METHOD AND APPARATUS FOR MEASURING THE PRESENCE AND CONCENTRATION OF PHARMACEUTICAL SUBSTANCES IN A MEDICAL FLUID ADMINISTERED BY A MEDICATION DELIVERY SYSTEM

• US 20090009764A1
• Filed: 07/05/2007
• Published: 01/08/2009
• Est. Priority Date: 07/05/2007
• Status: Active Grant

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Inventors: Slepicka, James S.
• Granted Patent: US 8,094,307 B2
• Time in Patent Office: Days
• US Class Current: 356/370
• CPC Class Codes: A61M 1/152 Details related to the interface between cassette and machine
• CPC Class Codes: A61M 1/1561 at least one cassette surface or portion thereof being flexible, e.g. the cassette having a rigid base portion with preformed channels and being covered with a foil
• CPC Class Codes: A61M 1/159 specially adapted for peritoneal dialysis
• CPC Class Codes: A61M 1/28 Peritoneal dialysis ; Other peritoneal treatment, e.g. oxygenation
• CPC Class Codes: A61M 1/288 Priming priming in extracorporeal blood circuits A61M1/3643
• CPC Class Codes: A61M 2205/123 with incorporated reservoirs
• CPC Class Codes: A61M 2205/125 with incorporated filters
• CPC Class Codes: A61M 2205/128 with incorporated valves
• CPC Class Codes: A61M 2205/3306 Optical measuring means
• CPC Class Codes: A61M 2205/3313 used specific wavelengths
• CPC Class Codes: A61M 5/142 Pressure infusion, e.g. using pumps
• CPC Class Codes: G01N 2021/4153 Measuring the deflection of light in refractometers
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10
• CPC Class Codes: G01N 21/21 Polarisation-affecting properties G01N21/19 takes precedence
• CPC Class Codes: G01N 21/274 Calibration, base line adjustment, drift correction
• CPC Class Codes: G01N 21/4133 Refractometers, e.g. differential
• CPC Class Codes: G01N 21/4788 Diffraction for sizing particles G01N15/0205

Abstract

Test equipment determines the contents of medical fluids to be delivered to a patient by a medication delivery system by measuring optical properties of the fluids. One system provides a non-invasive test that uses optical rotation caused by optically active pharmaceutical substances to determine the presence or absence of the pharmaceutical substances within a medical fluid. Another system provides a non-invasive test that uses refractive index properties to determine the concentration of a pharmaceutical substance within the fluid. A method for use is also disclosed.

Claims

1. A testing mechanism, comprising:

a light source located adjacent to a medical fluid, the medical fluid within a medical delivery system and the light source configured to generate a light beam directed through a portion of the medical delivery system and the medical fluid;

a first polarizer configured to receive the light beam and to allow a portion of the light beam optically rotated by a pharmaceutical substance within the medical fluid to be transmitted through the first polarizer;

a photodetector to provide a measurement of an intensity of the portion of the light beam transmitted through the first polarizer; and

a computer configured to use the measurement of the intensity to perform a matching check to determine whether the pharmaceutical substance is present in the medical fluid.

2. The testing mechanism of claim 1, wherein the light source is one of a laser and a light source configured to generate a light beam that is polarized in a single orientation.

3. The testing mechanism of claim 1, wherein the light beam generated by the light source is randomly polarized or has a wavelength from about 350 to about 900 nm.

4. The testing mechanism of claim 1, further including a second polarizer disposed between the light source and the medical fluid, wherein the second polarizer is at least one of:

(i) configured to polarize the light beam prior to the light beam being transmitted through the medical fluid; and

(ii) configured to polarize the light beam at a 90°

angle relative to the first polarizer.

5. The testing mechanism of claim 1, further including a polarization rotator disposed between the light source and the medical fluid, and optionally a second polarization rotator disposed before the photodetector.

6. The testing mechanism of claim 1, wherein the photodetector is a silicon photodiode or a photodetector configured to generate an output signal representing the measurement of intensity of the portion of the light beam transmitted through the first polarizer.

7. The testing mechanism of claim 1, further including a narrow pass filter configured to filter out ambient light or to pass a particular wavelength.

8. The testing mechanism of claim 1, wherein the portion of the medical delivery system comprises a medication container or tubing for use with the container.

9. The testing mechanism of claim 1, wherein the light beam is non-intrusive relative to the medical fluid.

10. The testing mechanism of claim 1, wherein the computer is configured to generate an output signal to the medication delivery system to provide an alert or to prevent the medication delivery system from delivering the medical fluid to a patient if the matching check determines that the pharmaceutical substance is present in the medical fluid in a concentration higher or lower than preset limits.

11. The testing mechanism of claim 1, wherein the computer is at least one of:

(i) configured to utilize the measurement of intensity to calculate a concentration of the pharmaceutical substance within the medical fluid;

(ii) configured to include a memory having a look-up table stored therein, wherein the look-up table includes an acceptable range of calculated concentrations of the pharmaceutical substance within the medical fluid;

(iii) configured to be operatively connected to an externally located database having a look-up table stored therein, wherein the look-up table includes an acceptable range of calculated concentrations of the pharmaceutical substance within the medical fluid;

(iv) configured to generate an output signal to the medication delivery system to provide an alert or to prevent the medical fluid from being delivered to a patient if the calculated concentration of the pharmaceutical substance is outside an acceptable range; and

(v) configured to generate an output signal to the medication delivery system to proceed with normal function if the calculated concentration of the pharmaceutical substance is within an acceptable range.

12. A testing mechanism, comprising:

a light source located adjacent to a medical fluid, the fluid within a medical delivery system and the light source configured to generate a light beam having a propagation axis;

a prism having an incidence surface, a reflective surface, and an interface surface for receiving, reflecting and refracting the light beam from the light source;

a photodetector configured to receive and measure at least one of an intensity and a position of the light beam transmitted or refracted through the medical fluid and a portion of the medical delivery system, the photodetector configured to generate an output signal representing at least one of the intensity and position of the light beam; and

a computer operatively connected to the photodetector, the computer configured to receive the output signal and perform a matching check to determine a quantity of a pharmaceutical substance within the medical fluid.

13. The testing mechanism of claim 12, wherein the interface surface comprises a diffraction grating.

14. The testing mechanism of claim 12, wherein the interface surface is formed at one of:

(i) Brewster'"'"'s angle relative to the incidence surface; and

(ii) an angle relative to the incidence surface to allow for total transmission of the light beam through the medical fluid.

15. The testing mechanism of claim 12, wherein a portion of the light beam is refracted through the medical fluid, wherein at least one of:

(i) the refracted portion of the light beam is measured by the array; and

(ii) the array generates an output signal to the computer corresponding to the intensity and the position of the refracted portion of the light beam received by the array.

16. The testing mechanism of claim 12, further including a second photodetector disposed adjacent to the reflective surface of the prism.

17. The testing mechanism of claim 16, wherein at least one of:

(i) a portion of the light beam is reflected from the interface surface through the reflective surface, and the second photodetector is positioned and configured to receive the reflected portion of the light beam;

(ii) the second photodetector is configured to generate an output signal to the computer representing at least one of intensity and position measured from the reflected portion of the light beam; and

(iii) the computer is configured to utilize the output signal from the first photodetector and the output signal from the second photodetector to calculate a refractive index of the medical fluid.

18. The testing mechanism of claim 12, further comprising a second photodetector configured to measure at least one of intensity and a position of a reflected portion of the light beam, wherein the computer is configured to utilize the output signal from the first photodetector and an output signal from the second photodetector to calculate a concentration of the pharmaceutical substance within the medical fluid.

19. The testing mechanism of claim 18, wherein the matching check compares at least one of:

(i) the calculated concentration of the pharmaceutical substance within an acceptable range, and if the calculated concentration is outside the acceptable range the computer is configured to generate an output signal to the medication delivery system to provide an alert or to prevent delivery of the medical fluid to a patient; and

(ii) the calculated concentration of the pharmaceutical substance within an acceptable range, and if the calculated concentration is within the acceptable range the computer is configured to generate an output signal to the medication delivery system to proceed with normal function of the medication delivery system.

20. The testing mechanism of claim 12, further including a beam expanding lens disposed between the light source and the prism, the beam expanding lens configured to receive the light beam and to produce multiple rays of light from the light beam.

21. The testing mechanism of claim 20, further including a second photodetector, which is at least one of:

(i) configured to receive reflected portions of the rays of light; and

(ii) a linear photodetector array.

22. The testing mechanism of claim 12, wherein the medical fluid has a target refractive index from about 1.3 to about 1.5.

23. A testing mechanism, comprising:

a light source positioned adjacent to a medical fluid, the medical fluid within a medication delivery system and the light source configured to generate a polarized light beam directed through the medical fluid and a portion of the medical delivery system;

a photodetector for providing a measurement of at least one of intensity, relative position, and relative optical rotation, of the light beam that was transmitted through the medical fluid and the portion of the medical fluid;

a memory configured to store signals from the photodetector or results from calculations performed on the signals, including signals or calculations from a baseline measurement, the baseline measurement optionally including a portion of the medical delivery system present between the light source and the photodetector; and

a computer operably connected to the memory and configured to use the signals or results stored in the memory to perform a matching check with respect to the baseline measurement to determine at least one of;

(i) whether a pharmaceutical substance is present in the medical fluid; and

(ii) if the pharmaceutical substance is present, a concentration of the pharmaceutical substance present in the medical fluid.

24. The testing mechanism of claim 23, further including a prism having an incidence surface, a reflective surface, and an interface surface, wherein the photodetector receives a portion of the light beam refracted from the prism.

25. The testing mechanism of claim 23, wherein the computer is operatively connected to a pharmacological database that includes a look-up table for use in the matching check for determining the concentration of the pharmaceutical substance present in the medical fluid, the look-up table including an acceptable range of calculated concentrations of the pharmaceutical substance within the medical fluid.

26. The testing mechanism of claim 23, wherein the portion of the medical delivery system comprises a medication container or tubing for use with the container.

27. A method of testing a medical fluid, the method comprising:

furnishing a first medical fluid in a medical container, the first medical fluid having an expected concentration of at least one pharmaceutical substance;

calibrating a testing device for optical properties using light rotation properties or refractive index of at least two test concentrations of the at least one pharmaceutical substance in the first medical fluid;

calculating a lookup table of optical property values for a plurality of concentrations of the at least one pharmaceutical substance in the first medical fluid;

storing the lookup table of optical property values in a computer or in a memory accessible to the computer;

optionally, calibrating the testing device for an optical property of at least a portion of the medical container;

introducing a second medical fluid having an expected concentration of at least one pharmaceutical substance into the testing device, wherein the second medical fluid may be the same as the first medical fluid or may be different;

testing the second medical fluid for a presence of the at least one pharmaceutical substance using the optical property and determining a concentration of the at least one pharmaceutical substance; and

determining whether the determined concentration is within a desired range for the second medical fluid.

28. The method of claim 27, further comprising administering the second medical fluid to a patient if the determined concentration is within the desired range.

29. The method of claim 27, wherein the second medical fluid is contained in a medical container and the testing device has been calibrated for optical activity by at least a portion of the medical container or tubing for use with the medical container.

30. The method of claim 27, wherein the optical property is caused by rotation of polarized light having a wavelength from about 350 nm to about 900 nm transmitted through the first and second medical fluids.

31. The method of claim 27, wherein the optical property is caused by refraction of light having a wavelength from about 350 nm to about 900 nm.