood sample, the analyzing system further including error determining means for determining an error between the desired and the measured dropped volumes, correction value obtaining means for obtaining a correction value from a correction table based on the determined error and correcting means for correcting the determined content level based on the obtained correction value; and

(g) a backlash preventing means for supplying a bias force to said feed screw from said rotor, said backlash preventing means enabling reliable determination of the rotative amount of said rotor.

2. A blood analyzing system according to claim 1, further including a translation table which stores the relationship between the intensity of the received light signal and the level of content of the specified component, wherein the correction table stores correction coefficients for the measured volume of the dropped blood sample and the level of content of the specified component of the blood sample, so that said content calculating circuit calculates the level of content of the specified component of the blood sample with reference to said translation table, and corrects calculated result with reference to said correction table when the measured volume of the dropped blood sample deviates from the predetermined drop volume.

3. The blood analyzing system according to claim 1, wherein said content calculating circuit compares said signal indicating the measured volume of the dropped volume with a predetermined volume, said content calculating circuit correcting a calculated result when said dropped volume does not equal said predetermined volume.

4. A blood analyzing system according to claim 1, wherein said motor, said gear, said feed screw and said piston are linearly aligned.

5. A blood analyzing system according to claim 4, wherein said pipet unit includes a switch

6. A blood analyzing system for analyzing the level of content of a component of a blood sample dropped onto a test slide, comprising:

(a) a pipet unit for dropping said blood sample in response to a desired dropped volume signal indicative of a desired dropped volume of the blood sample;

(b) a drop meter for measuring a volume of the dropped blood sample and outputting a measured drop volume signal, said drop meter being provided in said pipet unit, said pipet unit including a pump having a cylinder and a piston, a motor for generating power to reciprocate said piston in said cylinder, a gear coupled to a rotary shaft of said motor, and a piston actuator for converting rotary motion of an output shaft of said gear into a rectilinear motion to reciprocate said piston, said piston actuator including a rotor coupled to said output shaft of said gear, a feed screw whose one end is coupled to said piston, and a rotation preventing member for allowing only the reciprocation of said feed screw while preventing the rotation thereof, said rotor being threadably engaged with the other end of said feed screw, said rotor being rotated by said output shaft to reciprocate said screw, said drop meter determining the volume of the dropped blood sample based on the rotative amount of said rotor, said drop meter including a slit disc rotatable with said rotor, and a photo-interrupter for emitting light from one side of said slit disc and receiving the light from another side of said slit disc, said slit disc and said photo-interrupter comprising a rotation detector for determining rotor rotation indicative of a stroke of said piston;

(c) a light source for irradiating light to the test slide holding the dropped blood sample;

(d) an optical sensor for receiving the light reflected from the test slide and outputting a received light signal;

(e) an analyzing unit for receiving the received light signal and the drop volume signal to determine the level of content of the component of the blood sample, the analyzing system further including error determining means for determining an error between the desired and the measured dropped volumes, correction value obtaining means for obtaining a correction value from a correction table based on the determined error and correcting means for correcting the determined content level based on the obtained correction value; and

(f) a backlash preventing means for supplying a bias force to said feed screw from said rotor, said backlash preventing means enabling reliable determination of the rotative amount of said rotor.

7. A blood analyzing system according to claim 6, wherein said motor, said gear, said feed screw and said piston are linearly aligned.

8. A blood analyzing system according to claim 6, wherein said pipet unit includes a switch.