EP4051342A1 - In-line intravenous flow probe utilizing thermal mass flow characterization - Google Patents

Abstract

Described herein are flow probe devices that can be inserted in-line in an IV line, the flow probe devices including inlet tubing that fluidly couples with an upstream IV line (e.g., from an IV fluid bag), outlet tubing that fluidly couples with a downstream IV line (e.g., to a patient), a flow sensor to measure flow rates and/or volumes of the fluid flowing through the inlet tubing, a housing to secure the inlet tubing to increase laminar flow and/or to reduce turbulent flow of the fluid at an inlet of the flow sensor, and electronics for the flow sensor and for communicating (e.g., wirelessly or using a cable) flow data to a patient monitor or other external device. The flow probe devices disclosed herein can be disposable devices.

Description

IN-LINE INTRAVENOUS FLOW PROBE UTILIZING THERMAL MASS FLOW

CHARACTERIZATION

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims priority to U.S. Provisional Patent Application No. 62/926,815 filed October 28, 2019 and entitled “IN-LINE INTRAVENOUS FLOW PROBE UTILIZING THERMAL MASS FLOW CHARACTERIZATION,” the entire contents of which are incorporated by reference herein for all purposes.

BACKGROUND

Field

[0002] The present disclosure generally relates to a flow probe for use in-line in an intravenous line to measure fluid delivered to a patient.

Description of Related Art

[0003] Fluid boluses, sometimes referred to as fluid challenges, can be used in the fluid management of patients. A principle behind using fluid challenges is that by giving a small amount of fluid in a short period of time (e.g., a fluid bolus), the clinician can assess whether the patient has a preload reserve that can be used to increase the stroke volume with further fluids. Continuous cardiac output can be used to monitor a patient’s response to a fluid challenge. Therapy guided by determining patients’ responses to fluid challenges can lead to reduced hospital stays and fewer post-operative complications. Flow probes can facilitate the tracking of fluids delivered to the patient and can make the overall fluid management of the patient easier and more manageable.

SUMMARY

[0004] According to a number of implementations, the present disclosure relates to a flow probe device. The flow probe device includes a housing forming an open portion and an enclosed portion. The flow probe device also includes a flow sensor housed within the enclosed portion of the housing and configured to measure flow-related data of a fluid flowing through the flow sensor, the flow sensor including an inlet port and an outlet port. The flow probe device also includes inlet tubing having a proximal end fluidly coupled to the inlet port of the flow sensor and a distal end extending beyond a distal portion of the housing, the inlet tubing secured to the open portion of the housing such that the inlet tubing is straight over a distance of at least 7 cm distally from the inlet port of the flow sensor. The flow probe device also includes outlet tubing having a distal end fluidly coupled to the outlet port of the flow sensor and a proximal end extending beyond a proximal portion of the housing. The flow probe device also includes a printed circuit board enclosed within the housing and having an electrical connector configured to electrically couple the flow sensor to the printed circuit board.

[0005] In some embodiments, an inner diameter of the inlet tubing is substantially the same as an inner diameter of the inlet port of the flow sensor. In some embodiments, fluid flowing through the inlet tubing to the flow sensor experiences laminar flow at the inlet port of the flow sensor. In some embodiments, the flow-related data has an accuracy better than ±20%. In some embodiments, the device further includes an electrical cable coupled to the printed circuit board and extending proximally from a proximal end of the housing. In some embodiments, the printed circuit board is configured to provide wireless communication of the flow-related data measured by the flow sensor.

[0006] In some embodiments, the housing includes a distal clip at a distal end of the open portion of the housing and a middle clip between the distal clip and a distal end of the enclose portion, the distal clip and the middle clip configured to secure the inlet tubing in a straight line to the open portion of the housing. In further embodiments, the housing further forms a trench to secure the inlet tubing in a straight line to the open portion of the housing.

[0007] In some embodiments, the housing includes a cradle conforming to the flow sensor to maintain the flow sensor in a desired position and orientation. In further embodiments, the housing includes a rubber ring around the cradle to provide water protection.

[0008] In some embodiments, the inlet tubing further includes a connector at a distal end of the inlet tubing. In some embodiments, the outlet tubing further includes a connector at a proximal end of the outlet tubing. In further embodiments, the connector includes a rotating male luer connector.

[0009] In some embodiments, the housing forms an attachment feature configured to mate with a device attachment apparatus.

[0010] In some embodiments, the housing comprises a bottom portion, a middle portion, and a top portion. In further embodiments, the flow sensor is between the top portion and the middle portion of the housing. In further embodiments, the printed circuit board is between the bottom portion and the middle portion. In further embodiments, a compression force between the middle portion and the bottom portion ensure electrical connection between the flow sensor and the printed circuit board. [0011] According to a number of implementations, the present disclosure relates to a method of manufacturing a flow probe device. The method includes coupling inlet tubing to an inlet port of a flow sensor. The method also includes coupling outlet tubing to an outlet port of the flow sensor. The method also includes securing the flow sensor between portions of a housing. The method also includes attaching the inlet tubing to the housing extending distally from the inlet port of the flow sensor, the inlet tubing extending in a straight line at least 7 cm from the inlet port of the flow sensor. The method also includes securing a printed circuit board within the housing such that a connector of the PCB forms an electrical connection with electrical features of the flow sensor.

[0012] In some embodiments, an inner diameter of the inlet tubing is substantially the same as an inner diameter of the inlet port of the flow sensor. In some embodiments, the method further includes securing the inlet tubing to the housing using a distal clip at a distal end of the housing and a middle clip between the distal end of the housing and the inlet port of the flow sensor. In some embodiments, fluid flowing through the inlet tubing to the flow sensor experiences laminar flow at the inlet port of the flow sensor. In some embodiments, the method further includes electrically coupling an electrical cable to the printed circuit board, the electrical cable extending proximally from a proximal end of the housing. In some embodiments, the method further includes securing rubber rings around the flow sensor such that the housing is water resistant around the flow sensor.

[0013] For purposes of summarizing the disclosure, certain aspects, advantages and novel features have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, the disclosed embodiments may be carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Various embodiments are depicted in the accompanying drawings for illustrative purposes and should in no way be interpreted as limiting the scope of the claimed embodiments. In addition, various features of different disclosed embodiments can be combined to form additional embodiments, which are part of this disclosure. Throughout the drawings, reference numbers may be reused to indicate correspondence between reference elements. No inferences about dimensions should be made in view of the drawings as the drawings are not to scale. [0015] FIG. 1 illustrates a simplified diagram of a patient monitoring system that includes a flow probe device that senses a liquid flow rate (e.g., volume flow or mass flow) delivered to a patient.

[0016] FIG. 2 illustrates a diagram of an example flow probe device that can be inserted in-line into an IV line.

[0017] FIGS. 3 A and 3B illustrate schematic block diagrams of electrical components of example flow probe devices.

[0018] FIGS. 4A, 4B, 4C, and 4D provide various views of an example embodiment of a flow probe device.

[0019] FIG. 5 illustrates a middle portion of the housing of the flow probe device of FIGS. 4A-4D without the top portion to expose the enclosed portion.

[0020] FIGS. 6A and 6B illustrate the bottom portion of the housing of the flow probe device of FIGS. 4A-4D without the PCB installed (FIG. 6A) and with the PCB installed (FIG. 6B).

[0021] FIG. 7 illustrates an exploded view of the flow probe device of FIGS. 4A- 4D.

[0022] FIG. 8 illustrates an example flow sensor for use with the flow probe devices disclosed herein.

[0023] FIG. 9 illustrates a portion of a flow probe device with forces being applied to a top portion of an inlet tubing.

[0024] FIG. 10 illustrates a flow chart of an example method for manufacturing a flow probe device.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

[0025] The headings provided herein, if any, are for convenience only and do not necessarily affect the scope or meaning of the claimed embodiments.

Overview

[0026] A flow probe can be used to measure the fluid flow rate from a fluid source, like an intravenous (IV) fluid bag, to a patient. A flow probe can be in line between the fluid source and the patient. Positioning the flow probe in line between the fluid source and the patient can mean that the flow of fluids passes through the flow probe, that the flow probe is attached to the conduit carrying the fluid, or that the flow probe is positioned (at least partially) within the conduit carrying the fluid. This is to differentiate it between systems that measure fluid flow or fluid delivery using other means (e.g., other than using an in-line flow probe). These other means can include, for example, measuring changes in the weight of the fluid in the fluid source, measuring changes in the level of the fluid in the fluid source, measuring fluid at the patient end (e.g., fluid suctioned into a collection container), tracking movement of a piston or similar component in a pump, and the like. A flow probe can be configured to provide instantaneous measurements of the fluid flow rate by measuring fluid flow in the conduit. Measurements from a flow probe can be used to track fluid boluses to aid in the fluid management of the patient. Measurements from a flow probe can also be used to track maintenance fluid administrations which is fluid continuously administered at a relatively slow flow rate over a long period of time (e.g., as compared to fluid boluses).

[0027] Because measuring and monitoring fluid delivered to a patient can lead to improved patient outcomes, there is a need for a flow probe that can be easily and conveniently used with intravenous lines (or IVs). Accordingly, described herein are flow probe devices that can be inserted in-line in an IV line, the flow probe devices including inlet tubing that fluidly couples with an upstream IV line (e.g., from an IV fluid bag), outlet tubing that fluidly couples with a downstream IV line (e.g., to a patient), a flow sensor to measure flow rates and/or volumes of the fluid flowing through the inlet tubing, a housing to secure the inlet tubing to increase laminar flow and/or to reduce turbulent flow of the fluid at an inlet of the flow sensor, and electronics for the flow sensor and for communicating (e.g., wirelessly or using a cable) flow data to a patient monitor or other external device. The flow probe devices disclosed herein can be disposable devices.

[0028] The flow probe devices disclosed herein can be configured to provide an accurate recording of flow rate and fluid volume being administered to a patient in an IV line. The disclosed flow probe devices provide real-time measurements of fluid administered to a patient from an IV line. The disclosed devices can use a thermal mass flow rate sensor. The disclosed devices include a housing, inlet and outlet tubing, luer connectors for coupling to upstream and downstream IV lines, and electronics that interface with a monitoring system and that provide patient and operator safety.

[0029] Some embodiments of the disclosed flow probe devices orient a flow sensor in a vertical orientation. Inlet tubing and outlet tubing is driven over inlet and outlet barbs, respectively, of a flow sensor to direct fluid flowing through an IV line through the flow sensor. Luer fittings or connectors at the ends of the inlet tubing and the outlet tubing interface with upstream and downstream portions of the IV line. The housing of the device holds the flow sensor and tubing in a vertical line to improve or ensure sensor accuracy. This is accomplished due at least in part to the reduction in turbulent flow of the fluid upon entering the flow sensor. In certain implementations, the housing includes three pieces that hold the sensor in contact with a printed circuit board (PCB) and which provides electrical isolation and communication transfer. An elastomeric connector on the PCB provides an electrical connection between the flow sensor and the PCB. The housing can include an attachment feature to interface with devices or apparatuses that attach to an IV pole.

[0030] The disclosed flow probe devices can be used with an IV line that does not use a medical pump. Similarly, the disclosed flow probe devices can incorporate flow sensors that do not use a capacitive method of flow detection. The disclosed flow probe devices can use thermal mass technology in situations where the device is not attached to a pump with fluid line control. The disclosed flow probe devices can be used independently from a fluid delivery pump.

[0031] The disclosed flow probe devices can be used to track fluid delivery from a plurality of sources. For example, the disclosed flow probe devices can be used downstream of a Y-connector or other similar connector that combines fluids from different sources for delivery to a patient. In such embodiments, the flow probe devices can measure the fluid flow rate delivered to the patient wherein the fluid flow rate is a combination of flow rates from the individual fluid sources. In such instances, one or more of the fluid sources can be a pump such as a medical pump, infusion pump, or fluid delivery pump.

[0032] The following description illustrates some example embodiments in detail. Those of skill in the art will recognize that there are numerous variations and modifications of the present disclosure that are encompassed by its scope. Accordingly, the description of certain embodiments should not be deemed to limit the scope of the disclosure. In addition, the disclosed flow probe devices can be used in any suitable fluid monitoring system, such as the systems disclosed in U.S. Pat. Pub. No. 2018/0353680 published December 13, 2018 and entitled “ASSISTED FLUID DELIVERY SYSTEM AND METHOD,” which is incorporated by reference herein in its entirety and which forms part of this specification.

Example Flow Probe Devices

[0033] FIG. 1 illustrates a simplified diagram of a patient monitoring system that includes a flow probe device 100 that senses a liquid flow rate (e.g., volume flow or mass flow) delivered to a patient 50. Based at least in part on the sensed flow rate, the flow probe device 100 provides flow-related data that can be used to derive a volume of fluid being delivered. The fluid can be delivered from a fluid source 10 that can include an IV fluid bag, another in-line port, or a combination of the two. The system can include a monitor 30 that can receive the flow-related data from the flow probe device 100 and can display this information. In some embodiments, the monitor 30 can be configured to determine when a fluid bolus is being delivered based on flow rate data received from the flow probe device 100 and can differentiate this from fluid maintenance flow rates. A clinician can use this information to gain an understanding of the volume/mass of fluid the patient 50 has received. This system finds applicability in determining an amount of liquid delivered to the patient 50.

[0034] The system includes the fluid source 10 (e.g., an IV bag) with a fluid 12 to be delivered to the patient 50. The fluid source 10 is supported by an IV pole 20 that also supports the patient monitor 30 and a device attachment apparatus 40. Fluid 12 is delivered to the patient 50 through an upstream IV line 14 and a downstream IV line 16. Inserted between the upstream IV line 14 and the downstream IV line 16 is the flow probe device 100. The flow probe device 100 directs the fluid 12 through a flow sensor to measure fluid delivered to the patient 50. The data measured by the flow probe device 100 is sent to the monitor 30 through a cable 32. However, it should be understood that data may be communicated wirelessly to the monitor 30 in some embodiments.

[0035] The flow probe device 100 is configured to be easily attachable and detachable in-line into the IV line. The flow probe device 100 can include luer connectors or fittings or other suitable connectors to interface with the upstream IV line 14 and the downstream IV line 16. The flow probe device 100 can use an in-line thermal mass flow sensor to measure flow rate and/or fluid volume of the fluid delivered to the patient 50. In some embodiments, the flow sensor of the flow probe device 100 is shuntless in that all of the fluid flowing through the flow probe device 100 passes through the flow sensor. Such systems can be differentiated from systems that measure fluid flow or fluid delivery using other means such as by weight of the fluid in the fluid source, the level of fluid in the fluid source, a measure of fluid at the patient end (e.g., fluid suctioned into a collection container), movement of a piston or similar component in a pump, and the like. In addition, the flow probe device 100 can be configured to provide an instantaneous measurement of flow rate by measuring liquid flow through the flow probe device 100.

[0036] The cable 32 can be a reusable cable whereas the electrical cable of the flow probe device 100 can be disposable as an integral part of the device 100. In some embodiments, the flow probe device 100 does not include an electrical cable and is configured to provide wireless signals (e.g., near-field communication (NFC) or radio frequency identification (RFID) technologies may be used). In such embodiments, the attachment apparatus 40 can support a reader device that reads the wireless signals from the flow probe device 100 and the reader device connects wirelessly or with a cable to the monitor 30. In certain embodiments, the flow probe device 100 provides wireless signals directly to the monitor 30, e.g., using BLUETOOTH®, WiFi, or other suitable wireless communication protocols. In some embodiments, the attachment apparatus 40 can provide wireless power or wireless charging for a battery in the flow probe device 100. In certain embodiments, the flow probe device 100 does not include electrical cables. In such embodiments, data is communicated wirelessly, and an internal battery provides power to the flow probe device 100.

[0037] The flow probe data from the flow probe device 100 can be used to present flow-related data on the monitor 30 or another display. The flow-related data can be presented via numerical, textual, and/or pictorial information. Flow-related data can be displayed or presented along with hemodynamic data. The information presented can include a dynamic mass flow rate and/or a mass flow rate history. The information presented can also include one or more recommendations as to fluid administration protocols. In some embodiments, the monitor 30 provides a user interface to allow a user to adjust characteristics of the flow probe device 100. In some embodiments, the monitor 30 provides a user interface that provides diagnostic data, calibration data, status information, or other information related to the flow probe device 100.

[0038] Embodiments of the flow probe device 100 can provide dynamic, continuous, intermittent, or on-demand flow rate data in the form of analog or digital signals for use by the monitor 30 or a healthcare provider. In some embodiments, the flow probe device 100 can be cooperatively engaged with a flow controller and controlled by an algorithm. For example, the flow probe device 100 and a flow controller can be used in an open-loop or closed-loop feedback system to control liquid flow based at least in part on measured flow-related data from the flow probe device 100.

[0039] In some embodiments, the system also includes one or more physiological sensors that provide physiological data to the monitor 30. The physiological sensors can include a hemodynamic sensor, for example. The hemodynamic sensor can be the FLOTRAC® sensor, in certain implementations. The physiological sensor can be configured to provide information capable of being transformed into one or more forms of heart output data. In some embodiments, an oximetry device can be used as part of the physiological sensor. In certain embodiments, the oximetry device can be a finger cuff device that is integrated with the system, system electronics, and/or the monitor 30. The system can utilize the physiological data in an algorithm to determine how the patient 50 responds to administered fluid volumes. Based on the correlated sensed data from the flow probe device 100 and the data from the physiological sensor, the algorithm can determine the response of the patient 50, provide information (e.g., a recommendation) to the clinician regarding subsequent bolus administration, and/or control the amount and rate of volume of fluid delivered to the patient 50, e.g., using a flow controller.

[0040] FIG. 2 illustrates a diagram of an example flow probe device 200 that can be inserted in-line into an IV line. The flow probe device 200 includes a housing 210, tubing 220, electrical connection 230, and a flow sensor 240. The flow probe device 200 can be configured to be disposable.

[0041] The housing 210 includes an open portion 212 that allows fluid flowing through inlet tubing 224 to be observed by an operator, e.g., a clinician, and an enclosed portion 214 that houses the flow sensor 240. Although the flow sensor 240 is shown here, it is to be understood that the housing can cover and protect the flow sensor 240 in the enclosed portion 214.

[0042] The housing 210 is configured to support a length of inlet tubing 224 upstream of the flow sensor 240. The housing 210 ensures straightness of the inlet tubing 224 over a prescribed or desired distance to achieve targeted flow characteristics of the fluid entering the flow sensor 240. In some embodiments, the length of inlet tubing 224 that is supported in a substantially straight configuration is at least about 5 cm, at least about 7 cm, at least about 10 cm, or at least about 15 cm. The targeted flow characteristics include substantially laminar flow and/or substantial elimination of turbulent flow upon entering the flow sensor 240.

[0043] The inlet tubing 224 can be configured so that an inner diameter substantially matches an inner diameter of a conduit through the flow sensor 240, or an inlet conduit 242 of the flow sensor 240. Matching the inner diameter of the inlet tubing 224 to the inner diameter of the sensor inlet 242 can increase measurement accuracy along with the straightness of the inlet tubing 224 immediately upstream of the sensor inlet 242. The increase in accuracy may be due at least in part to increasing laminar flow and/or reducing turbulence over the length of the straight portion of the inlet tubing 224. The increase in accuracy may also be due at least in part to reducing the introduction of turbulence into the flow caused by mismatched inner diameters at the transition between the inlet tubing 224 and the sensor inlet 242. [0044] A portion of the inlet tubing 224 extends above the housing 210 to facilitate connection with an upstream portion of an IV line using a connector 222. In some embodiments, the length of inlet tubing 224 unsupported above the housing 210 is less than or equal to about 5 cm or greater than or equal to about 1 cm and/or less than or equal to about 4 cm.

[0045] The flow probe device 200 also includes outlet tubing 226 that couples to a sensor outlet 244. The outlet tubing 226 includes a connector 228 to interface with a downstream IV line to deliver the fluid to a patient.

[0046] The flow probe device 200 also includes an electrical cable 230 to receive power and to communicate data. The electrical cable 230 can include an electrical connector 232 to interface with a compatible electrical connector of a reusable cable that may be connected to an external device such as a patient monitor, for example.

[0047] The flow sensor 240 can be any suitable flow sensor such as a thermal mass flow sensor. Thermal mass flow probes or sensors typically determine a flow rate of a fluid or liquid by measuring thermal characteristics of the fluid and sensor. The thermal characteristics, such as temperature and heat, are related to the flow rate of the fluid. Thus, by measuring a temperature profile of a flowing fluid or tracking an amount of heat applied to a heater a flow probe can determine an estimate of the fluid flow rate. Thermal mass flow probes can be calorimetric flow probes or hot-wire flow probes, for example. The flow sensor 240 may also be a thermal mass flow probe that combines calorimetric and anemometric (e.g., hot-wire) elements to provide a hybrid approach to determining flow rate of a liquid. The flow sensor 240 can be shuntless (e.g., there is no secondary passageway or lumen for a portion of the liquid to flow through for measurement purposes). In such embodiments, the entire volume of liquid to be measured flows through a single, continuous passage for the length of the flow sensor. In some embodiments, the flow sensor can use technology similar to that described in U.S. Pat. No. 6,813,944, which is incorporated by reference herein in its entirety.

[0048] The flow probe device 200 can be configured to achieve a targeted accuracy in fluid-related measurements such as flow rate and/or fluid volume. In some embodiments, the targeted accuracy is about ±20%, about ±10%, or about ±5%. The flow probe device 200 can be configured to achieve the targeted accuracy with flow rates in a range from at least about 0 mL/min (e.g., no flow) and/or less than or equal to about 180 mL/min, at least about 5 mL/min and/or less than or equal to about 170 mL/min, at least about 10 mL/min and/or less than or equal to about 100 mL/min, or at least about 15 mL/min and/or less than or equal to about 70 mL/min. The flow probe device 200 can be configured to achieve the targeted accuracy with fluid temperatures that range from at least about 5°C and/or less than or equal to about 50°C, at least about 15°C and/or less than or equal to about 45°C, at least about 20°C and/or less than or equal to about 40°C, or at least about 22°C and/or less than or equal to about 38°C. The flow probe device 200 can be configured to function with crystalloid and colloid fluids (e.g., plasmalyte, lactated ringers, sodium chloride 0.9%, albumin 5%, Dextran 40, hetastarch/hydroxyethyl starch 6%, etc.).

[0049] The targeted accuracy can be achieved through various aspects of the flow probe device 200. For example, the straightness of the inlet tubing 224 contributes to the accuracy. In some embodiments, the inlet tubing 224 is supported in a substantially straight line by the housing 210 for at least 5 cm, at least 7 cm, at least 10 cm, for at least 15 cm, or at least 1 mm per 1 mL/min of fluid flow. The durometer of the inlet tubing 224 may also contribute to achieving the targeted accuracy. The inlet tubing 224 can be sufficiently hard to resist deformation while also being sufficiently compliant to conform to the sensor inlet 242. This also may contribute to measurement accuracy by substantially matching inner diameters of the inlet tubing 224 and the sensor inlet 242 to reduce fluid turbulence upon entering the flow sensor 240. These elements can contribute to measurement accuracy by increasing laminar flow at the sensor inlet 242.

[0050] The flow probe device 200 is configured to function with standard IV lines and within standard clinical workflows. The measurements acquired by the flow probe device 200 can be displayed so a clinician or other operator can tailor treatment protocols based on these measurements in conjunction with patient physiological data (e.g., cardiac output). The flow probe device 200 is configured to expose the inlet tubing 224 for fluid line visibility. In some embodiments, the flow probe device 200 is also configured to measure the temperature of the fluid flowing through the device 200. The flow probe device 200 can be used with patient monitoring systems, such as the example systems described in U.S. Patent Application Publication No. 2018/0353680 published December 13, 2018 and entitled “ASSISTED FLUID DELIVERY SYSTEM AND METHOD,” which is incorporated by reference herein in its entirety.

[0051] FIGS. 3 A and 3B illustrate schematic block diagrams of electrical components of example flow probe devices 300a, 300b. The flow probe device 300a can be any of the flow probes described herein and can include a flow sensor 340, similar to the flow sensor 240 described herein with reference to FIG. 2. The flow sensor 340 is electrically coupled to a printed circuit board (PCB) 350a through a connector 352. The connector 352 can be an elastomeric connector that is pressed into contact with the flow sensor 340 by a housing of the device 300a. The PCB 350a is also electrically coupled to an external device 380, such as a patient monitor.

[0052] The flow sensor 340 receives power from the PCB 350a and provides electrical signals indicative of measurements of flow rate and/or fluid volume to the PCB 350a through the connector 352. Power can be received from the monitor 380 through the monitor cable 382, the power being delivered to the PCB through the electrical cable 330. Similarly, data from the flow sensor 340 can be provided to the monitor 380 through the PCB 350a via the electrical cable 330.

[0053] The PCB 350a can be configured to provide isolation to improve patient and operator safety. The PCB 350a can include electrical components specifically configured to operate with the flow sensor 340. In some embodiments, the connector 352 is not a spring- loaded connector. In some embodiments, the monitor cable 382 is a reusable cable that includes a USB microcontroller and/or an I2C microcontroller so that a USB signal is used to communicate with the monitor 380 and an I2C signal is used to communicate with the PCB 350a.

[0054] The PCB 350a includes electronics that may include a flow sensor controller, one or more temperature sensors, a power supply (e.g., a battery), wireless and/or wired communication systems and ports, one or more data stores to store measurement data, calibration data, algorithms, computer-executable instructions, and the like.

[0055] The flow probe device 300b of FIG. 3B removes the cable 330 and instead includes an antenna 331 coupled to a PCB 350b to provide wireless communication to the monitor 380 that includes a complementary antenna 381 for wireless communication. It is to be understood, however, that the disclosed flow probe devices can include electrical cables and wireless communication components to provide wired communication, wireless communication, and both wired and wireless communication. In some embodiments, the flow probe device 300b includes a battery to provide power to the PCB 350b.

Example Embodiment of a Flow Probe Device

[0056] FIGS. 4A, 4B, 4C, and 4D provide various views of an example embodiment of a flow probe device 400. FIG. 4A illustrates an elevated perspective view of the flow probe device 400, FIG. 4B illustrates a front view of the flow probe device 400,

FIG. 4C illustrates a side view of the flow probe device 400, and FIG. 4D illustrates a back view of the flow probe device 400. [0057] The flow probe device 400 includes housing 410 comprising a bottom portion 410a, a middle portion 410b, and a top portion 410c that are secured together to form the housing. In some embodiments, each portion 410a, 410b, 410c are snap-fit together. Each portion 410a, 410b, 410c can be injection-molded plastic. The housing 410 forms an open portion 412 and an enclosed portion 414. The open portion 412 exposes an inlet tubing 424 and the enclosed portion 414 houses the flow sensor 440 (described in greater detail herein with reference to in FIG. 5). The open portion 412 allows the inlet tubing 424 to be viewed and the liquid flowing through the inlet tubing 424 to be viewed. The enclosed portion 414 ensures the inlet tubing 424 interfaces with the sensor 440 in a singular axial pathway. In some embodiments, the enclosed portion 414 is configured to not be readily removed to prevent a user interacting or coming into contact with the sensor 440 or other component within the enclosed portion 414.

[0058] The housing 410 can be about 16 cm in length from a top portion to a bottom portion, at least about 8 cm in length and/or less than or equal to about 25 cm in length, or at least about 10 cm in length and/or less than or equal to about 20 cm in length. The top of the inlet tubing 424 and the bottom of the outlet tubing 426 can extend above and below, respectively, the housing 410 thereby increasing the total length of the flow probe device 400. In some embodiments, the top of the inlet tubing 424 can extend at least about 1 cm above the housing 410 and/or less than or equal to about 5 cm above the housing 410 or at least about 2 cm above the housing 410 and/or less than or equal to about 4 cm above the housing 410.

[0059] The housing 410 includes a top clip 411 and a middle clip 413 that together help to secure the inlet tubing 424 in place. The clips 411, 413 help to prevent the inlet tubing 424 from bowing due to forces applied to a top portion of the inlet tubing 424 (e.g., at an inlet connector 422). In addition, the housing 410 may form a trench 429 in which the inlet tubing 424 is secured. The clips 411, 413 are configured to make removal of the inlet tubing 424 difficult and insertion of the inlet tubing 424 easy. The clips 411, 413 can include a through-hole design for molding undercut clips. In some embodiments, the flow probe device 400 can include one or more additional clips (not shown) such as near a distal end to aid in securing the bottom portion 410a to the middle portion 410b. The trench 429 can be a circular slot that extends along the length of the open portion 412. The circular slot can aid in making the fluid path visible to a user.

[0060] The clips 411, 413 and/or the trench 429 formed on the housing 410 cause the inlet tubing 424 to be substantially straight over a targeted distance to increase or improve accuracy of the flow-related measurements. The improved accuracy is due at least in part to the increase in laminar flow at an inlet of the flow sensor 440. In some embodiments, the distance from the top clip 411 to the inlet of the sensor is at least 5 cm, at least 7 cm, at least 10 cm, at least 13 cm, at least 15 cm, or at least 1 mm per 1 mL/min of a maximum or expected high flow rate. As described herein, the straightness of the inlet tubing 424 contributes to achieving the targeted accuracy of the flow-related measurements, wherein the targeted accuracy is at least better than about ±20%, at least better than about ±10%, or at least better than about ±5%.

[0061] The housing 410 can include color that can be used to transmit meaning and/or functionality of the flow prove device 400 in critical care. The housing 410 can be configured so that an LED 451 on the PCB 450 can shine through the housing 410 (e.g., through the material of the housing 410, through a window formed by the housing 410, or the housing can include a hole to expose the LED 451) to indicate when the flow probe device 400 is receiving power, in error, acquiring data, transmitting data, etc. In some embodiments, the color of the housing 410 can indicate that the flow probe device 400 is a fluid usage device. In certain implementations, the color of the housing 410 can be incorporated into a GUI on a connected monitor.

[0062] The housing 410 can be configured to be thinner at the top to allow fingers to move behind the flow probe device 400 when attaching it to a device attachment apparatus (e.g., the apparatus 40 described herein with reference to FIG. 1). The housing 410 forms an attachment feature 416 that is configured to mate with a corresponding feature on a device attachment apparatus. In some embodiments, the attachment feature 416 is configured to prevent the flow probe device 400 from being installed upside down.

[0063] The inlet tubing 424 and the outlet tubing 426 can be configured to be sufficiently rigid so that it has a tensile strength sufficient to withstand liquid pressures expected to be used in the fluid delivery system. The outlet tubing 426 can include a connector 428 such as a rotating male luer connector. The rotating male luer connector may be advantageous because it allows the flow probe device 400 to be secured in place when securing a downstream portion of the IV line to the outlet tubing 426 (e.g., the flow probe device 400 does not need to be rotated to make the connection between the outlet tubing 426 and the downstream IV line). The inlet tubing 424 includes a connector 422 to fluidly couple to an upstream IV line. The connector 422 can be a female luer connector or a male luer connector. Other connectors may be used as well and may be selected based on expected connectors available on the upstream and downstream IV lines. [0064] In some embodiments, the tubing 420 includes a flow control component (not shown) such as a pinch valve or stop cock at the top of the flow probe device 400. This allows an operator to stop the flow of fluid using the flow probe device 400.

[0065] The flow probe device 400 includes an electrical cable 430 with an electrical connector 432 at an end of the cable 430. The electrical cable 430 provides electrical connection to a monitoring system or other external device or system. In some embodiments, the flow probe device 400 includes wireless communication capabilities in addition to or instead of the electrical cable 430. In some embodiments, the electrical cable 430 can be about 12 in. in length. In some embodiments, the electrical cable 430 can be configured to withstand a pull force of about 20 lb. The electrical cable 430 extends from the bottom of the flow probe device 430. This configuration may be advantageous because it reduces exposure of the cable 430 to the IV fluid. The electrical cable 430 (and the PCB 450) can be rated for communication speeds on one or more channels of at least about 4 MHz and/or about 2 Mbps. The electrical cable 430 (and the PCB 450) can be configured to communicate via differential transmission and/or to receive RS-485 signal pairs.

[0066] FIG. 5 illustrates a middle portion 410b of the housing 410 without the top portion 410c to expose the enclosed portion 414. The middle portion 410b forms a cradle 415 to hold and to secure the flow sensor 440 in place, in a correct or desired orientation. The cradle 415 is configured to conform to the sensor 440. In some embodiments, the cradle 415 and the sensor 440 are asymmetrical to ensure that the sensor 440 can be installed in a single orientation. The sensor 440 can include indicator arrows 441 to illustrate the correct direction of fluid flow through the sensor. Although not shown in FIG. 5, the top portion 410c includes a corresponding cradle to mate with the sensor 440 so that when the top portion 410c is secured to the middle portion 410b, the sensor 440 is substantially secured in place in a correct orientation.

[0067] The middle portion 410b includes channels 417a that are configured to receive rubber rings to provide water resistance for the flow probe device 400. Water resistance of the flow probe device 400 is beneficial for patient safety and useful in critical care implementations because it contains the IV solution (e.g., saline) within the flow probe device 400, shielding the electronics from the solution. The channels 417a can receive O- rings to prevent electrical connections from contacting the IV fluid. The compression force between the top portion 410c and the middle portion 410b compress the O-rings to contribute to the water resistance of the flow probe device 400. [0068] The sensor 440 can be a thermal mass flow sensor, as described elsewhere herein. The sensor 440 can include an inlet 442 and an outlet 444. The inlet tubing 424 can be configured to be pushed over the inlet 442 to form a fluid inlet channel to the sensor 440. Similarly, the outlet tubing 426 can be configured to be pushed over the outlet 444 to form a fluid outlet channel from the sensor 440.

[0069] FIGS. 6 A and 6B illustrate the bottom portion 410a of the housing 410 without the PCB 450 installed (FIG. 6A) and with the PCB 450 installed (FIG. 6B). The bottom portion 410a of the housing forms mounting cylinders 418 for the PCB 450. The bottom portion 410a forms cable strain relief features 419 to support the electrical cable 430 that extends from the PCB 450 out of the flow probe device 400. The bottom portion 410a forms channels 417b that are configured to receive rubber rings to provide water resistance for the flow probe device 400. The compression force between the bottom portion 410a and the middle portion 410b compress the O-rings to contribute to the water resistance of the flow probe device 400.

[0070] In some embodiments, the electrical cable 430 can be a molded DPT cable. In some embodiments, the PCB 450 provides wireless communication capabilities and can include or not include the electrical cable 430. In some embodiments, the PCB 450 includes NFC and/or RFID technology to provide power to the flow probe device 400. In some embodiments, the PCB 450 uses wireless technology to receive power and to transmit and receive data.

[0071] The PCB 450 includes a connector 452 configured to electrically couple the PCB 450 to the sensor 440. The connector 452 can be an elastomer connector that includes conductive and non-conductive layers sandwiched together. When the bottom portion 410a is secured to the middle portion 410b, the compressive forces ensure a stable electrical connection between the sensor 440 and the PCB 450 via the connector 452. In some embodiments, the connector 452 does not include spring-loaded pins.

[0072] The PCB 450 includes isolation circuitry. The circuitry of the PCB 450 includes the circuitry to power and to control the sensor 440. The circuitry is part of the disposable flow probe device 400 so that the circuitry for controlling the flow sensor 440 can be part of a disposable device. In some embodiments, the isolation circuitry provides an isolation barrier from patient monitor drive circuitry to the flow sensor 440. In certain implementations, the isolation circuitry is rated for > 2 MOPP (or means of patient protection). [0073] FIG. 7 illustrates an exploded view of the flow probe device 400. The exploded view illustrates that the sensor 440 is sandwiched between the top portion 410c and the middle portion 410b of the housing 410 wherein the middle portion 410b and the top portion 410c include extruded features that conform to the sensor 440, the inlet tubing 424, and outlet tubing 426. The middle portion 410b also includes a trench 429 with clips 411, 413 to secure the inlet tubing 424 in a substantially straight line from the sensor inlet 442 to the top clip 411 of the housing 410. The exploded view also illustrates that the PCB 450 is sandwiched between the bottom portion 410a and the middle portion 410b of the housing 410 wherein the middle portion 410b and the bottom portion 410a include extruded features that conform to the PCB 450. In addition, the compression between the middle portion 410b and the bottom portion 410a ensure a secure electrical connection between the sensor 440 and the PCB 450 via the connector 452. The electrical connection to the PCB 450 is provided through electrical contacts on the PCB 450 and exposed electrical pads on the sensor 440, for example. The electrical connection is maintained through pressure of the top portion 410c of the housing 410 on the sensor 440 and the bottom portion 410a of the housing 410 on the PCB 450, wherein inward compression forces maintain electrical connection between the connector 452 and the sensor 440 and prevent relative movement of the components.

[0074] The bottom portion 410a also includes supports to prevent or reduce PCB deflection, to provide cable strain relief, and to provide channels for rubber rings to provide water resistance. The middle portion 410b also includes supports to protect and to secure the sensor 440, to provide strain relief to the inlet tubing 424 and to the outlet tubing 426, and to provide channels for rubber rings to provide water resistance, as described elsewhere herein.

[0075] FIG. 8 illustrates an example flow sensor 840 for use with the flow probe devices disclosed herein. The flow sensor 840 includes an inlet barb 842 and an outlet barb 844. To fluidly couple the flow sensor 840 to a flow probe device, an inlet tubing 824 is driven over the inlet barb 842 and an outlet tubing 826 is driven over the outlet barb 844. The inlet tubing 824 and the outlet tubing 826 can be sufficiently compliant to be driven over the sensor barbs. Moreover, inlet tubing 824 and the outlet tubing 826 can be sufficiently rigid to stay attached to the inlet barb 842 and to the outlet barb 844.

[0076] The inner diameter, ID, of the inlet tubing 824 can be configured to substantially match the size of the inlet barb 842 to increase flow sensor 840 accuracy. Accuracy is increased due at least in part to the reduction of turbulent flow and/or the increase of laminar flow at the inlet barb 842. By matching inner diameters, continuity of the fluid path is maintained thereby reducing the introduction of turbulent flow into the system. This in turn reduces fluctuations and inaccuracies in the measurements acquired by the flow sensor 840.

[0077] FIG. 9 illustrates a portion of a flow probe device 900 with forces being applied to a top portion of an inlet tubing 924. The flow probe device 900 is similar to the flow probe devices disclosed herein. The top clip 911 is configured to secure a top portion of the inlet tubing 924 to the housing 910. When a downward or horizontal force is applied to a top portion of the inlet tubing 924 (e.g., the portion extending beyond the housing 910), a middle part of the inlet tubing 924 tends to bow away from the housing 910. This reduces the straightness of the inlet tubing, thereby adversely affecting the accuracy of the flow-related measurements acquired by a flow sensor of the flow probe device 900. Accordingly, to reduce or to prevent this bowing, a middle clip 913 is included on the housing 910 to resist this bowing and to maintain the straightness of the inlet tubing 924. The top clip 911 and the middle clip 913 are included to maintain straightness of the inlet tubing 924 while providing visibility of the inlet tubing 924 to allow observation of fluid flow through the inlet tubing 924. One or more clips may also be included to increase the number of attachment points of the inlet tubing 924 to the housing 910 to reduce or to prevent bowing when a protruding portion of the inlet tubing 924 experiences downward and horizontal forces. In some embodiments, the middle clip 913 is between about 4 cm and about 7 cm from the top clip 911. A trench 929 may also be included to aid in maintaining straightness of the inlet tubing 924.

Example Methods of Manufacturing a Flow Probe Device

[0078] FIG. 10 illustrates a flow chart of an example method 1000 for manufacturing a flow probe device. The method 1000 can be used to manufacture any of the flow probe devices described herein with reference to FIGS. 1-9.

[0079] In block 1005, inlet tubing and outlet tubing are coupled to an inlet port and an outlet port of a flow sensor, respectively. The inner diameter of the inlet tubing can be configured to substantially match an inner diameter of the inlet port of the flow sensor to reduce turbulent flow of a fluid entering the flow sensor and/or to increase laminar flow of the fluid entering the flow sensor.

[0080] In block 1010, the flow sensor with attached inlet and outlet tubing is secured between portions of a housing of the flow probe device. The portions of the housing can include extruded portions conforming to the flow sensor with the attached inlet and outlet tubing to secure the flow sensor in a desired orientation and location. The compression between portions of the housing can be configured to secure the flow sensor in place.

[0081] In block 1015, the inlet tubing is attached to the housing extending upwards from the inlet port of the flow sensor. The inlet tubing is attached in such a way as to provide a substantially straight path over a desired distance prior to the inlet port of the flow sensor. In some embodiments, the desired distance is at least 5 cm, at least 7 cm, at least 10 cm, at least 15 cm, or at least 1 mm per 1 mL/min of flow rate. The housing can include two or more clips or a trench with features to secure the inlet tubing within the trench. In some embodiments, the inlet tubing can be adhered to the trench without the use of clips.

[0082] In block 1020, the PCB is secured between portions of the housing. The compressive forces between the portions of the housing can ensure a secure electrical connection between the PCB and the flow sensor via an electrical connector of the PCB and electrical pads of the flow sensor. In some embodiments, the electrical connector of the PCB is an elastomeric connector.

Additional Embodiments and Terminology

[0083] The terms “subject” and “patient” are used interchangeably herein and relate to mammals, inclusive of warm-blooded animals (domesticated and non-domesticated animals), and humans. The terms “clinician” and “healthcare provider” are used interchangeably herein.

[0084] The term “sensor” as used herein relates to a device, component, or region of a device capable of detecting and/or quantifying and/or qualifying a physiological parameter of a subject. The phrase “system” as used herein relates to a device, or combination of devices operating at least in part in a cooperative manner, that is inclusive of the “sensor.” Sensors generally include those that continually measure the physiological parameter without user initiation and/or interaction (“continuous sensing device” or “continuous sensor”). Continuous sensors include devices and monitoring processes wherein data gaps can and/or do exist, for example, when a continuous pressure sensor is temporarily not providing data, monitoring, or detecting. Sensors also generally include those that intermittently measure the physiological parameter with or without user initiation and/or interaction (“intermittent sensing device” or “intermittent sensor”). In some embodiments, sensors, continuous sensing devices, and/or intermittent sensing devices relate to devices, components, or regions of devices capable of detecting and/or quantifying and/or qualifying a physiological hemodynamic parameter of a subject. [0085] The phrases “physiological data,” “physiological parameter,” and/or “hemodynamic parameter” include without limitation, parameters directly or indirectly related to providing or calculating blood pressure (BP), stroke volume (SV), cardiac output (CO), end-diastolic volume, ejection fraction, stroke volume variation (SVV), pulse pressure variation (PPV), systolic pressure variations (SPV), extravascular lung water index (ELWI), pulmonary vascular permeability index (PVPI), global end-diastolic index (GEDI), global ejection fraction (GEF), systolic volume index (SVI), arterial blood pressure (ABP), cardiac index (Cl), systemic vascular resistance index (SVRI), peripheral resistance (PR), central venous saturation (Scv02), and plethysmographic variability index (PVI). Hemodynamic parameters are inclusive of the absolute value of such parameters, a percentage change or variation in the parameters since an event was recorded, and an absolute percentage change within a previous time segment.

[0086] The phrases “electronic connection,” “electrical connection,” “electrical contact” as used herein relate to any connection between two electrical conductors known to those in the art. In some embodiments, electrodes are in electrical connection with (e.g., electrically connected to) the electronic circuitry of a device.

[0087] The term and phrase “electronics” and “system electronics” as used herein relate to electronics operatively coupled to the sensor and configured to measure, process, receive, and/or transmit data associated with a sensor, and/or electronics configured to communicate with a monitor or a data acquisition device.

[0088] The phrases “operatively connected,” “operatively linked,” “operably connected,” and “operably linked” as used herein relate to one or more components linked to one or more other components, such that a function is enabled. The terms can refer to a mechanical connection, an electrical connection, or any connection that allows transmission of signals between the components. For example, one or more transducers can be used to detect pressure and to convert that information into a signal; the signal can then be transmitted to a circuit. In such an example, the transducer is “operably linked” to the electronic circuitry. The terms “operatively connected,” “operatively linked,” “operably connected,” and “operably linked” include wired and wireless connections.

[0089] The term and phrase “controller,” “processor” or “processing module,” as used herein relates to components and the like designed to perform arithmetic or logic operations using logic circuitry that responds to and processes basic instructions, for example, instructions that drive a computer and/or perform calculations of numbers or their representation (e.g., binary numbers). [0090] The terms “substantial” and “substantially” as used herein relate to a sufficient amount that provides a desired function. For example, an amount greater than 50 percent, an amount greater than 60 percent, an amount greater than 70 percent, an amount greater than 80 percent, or an amount greater than 90 percent.

[0091] Although certain preferred embodiments and examples are disclosed below, inventive subject matter extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses and to modifications and equivalents thereof. Thus, the scope of the claims that may arise herefrom is not limited by any of the particular embodiments described herein. For example, in any method or process disclosed herein, the acts or operations of the method or process may be performed in any suitable sequence and are not necessarily limited to any particular disclosed sequence. Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding certain embodiments; however, the order of description should not be construed to imply that these operations are order dependent. Additionally, the structures, systems, and/or devices described herein may be embodied as integrated components or as separate components. For purposes of comparing various embodiments, certain aspects and advantages of these embodiments are described. Not necessarily all such aspects or advantages are achieved by any particular embodiment. Thus, for example, various embodiments may be carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other aspects or advantages as may also be taught or suggested herein.

[0092] Conditional language used herein, such as, among others, “can,” “could,” “might,” “may,” “e.g.,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is intended in its ordinary sense and is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more embodiments. The terms “comprising,” “including,” “having,” “characterized by,” and the like are synonymous, are used in their ordinary sense, and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list. Conjunctive language such as the phrase “at least one of X, Y and Z,” unless specifically stated otherwise, is understood with the context as used in general to convey that an item, term, element, etc. may be either X, Y or Z. Thus, such conjunctive language is not generally intended to imply that certain embodiments require at least one of X, at least one of Y and at least one of Z to each be present.

[0093] Reference throughout this specification to “certain embodiments” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least some embodiments. Thus, appearances of the phrases “in some embodiments” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment and may refer to one or more of the same or different embodiments. Furthermore, the particular features, structures or characteristics can be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0094] It should be appreciated that in the above description of embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim require more features than are expressly recited in that claim. Moreover, any components, features, or steps illustrated and/or described in a particular embodiment herein can be applied to or used with any other embodiment(s). Further, no component, feature, step, or group of components, features, or steps are necessary or indispensable for each embodiment. Thus, it is intended that the scope of the inventions herein disclosed and claimed below should not be limited by the particular embodiments described above but should be determined only by a fair reading of the claims that follow.

[0095] The present disclosure describes various features, no single one of which is solely responsible for the benefits described herein. It will be understood that various features described herein may be combined, modified, or omitted, as would be apparent to one of ordinary skill. Other combinations and sub-combinations than those specifically described herein will be apparent to one of ordinary skill and are intended to form a part of this disclosure. Various methods are described herein in connection with various flowchart steps and/or phases. It will be understood that in many cases, certain steps and/or phases may be combined together such that multiple steps and/or phases shown in the flowcharts can be performed as a single step and/or phase. Also, certain steps and/or phases can be broken into additional sub-components to be performed separately. In some instances, the order of the steps and/or phases can be rearranged, and certain steps and/or phases may be omitted entirely. Also, the methods described herein are to be understood to be open-ended, such that additional steps and/or phases to those shown and described herein can also be performed.

[0096] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” 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. 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. 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. The word “exemplary” is used exclusively herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations.

[0097] The disclosure is not intended to be limited to the implementations shown herein. Various modifications to the implementations described in this disclosure may be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. The teachings of the invention provided herein can be applied to other methods and systems and are not limited to the methods and systems described above, and elements and acts of the various embodiments described above can be combined to provide further embodiments. Accordingly, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure.

Claims

WHAT IS CLAIMED IS:

1. A flow probe device comprising: a housing forming an open portion and an enclosed portion; a flow sensor housed within the enclosed portion of the housing and configured to measure flow-related data of a fluid flowing through the flow sensor, the flow sensor including an inlet port and an outlet port; inlet tubing having a proximal end fluidly coupled to the inlet port of the flow sensor and a distal end extending beyond a distal portion of the housing, the inlet tubing secured to the open portion of the housing such that the inlet tubing is straight over a distance of at least 7 cm distally from the inlet port of the flow sensor; outlet tubing having a distal end fluidly coupled to the outlet port of the flow sensor and a proximal end extending beyond a proximal portion of the housing; and a printed circuit board enclosed within the housing and having an electrical connector configured to electrically couple the flow sensor to the printed circuit board.

2. The device of claim 1, wherein an inner diameter of the inlet tubing is substantially the same as an inner diameter of the inlet port of the flow sensor.

3. The device of any of claims 1-2, wherein fluid flowing through the inlet tubing to the flow sensor experiences laminar flow at the inlet port of the flow sensor.

4. The device of any of claims 1-3, wherein the flow-related data has an accuracy better than ±20%.

5. The device of any of claims 1-4 further comprising an electrical cable coupled to the printed circuit board and extending proximally from a proximal end of the housing.

6. The device of any of claims 1-5, wherein the printed circuity board is configured to provide wireless communication of the flow-related data measured by the flow sensor.

7. The device of any of claims 1-6, wherein the housing includes a distal clip at a distal end of the open portion of the housing and a middle clip between the distal clip and a distal end of the enclose portion, the distal clip and the middle clip configured to secure the inlet tubing in a straight line to the open portion of the housing.

8. The device of claim 7, wherein the housing further forms a trench to secure the inlet tubing in a straight line to the open portion of the housing.

9. The device of any of claims 1-8, wherein the housing includes a cradle conforming to the flow sensor to maintain the flow sensor in a desired position and orientation.

10. The device of claim 9, wherein the housing includes a rubber ring around the cradle to provide water protection.

11. The device of any of claims 1-10, wherein the inlet tubing further includes a connector at a distal end of the inlet tubing.

12. The device of any of claims 1-11, wherein the outlet tubing further includes a connector at a proximal end of the outlet tubing.

13. The device of claim 12, wherein the connector includes a rotating male luer connector.

14. The device of any of claims 1-13, wherein the housing forms an attachment feature configured to mate with a device attachment apparatus.

15. The device of any of claims 1-14, wherein the housing comprises a bottom portion, a middle portion, and a top portion.

16. The device of claim 15, wherein the flow sensor is between the top portion and the middle portion of the housing.

17. The device of any of claims 15-16, wherein the printed circuit board is between the bottom portion and the middle portion.

18. The device of any of claims 15-17, wherein a compression force between the middle portion and the bottom portion ensure electrical connection between the flow sensor and the printed circuit board.

19. A method of manufacturing a flow probe device, the method comprising: coupling inlet tubing to an inlet port of a flow sensor; coupling outlet tubing to an outlet port of the flow sensor; securing the flow sensor between portions of a housing; attaching the inlet tubing to the housing extending distally from the inlet port of the flow sensor, the inlet tubing extending in a straight line at least 7 cm from the inlet port of the flow sensor; and securing a printed circuit board within the housing such that a connector of the PCB forms an electrical connection with electrical features of the flow sensor.

20. The method of claim 19, wherein an inner diameter of the inlet tubing is substantially the same as an inner diameter of the inlet port of the flow sensor.

21. The method of any of claims 19-20 further comprising securing the inlet tubing to the housing using a distal clip at a distal end of the housing and a middle clip between the distal end of the housing and the inlet port of the flow sensor.

22. The method of any of claims 19-21, wherein fluid flowing through the inlet tubing to the flow sensor experiences laminar flow at the inlet port of the flow sensor.

23. The method of any of claims 19-22 further comprising electrically coupling an electrical cable to the printed circuit board, the electrical cable extending proximally from a proximal end of the housing.

24. The method of any of claims 19-23 further comprising securing rubber rings around the flow sensor such that the housing is water resistant around the flow sensor.