Hematocrit and oxygen saturation blood analyzer

• US 5,066,859 A
• Filed: 05/18/1990
• Issued: 11/19/1991
• Est. Priority Date: 05/18/1990
• Status: Expired due to Fees

• Current Assignee: U.S. Alcohol Testing Of America, Inc. (Substance Abuse Technologies, Inc.)
• Original Assignee: U.S. Alcohol Testing Of America, Inc. (Substance Abuse Technologies, Inc.)
• Inventors: Karkar, Maurice N., Velnosky, James C.
• Primary Examiner(s): Westin, Edward P.
• Assistant Examiner(s): BEYER, JAMES
• Application Number:
  US07/526,184
• Time in Patent Office: 550 Days
• Field of Search: 250/339, 356/41, 128/633, 128/664
• US Class Current: 250/339.09
• CPC Class Codes: G01N 2015/055 for hematocrite determination
• CPC Class Codes: G01N 2021/3181 using LEDs
• CPC Class Codes: G01N 2021/4709 Backscatter
• CPC Class Codes: G01N 2035/1062 for testing the liquid while it is in the transfer device
• CPC Class Codes: G01N 21/51 inside a container, e.g. in an ampoule G01N21/53 takes precedence
• CPC Class Codes: G01N 33/4925 measuring blood gas content, e.g. O2, CO2 , HCO3

Abstract

An improved blood analyzing device is disclosed for measuring the hematocrit and oxygen saturation levels of a quantity of blood. The device comprises a housing having a carriage assembly electrically interfaced thereto. Disposed within the carriage assembly is a light emitting means and a plurality of light detecting optical sensors which are used to provide hematocrit and oxygen saturation signals based on the scattering of light within a blood containment vessel disposed within the carriage. Signals generated from the sensors are processed by control electronics disposed within the housing so as to output a hematocrit measurement which is compensated for the effects of oxygen saturation, pH, and temperature, and an oxygen saturation measurement which is compensated for the effects of hematocrit, pH, and temperature.

Claims

1. An apparatus for measuring hematocrit and oxygen saturation levels of a volume of blood, comprising:

a housing including a key pad and display panel thereon;

a receptacle sized to store a quantity of blood therein;

a carriage electrically connected to said housing, said carriage being sized and configured to receive and support said receptacle;

a light source disposed adjacent said carriage, said light source being operative to illuminate said quantity of blood within said receptacle with first and second wavelengths of light;

a first sensing means disposed adjacent said carriage for producing a hematocrit signal as a function of said first wavelength of light after scattering thereof by said blood;

a second sensing means disposed adjacent said carriage for producing an oxygen saturation signal as a function of said first and said second wavelengths of light after scattering thereof by said blood;

a third sensing means disposed adjacent said carriage for producing a calibration signal for the purpose of calibrating said apparatus; and

a signal processing means disposed within said housing, said signal processing means comprising;

(a) means for filtering said hematocrit signal and said oxygen saturation signal from system noise and outside interference;

(b) means for producing an adjusted hematocrit signal and an adjusted oxygen saturation signal, said adjusted hematocrit signal comprising said hematocrit signal as compensated for effects of oxygen saturation, temperature, and blood pH and said adjusted oxygen saturation signal comprising said oxygen saturation signal as compensated for effects of hematocrit, temperature, and blood pH; and

(c) means for converting said adjusted hematocrit signal and said adjusted oxygen saturation signal to hematocrit and oxygen saturation measurements for output on said display panel.

2. The apparatus as defined in claim 1 wherein said means for producing adjusted hematocrit and oxygen saturation signals comprises a memory module, said memory module being used to store data tables which are accessed to produce said adjusted hematocrit signal and said adjusted oxygen saturation signal.

3. The apparatus as defined in claim 1 wherein said carriage is configured in a manner so as to allow said hematocrit and said oxygen saturation levels to be measured while said quantity of blood is in a flowing mode.

4. The apparatus as defined in claim 1 wherein said carriage is configured in a manner so as to allow said hematocrit and said oxygen saturation levels to be measured while said quantity of blood is in a static mode.

5. The apparatus as defined in claim 4 wherein said apparatus includes a blood mixing mechanism to prevent red blood cells from settling in said receptacle when said hematocrit and said oxygen saturation measurements are being taken.

6. The apparatus as defined in claim 5 wherein said blood mixing mechanism comprises a shaft having a first end and a second end, said first end being attached to said carriage and said second end being attached to a motor disposed within said housing, said motor being operative to resonate said carriage.

7. The apparatus as defined in claim 5 wherein said blood mixing mechanism comprises an ultrasound emitter mounted to said carriage in a manner wherein sound waves from said emitter are directed toward said receptacle.

8. The apparatus as defined in claim 4 wherein said carriage includes a magnetizing means for subjecting said quantity of blood contained within said receptacle to magnetic effects to pull proteins away from red blood cells contained in said blood.

9. The apparatus as defined in claim 1 wherein said carriage is releasably connected to said housing so as to be interchangeable with other carriages which are of similar design but sized and configured to accommodate different receptacle sizes.

10. The apparatus as defined in claim 1 wherein said light source comprises first and second light emitting diodes, wherein light from said first diode and said second diode is merged into a single light emission path.

11. The apparatus as defined in claim 10 wherein said light emission path comprises a first opticalfiber having a proximal end and a distal end, said distal end including an optical splitter disposed thereon which is operable to channel light from said first diode and said second diode into said first optical fiber.

12. The apparatus as defined in claim 11 wherein said first diode is fabricated in a manner so as to produce and emit light from said first wavelength and said second diode is fabricated in a manner so as to produce and emit light from said second wavelength.

13. The apparatus as defined in claim 12 wherein said first diode is active at different times than said second diode.

14. The apparatus as defined in claim 11 wherein said carriage comprises:

an elongate, horizontally oriented lower member having top and bottom surfaces, said top surface including a longitudinally extending recessed portion disposed therein which is sized and configured to receive said receptacle, said recessed portion further defining a first longitudinal axis on an interior surface thereof; and

an elongate, horizontally oriented upper member, said upper member being movable between an open position and a closed position and having top and bottom surfaces, said bottom surface defining a second longitudinally extending axis thereon;

said upper member being cooperatively engaged to said lower member such that when said upper member is in said closed position, said bottom surface of said upper member opposes said top surface of said lower member in a manner wherein said second longitudinal axis is in vertical alignment with and parallel to said first longitudinal axis.

15. The apparatus as defined in claim 14 wherein said first optical fiber is disposed within said carriage in a manner wherein said proximal end of said first optical fiber is positioned within said recessed portion at a point on said first longitudinal axis.

16. The apparatus as defined in claim 15 wherein said second sensing means for producing an oxygen saturation signal comprises:

second and third optical fibers having proximal ends positioned on said first longitudinal axis on opposite sides of and equal distances from said proximal end of said first optical fiber;

wherein a signal generated by the receipt of scattered light into said third optical fiber is used to compensate a signal generated by the receipt of scattered light into said second optical fiber in producing said oxygen saturation signal.

17. The apparatus as defined in claim 16 wherein said first sensing means for producing a hematocrit signal comprises:

fourth and fifth optical fibers having proximal ends positioned on said first longitudinal axis on opposite sides of and equal distances from said first optical fiber, and equal distances from said second and third optical fibers, such that said second optical fiber is disposed between said first and fourth optical fibers, and said third optical fiber is disposed between said first and fifth optical fibers;

wherein a signal generated by the receipt of scattered light into said fifth optical fiber is used to compensate a signal generated by the receipt of scattered light into said fourth optical fiber in producing said hematocrit signal.

18. The apparatus as defined in claim 17 wherein said third sensing means for producing a calibration signal comprises:

sixth and seventh optical fibers having proximal ends positioned on said second longitudinal axis in an orientation such that when said upper member is in said closed position, said sixth optical fiber is positioned at a point one-half the distance between said first optical fiber and said fourth optical fiber, and said seventh optical fiber is positioned at a point one-half the distance between said first optical fiber and said fifth optical fiber;

wherein a signal generated by the receipt of scattered light into said seventh optical fiber is used to compensate a signal generated by the receipt of scattered light into said sixth optical fiber in producing said calibration signal.

19. The apparatus as defined in claim 4 wherein said receptacle comprises:

a syringe comprising an elongate, tubular member having a generally planar window disposed within a portion thereof, said window being constructed of a material which provides a repeatable optical path for said first and second wavelengths of light.

20. The apparatus as defined in claim 19 wherein said window is concave.

21. The apparatus as defined in claim 19 wherein said window is convex.

22. The apparatus as defined in claim 19 wherein said syringe includes means to orient said syringe within said carriage such that light from said light source enters said syringe through said window and is reflected back through said window into said first sensing means and said sensing means.

23. The apparatus as defined in claim 4 wherein said receptacle comprises:

a syringe comprising an elongate tubular member constructed of a material which provides a repeatable optical path for said first and second wavelengths of light.

24. An apparatus for measuring hematocrit and oxygen saturation levels of a volume of blood comprising:

a housing;

a receptacle sized to store a quantity of blood therein;

means formed on said housing for supporting said receptacle;

a first sensing means carried by said housing for generating an electrical signal in response to detection of hematocrit in said quantity of blood;

a second sensing means carried by said housing for generating an electrical signal in response to detection of oxygen saturation in said quantity of blood;

means for oscillating said supporting means to maintain red blood cells in suspension in said quantity of blood within said receptacle; and

means for magnetizing said supporting means to pull proteins away from said red blood cells.

25. An apparatus for measuring hematocrit and oxygen saturation levels of a volume of blood comprising:

a first means for producing a hematocrit signal as a function of the scattering of light from an infrared wavelength by said blood;

a second means for producing an oxygen saturation signal as a function of the scattering of light from a red wavelength and said infrared wavelength by said blood;

a third means for filtering said hematocrit signal and said oxygen saturation signal for system noise and outside interference;

means for producing an adjusted hematocrit signal and an adjusted oxygen saturation signal, said adjusted hematocrit signal comprising said hematocrit signal as compensated for effects of oxygen saturation, temperature, and blood pH and said adjusted oxygen saturation signal comprising said oxygen saturation signal as compensated for effects of hematocrit, temperature, and blood pH; and

means for producing hematocrit and oxygen saturation measurements as a function of said adjusted hematocrit and oxygen saturation signals.

26. The apparatus as defined in claim 25 wherein said apparatus further comprises means for calibrating said apparatus.