Patent Application
20250224082
Cryogenic storage devices have a variety of applications. For example, such storage devices may be used to store biological samples used in testing. Such storage devices often use liquid nitrogen to maintain low temperatures.
Cryogenic storage devices often include both a storage container and a supply of cryogenic fluid. The supply of cryogenic fluid may be fluidically connected to the storage container and may supply cryogenic fluid to the storage container to maintain a desired liquid fill level that may be needed to maintain low temperatures within the storage container.
Typical approaches may use a differential pressure within the storage container to determine an approximate liquid fill level within the storage container. However, this arrangement has drawbacks. For example, such a differential pressure measurement system may become clogged during normal operation of the storage container, for example due to condensation which may form due to introduction of moisture when the container is opened and closed. Such a clogging event may result in incorrect fill level measurements, or may fail to identify when fluid is below an alarm level. Still further, existing cryogenic storage devices lack adequate visibility into the device for retrieval of stored items (e.g., biologic samples and the like). Recently, lighting arrangements have been introduced into such cryogenic storage containers. However, these lighting arrangements are often difficult to access and service, particularly at the low temperatures involved within the interior volume of a cryogenic storage container.
Still further, use of cryogenic storage containers may be difficult at times, for example when the calibration or initial calibration is required to obtain accurate fill level information. A lengthy calibration process involving use of a dipstick and both depressurized and pressurized calibration processes may be required, which may result in significant delay between a time of installation and a time when a cryogenic storage container becomes available for use.
It is in view of these issues the cryogenic storage control system and storage assembly of the present disclosure is provided.
In general terms, a cryogenic storage control system and storage device assembly are provided. The cryogenic storage control system may utilize a dual fill level measurement arrangement in which a differential pressure-based fill level determination is compared to a fill level determined from an array of thermistors positioned at varying depths within the cryogenic storage container. Significant disagreement between fill level determinations may result in an alert being generated by a control system. Additionally, various operational processes may be implemented to ensure proper operation including calibration processes, monitoring processes, and maintenance processes. In some further examples, a lighting assembly with a readily replaceable lighting element may be provided that can be installed within an interior volume of such a cryogenic storage device.
In an example aspect, a cryogenic storage assembly includes a cryogenic storage container having an interior volume. The cryogenic storage assembly further includes a differential pressure system configured to obtain a differential pressure measurement within the interior volume, and a thermistor array assembly positioned within the interior volume, the thermistor array including a plurality of thermistors positioned at predetermined depths within the interior volume. The cryogenic storage assembly further includes a cryogenic storage control system including a processor and a memory. The cryogenic storage control system is configured to: obtain, via the differential pressure system, a pressure at a top of the interior volume and a pressure proximate to a bottom of the interior volume, and determine an estimated fill level of cryogenic liquid within the interior volume; obtain, via the thermistor array, a resistance of each thermistor indicative of a temperature at each of the predetermined depths, and determine a second estimated fill level of cryogenic liquid within the interior volume based on the temperature; compare the estimated fill level to the second estimated fill level; and based on a difference between the estimated fill level and the second estimated fill level being above a threshold, generating an alert indicating malfunction of at least one of the differential pressure system or the thermistor array assembly.
In a further example aspect, a method of operating a cryogenic storage system is disclosed. The method includes obtaining, via a differential pressure system, a pressure at a top of an interior volume of a cryogenic storage container and a pressure proximate to a bottom of the interior volume, and determining an estimated fill level of cryogenic liquid within the interior volume. The method also includes obtaining, via a thermistor array disposed within the interior volume and including a plurality of thermistors positioned at predetermined depths within the interior volume, a resistance of each thermistor indicative of a temperature at each of the predetermined depths, and determining a second estimated fill level of cryogenic liquid within the interior volume based on the temperature. The method further includes comparing the estimated fill level to the second estimated fill level. The method also includes, based on a difference between the estimated fill level and the second estimated fill level being above a threshold, generating an alert indicating malfunction of at least one of the differential pressure system or the thermistor array assembly.
In a still further example aspect, a cryogenic storage assembly is disclosed. The cryogenic storage assembly includes a cryogenic storage container having an interior volume, a differential pressure system configured to obtain a differential pressure measurement within the interior volume, and a thermistor array assembly positioned within the interior volume, the thermistor array including a plurality of thermistors positioned at predetermined depths within the interior volume. The assembly further includes a display communicatively coupled to the controller, the display providing a control user interface, and a cryogenic storage control system including a controller. The controller is configured to: obtain, via the differential pressure system, a pressure at a top of the interior volume and a pressure proximate to a bottom of the interior volume, and determine an estimated fill level of cryogenic liquid within the interior volume; obtain, via the thermistor array, a resistance of each thermistor indicative of a temperature at each of the predetermined depths, and determine a second estimated fill level of cryogenic liquid within the interior volume based on the temperature; compare the estimated fill level to the second estimated fill level; and based on a difference between the estimated fill level and the second estimated fill level being above a threshold, generate an alert indicating malfunction of at least one of the differential pressure system or the thermistor array assembly.
As briefly described above, embodiments of the present invention are directed to a cryogenic storage assembly that includes a cryogenic storage control system interfaced to a cryogenic storage container. Such a system has a number of aspects that provide advantages relative to existing systems.
In some examples, a cryogenic storage system includes an array of thermistors or other temperature sensing devices that may be positioned at predetermined depths within a cryogenic storage container. By obtaining sensor readings from each of the thermistors in the array, a liquid level may be determined. This liquid level may be used in conjunction with, or as a replacement for, a liquid level determined through differential pressure determinations between a top portion and a bottom portion of the cryogenic storage container as is generally used in such container systems today. Accordingly, in case of failure of one or the other of these systems, appropriate liquid level measurements may be maintained and communicated to other systems remotely. Additionally, when differential pressure and thermistor-based level sensing are in disagreement, alerts may be generated. Accordingly, a liquid level validation process may be performed.
In other examples, a calibration process may be performed associated with a cryogenic storage container. Such a calibration process may involve performing a high-pressure calibration test, and then de-pressurizing the cryogenic storage container and performing a dipstick-based test. By performing the high-pressure calibration test first, a user may avoid having to await re-pressurization to complete calibration.
In further examples, a lighting assembly may be positionable within an interior volume of the cryogenic storage container. The lighting assembly may be configured to eliminate upon detection of opening of the cryogenic storage container, and may include a lighting element that is easily replaceable even at extreme temperatures. Specifically, a lighting element, such as a light emitting diode array, may be positioned on a lighting assembly and at a location within the interior volume that is easily accessible and replaceable for maintenance purposes. A mechanism for retention and replacement of portions of such a lighting assembly are provided.
Still further, in some examples, an automated purge process may be performed at predetermined times by the cryogenic storage system. For example, a gas which corresponds to the vaporized or evaporated cryogenic fluid may be routed through the differential pressure lines that lead into the cryogenic storage container. By periodically opening valves to route such gas through differential pressure tests lines, the cryogenic storage system may mitigate the effect of potential condensation that may form in those lines, thereby reducing the extent to which compensation might freeze and cause clogged lines. Such a purge process may be performed periodically (e.g., daily at particular times of day, or of the week) or upon initial fill of the cryogenic storage container.
In still further examples, the above features of a cryogenic storage system and operational processes may be easily programmable via a control system, for example via a touch screen display that presents a series of user interfaces facilitating control of such a system. The programmable processes, and user interfaces, provide improved and simplified control over such a cryogenic storage system, thereby improving overall user experience.
Referring first to
In the example illustrated, the cryogenic storage system 100 includes a storage container 102 operatively connected to a control system 104. The control system may include a fluid level monitoring system 110, a supply level system 112, a vacuum measurement system 114, a gas level measurement system 116, and a controller 120. The control system 104 may further be operatively connected to a supply container 130 that holds a supply of cryogenic fluid. The control system 104 may control flow of cryogenic fluid from the supply container 130 to the storage container 102 as needed, for example by actuating particular valves at a defined timing or schedule, or in response to particularized events, and the like. The control system 104 may also monitor operating conditions of the cryogenic storage system 100 generally, including conditions within the storage container 102.
In example embodiments, the fluid level monitoring system 110 may include a differential pressure system 150 and a thermistor system 152. The differential pressure system 150 can include two tubes originating on an upper head of the storage container and extending into the interior volume of the storage container where cryogenic fluid is present. In some configurations, a high-pressure port connects to a tube extending to and terminating in a lower portion of the storage container 102 within its interior volume, while a second lower pressure tube extends into an upper section of the interior volume (e.g., above an intended fill level). Liquid cryogenic fluid presses against gaseous evaporation, such that as there is more liquid cryogenic fluid within the container, the pressure will increase on the higher-pressure measurement. A differential maintained between the high pressure and low pressure is utilized to determine a level of liquid cryogenic fluid in the storage container 102. A buildup of pressure in the storage container 102 due to evaporation is measured by both high pressure and low-pressure ports. The high pressure and the low-pressure measurements are communicated to the controller 120, which interprets the differential pressure into a level.
In some implementations, the thermistor system 152 includes a set of thermistors installed onto a printed circuit board at particular locations along the length of the circuit board. The circuit board may be installed into a tube extending down through the annular space into the interior volume of the storage container where cryogenic fluid is present. In some implementations, the tube has entry points into the inner chamber at two points. The first point may be proximate a bottom of the storage container to allow cryogenic fluid to enter the tube and achieve equilibrium with the level inside the storage container. The second entry point can be located in the upper part of the inner chamber above the pool of cryogenic fluid, allowing fluid to flow into the tube to a level that is the same elsewhere within the storage container. Accordingly, the thermistors may be exposed to the cryogenic fluid and may experience a corresponding resistance change that may be detected by the controller 120, and a liquid level within the storage container 102 may therefore be calculated. Details regarding a thermistor assembly useable within a cryogenic storage system are provided below.
In example embodiments, the supply level system 112 may monitor a level of cryogenic fluid available in the supply container 130. The supply level system 112 may be implemented similarly to the fluid level monitoring system 110 described above, or may alternatively only include one of the types of fluid monitoring (e.g., differential pressure or use of a thermistor array).
In example embodiments, the vacuum measurement system 114 and gas level measurement systems 116 may optionally be included as well, and may be used to measure other operational aspects of the cryogenic storage system 100.
In example embodiments, the processor 120 may be a microprocessor-based controller and may be communicatively connected to various sensing systems of the cryogenic storage system 100, as well as to output and/or user interface devices. An example of a control system 104 implementing such a processor 120 is illustrated in
In example implementations, the control system 104 may be communicatively connected to a remote computing system, for example via cloud 140. One or more remote computing systems may be able to access and control the cryogenic storage system 100 via such communication connection. In some examples, a cloud account may be made accessible to one or more users who may monitor operation of the cryogenic storage system 100. In such implementations, such remote users, for a user of the control system 104, may view, monitor, and change settings related to operational parameters of one or more cryogenic storage systems 100, including the one shown as well as others that may be maintained within a common account or by the same organization.
In the example shown, the cryogenic storage control system 200 includes the processor 120, as well as a memory 202 storing control instructions 204 usable to implement the operation, monitoring, communication, and maintenance processes described herein. In this example, the cryogenic storage control system 200 further includes a communication interface 206, a control and sensor interface 208, and a display interface 210.
In examples, the communication interface 206 facilitates communication with one or more external systems, such as a cloud system or other remote computing devices. The communication interface 206 may include a wired communication interface and/or a wireless communication interface according to any of a variety of communication protocols (e.g., Wi-Fi, ethernet-based communication, and the like). The control and sensor interface 208 includes a local communication bus usable to carry signals between one or more sensor circuits, control circuits, and the processor 120. For example, the control and sensor interface 208 receives signals from temperature and/or pressure sensors used as liquid level, gas level, or other types of sensors associated with the cryogenic storage container, and may send commands to one or more valves that actuate to allow flow of cryogenic fluid between a supply and the storage container. Other types of control mechanisms are possible as well.
In the example shown, the display interface 210 is communicatively connected to a display 220, such as a touch screen display that may be positioned proximate to the cryogenic storage container 102. An example of such a touchscreen displayed is illustrated in example embodiments described below. In general, the display interface 210 generates user interfaces to be presented on the display 220 based on execution of the control instructions 204. Specific user interfaces and operations are described in further detail below in Parts III-IV.
Referring to
In the example shown, the cryogenic storage assembly 300 includes a cryogenic storage container 302 and a cryogenic storage control system 304, implemented as a head unit on the cryogenic storage container.
The cryogenic storage container 302, as implemented, is cylindrical and has an interior volume 305 surrounded by insulating sidewalls 306. The cryogenic storage container 302 includes a base 308 having a plurality of mounted caster wheels 310 mounted thereon for portability. A set of handles 311 allows for manual manipulation of position of the cryogenic storage container.
The cryogenic storage control system 304 includes a touch screen control interface 312, as well as an access port 314 (enclosed by cover 364) providing access into the interior volume 305 of the cryogenic storage container 302, for example through a top wall arrangement 313 including one or more insulating walls of the cryogenic storage container.
As seen most clearly in
In the example shown, the assembly support 371 is mountable within the interior volume 305 via bolts 365, and the lighting element array 372, and removable circuit board 373, are held in place onto the card edge of circuit board 374 via a spring clip 376. The spring clip is retained by notches 377a-b, and retains the circuit board 373 by extending over tab portions 373a-b of that circuit board. The spring clip 376 is readily removable manually and oriented toward the cover 364, such that a user may easily reach into the interior volume 305 and release the spring clip 376 in order to replace the lighting element array 372.
As seen most clearly in
In the example shown in
As seen most clearly in
Referring to
Referring now to
In particular, in the liquid level display graphic, a plurality of sub graphic indicators are presented along a side of an overall liquid level display. Within the liquid level display, a total level of liquid cryogenic fluid is displayed, alongside fluid usage. The sub graphic indicators generally correspond to depth at which individual thermistors of a thermistor array are disposed, and graphically illustrates a comparison between the thermistor array readings and the level that is displayed within the main graphic. In some examples, the level within the main graphic may be obtained through a differential pressure assessment, and may be visually comparable to the sub graphic indicators to determine agreement between the two for purposes of liquid level monitoring.
Although illustrated as an “auto filling” status, other statuses may be usable as well. In example implementations, a quick chill status, a manual defogging status, a manual filling status, and auto the fog status may be used in addition to the auto filling status.
As seen in
Referring now to
If both a thermistor and differential pressure system are present, or if at least a differential pressure measurement system is present, flow within the overall process may proceed to obtaining a civil level estimate via the differential pressure system (step 4502). Obtaining a fill level from the differential pressure system may include, for example, determining a pressure at a top of an interior volume within the cryogenic storage container (e.g., above a fill line), as well as at a bottom of the interior volume (e.g., below the fill line). By comparing the pressures, and approximate fill level or liquid level may be determined.
Additionally, either before or after the differential pressure based fill level determination is performed, a fill level may be obtained using a thermistor array present within the cryogenic storage assembly (step 4504). Obtaining the fill level using the thermistor array may include obtaining signal values from each thermistor (e.g., voltage or resistance values), and determining, from those signal values, a temperature at each of a plurality of predetermined depths within the interior volume of the cryogenic storage container. The temperature at each of the predetermined depth may generally correspond to whether liquid or gas is present at that depth. Accordingly, it is possible to identify a fill level, at least approximately, with a sufficient number of and spacing of thermistors positioned at varying depths within the interior volume of the cryogenic storage container.
In the example as illustrated, a comparison is performed between the fill level determined using differential pressure, and the fill level determined using the thermistor array (at operation 4506). If a significant difference between the two syllables exists, it is likely that an error has occurred in one or the other of those fillable determining subsystems, or that they are otherwise inconsistent (e.g., one or both systems being miscalibrated). Accordingly, an error may be generated, or an alert may be generated, indicating the discrepancy between the two systems. Whether an alert or an error is generated might depend on which system indicates a discrepancy, and/or the severity of the discrepancy. For example, an alert may only be generated if no signal is obtained from the thermistor array, because it may be disabled or otherwise not present. However, an alert might be generated if a significant mismatch between the thermistor array and the differential pressure fill levels are determined. This may indicate a blockage in one or both of the inlet ports used for the differential pressure monitoring system or other error.
To the extent of an error or alert is generated, operation may return to reattempt determination of a fill level, for example via either the differential pressure measurement system or the thermistor array. Additionally, or in the alternative scenario where there is agreement between the differential pressure based fill level and the thermistor-based fill level, the fill level may continue to be monitored, and displayed on a user interface, such as may be presented on a display (step 4506). An example of such a display is illustrated in
In the example shown, a fill level determination operation 4510 response to determining whether the fill level is outside predetermined thresholds. In particular, a fill level may generally be agreed on by both the differential pressure-based fill level system and the thermistor array, but that the fill level may be outside of desirable operating parameters. If not outside of the desired operating parameters (e.g., everything is working appropriately), operational flow may return to step 4502, to continue monitoring fill levels. However, if outside of operating parameters, one or more additional operations may be initiated by the control system (step 4512). The one or more additional operations may include operations such as initiating a fill of the storage container from a separate cryogenic liquid supply, such as seen in
In the example control method 4600 described herein, a pressure calibration process may be performed prior to performing a liquid level calibration process. In this way, a user need not await re-pressurization of the cryogenic storage container to perform the pressure calibration, but instead may immediately initiate use of a cryogenic storage system after performing the liquid level calibration described herein. Specifically, in the example shown, a pressure calibration is performed (at step 4602). The pressure calibration process is performed to calibrate a pressure reading from within the interior volume of the cryogenic storage container while at a pressure greater than an atmospheric pressure.
In the example shown, after the pressure calibration is performed, a liquid level calibration is performed using an open container method (step 4604). The liquid level calibration may include accessing the interior volume (thereby changing the interior pressure to an atmospheric pressure), inserting a dipstick, and viewing a frost line at which a liquid level exists. After the cryogenic storage container is closed, the user may use a user interface, such as described above, to enter calibration values for both pressure calibration and liquid level calibration (step 4606). The user may then immediately utilize the cryogenic storage container without requiring the user to wait for complete free pressurization before completing the pressure calibration process.
Embodiments of the present invention, for example, are described above with reference to block diagrams and/or operational illustrations of methods, systems, and computer program products according to embodiments of the invention. The functions/acts noted in the blocks may occur out of the order as shown in any flowchart. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
The description and illustration of one or more embodiments provided in this application are not intended to limit or restrict the scope of the invention as claimed in any way. The embodiments, examples, and details provided in this application are considered sufficient to convey possession and enable others to make and use the best mode of claimed invention. The claimed invention should not be construed as being limited to any embodiment, example, or detail provided in this application. Regardless of whether shown and described in combination or separately, the various features (both structural and methodological) are intended to be selectively included or omitted to produce an embodiment with a particular set of features. Having been provided with the description and illustration of the present application, one skilled in the art may envision variations, modifications, and alternate embodiments falling within the spirit of the broader aspects of the general inventive concept embodied in this application that do not depart from the broader scope of the claimed invention.
The present application claims priority from U.S. Provisional Patent Application No. 63/619,612, filed on Jan. 10, 2024, the disclosure of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63619612 | Jan 2024 | US |
