Cartridge-based analytical instrument using centrifugal force/pressure for metering/transport of fluids

• US 6,348,176 B1
• Filed: 02/11/1999
• Issued: 02/19/2002
• Est. Priority Date: 02/11/1999
• Status: Expired due to Fees

• Current Assignee: Careside Incorporated
• Original Assignee: Careside Incorporated
• Inventors: Boyd, Douglas E., Reid, William, Kennedy, Daniel, Ramey, James, Storvick, David, Stoughton, John W., Mathews, Glen T., Riedel, Richard A., Hutchinson, James S., Hammer, Roger
• Primary Examiner(s): Soderquist, Arlen
• Application Number:
  US09/248,737
• Time in Patent Office: 1,104 Days
• Field of Search: 422/63-67, 422/72, 422/68.1
• US Class Current: 422/64
• CPC Class Codes: G01N 2035/00504 combined with carousels
• CPC Class Codes: G01N 35/00029 provided with flat sample substrates, e.g. slides G01N35/028 takes precedence

Abstract

An analytical instrument for analyzing fluids. The instrument includes a cartridge carousel assembly which receives analytical cartridges. The analytical cartridges include a centrifugal force-operated sample metering/separation system, a pressure-operated sample transport system, and a test element which provides a detectable analytical property of a fluid sample. The cartridge carousel assembly includes a cartridge rotor plate which has a plurality of cartridge ports which receive the cartridges. A rotary drive mechanism rotates the cartridge rotor plate to provide rotation of the plate which activates the centrifugal force-operated sample metering/separation system of the cartridge. The instrument includes a sample transport actuator which activates the pressure-operated sample transport system of the cartridge. In addition, the instrument includes a detector which measures the detectable analytical property of the fluid sample after the sample metering and transport systems have been activated. The instrument includes tracking and control systems which track and control the rotary drive mechanism and sample transport actuator to provide coordinated operation of the centrifugal force-operated sample metering/separation system and the pressure operated sample transport system wherein the coordinated operation provides delivery of a metered amount of sample to the test element of the test cartridge. Further, the tracking and control unit includes a user-input interface for receiving data input from a user of the instrument, a central processing unit, a real-time processor, and a data output interface which provides output of results of the measurements made by the instrument.

Claims

1. An analytical instrument for analyzing fluid sample in an analytical cartridge, said cartridge having a sample metering/separation system that is operated by centrifugal force, a sample transport system that is operated by pressure and a test element which provides a detectable property of said fluid sample, said sample transport system including a flexible septum that can be moved from a relaxed position to one or more compressed positions wherein movement from said relaxed position to said one or more compressed positions provides pressurization of said sample transport system and wherein said cartridge further includes a vent for said sample metering/separation system, said instrument comprising:

A) a cartridge carousel assembly which receives one or more of said analytical cartridges, said cartridge carousel assembly comprising;

a) a cartridge rotor plate which comprises a center and a plurality of cartridge ports which are located in spaced relation radially outward from said center, said cartridge ports being shaped to receive said cartridges; and

b) a rotary drive mechanism which rotates said cartridge rotor plate about the center thereof, wherein rotation of said cartridge rotor plate activates said centrifugal force operated sample metering/sample system;

B) a sample transport actuator which activates the pressure operated sample transport system of said cartridge, said sample transport actuator comprising;

a septum actuator having a surface which is movable into contact with said flexible septum of said cartridge to move said septum from said relaxed position to said one or more compressed positions when said cartridge is located in said cartridge carousel assembly, said septum actuator comprising a septum rod comprising a tip which comprises said surface which is movable into contact with said septum;

a vent seal element having a surface which is movable to a position which seals said vent, said vent seal element comprising a seal rod comprising a tip which comprises said surface which seals said vent; and

a sample actuator mechanism which jointly moves said septum actuator and vent seal element to provide movement of said flexible septum and sealing of said vent wherein said vent is sealed prior to movement of said septum from said relaxed position to said one or more compressed positions and wherein said vent is unsealed prior to movement of said septum from said one or more compressed positions to said relaxed position, said sample actuator mechanism comprising;

a connector block which connects said septum rod to said seal rod to provide joint movement of said septum rod and said seal rod, said seal rod being oriented relative to said septum rod such that said seal rod tip contacts said vent on said cartridge prior to compression of said septum by said septum rod; and

an actuator motor which moves said connector block so that said septum rod and seal rod move jointly between retracted positions and extended positions;

a release mechanism connected to said seal rod wherein said release mechanism withdraws said seal rod tip from contact with said vent prior to movement of said connector block to withdraw said septum rod from contact with said septum;

C) a detector which measures said detectable analytical property of said fluid sample which is provided by the test element of said cartridge when said cartridge is located in said cartridge carousel assembly; and

D) a tracking and control unit which tracks and controls said rotary drive mechanism and sample transport actuator, said tracking and control unit comprising a user input interface for receiving data input from a user of the instrument, a central processing unit, a real time processor and a data output interface which provides output of results of the measurements made by said detector.

2. An analytical instrument for analyzing fluid sample in an analytical cartridge according to claim 1 wherein said instrument further comprises a reagent transport actuator which activates a pressure operated reagent transport system which is present in said cartridge and wherein said tracking and control unit provides tracking and control of said rotary drive mechanism, pressure operated sample transport system and pressure operated reagent transport system wherein said coordinated operation provides delivery of a metered amount of sample fluid and an aliquot of reagent to the test element of said cartridge.

3. An analytical instrument for analyzing fluid sample in an analytical cartridge according to claim 1 wherein said cartridge includes a reagent transport system that includes a flexible pouch that can be moved from a relaxed position to one or more compressed positions to provide movement of reagent within said cartridge, said instrument further comprising a reagent transport actuator that activates said reagent transport system when said cartridge is located in said cartridge carousel assembly said reagent transport actuator comprising:

a reagent pouch actuator having a surface which is movable into contact with said reagent pouch of said cartridge when said cartridge is located in said cartridge carousel assembly to move said pouch from said relaxed position to one or more of said compressed positions; and

a reagent actuator mechanism that moves said reagent pouch actuator into contact with said reagent pouch to provide movement of said pouch from said relaxed position to one or more of said compressed positions.

4. An analytical instrument for analyzing fluid sample in an analytical cartridge according to claim 3 wherein said reagent pouch actuator comprises a reagent rod comprising a tip which comprises said surface which is movable into contact with said reagent pouch and said reagent actuator mechanism comprises a reagent actuator motor which moves said reagent rod between a retracted position and extended positions where said reagent rod tip is in contact with said reagent pouch.

5. An analytical instrument for analyzing fluid sample in an analytical cartridge according to claim 1 wherein said cartridge ports each comprise a cartridge dock which is shaped to receive said cartridges and a balance weight dock which is located radially inward from said cartridge dock, said cartridge dock being shaped to receive a balance weight, said analytical instrument further comprising:

a locking mechanism which holds said cartridge in said cartridge dock during rotation of said cartridge rotor plate;

a balancing mechanism which comprises a balance weight wherein said balance weight is movable to said balance weight dock when said cartridge is inserted into said cartridge dock and wherein said balance weight remains in said cartridge dock during rotation of said cartridge rotor plate when a cartridge is not present in said cartridge dock;

an ejection mechanism which ejects said cartridge from said cartridge port; and

wherein said tracking and control unit tracks and controls said locking mechanism and said ejection mechanism.

6. An analytical instrument for analyzing fluid sample in an analytical cartridge according to claim 1 which is adapted for use with cartridges that have a top side, bottom side, and a test element which includes an optical element that is optically accessible form only one side of said cartridge and wherein said optical element provides an optically detectable analytical property of said fluid, said detector comprising:

an optical detector which measures said detectable analytical property of said fluid sample which is provided by the optical element of said cartridge, said optical detector comprising;

a) a radiation source located relative to said cartridge rotor to provide an incident beam of radiation which contacts said optical element and wherein a return beam of radiation is emitted by said optical element in response to contact by said incident beam of radiation; and

b) a return beam detector which measures said return beam of radiation wherein said radiation source and return beam detector are both located on the same side of said cartridge when it is located within said cartridge rotor plate; and

wherein said tracking and control unit tracks and controls said rotary drive mechanism and said detector to provide coordinated operation so that said optical detector can make measurements of said optical element while said cartridge rotor is stationary or rotating.

7. An analytical instrument according to claim 6 wherein said radiation source comprises:

a plurality of light emitting diodes which are arranged to form an arcuate array of light emitting diodes which corresponds to the arcuate path of said optical element as said cartridge travels in said cartridge rotor plate during rotation of said cartridge rotor plate.

8. An analytical instrument according to claim 6 wherein said radiation source comprises one or more light emitting diodes which emit radiation in a wavelength selected from the group consisting of ultra-violet, visible and infra-red.

9. An analytical instrument according to claim 8 wherein said radiation source comprises:

a first light emitting diode which emits radiation consisting of a wavelength of about 425 nanometers;

a second light emitting diode which emits radiation consisting of a wavelength of about 505 nanometers;

a third light emitting diode which emits radiation consisting of a wavelength of about 570 nanometers;

a fourth light emitting diode which emits radiation consisting of a wavelength of about 590 nanometers;

a fifth light emitting diode which emits radiation consisting of a wavelength of about 615 nanometers; and

a sixth light emitting diode which emits radiation consisting of a wavelength of about 655 nanometers.

10. An analytical instrument according to claim 6 wherein the optically accessible portion of said optical element has a cross-sectional area and wherein said radiation source comprises a collimator which directs said incident beam of radiation onto said optical element as a collimated incident beam which has a cross-section which is substantially less than the cross-section of said optically accessible portion.

11. An analytical instrument according to claim 10 wherein said radiation source comprises multiple collimators wherein said radiation source comprises multiple collimators wherein the cross-sections of said collimated incident beams are not the same.

12. An analytical instrument according to claim 10 wherein said tracking and control unit is set to take multiple measurements of the optical element by exposing said optical element to a plurality of collimated incident beams and measuring the resultant plurality of return beams.

13. An analytical instrument for analyzing fluid sample in an analytical cartridge according to claim 1 which is adapted for use with cartridges that have a top side, bottom side, and a test element which includes an electrochemical element that is electrically accessible from only one side of said cartridge and wherein said electrochemical element provides an electrically detectable analytical property of said fluid, said detector comprising:

an electrical detector which measures said electrically detectable analytical property of said fluid sample which is provided by the electrochemical element of said cartridge when said cartridge is located in said carousel assembly, said electrochemical detector comprising;

a) an electrical probe comprising a surface which is movable between a retracted position and an extended position where said electrical probe is in contact with said electrochemical element to provide measurement of said electrically detectable analytical property; and

b) a probe actuator assembly which moves said electrical probe between said retracted position and said extended position; and

wherein said tracking and control unit tracks and controls said rotary drive mechanism and said electrical detector to provide coordinated operation so that said electrical detector can make measurements of said electrochemical element while said cartridge rotor is stationary.