Disposable, pre-calibrated, pre-validated sensors for use in bio-processing applications

• US 20070126794A1
• Filed: 12/05/2005
• Published: 06/07/2007
• Est. Priority Date: 12/05/2005
• Status: Active Grant

• Current Assignee: Parker Intangibles LLC (Parker-Hannifin Corporation)
• Original Assignee: SenCal, LLC
• Inventors: Uhen, David, Schick, Karl
• Granted Patent: US 7,857,506 B2
• Time in Patent Office: Days
• US Class Current: 347/44
• CPC Class Codes: A61M 1/3621 Extra-corporeal blood circuits single-needle circuits A61M1/30
• CPC Class Codes: A61M 1/3669 Electrical impedance measurement of body fluids; transducers specially adapted therefor
• CPC Class Codes: A61M 2205/6018 providing set-up signals for the apparatus configuration
• CPC Class Codes: G01N 27/10 Investigation or analysis specially adapted for controlling or monitoring operations or for signalling

Abstract

Disposable, pre-sterilized, and pre-calibrated, pre-validated conductivity sensors are provided. These sensors are designed to store sensor-specific information, such as calibration and production information, in a non-volatile memory chip on the sensor. The sensors are calibrated using 0.100 molar potassium chloride (KCl) solutions at 25 degrees Celsius. These sensors may be utilize with in-line systems, closed fluid circuits, bioprocessing systems, or systems which require an aseptic environment while avoiding or reducing cleaning procedures and quality assurance variances.

Claims

1. A method of manufacturing a disposable conductivity sensing device for a bio-processing fluid, comprising:

providing a conduit for directing a bio-processing fluid;

positioning a sensor component and a memory component on the conductivity sensing device such that said sensor component electrically interacts with bio-processing fluid flowing through the conduit;

running a calibration fluid through the conduit, said calibration fluid having a known conductivity value;

measuring an electrical value of the sensory component during said running of the calibration fluid through the conduit in order to measure the conductivity for the calibration fluid as detected by the particular sensing device, said electrical value being selected from current, voltage and combinations thereof;

calculating a cell constant for said particular sensing device by mathematically combining said known conductivity value of the calibration fluid with the measured conductivity value thereof;

storing the cell constant in the memory component on the sensing device in order to provide a pre-calibrated sensing device;

calculating a statistical performance value based on individual measurement performances of a plurality of said pre-calibrated sensing devices within a sensor production batch; and

storing the statistical performance value in the memory component on the sensing device.

2. The method of claim 1 further comprising:

determining the actual temperature value of the calibration fluid;

utilizing the sensing device to measure the temperature value of the calibration fluid;

calculating a temperature offset for said particular sensing device by mathematically combining said actual temperature value with the measured temperature value thereof; and

storing the temperature offset in the memory component on the sensing device.

3. The method of claim 1 further comprising:

producing a production lot, said production lot being comprised of at least one or more sensing devices;

analyzing at least one or more sensing devices to determine statistical information about the production lot; and

storing the statistical information in the memory component on each sensing device in the production lot.

4. The method of claim 1 further comprising:

wherein said storing of the statistical performance value in the memory component on the sensing device provides an “

out-of-box”

variance value.

5. The method of claim 4, further including storing calibration information associated with the sensing device selected from the group consisting of a production lot number, statistical data associated with the production lot, a fluid conduit size, a unique serial number of the sensing device, a manufacturing date, a calibration date, a temperature offset, type of fluid used for calibration, temperature of the fluid used during calibration, said “

out-of-box”

variance value, and combinations thereof.

6. A method of measuring the conductivity of a bio-processing fluid, comprising:

providing a disposable sensor assembly having a sensor component, a memory component and a conduit for directing a bio-processing fluid for electrical interaction with the bio-processing fluid flowing through the conduit;

running a bio-processing fluid through the conduit of the sensor assembly;

passing a current through the sensor component during said running of the bio-processing fluid through the conduit and measuring a resulting change in an electrical value across the sensor component, said change in electrical value being a conductivity value that is indicative of a measured conductivity of the bio-processing fluid;

retrieving a constant stored on the memory component of the sensor assembly; and

calculating the actual conductivity of the bio-processing fluid, said calculating comprising mathematically combining the measured conductivity value with said constant.

7. The method according to claim 6 further comprising:

measuring the temperature value of the bio-processing fluid running through the conduit;

retrieving a temperature offset stored on the memory component of the sensor assembly; and

calculating the actual temperature of the bio-processing fluid, said calculating comprising of mathematically combining the measured temperature value with said temperature offset.

8. The method according to claim 6, wherein said calculating of the actual conductivity comprises mathematically combining said calculated actual temperature with said measured conductivity value and with said constant.

9. The method according to claim 6, wherein said mathematically combining includes multiplying the measured conductivity value by said constant.

10. The method according to claim 7, wherein said mathematically combining includes dividing the measured conductivity value by said constant.

11. A disposable sensor for measuring the conductivity of a bio-processing fluid, comprising:

a conduit for directing a bio-processing fluid;

a sensing portion having a memory component, said sensing portion being arranged for sensing conductivity of bio-processing fluid passing through said conduit, said sensing portion having a structure for measuring the temperature; and

said apparatus is made of inexpensive disposable material suitable for single use of the apparatus.

12. The sensor of claim 11, wherein said memory component is a non-volatile memory chip

13. The sensor of claim 11, wherein said memory component contains calibration information including a statistical performance value based on individual measurement performances of a plurality of said disposable sensors.

14. The sensor of claim 11, wherein said sensing portion comprises a printed circuit board.

15. The sensor of claim 11, wherein said structure for measuring the temperature of the bio-processing fluid includes at least one thermistor.

16. The sensor of claim 11, wherein said sensing portion is composed of at least one electrode being arranged such that same is in contact with said bio-processing fluid during use of the apparatus.

17. The sensor of claim 16, wherein said sensing portion is composed of four electrodes being arranged such that said electrodes are in contact with said bio-processing fluid during use of the apparatus.

18. The sensor of claim 11, further comprising a user interface, said user interface being connectable with said sensing portion.

19. The sensor of claim 18, wherein said user interface drives a current through the sensing portion, and said user interface is able to calculate the conductivity of the bio-processing fluid.

20. The sensor of claim 18, wherein said user interface has the ability to access, retrieve, or modify the data stored in the said non-volatile memory chip.

21. The sensor of claim 11, wherein said memory component is a non-volatile memory chip, said non-volatile memory chip being able to store calibration data, said sensing portion having four electrode pins, said electrode pins being arranged such that they are in contact with bio-processing fluid passing through said conduit, at least a portion of said conduit and said sensing portion being arranged within a impermeable housing.