FLUID SENSOR CARTRIDGE

A fluid sensor cartridge that can be used to monitor composition of constituent materials or characteristics of a sample fluid or a patient's blood. The fluid sensor cartridge can be connected in-line with a medical device during a medical treatment. The fluid sensor cartridge can utilize one or more valves, one or more channels, and one or more reservoirs to enable sampling, sensing, and calibrating of a sample fluid or a patient's blood in one container with minimal amounts of sample/blood and calibration fluid.

BACKGROUND

Field

The field relates to a fluid sensor cartridge.

Description of the Related Art

Treatment procedures, such as dialysis procedures, may need to be performed on a regular basis in a hospital setting or outpatient facility. It can be desirable to monitor the constituent materials of the patient's blood and/or a treatment fluid during the treatment procedures in real-time. Blood or fluid tests in the lab or with one-time use card-style sensors before or after the treatment can be inaccurate, inconvenient, time-consuming, and economically costly to the patient and the clinician. Enabling such real time testing and monitoring to be performed with a small cartridge that can be connected in-line to a medical device can advantageously improve the accuracy, convenience, efficiency, and affordability of the procedures.

SUMMARY

In one embodiment, a fluid cartridge sensor described herein comprises a sensor assembly including a fluid pathway and one or more sensing elements in fluid communication with the fluid pathway; a first fluid inlet configured to provide a first sample fluid to the fluid pathway; a first valve configured to selectively direct the first sample fluid to the fluid pathway; a second fluid inlet configured to provide a second fluid to the fluid pathway; and a second valve configured to selectively direct the second fluid to the fluid pathway.

In some aspects, the fluid sensor cartridge further includes a first drain in fluid communication with the fluid pathway, the first drain to convey fluid from the fluid pathway to a waste reservoir.

In some aspects, the fluid cartridge sensor includes a container including a calibration fluid reservoir to hold a calibration fluid and a waste reservoir; a sensor assembly including a fluid pathway and one or more sensing elements in fluid communication with the fluid pathway; a first fluid inlet configured to provide a first sample fluid to the fluid pathway; a second fluid inlet configured to provide at least a second fluid to the fluid pathway; and a first drain in fluid communication with the fluid pathway, the first drain to convey fluid from the fluid pathway to the waste reservoir.

In some aspects, the fluid sensor cartridge further includes a first valve configured to selectively direct the first sample fluid to the fluid pathway and a second valve configured to selectively direct the second fluid to the fluid pathway.

In some aspects, the first valve includes a rotatable plug valve having a plurality of operating positions.

In some aspects, the second valve includes a face valve including a plate having a plurality of openings, the face valve rotatable relative to the first and second fluid inlets.

In some aspects, the fluid sensor cartridge further includes a plunger configured to control flow of fluid in the fluid pathway.

In some aspects, the fluid sensor cartridge further includes a third valve configured to fluidly connect the fluid pathway to the plunger.

In some aspects, the third valve includes a second rotatable plug valve having a plurality of operating positions.

In some aspects, the fluid sensor cartridge further includes a second drain spaced apart from the first drain, wherein the plurality of openings includes a setup mode fluid inlet opening and a setup mode drain opening, wherein during a setup mode of the fluid sensor cartridge, the setup mode fluid inlet opening at least partially overlaps with the second fluid inlet, the setup mode drain opening at least partially overlaps with the second drain, and the first drain is occluded.

In some aspects, wherein in the setup mode, the first valve is in a closed position to inhibit fluid flow into or out of the fluid pathway through the first valve.

In some aspects, the plurality of openings includes a calibration mode fluid inlet opening and a calibration mode drain opening, wherein during a calibration mode of the fluid sensor cartridge, the calibration mode fluid inlet at least partially overlaps with the second fluid inlet and the calibration mode drain opening at least partially overlaps with the first drain.

In some aspects, the calibration mode fluid inlet opening and the calibration mode drain opening are disposed at generally opposite circumferential positions of the plate.

In some aspects, wherein in the calibration mode, the first valve is in a closed position to inhibit fluid flow into or out of the fluid pathway through the first valve.

In some aspects, the plurality of openings includes a quality control (QC) mode fluid inlet opening and a QC mode drain opening, wherein during a QC mode of the fluid sensor cartridge, the QC mode fluid inlet opening at least partially overlaps the second fluid inlet and the QC mode drain opening at least partially overlaps the first drain.

In some aspects, the plurality of openings includes a plurality of QC mode fluid inlet openings and a plurality of QC mode drain openings, the fluid sensor cartridge including a plurality of QC operating modes.

In some aspects, wherein in the QC mode, the first valve is in a closed position to inhibit fluid flow into or out of the fluid pathway through the first valve.

In some aspects, the fluid sensor cartridge further includes a third drain to convey fluid to the waste reservoir, wherein the plurality of openings includes a valve drain opening, wherein in a valve flush mode of the fluid sensor cartridge, the valve drain opening at least partially overlaps the third drain, the third drain disposed below the first valve.

In some aspects, wherein in the valve flush mode, the first valve is at least partially open to permit a calibration fluid to flush the first valve to the waste reservoir.

In some aspects, wherein in the valve flush mode, the first drain is occluded.

In some aspects, the fluid sensor cartridge has an inflow mode in which the first valve is at least partially open to provide the sample fluid to the fluid pathway.

In some aspects, the plurality of openings includes a sample fluid drain opening, and, wherein, in the inflow mode, the sample fluid drain at least partially overlaps with the first drain.

In some aspects, the fluid sensor cartridge has a sense mode in which the sensor assembly transduces one or more fluid properties of the sample fluid in the fluid pathway.

In some aspects, in the sense mode, the first drain is occluded.

In some aspects, the second valve further includes a gasket disposed over the plate of the second valve, the gasket including a plurality of gasket openings, the second valve rotatable relative to the gasket.

In some aspects, the fluid sensor cartridge further includes a manifold over the gasket, the manifold including the first fluid inlet, the second fluid inlet, and the first drain.

In some aspects, the first valve is disposed in an opening of the manifold.

In some aspects, the fluid sensor cartridge further includes a wicking pad disposed in an aperture of the gasket.

In some aspects, the wicking pad is configured to selectively occlude and expose the second fluid inlet upon rotation of the second valve.

In some aspects, the sensor assembly includes a plurality of first electrodes exposed to the fluid pathway.

In some aspects, the sensor assembly further includes a second electrode spaced apart from the plurality of first electrodes.

In some aspects, the second electrode is disposed along a second fluid pathway spaced from the fluid pathway, an angled segment fluidly connecting the first and second fluid pathways.

In some aspects, the angled segment and the second fluid pathways are configured to maintain fluid in the second fluid pathway.

In some aspects, the fluid sensor cartridge further includes a container, the face valve disposed at a first end portion of the container.

In some aspects, the fluid sensor cartridge further includes a calibration fluid reservoir in the container and a calibration fluid plunger configured to drive the calibration fluid along a calibration channel of the container and out of the container through a calibration fluid inlet opening of the plate.

In some aspects, the fluid sensor cartridge further includes a waste reservoir in communication with at least one drain opening of the plate.

In some aspects, the waste container is disposed around the calibration reservoir.

In some aspects, the fluid sensor cartridge further includes a plurality of reservoirs in the container and a corresponding plurality of plungers, each configured to drive a corresponding fluid and out of the container through a corresponding fluid inlet opening of the plate.

In some aspects, the fluid sensor cartridge further includes a plurality of straws, each disposed inside each of the plurality of reservoirs, a corresponding fluid flowing through the straws and through a corresponding fluid inlet opening of the plate.

In some aspects, the plurality of reservoirs includes a plurality of QC reservoirs containing a corresponding plurality of QC fluids.

In some aspects, the fluid sensor cartridge further includes a mechanical interface at a second end portion of the container, the mechanical interface configured to removably couple to a reader assembly which is configured to impart rotation to the mechanical interface and the container.

In some aspects, the mechanical interface includes a gear.

In some aspects, the fluid sensor cartridge further includes an electrical interface electrically connected to the sensor assembly, the electrical interface configured to removably couple to the reader assembly.

In some aspects, the fluid sensor cartridge further includes the reader assembly.

In some aspects, the reader assembly includes a controller configured to drive one or more plungers to move the second fluid to the fluid pathway.

In some aspects, the controller is configured to automatically switch between a plurality of operating modes.

In some aspects, the plurality of operating modes includes at least two of a setup mode, a sample inflow mode, a sense mode, a calibration mode, one or more valve flush modes, and a quality control (QC) mode.

In some aspects, the fluid sensor cartridge further includes tubing in fluid communication with the first inlet, the tubing configured to connect with a medical device.

In some aspects, the fluid sensor cartridge further includes one or more air inlets in fluid communication with the fluid pathway.

In some aspects, the one or more air inlets are configured to fluidly connect to ambient air.

In some aspects, the one or more air inlets includes a vacuum port configured to pull from a reservoir to overcome a negative pressure of the first sample fluid.

In some aspects, the each air inlet is configured to at least partially overlap with the second fluid inlet, the plunger pulling air from ambient air through the second fluid inlet to the fluid pathway.

In some aspects, the fluid sensor cartridge further includes one or more cavities in the container exposed to ambient air, wherein the one or more air inlets are disposed on the cavities.

In another embodiment, a fluid sensing method includes opening a first plug valve to provide a first sample fluid to a fluid pathway to expose a sensor assembly to at least the first sample fluid; transducing at least one fluid property of the first sample fluid with the sensor assembly; and rotating a second face valve to provide a second fluid to the fluid pathway to flush the sensor assembly, the second fluid flowing along the fluid pathway through a first drain to a waste reservoir.

In some aspects, the method further includes, before transducing, closing the first plug valve and rotating the second face valve to occlude the first drain.

In some aspects, the method further includes rotating the second face valve to provide a third fluid to the fluid pathway, the third fluid flowing along the fluid pathway through the first drain, the third fluid including a quality control (QC) fluid.

In some aspects, the method further includes rotating the second face valve to provide a plurality of fluids to the fluid pathway through a plurality of corresponding openings, each of the one or more fluids flowing along the fluid pathway through the first drain.

In some aspects, the method further includes at least partially opening the first plug valve, and rotating the second face valve to provide the second fluid to the first plug valve to flush the first plug valve, the second fluid flowing through the first plug valve through a valve drain to the waste reservoir.

In some aspects, the method further includes rotating a third plug valve to fluidly connect the fluid pathway to a plunger and controlling flow of fluid in the fluid pathway with the plunger.

In some aspects, the method, further including rotating the third plug valve to provide the fluid in the fluid pathway to flow through the third plug valve through the first drain to the waste reservoir.

In some aspects, the method further includes, before transducing and when the fluid in the fluid pathway is a mixture of the sample fluid and another fluid, closing the third plug valve to the fluid pathway, controlling flow of the mixture of fluid between the third plug valve and the plunger through the third plug valve through the first drain to a waste reservoir with the plunger, rotating the third plug valve to fluidly connect the fluid pathway to the plunger, controlling a flow of sample fluid to the fluid pathway with the plunger, and repeating the process until the fluid in the fluid pathway includes substantially of only the sample fluid.

In some aspects, the method further includes rotating the second face valve and rotating the third plug valve to provide the second fluid to the third plug valve to flush the third plug valve and the plunger, the second fluid flowing through the third plug valve to the plunger; and rotating the third plug valve and pushing the plunger to drive the fluid between the third plug valve and the plunger through the first drain to the waste reservoir.

In some aspects, the method further includes pulling air from one or more cavities open to ambient air to introduce air bubbles to fluid in the fluid pathway.

DETAILED DESCRIPTION

Various embodiments relate herein to a fluid sensor cartridge configured to be connected in-line to a medical device, such as a dialysis treatment system.FIGS.1-22Bshow an embodiment of the fluid sensor cartridge100and a plurality of modes the fluid sensor cartridge100can be operated in. In some embodiments, the fluid sensor cartridge100can include a tubing102configured to fluidly connect to a treatment system of the medical device. For example, in kidney hemodialysis systems, blood can be transferred from the patient, through the dialysis treatment system, and back in the patient, to treat the patient's blood. In a peritoneal dialysis (PD) system, the treatment system can pump dialysate in a circulation through the abdominal cavity. During a treatment procedure, it can be important to monitor the composition of constituent materials in the patient's blood, such as creatinine, potassium, sodium, or any other constituent material that should be monitored and/or the composition of constituent materials in a sample fluid, such as a treatment fluid (e.g., dialysate). In addition, it can also be important to monitor characteristics (e.g. pH, conductivity, etc.) of the patient's blood or that of a sample fluid. The fluid sensor cartridge100can be placed upstream or downstream of the treatment system or a filter to monitor the constituent materials in a sample fluid10.

In some embodiments, the fluid sensor cartridge100can include a lid104coupled to the manifold110to protect components on the fluid sensor cartridge100. In some embodiments, the lid104can be transparent or semi-transparent so that a fluid inside the fluid pathway can is visible to a user.

Beneficially, the fluid sensor cartridge100can be sized and configured to accurately monitor multiple different constituents in a sample at the same time and require minimal amount of sample (e.g. blood or treatment fluid) to complete a test. For example, as shown inFIGS.6A-6B, the fluid sensor cartridge100can have a container150comprising multiple reservoirs to hold a plurality of quality control (QC) fluids and a calibration fluid20. In some embodiments, the multiple reservoirs can include a first QC reservoir151, a second QC reservoir152, a third QC reservoir153, a fourth QC reservoir154, and a calibration reservoir155. In some embodiments, the container150can also include a reservoir filled with air or any other kind of fluids to fit different needs. The capability of holding and testing with a plurality of QC/calibration fluids enables accurate testing of multiple different constituents in a sample and testing constituents for many times over multiple days. Further, the fluid pathway can be configured to be of a minimal length to reduce the sample size required to complete a test.

In some embodiments, the fluid sensor cartridge100can further comprise a manifold110coupled to the container150as shown inFIG.2A-2B. The manifold110can hold a main fluid pathway108and one or more sensing elements. In some embodiments, the one or more sensing elements can comprise a plurality of primary electrodes122(e.g. ion and/or metabolite sensors) that, when exposed to the sample fluid10, transmit one or more signals indicative of one or more constituent components of the sample fluid10. As shown, the main fluid pathway108can extend over the primary electrodes122to expose the primary electrodes122to the sample fluid10. In some embodiments, the manifold110can also include a secondary fluid pathway119fluidly connected to the main fluid pathway108by an angled sideway120(seeFIG.3-4A). A fluid (e.g. calibration fluid20, QC fluids30, or the sample fluid10) can be maintained in the secondary fluid pathway119due to the angle of the angled sideway120, such that, during operation of the fluid sensor cartridge100, the fluid can be maintained over the secondary fluid pathway119. In some embodiments, the one or more sensing elements can further include one or more secondary electrodes121positioned in the secondary fluid pathway119and exposed to the fluid in the secondary fluid pathway119. In some embodiments, the one or more sensing elements can all be positioned on a sensor assembly124.

As shown inFIG.3, the fluid sensor cartridge100can include a plug valve140coupled to the manifold110and configured to switch between a plurality of positions including an open position O allowing the sample fluid10to flow in via a sample fluid inlet129and a closed position X closed to the tubing102. In some embodiments, the plug valve140can be switched between the plurality of positions by rotating a knob coupled to the plug valve140. In some embodiments, the fluid sensor cartridge100can further include a face valve130coupled to the container150and include a plurality of drains or inlet openings as shown inFIG.4A-5B. The face valve130can be configured to switch between a plurality of operational modes by aligning openings of the reservoirs to the drain holes or inlets on the manifold110. In some embodiments, in each operating mode, the face valve130can include a corresponding mode indicia132, visible through an opening on the manifold110. In some embodiments, the face valve130can include a gasket136disposed over and configured to rotate relative to a plate of the face valve134(“face plate134”) to occlude or leave open the openings on the face valve130. The fluid sensor cartridge100can thereby feed the plurality of QC fluids30/calibration fluid20to the main fluid pathway108through the same QC/calibration fluid inlet opening128on the manifold110. After use, the fluids (e.g. QC, calibration, and sample fluids) can all go to a waste reservoir156through their respective drains openings.

Also beneficially, the fluid sensor cartridge100can be sized and configured to be used as disposable in a clinical setting such as a hospital or clinic, or at home by the patient, requiring minimal efforts by the user. For example, the QC/calibration fluid inlet opening128on the manifold110can connect to the treatment system by way of a quick connection such as a Luer lock or other fluid coupling. In some embodiments, the fluid sensor cartridge100can mechanically and electrically connect to a reader assembly190as shown inFIG.1. The reader assembly190can mechanically couple to the fluid sensor cartridge100on one end via a mechanical interface192. The mechanical interface192can comprise a motor and a gear160(see.FIG.2A) that is coupled to the face valve130and configured to rotate the face valve130, in cooperation with the plug valve140, to achieve different the operating modes. In some embodiments, the reader assembly190can electrically couple to the fluid sensor cartridge100on another end via an electrical interface191. In some embodiments, the sensor assembly124on the manifold110of the fluid sensor cartridge100can include a connector106to allow the124be connected to the electrical interface191of the reader assembly190. In some embodiments, the reader assembly190can further comprise a controller configured to drive one or more plungers to move fluids to the main fluid pathway108. In some embodiments, each reservoir has a corresponding plunger attached to it to push or pull the fluid inside the reservoir. The controller can also be configured to control the face valve130, in cooperation with operation of the plug valve140, to automatically switch between the plurality of operating modes.

In some embodiments, the face valve130can include one or more QC inlet (e.g., four QC inlets171-174), one or more calibration fluid inlet (e.g., three calibration fluid inlets175-177), one or more drains (e.g., a SET mode drain178, a fluid in drain179, a CAL mode drain180, and four QC drains181-184, and/or one or more valve drains185). In some embodiments, the plurality of operating modes can include one or more of a setup mode1004, an inflow mode1000, a sense mode (also a ship mode)1002, a calibration mode1006, a valve flush mode1008, and one or more QC modes1010(seeFIG.8). As shown inFIG.8, each of the operating modes can correspond to an open position (marked as “O”) or a closed position (marked as “X”) of each of the inlets or drains on the face valve and the manifold.

In some embodiments, the fluid sensor cartridge100can be shipped and sent to a user in the sense/ship mode1002(seeFIG.13A-13B), in which the plug valve140can be configured to be closed to the outside environment and all the drains closed to the reservoirs, leaving only a vacuum port112open. In some embodiments, the vacuum port112can be configured to be either exposed to ambient air or connected to a vacuum source, allowing the fluid sensor cartridge100to operate in both negative and positive pressures. For example, the vacuum port112can pull from a reservoir filled with air to overcome negative pressure in the sample fluid.

When the fluid sensor cartridge100arrives with the user, the user can first operate the fluid sensor cartridge100in a setup mode (SET)1004as shown inFIG.9A-10B. In the setup mode1004, in some embodiments, the calibration fluid inlet opening128on the manifold110can be configured to be open to the calibration reservoir155through the first calibration fluid inlet175, and a secondary drain hole117be configured to open to the waste reservoir156via the setup mode drain178, while the plug valve140and other drains remain closed. In this mode, calibration fluid20can be purged into the main fluid pathway108, run over the primary and secondary electrodes122and121, and go to the waste reservoir156through the secondary drain hole117to the secondary drain116and the setup mode drain178.

When the fluid sensor cartridge100and the patient are ready for a test using the fluid sensor cartridge100, the user can operate the fluid sensor cartridge100in a fluid in or inflow mode (IN)1000as shown inFIG.11A-12. In the fluid in mode1000, in some embodiments, the plug valve140can be configured to be open and connected to the tubing102and a primary drain hole115be open to the waste reservoir156through a fluid in drain179on the face valve130. In this mode, a sample fluid10(e.g. patient's blood) can enter the main fluid pathway108through the open plug valve140, run over the primary electrodes122, and go to the waste reservoir156through the primary drain114. When the sample fluid10is in the main fluid pathway108, in some embodiments, the user can operate the fluid sensor cartridge100by rotating both the face valve130and the plug valve140to stop the sample fluid10in the main fluid pathway108to achieve the sense mode (SNS)1002. Therefore, measurement can take place while the sample fluid10is stationary in the sense mode1002.

In the sense mode1002, in some embodiments, the plug valve140can be configured to be closed to the outside environment and all the drains closed to the reservoirs as shown inFIG.13A-14. For example, the primary drain hole115can be occluded by the face plate134and closed to the waste reservoir156. In this mode, the sample fluid10can stay in the main fluid pathway108for a desired period of time, and the primary electrodes122be exposed to the sample fluid10to sense the constituents in the sample fluid10.

After the sample fluid10has run through the main fluid pathway108in the fluid in mode1000or the sense mode1002, the main fluid pathway108and/or the secondary fluid pathway119can be cleaned and the fluid sensor cartridge100calibrated in the calibration mode (CAL)1006as shown inFIG.15A-16. In the calibration mode1006, in some embodiments, the plug valve140can remain closed, the face valve130is rotated such that the primary drain hole115can be open to the waste reservoir156through a calibration mode drain180, and the calibration fluid inlet opening128on the manifold110be configured to be open to the calibration reservoir155through a second calibration fluid inlet176. In this mode, the calibration fluid20can be purged into the main fluid pathway108, run over the primary electrodes122, and to the waste reservoir156through the primary drain114. The main fluid pathway108and the primary electrodes122can thereby be cleaned and reset in the calibration mode1006.

In some embodiments, the plug valve140can similarly be flushed and cleaned in the valve flush mode (VLV)1008as shown inFIG.17A-18B. In the valve flush mode1008, the plug valve140is in the open position O in which the plug valve140can be configured to be open to the main fluid pathway108but closed to the tubing102. Further, in some embodiments, the plug valve140and the face valve130can be coordinated such that the plug valve140is open to the waste reservoir156through a valve flush pathway109and the one or more valve drains185. In this mode, the calibration fluid inlet opening128on the manifold110can be configured to be open to the calibration reservoir155through a third calibration fluid inlet177, and the primary and secondary drain holes115and117all be closed so that calibration fluid20would only flow towards the plug valve140.

In some embodiments, the fluid sensor cartridge100can further include one or more QC modes1010to calibrate the sensing elements and maintain quality control of the sensing elements as shown inFIG.19A-20. In the illustrated embodiment, there are four QC reservoirs151-154(seeFIGS.6A-6B) holding four different QC fluids, so there can be four QC modes and four QC inlets171-174corresponding to the four QC fluids. As an example, in some embodiments, to calibrate the primary electrodes122using the first QC fluid from the first QC reservoir151, the calibration fluid inlet opening128on the manifold110can be configured to be open to the first QC reservoir151through a first QC inlet171, and the primary drain hole115be configured to be open to the waste reservoir156through a first QC drain181. In this QC mode1010, the first QC fluid from the first QC reservoir151may be purged into the main fluid pathway108through the calibration fluid inlet opening128on the manifold110, run through the primary electrodes122, and go the waste reservoir156through the primary drain114. The sensed data can allow the sensing elements (e.g., the primary electrodes122) to be electrically calibrated using pre-determined metrices (e.g., concentrations of the QC fluids).

In some embodiments, one or more plungers can be coupled to a bottom end of one or more of the reservoirs to control a flow of the QC or calibration fluid into the main fluid pathway108. In some embodiments, the one or more plungers can act as a syringe to push or purge the fluids into the main fluid pathway108. For example, as shown inFIG.7A, a calibration plunger164can be coupled to bottom end of the calibration reservoir155and configured to be pushed into the calibration reservoir155and purge the calibration fluid20up to the main fluid pathway108through the calibration channel142and the third calibration inlet177on the face valve130. In some embodiments, one or more QC plungers162can also be included to purge the one or more QC fluids (FIG.2B).

In accordance with various embodiments, to better control the flow and volume of fluids (e.g., calibration fluid, QC fluids, etc.) in a fluid sensor cartridge and simplify the control the motor and controller system, it may be beneficial to include an external plunger230that can be fluidly connected to the main fluid pathway208in a fluid sensor cartridge200as shown inFIG.24-32C. Unless otherwise noted, elements of the fluid sensor cartridge200may have similar functions or operate similarly as similarly-numbered elements of the fluid sensor cartridge100. In some embodiments, the external plunger230can work as a syringe to pull fluids into or out of the main fluid pathway208at a certain rate and for a certain volume as needed. In some embodiments, the external plunger230can be controllable by hand or by the controller of the reader assembly190. With the external plunger230, which may be in direct fluid connection with the main fluid pathway208, a plurality of fluids can be driven by the same external plunger230through their respective inlets or openings, which can overlap with the calibration fluid inlet opening228on the manifold210by rotating the face valve230, and through the main fluid pathway208. In some embodiments, reservoirs without a corresponding plunger directly attached to them can each include a straw so that the external plunger230in fluid connection with the fluid pathway can pull fluids from, e.g., the QC reservoirs251-254through the straws51-54(seeFIG.31A-31B).

In some embodiments, the fluid sensor cartridge200may further include a third valve242(e.g. a second plug valve) configured to switch between different positions, allowing the external plunger230to control either a fluid in the main fluid pathway208or to control only a fluid between the third valve242and the external plunger230. In some embodiment, the third valve242can be positioned in an opening of the manifold210above the primary drain214as shown inFIG.27, wherein the primary drain214can comprise one or more drain openings215to align with one or more openings of the third valve242.

In some embodiments, the sensor fluid cartridge200can include additional operating modes with the external plunger230and the third valve242. For example, the third valve242can be configured to be closed to the external plunger230in a calibration mode2006, letting calibration fluid20be driven up and clean the third valve242, through the primary drain214and to the waste reservoir256as shown inFIG.29.

In some embodiments, in a plunger flush mode2012, the third valve242can also be configured to be open to both the main fluid pathway208and the external plunger230to let the calibration fluid20flow through the main fluid pathway208and flush the external plunger230(seeFIG.30A). After flushing the external plunger230, in the plunger flush mode2012, the third valve242can be rotated to be closed to the main fluid pathway208so that the external plunger230can be operated to push the calibration fluid20through the primary drain214to the waste reservoir256(seeFIG.30B).

In some embodiments, a fluid in mode (IN or inflow mode)2000for the fluid sensor cartridge200can operate differently that that for the fluid sensor cartridge100with the external plunger230and the third valve242as shown inFIG.28A-28E. In the inflow mode2000, the external plunger230can pull the sample fluid10through the main fluid pathway208with the third valve242in an open position O, fluidly connecting the main fluid pathway208and the external plunger230. If the main fluid pathway208was previously filled with another fluid, and after pulling the sample fluid10into the main fluid pathway208, the main fluid pathway208might be filled with a mixture of the sample fluid10and the other fluid (e.g., calibration fluid20) as shown inFIG.28A. In this case, the third valve242can first be configured to be closed to the main fluid pathway208(seeFIG.28B), allowing the external plunger230to drive the mixture of fluids through the primary drain214to the waste reservoir256. Then, the third valve242can be configured to be open again, allowing the external plunger230to drive more sample fluid into the fluid pathway. In some embodiments, this process can be repeated for multiple times until the main fluid pathway208is filled solely with the sample fluid10and ready for sensing of the sample fluid10(seeFIG.28C). Similarly, the QC modes2010can implement the same repeated process to ensure the main fluid pathway208is not filled with a mixture of different fluid for better quality control.

Finally, it can be advantageous to include a mechanism of introducing air bubbles to the fluids (e.g. QC/calibration fluids) so that less amount of fluids would be used to operate the fluid sensor cartridge100/200during one or more operating modes. Additionally, air may be introduced to act as a barrier between two different fluids, e.g., when switching between operating modes. In some embodiments, the fluid sensor cartridge100can be configured to allow an opening195open to the atmosphere to be aligned with the calibration fluid channel142and fluidly connected to the calibration reservoir155such that pulling the plunger164coupled to the calibration reservoir155can introduce air to the calibration fluid20. In some embodiment, a wicking pad138positioned between the face valve130and the manifold110, inside the wicking pad138, can also be used to introduce air bubbles (seeFIGS.21A-22B). For example, in the calibration mode1006after sense mode1002for the fluid sensor cartridge100, introduction of air bubbles into the calibration fluid20can reduce the amount of the calibration fluid20required and more efficiently flush out the sample fluid10remains in the main fluid pathway108. In some embodiments, as shown inFIGS.21A-23B, air bubbles41can be introduced by rotating the face valve130to align the calibration fluid channel142to a calibration inlet (e.g., the second calibration fluid inlet176) and to a wicking pad138(seeFIGS.22A-22B), purging the calibration fluid20out through a calibration fluid channel142, letting a portion of the calibration fluid20to be absorbed by pad projection139of the wicking pad138, and leaving air bubbles41in the calibration fluid20in calibration fluid channel142(seeFIG.23B). In some embodiments, the face valve130can then be rotated to align the second calibration fluid inlet176to the calibration fluid inlet opening128on the manifold110on the manifold and allow the calibration fluid20having air bubbles to enter the fluid pathway108.

In other embodiments, as shown inFIGS.32A-32C, the container250can include one or more ports exposed to ambient air (e.g., a first air port258and a second air port259). The air ports258and259can have corresponding air inlet openings (e.g., a first air inlet opening298and a second air inlet opening299) on the face valve230that can be configured to overlap with the calibration fluid inlet opening228on the manifold210. For example, in some embodiments, the face valve230can be rotated to align a first air inlet opening298to the calibration fluid inlet opening228on the manifold210; and the external plunger230in fluid connection with the main fluid pathway208can be operated to pull air through the calibration fluid inlet opening228to the main fluid pathway208to introduce air to a fluid or between two different fluids. In some embodiments, the external plunger230can also be operated to push air in the main fluid pathway208back to the calibration channel242to introduce air bubbles into the calibration fluid20when needed.

Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” “include,” “including” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” The word “coupled”, as generally used herein, refers to two or more elements that may be either directly connected, or connected by way of one or more intermediate elements. Likewise, the word “connected”, as generally used herein, refers to two or more elements that may be either directly connected, or connected by way of one or more intermediate elements. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Moreover, as used herein, when a first element is described as being “on” or “over” a second element, the first element may be directly on or over the second element, such that the first and second elements directly contact, or the first element may be indirectly on or over the second element such that one or more elements intervene between the first and second elements. Where the context permits, words in the above Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.