How to thaw a frozen bag

Abstract

This invention provides a consistent and reproducible thawing method and system for frozen samples in bag-type storage containers. [Solution] The method and system may allow multiple sizes of bag-type storage containers to be used with the same apparatus. A subset of multiple sensors may be qualified for the thawing method. The method may further include heating the frozen sample using a first heater bank and a second heater bank. Furthermore, the method may include measuring multiple second temperatures of the bag-type container. At a second threshold temperature, or shortly after the second threshold temperature, the method may include heating using the first heater bank and terminating heating using the second heater bank. The method may also include terminating heating of the partially thawed sample using the first heater bank after the partially thawed sample has been heated for a certain period of time using the first heater bank.

Description

Technical Field

[0001] (Related Application) This application claims priority based on U.S. Provisional Application No. 62 / 962,733, filed on January 17, 2020, the entire disclosure of which is incorporated herein by reference in its entirety for all purposes.

Background Art

[0002] Cryopreservation of cells in suspension is an established and accepted technique for long-term storage and recovery of viable cells. As a general method, cells are suspended in a cryopreservation medium containing a salt solution, buffer, nutrient, growth factor, protein, and cryopreservative. Thereafter, the cells are dispensed into storage containers of a desired size and volume, and the temperature of the container is decreased until the contents of the container freeze. Typical long-term storage conditions include storage in liquid nitrogen vapor where the temperature is usually between -196°C and -150°C. Vial or bag-type storage containers may be used for storage of such sample liquids, depending on the specific volume or use of the cryopreserved sample.

[0003] To successfully recover viable cells stored in such a manner, it is important to minimize the growth of harmful ice crystals in the intracellular region during both the freezing and thawing processes. Returning a sample from the cryopreserved state involves thawing the sample to a completely liquid state. During the thawing process, the rate of temperature change can affect the viability of the cryopreserved cells. The solid contents of the sample storage container contain large islands of crystallized water, between which are arranged channels of glassy water-soluble substances intermixed with small nuclei of ice crystals. There is an opportunity for rearrangement of water molecules within the sample, including thermodynamically favorable growth of small ice nuclei within the cells, during the transition until the phase change from the cryopreservation temperature to the completely liquid state is complete. Growth of ice crystals within the cells can be potentially cell-damaging, and since the extent of crystal growth is a time-dependent phenomenon, it is desirable to minimize the time interval of the transition through the phase change.

[0004] Rapid temperature changes in a sample container are typically achieved by partially immersing the container in a water bath set to approximately 37°C. While increasing the water bath temperature yields faster thawing rates, immersion creates a temperature gradient within the container, with the highest temperature located at the container walls. This results in a transient thermodynamic state where, even with frozen material nearby, the temperature of the liquid-solid mixture exceeds its melting point. Therefore, the temperature gradient within the container imposes an upper limit on the water bath temperature. Furthermore, since common cryoprotectants are toxic to cells, varying exposure of cells in the liquid state over time and temperature can lead to variability in cell viability upon completion of the thawing process. Because the toxicity of cryoprotectants intensifies at higher temperatures, lower liquid temperatures are desirable. Therefore, several thawing protocols typically include a rapid thawing phase that ends while a small amount of solid material remains in the sample container. After removal from the water bath, the sample temperature rapidly equilibrates to a temperature near the phase change temperature. The thawing protocol typically aims to minimize the time the thawed sample is held in a concentrated state of cryoprotection, and subsequent steps such as sample dilution or replacement of the cryopreservation medium with the culture medium are usually applied at the shortest possible intervals.

[0005] Several methods have been proposed to automate the thawing of samples, but further improvements are possible, especially for samples stored in bag-type cryopreservation containers (called "cryobags"). [Overview of the Initiative]

[0006] This disclosure generally relates to systems and methods for thawing frozen samples in bag-type storage containers. In various embodiments, this disclosure relates to systems, apparatus and methods for cryopreservation of cells, tissues and fluids, and for the recovery of cryopreserved cells, tissues and fluids.

[0007] Embodiments of the present invention may enable consistent and reproducible thawing of frozen samples in bag-type storage containers. Thawing may be performed to the extent that some of the solid phase remains in the liquid phase. Embodiments may also allow multiple sizes of bag-type storage containers to be used in the same apparatus.

[0008] Embodiments of the present invention may include a method for thawing a frozen sample in a bag-type container. The method may include measuring a plurality of first temperatures of the bag-type container in contact with a first surface and a second surface. Each of the plurality of first temperatures may be measured by a different sensor among a plurality of sensors. Each of the plurality of sensors may be configured to measure the temperature at a different location on the bag-type container. The method may include comparing each of the plurality of first temperatures to a first threshold. The method may include using the comparison to identify a subset of the plurality of sensors, where each sensor in the subset of sensors measured a first temperature below the first threshold. The method may further include heating the frozen sample using a first heater bank and simultaneously heating the frozen sample using a second heater bank. In addition, the method may include measuring a plurality of second temperatures of the bag-type container using a subset of the plurality of sensors. A second temperature among the plurality that exceeds a second threshold may indicate the presence of a partially thawed sample in the bag-type container. At or shortly thereafter, the method may include heating the partially thawed sample using the first heater bank and terminating the heating of the partially thawed sample using the second heater bank. The method may also include terminating the heating of the partially thawed sample using the first heater bank after the partially thawed sample has been heated for a certain period of time using the first heater bank.

[0009] Furthermore, the embodiment may include a defrosting system. The defrosting system may include a defrosting device. The defrosting device may include a first surface, a second surface, a plurality of sensors, a first heater bank, and a second heater bank. The defrosting system may also include a computer system. The computer system may include instructions that control the defrosting device to perform a defrosting method when executed.

[0010] A better understanding of the properties and advantages of the embodiments of the present invention can be obtained by referring to the following detailed description and accompanying drawings. [Brief explanation of the drawing]

[0011] [Figure 1A] This figure shows an exemplary thawing device according to an embodiment of the present invention, with the plate, heater, and sensor shown in detail. [Figure 1B] This figure shows an exemplary thawing device according to an embodiment of the present invention, with the plate, heater, and sensor shown in detail. [Figure 1C] This is an exploded view of an exemplary thawing device according to an embodiment of the present invention, showing in detail the plate, heater, and sensor. [Figure 2] This invention describes a method for thawing a frozen sample in a bag-type container according to an embodiment of the present invention. [Figure 3] The diagram shows an exemplary thawing device according to an embodiment of the present invention, in which the upper part of the outer shell has been removed. [Figure 4] This is an upper front right view of the apparatus according to an embodiment of the present invention, in which additional parts of the apparatus have been selectively removed to show in detail the temperature sensor on the heater plate. [Figure 5] A cross-sectional view of a thermal sensor according to an embodiment of the present invention is shown. [Figure 6] This shows a computer system according to an embodiment of the present invention. [Modes for carrying out the invention]

[0012] Conventional methods for thawing cells stored in freeze bags involve rapidly warming the cells in a warm water bath (e.g., 37°C) until the last ice is about to melt, and then slowly diluting the cells in culture medium. Overheating the sample can cause the cells to begin metabolizing and can lead to poisoning from dimethyl sulfoxide (DMSO), which is commonly used in the freezing process. Generally, thawing cryopreserved cells and tissues is performed by laboratory technicians, and the protocols applied may vary not only among laboratory technicians but also method-dependent. The completion of sample thawing is generally judged subjectively by each individual technician, which can lead to differences in thawing rate or overheated samples. While it is theoretically possible to achieve a reproducible thawing profile through the use of a water bath and manual control of freeze bag insertion, the expected variability in the degree of adherence to technique and protocol, especially when combined with the need to frequently remove the freeze bags from the water bath to monitor the thawing state, makes deviations from a standard profile almost certain. Removing a freezing bag from a water tank interrupts the transfer of heat energy from the water to the bag, and visual assessment of the thawing state is often difficult, potentially further complicated by the presence of labels or printed writing surfaces provided as integrated features of the freezing bag product. Furthermore, the water tank itself is a source of contamination, and unintentionally submerging the sealed joint of the freezing bag can lead to the introduction of the water's liquid into the contents of the freezing bag when opening or removing the sealed joint.

[0013] Embodiments of the present invention may enable consistent and reproducible thawing of frozen samples in freezing bags. Multiple freezing bags of different sizes may be thawed in the same apparatus. Some freezing bags may be substantially smaller in size than the heating plate used for thawing. In embodiments of the present invention, excessive thawing and damage to the samples can be avoided by ramping down or stopping a heater located away from a freezing bag considerably smaller than the heating plate. The latent heat of the heating plate may be sufficient to thaw a portion of the freezing bag. Other heaters may continue thawing another portion of the freezing bag located in contact with or near the heater.

[0014] (I. Overview) A thawing system may be designed to thaw the frozen contents of a standard freezing bag, which is a type of bag-shaped container. Freezing bags are available in nominal volumes ranging from 25 ml to over 1000 ml, but in most cases are intended to contain a portion of the nominal size, so the maximum cross-sectional thickness of the bag is approximately 0.4 inches when the bag is frozen in a flat orientation. Freezing bags are typically rectangular in shape and are provided with a system of tubes for filling the bag. After filling and before freezing, the filling tubes are heat-sealed and trimmed so that the tubes do not protrude from the bag by more than about 1 inch. In addition to the tubes, the same end region of the freezing bag typically has two or more port features, which are sealed until they are penetrated by connector tube couplings. The contents of the bag are removable through the connector tube couplings. The region of the freezing bag where the ports are located is referred to as the neck or proximal end of the freezing bag. The thawing system receives the frozen bag and its contents in a frozen state with an initial temperature of approximately -70°C to -196°C, and rapidly raises the temperature of the bag and its contents until the contents are mostly liquid, exceeding the phase change temperature. To visually demonstrate that the thawed contents of the container have not been exposed to unacceptable high temperatures, the cryopreservation industry has adopted the practice of expecting some solid residue to be present at the completion of the thawing process.

[0015] The thawing system may accept a range of sizes for the frozen bags, and a range of fill volumes may apply for each size of frozen bag. The device may thaw the contents of the bag at a rate approximating the thawing rate that a frozen bag would experience when immersed in a water bath at a temperature of approximately 37°C. The thawing system may agitate the contents of the bag during the thawing process to maintain a uniform temperature distribution, and may automatically terminate the thawing process if some solid phase remains in the bag.

[0016] Figures 1A, 1B, and 1C show the plates, heater, and sensor of the thawing unit 100. The thawing unit 100 may include two aluminum plates (e.g., a lower plate 104 and an upper plate 108) that contact the main upper and lower surfaces of the freezing bag with light clamping pressure to ensure optimal contact between the plates and the bag. The lower plate 104 may be configured as an extendable drawer, thus forming an area that accommodates the largest bag size (e.g., 1000 ml). The freezing bag may be positioned between the lower plate 104 and the upper plate 108, and the port of the freezing bag may be positioned to the left of the plates in the drawings. The upper plate 108 may be hinged to an axis parallel to the longitudinal direction of the freezing bag, so that the plate may swing to mix the contents of the bag during the thawing process. In addition, the upper plate 108 may be limited to the area of ​​the freezing bag where no port features are present, so that the port does not limit the clamping pressure of the upper plate on the portion of the freezing bag where the contents are located. Thus, ports for all bag sizes may be intentionally positioned in the same area of ​​the lower plate, so that as the bag size and capacity increase, the bag extends from the port area into the distal area of ​​the plate. "Upper," "lower," "bottom," and "top" are used for convenience to describe the orientation of the bag or plate. However, freezing bags and plates may be positioned longitudinally, or at any angle between transverse and longitudinal.

[0017] The lower plate 104 may include a set of thermal sensors 112 (sensors 112a-e) embedded in an insulating medium, so that when the freezing bag is stationary on the lower plate 104, sensors 112a-e are thermally coupled to the bag rather than the lower plate 104. Sensors 112a-e may report the temperature of the bag surface, which is offset by a few degrees from the contents of the freezing bag on the inner wall opposite the sensors. The plate sensors may report a close surrogate temperature for the bag contents, and the thawing process may be triggered by reaching a predetermined pre-set temperature threshold, which is related to a phase transition state in which a low proportion of solid phase remains in the bag solution, as the mixing system promotes a uniform temperature in the freezing bag contents. The set of thermal sensors 112 may be distributed along a line on the lower plate 104. The set of thermal sensors 112 may be distributed so that a freezing bag of a given size typically contacts two or more sensors. As a result of different freezing bag geometries, sensors 112a-e may not be evenly distributed across the plate. The thaw termination temperature threshold may be configured such that all participating temperature sensors must exceed the threshold to terminate thawing. As a safety mechanism, temperature readings from sensors exceeding the threshold may be used to monitor a secondary temperature threshold for overheating and trigger the termination of the thawing process to prevent the temperature from rising to a range that is potentially detrimental to the viability of the biological suspension in the frozen bag solution.

[0018] The set of thawing control variables may include temperature values ​​that define thresholds that a given bag temperature sensor must reach to qualify for participation in the thawing control process. For example, the lower plate 104 may include five distinct temperature sensors (e.g., sensors 112a, 112b, 112c, 112d, and 112e) strategically distributed along the centerline of the lower plate 104 so as to also contact the freezing bag along the centerline. Because the length of the bag varies depending on the nominal capacity of the freezing bag, some of the sensors 112a-e will not be coupled to the bag in the case of low-capacity bags. Identification of sensors capable of coupling to a given capacity freezing bag may be done using a variable table or dynamically by the absence of a temperature drop at the start of the thawing cycle. However, if the bottom surface of the freezing bag is not flat or has gas pockets or depressions, the sensors reporting the temperature of the freezing bag may provide artifactual information. Therefore, each sensor may be required to report a temperature drop of a sufficient value to qualify in the thawing process control algorithm. If no sensor detects a temperature drop threshold after a certain time limit, this error condition can be communicated to the user via a display screen. This time limit, which is a few seconds after the start of the thawing process, may be stored in a set of control variables. The qualification failure event may be coupled to an algorithmic sequence that terminates the thawing process and ejects the frozen bag from the device.

[0019] The data stream from the freezing bag temperature sensor may be stored and monitored by a graphic display, or transferred to portable media along with metadata of a specific decompressed file for archiving for review.

[0020] [A. Thawing Stage] The frozen bag thawing process may be divided into two stages. The first stage may be a temperature transition stage where the inflow of thermal energy into the bag and its contents serves mainly to transition the temperature from the freezing start temperature to the start of the phase change of the contents of the frozen bag. The start of the phase change may be characterized by the initial formation of a liquid phase in the frozen bag. Since the contents of the frozen bag typically contain complex aqueous formulations, the phase change is not a sharp change but rather spreads over a temperature range. When the phase change starts during the thawing process, the liquid phase may spread across the inner surface of the frozen bag, and thus the bag conforms to the plate surface, increasing the thermal contact between the bag and the heating plate. The interval from the start of the phase change to the end of the thawing process may be defined as the second stage.

[0021] The upper plate 108 and the lower plate 104 may each include two banks of flat resistive mat heaters. In the lower plate 104, a first bank 116 of heaters may be disposed in the proximal or neck region of the bag, and a second bank 120 of heaters having a greater wattage may be disposed distally from the first bank 116 with respect to the neck and port regions of the frozen bag. In the upper plate 108, a third bank 124 of heaters may be disposed in the proximal or neck region of the bag, and a fourth bank 128 of heaters having a greater wattage may be disposed distally from the third bank 124. Each bank is shown as including two identical heaters, but in embodiments, the number of heaters may be smaller or larger. Using only one heater bank per plate may result in excessive thawing of the distal portion of the bag. Using an excessive number of heater banks per plate may result in unnecessary process complexity and increased cost. However, in certain embodiments, additional heater banks may be used (e.g., a total of 3, 4, 5, 6, 7, 8 or 9 or more). Further segmentation of the distal heater bank may be used for bags having segmented bags or septum boundaries.

[0022] The mat heater may be uniform in energy output per unit area, and heaters with higher wattage cover a wider area than the neck heater with lower wattage. In the range of the size of the freezing back, as the size of the freezing bag decreases, larger areas of both the upper and lower plates become free of heat sinks, and thus the temperature rises at a rate greater than the area of the plate in contact with the freezing back. The net result of the temperature difference in the plate may be an increase in heat influx to the distal end of the freezing back, and thus may impose a transition through a phase change at a rate greater than in the neck region. If the thawing algorithm ends thawing based on a high sensor reading in the distal region, the neck region may remain solid, and thus the thawing process at the end is non-uniform.

[0023] [B. Stage Transition Control] To establish a balanced thaw end point for different freezing back sizes, the system may be required to identify the size of the freezing back. The size of the freezing back may be dynamically identified through sensors or user input. Identifying the size may identify a table input for a set of variables that control the thawing process for a particular bag size. The variable table may include time point values that may be used to trigger the transition from the first thaw stage to the second thaw stage. The stage transition may be controlled by temperature set points that may be triggered by any combination of temperature sensor data streams of eligible freezing bags. The neck and distal heater banks on the upper and lower plates may be individually controlled by local temperature sensor feedback loops through a PID algorithm to achieve and maintain the set point temperature. The initial or first stage temperature setting may be applied to all heater banks to achieve a rapid freezing bag temperature transition to the start of the phase change.

[0024] After the initiation of the phase change, a second group of temperature settings may be applied to the neck heater bank (e.g., first bank 116 and third bank 124) and distal heater bank (e.g., second bank 120 and fourth bank 128) to balance the phase change process of the freeze bag contents over the length of the freeze bag. Heater setting transitions for medium and small bags may be stored in a variable table. The variable table may be used to input control variables based on empirical data. The control variables may be adjusted to optimize the outcome of the thawing process. As an example, a nominal freeze bag of 250 ml may contain 30 ml to 70 ml of biological material contents, and the freeze bag may occupy about half of the plate area. In the first stage of the thawing process, the temperature of the proximal or neck portion of the plate, along with the distal portion, is controlled down to the first stage setpoint. However, under a heat sink load, both plates may experience a temperature drop. As a result of the temperature drop, the heater bank may be activated to respond to the temperature drop, attempting to return the plate to the temperature setpoint.

[0025] In the second stage of thawing, as the temperature of the freezing bag approaches a predetermined temperature endpoint, the demands on the heating system may be reduced to return the plate temperature to the setpoint. However, the distal portion of the plate not in contact with the freezing bag may contain substantial residual thermal energy that can move toward the proximal end of the plate toward the freezing bag heat sink. If left uncompensated, this additional distal region plate thermal energy may cause the distal region of the freezing bag to thaw before the proximal region of the freezing bag. Therefore, the second-stage heater settings may be coupled in this respect so that the distal heaters transition to a lower temperature setting, thus ensuring a uniform distribution of thermal energy across the plate. In some situations, the proximal heater bank may transition to a higher temperature setting, so that the PID control loop applies a larger amount of energy inflow. Temperature setpoints for all bag sizes may be optimized by prior testing with specific bag solutions. In addition to the stage plate temperature setting, an idle plate temperature setting may also be selected as the holding temperature before and during the thawing procedure. The transition of the plate temperature setting from the first stage to the second stage may be triggered by temperature data provided by the freezing bag temperature sensor, the time after the thawing start setting, or a combination of both controls.

[0026] The temperature settings for the thawing stage and idle plate, stage transition signal settings, sensor thresholds for qualification, thawing completion temperature, and high temperature limit may be stored as a profile for a specific thawing application. The profile may also include other control values ​​related to the operation of the instrument, such as a target value for plate clamp pressure and an absolute thawing time value, the absolute thawing time value providing a safe backstop to prevent unexpected failure conditions from causing excessive thawing or overheating. The profile may be stored in a database for arbitrary recall and loaded into thawing control variables to execute the desired thawing conditions. The thawing profile may be transferred to a portable storage medium or cloud storage, and in addition, external thawing profiles may be transferred from the portable storage medium or cloud storage to the instrument profile storage database.

[0027] (II. Exemplary Methods) Figure 2 shows an exemplary method 2000 for thawing a frozen sample in a bag-type container. The bag-type container may be any of the freezing bags described herein. The freezing bags may have nominal sizes of 25, 50, 250, 500, 750, or 1,000 ml. Method 2000 may include using any of the systems described herein. Method 2000 may further include the details of the thawing process described above.

[0028] The bag-type container may include ports. The ports of the bag-type container may be located near the first end of the first surface and the first end of the second surface. The bag-type container may have a surface area smaller than the surface area of ​​the first surface, and may have a surface area smaller than the surface area of ​​the second surface. The surface area of ​​the first surface may be the same as the surface area of ​​the second surface. The surface area of ​​the bag-type container may be 10% to 20%, 20% to 30%, 30% to 40%, 40% to 50%, 50% to 60%, 60% to 70%, 70% to 80%, 80% to 90%, or 90% to 95% of the surface area of ​​the first surface or the second surface. The length of the bag-type container, excluding the ports, may vary in the range of 1 to 2 inches, 2 to 3 inches, 3 to 6 inches, 6 to 8 inches, 8 to 12 inches, or 12 inches or more. The surface may be longer than the length of the longest bag-type container used for thawing, but it may also accommodate a much smaller bag-type container without excessively thawing the contents.

[0029] The first and second surfaces may be oriented transversely such that one surface is the bottom and the other is the top. The first and second surfaces may be oriented longitudinally or at an angle between the transverse and longitudinal directions. One plate may be larger than the other plate. In one embodiment, the surface area of ​​the first surface may be 0% to 10%, 10% to 20%, 20% to 30%, 30% to 40%, 40% to 50%, or 50% to 100% larger than the surface area of ​​the second surface. The surface may be any of the surfaces or plates described herein. Any thermal conductive surface may be used that includes a flexible material which may be or may include a gel, liquid, woven fabric, nonwoven fabric, or screen.

[0030] The bag-shaped container may overlap the first surface in the first portion of the first surface, but may not overlap the first surface in the second portion of the first surface. The bag-shaped container may overlap the second surface in the first portion of the second surface, but may not overlap the second surface in the second portion of the second surface. The first heater bank may be positioned closer to the first portion of the first surface and the first portion of the second surface than to the second portion of the first surface and the second portion of the second surface. The second heater bank may be positioned closer to the second portion of the first surface and the second portion of the second surface than to the first portion of the first surface and the first portion of the first surface.

[0031] In the embodiments, the first heater bank may be positioned closer to the first edge of the first surface and the first edge of the second surface than the second heater bank is positioned closer to the first edge of the first surface and the first edge of the second plate. In the embodiments, both the first and second heater banks may be located within the first surface and may be configured to provide temperature readings for a bag-type container in contact with the first surface. In these and other embodiments, the second surface may include a third heater bank and a fourth heater bank. The third heater bank may be aligned with the first heater bank, and the fourth heater bank may be aligned with the second heater bank. The first heater bank may be identical to the third heater bank. The second heater bank may be identical to the fourth heater bank. Each heater bank may contain 1, 2, 3, 4, or 5 or more heaters.

[0032] In one embodiment, lines perpendicular to the main surface of the first surface (e.g., a plate) extend through the second heater bank but not through the bag-type container. The first surface may be parallel to the second surface. In one embodiment, lines perpendicular to the main surface of the first surface (e.g., a plate) extend through the second heater bank and through the bag-type container.

[0033] Method 2000 may include receiving user input that identifies the size of the bag-type container. In one embodiment, the only input received from the user is the size of the bag-type container. Method 2000 may also include receiving user input that identifies the type of medium in the bag-type container. In one embodiment, Method 2000 may include loading the bag-type container into a drawer of the device. Method 2000 may also include bringing the bag-type container into contact with a first surface of the sample thawing device. In addition, Method 2000 may include bringing the bag-type container into contact with a second surface. Method 2000 may further include clamping the bag-type container between the first and second surfaces.

[0034] In block 2002, method 2000 may include measuring a plurality of first temperatures of a bag-type container in contact with a first surface and a second surface. Each of the plurality of first temperatures may be measured by a different sensor from the plurality of sensors. Each of the plurality of sensors may be configured to measure temperature at different locations on the bag-type container. The plurality of sensors may include 5 sensors, 2 to 5 sensors, 5 to 8 sensors, 8 to 10 sensors, or more than 10 sensors. The plurality of sensors do not have to be uniformly distributed across the first and second surfaces. The bag-type container may be in contact with at least 2, 3, 4, or 5 or more sensors. One surface may contain sensors, while the other surface may not have sensors. In some embodiments, sensors may be present on both surfaces.

[0035] In block 2004, method 2000 may include comparing each of a plurality of first temperatures to a first threshold. The first threshold may be lower than the temperature of the bag container measured when the bag container first comes into contact with the first and second surfaces. The first threshold may depend on the size of the bag container and / or the medium. For example, the first threshold may be -10°C, -30°C to -20°C, -20°C to -10°C, or -10°C to 0°C. In embodiments, the first threshold may be a temperature difference, and the measured first temperature may also be a temperature difference. For example, the first threshold may be a temperature difference of -15°C. The first threshold may be specific to a particular period. For example, the period may be 30 to 45 seconds, 45 to 60 seconds, or 1 to 2 minutes after the freezing bag has been clamped to both surfaces, or thereafter or before.

[0036] In block 2006, method 2000 may include identifying a subset of multiple sensors by comparison. The subset of multiple sensors may be considered eligible for the thawing process. Each sensor in the subset of multiple sensors may measure a first temperature lower than a first threshold. The subset of multiple sensors may include fewer sensors than the multiple sensors. In one embodiment, the subset of multiple sensors may be multiple sensors.

[0037] The subset may be identified using the size of the bag-type container. The size of the bag-type container may be received through user input or identified by sensors. Sensors identified as being outside the area of ​​the bag-type container may be excluded from the subset of sensors.

[0038] In block 2008, method 2000 may include heating a frozen sample using a first heater bank and simultaneously heating a frozen sample using a second heater bank. Heating of the frozen sample may occur before, simultaneously with, or after measuring a plurality of first temperatures. Heating a frozen sample using the first heater bank may include targeting surface temperature setpoints in the range of 37°C to 45°C, 37°C to 40°C, 40°C to 42°C, 42°C to 45°C, 45°C to 50°C, or higher than 50°C for the first and second heater banks. This temperature may be the surface temperature measured separately from the plurality of sensors measuring the temperature of the bag container. The first and second heater banks may have the same temperature setpoint. Heating may be controlled by a PID loop or any suitable control loop. Heating may include a third heater bank and a fourth heater bank. Method 2000 may include stirring the surface and the bag container during heating.

[0039] In block 2010, method 2000 may include measuring multiple secondary temperatures of a bag-type container using a subset of multiple sensors. The multiple secondary temperatures may relate to the thawing time or period. The temperature profile may be determined from the measured temperatures and times.

[0040] In block 2012, method 2000 may include heating a partially thawed sample using a first heater bank while terminating heating of the partially thawed sample using a second heater bank when the second temperatures of a plurality of second temperatures exceed a second threshold. The second threshold may be in the range of 0°C to 8°C, including 0°C to 4°C. In one embodiment, the second threshold may be a temperature difference, and the measured second temperature may be a temperature difference. The temperature difference may be a difference relative to the first threshold. In one embodiment, it is required that only one of a plurality of second temperatures exceeds the threshold. The one second temperature may be the first or last second temperature in the time series to exceed the threshold. In one embodiment, it is required that two second temperatures, a plurality of second temperatures, or all second temperatures exceed the threshold. In one embodiment, the second threshold may be an array of temperatures. For example, the second threshold may include a value for the highest second temperature and a value for the lowest second temperature. In one embodiment, it is required that the average or median of a plurality of second temperatures exceeds the threshold. Furthermore, the second threshold may be an array of temperatures. For example, the second threshold may include a value for the highest second temperature and a value for the lowest second temperature. If any, all, or some of the values ​​in the array are exceeded, it may be considered that the second threshold has been exceeded. The second threshold may be determined empirically or by using the size of the bag-type container and / or the medium.

[0041] Terminating the heating of a partially thawed sample using the second heater bank may include lowering the temperature setpoint of the second heater bank. Lowering the temperature setpoint below the heater bank temperature may effectively terminate heating by the heater bank. However, if the surface temperature falls below the temperature setpoint, the second heater bank may be reactivated.

[0042] In Block 2014, Method 2000 may include heating the partially thawed sample using the first heater bank for a period of time, and then terminating the heating of the partially thawed sample using the first heater bank. In one embodiment, when the heating of the partially thawed sample using the first heater bank is terminated, the majority of the partially thawed sample is aqueous solution, with the solid phase remaining in the partially thawed sample. For example, 70% to 80%, 80% to 90%, 90% to 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, or 99.99% of the mass or volume of the contents is liquid phase, with the remainder being solid phase. The remaining solid phase may be granular. The solid phase may be fine particles substantially uniformly distributed through the bag-type container. The partially thawed sample may be in a state resembling fine slush.

[0043] In one embodiment, the heating of a partially thawed sample may be terminated at a predetermined time. The predetermined time may be calculated using an empirically determined phase change period. The predetermined time may be 30 seconds to 1 minute, 1 to 3 minutes, 3 to 5 minutes, 5 to 7 minutes, 7 to 10 minutes, 10 to 15 minutes, or 15 minutes or more after the first threshold is reached. In one embodiment, the predetermined time may be a safety backstop to prevent overheating in the event of a malfunction or abnormality.

[0044] In one embodiment, method 2000 may further include measuring multiple third temperatures of a bag-type container using a subset of multiple sensors. When the third temperatures of the multiple third temperatures exceed a third threshold, heating of the partially thawed sample using the first heater bank may be terminated. The third threshold may be in the range of 4°C to 25°C. The third threshold may be determined empirically and may vary based on the size of the bag-type container and / or the medium. Like the second threshold, the third threshold may be a temperature difference. The third temperature may be a temperature difference. In addition, similar to the second threshold, the third threshold may not be based solely on the third temperature and may include multiple third temperatures or statistical values ​​of multiple third temperatures. Furthermore, similar to the second threshold, the third threshold may be an array of temperatures. For example, the third threshold may include the highest third temperature value and the lowest third temperature value. When any, all, or some of the values ​​in the array exceed the third threshold, it may be considered that the third threshold has been exceeded. For example, if the lowest third temperature is higher than 4°C, or the highest third temperature is higher than 12°C, it may be considered that the third threshold has been exceeded.

[0045] In one embodiment, multiple third temperatures may be compared to a reference temperature profile. If the third temperatures of the multiple third temperatures deviate significantly from the reference temperature profile, the partially thawed sample is heated using the first heater bank. The deviation from the reference temperature profile may indicate a leak, overfilling, underfilling, or an abnormality in the bag container or apparatus. Heating may include not only the third temperature but also multiple third temperatures, or statistical values ​​of multiple third temperatures, as described in other thresholds.

[0046] Method 2000 may include removing the bag-type container from the apparatus after completing the heating of the partially thawed sample using the first heater bank. In one embodiment, after the heating is completed, the drawer containing the first surface may be automatically opened. The solid phase in the bag-type container may become liquid phase between 10 to 20 seconds, 20 to 30 seconds, or 30 to 60 seconds after being removed from the first surface.

[0047] In one embodiment, method 2000 may include thawing a second frozen sample in a second bag-type container that is in contact with the first and second surfaces. The second bag-type container may have a different size from the first bag-type container. The thawing process for the second bag-type container may include any of the methods described for thawing bag-type containers.

[0048] (III. Exemplary Systems) Exemplary systems that can be used in conjunction with the methods described herein may include the systems described in BioLife Solutions ThawSTAR® CB and U.S. application No. 16 / 054,454 filed on 3 August 2018, the entire contents of which are incorporated herein by reference for all purposes. Exemplary systems may be combined with, and may include, the embodiments of the apparatus shown in Figures 1A, 1B, and 1C.

[0049] Figure 3 shows the internal components of the defrosting unit 100, and in particular shows a portion of the defrosting unit 200 with the top shell, touchscreen cowl, touchscreen interface, and front panel removed. The rear panel 135 is shown. The top heater plate 240 is shown, but may be formed from a material that generally has high thermal conductivity, such as aluminum, aluminum alloy, copper, copper alloy, stainless steel, carbon fiber, or graphene material. In such embodiments, the top heater plate 240 may have a thermal conductivity of 12 to 400 watts per meter, per Kelvin (κ = 12 to 400 W / (m·K)), or an increment or gradient of conductivity within that range. There are two or more heaters 255 coupled to the top surface of the top heater plate 240. In some embodiments, the heaters 255 may be resistance heaters, such as flexible silicone mat heaters. In other embodiments, the heaters 255 may cover most of the surface area of ​​the top surface of the top heater plate 240. In one embodiment, two heaters 255 are separated by a gap 256 that allows the passage or placement of one or more thermistors 257 between them. The one or more thermistors 257 may be embedded in the upper heater plate 240 to monitor the temperature of the upper heater plate 240 and may provide thermal measurement information to a control unit, so the temperature may be controlled by a feedback circuit of the control unit that regulates the energy applied to the two heaters 255. In one embodiment, the heaters 255 on or inside the upper heater plate 240 can be operated on an independent control circuit so that the thermal input to the heater plate may be actively regulated (manually by operator input or automatically by an algorithm) to balance the local temperature of the upper heater plate 240 in accordance with any non-uniform heat sinks that may come into contact with the upper heater plate 240.In one embodiment, the number of individual heaters 255 on the upper plate may be three or more to apply greater regional control of the temperature of the upper heater plate 240, providing more precise control and dynamic balance of heat input to the plate, thereby enabling the thawing unit to accept bag-type containers of a wide range of sizes and volumes and thaw them uniformly.

[0050] In one embodiment, the heaters 255 may be individually controlled as a subset based on their position on the upper surface of the upper heater plate 240. For example, heaters 255 located on the front of the upper heater plate 240 may be regulated to a different temperature than heaters located on the rear of the upper heater plate 240. Alternatively, or in combination, heaters 255 located on the left side of the upper heater plate 240 may be regulated to a different temperature than heaters located on the right side of the upper heater plate 240. In a further embodiment, the heaters 255 may be thermally insulated from each other and / or from the rest of the defrosting device on the surface of the upper heater plate 240.

[0051] The upper heater plate 240 is attached to the cantilever assembly 202 by two concentric ring surface bearings so as to interface with three flanged dry bearings 250 that rotate on shafts embedded in each of the two cantilever arms 205. The cantilever assembly 202 may also be considered a cantilever clamping mechanism formed by the two cantilever arms 205, a cross plate 210, and a push bar 215. A circular bearing race 245 restricts the movement of the upper heater plate 240 to rotation around an axis that coincides with the intersection of a horizontal plane passing through the center of the freezing bag and a front vertical plane passing through the centerline of the freezing bag. The two cantilever arms 205 are joined by two cross plates 210 that reinforce the cantilever assembly and prevent distortion of the assembly under uneven clamping loads. The cantilever arms 205 rotate on two pivots 225 that connect to two bearing blocks (shown in Figure 4 below), also attached to the base plate 285. The cantilever beam assembly 202 is articulated as a whole by a push bar 215 attached to both cantilever beam arms 205 via two pivot bearings 220. The push bar 215 is articulated by a force generated by a screw jack mechanism 290.

[0052] A model of a standard cryopreservation bag is shown as a container 260 clamped between an upper heater plate 240 and a lower heater plate 230. The lower heater plate 230 is positioned on a frame support 235, which is part of an extendable drawer 265 and is movable with it. The lower heater plate 230 is formed of the same or different material having corresponding thermal conductivity, as described with respect to the upper heater plate 240. By releasing the clamping pressure generated by the screw jack mechanism 290 and raising the cantilever assembly 202 and the mounted upper heater plate 240, the drawer 265 (and the container 260 positioned inside it) can be extended forward from the rest of the apparatus on a roller bearing slide. The forward and backward movement of the drawer 265 allows any suitable preservation bag (indicated here by the container 260) to be introduced into and removed from the apparatus.

[0053] Further illustrating is a graphics control circuit board 280 mounted on the upper shell, containing a separate non-temporary computer-readable medium, and electronically connectable to a touchscreen interface 140 and / or access port 145. A peripheral circuit board 295 contains a separate non-temporary computer-readable medium and includes a microcontroller for controlling the mechanical and electrical power components of the device. The decompression unit 200 may further include a power cord, a power switch interface module 270, a cooling fan 292, and a wire link-chain harness 267 (shown as a volume-filling basic element).

[0054] Figure 4 shows the internal components of the thawing unit 200, focusing on the temperature sensors incorporated into the structure of the lower heater plate 230. In particular, the multiple container temperature sensor islands 675 are located in and pass through the body of the lower heater plate 230, and thus the temperature sensor islands 675 can monitor the surface temperature of cryopreservation containers placed on or clamped thereto on the surface of the lower heater plate 230. The multiple temperature sensor islands 675 are distributed along the lateral centerline of the lower heater plate 230. The spacing between the temperature sensor islands 675 is an arrangement that generally provides contact between two or more temperature sensor islands 675 and a standard cryopreservation bag container, which represents most commercially available bag container products. In one embodiment, for example, in a 25 mm storage container with a relatively small surface area, only one temperature sensor island 675 may be in contact with the storage container. In one embodiment, two temperature sensor islands 675 may have a distribution and size such that they are in contact with a 25 mm storage container. In contrast to the upper heater plate 240, the position of the temperature sensor island 675 within the lower heater plate 230 has the advantage that gravity, when the contents reach the liquid phase, displaces any gas pockets present inside the container on the bottom side of the container, thus providing an optimal heat path between the contents and the temperature sensor island 675. In other words, any air bubbles in the freezing bag rise to the top of the bag, and the bottom of the bag becomes substantially flat on the surface of the lower heater plate 230, maximizing contact with the available heat sensor. Another advantage of placing the sensor on the lower heater plate 230 is that its position is stationary, whereas a sensor placed on the upper heater plate 240 would be subjected to vibration as part of the thawing process. Naturally, it is recognized that in some embodiments, a heat sensor placed on the upper heater plate 240 may offer alternative advantages, such as targeting a specific location for heat measurement in a particular container. In further embodiments, the heat sensor may be a thermocouple, a thermistor, an IR sensor, or an RTD sensor.

[0055] A further embodiment of the sample thawing apparatus may include a communication module, formed by a non-transient computer-readable medium, configured to transmit sample data from other devices, including thermal data relating to a sample container held by the thawing apparatus. The communication module can directly engage with the temperature sensors of the sample thawing apparatus, such as a temperature sensor island 675. The communication module may also be electronically coupled with a graphic control circuit board 280, a peripheral circuit board 295, and a touchscreen interface 140 to enable control of all aspects of the apparatus. The communication module may be further configured to communicate with a remote microprocessor (e.g., a cloud-based server or computer) to sort and display data. The communication module may be configured to receive instruction data or sample vial identification data and to appropriately control the heating of the sample vial.

[0056] Figure 5 schematically shows a cross-section of the lower heater plate sensor 800 (alternatively referred to as the “thermal sensor”), which is a subcomponent of the sensor island. An insulating disk 810 is positioned in a cylindrical recess in the lower heater plate 230, supported by a ring flange 805, which may be an integrated structure of the lower heater plate 230. In one embodiment, the insulating disk may be fixed to a thermally conductive material to which a thermocouple or other temperature sensor structure is attached. In one embodiment, the insulating disk 810 may be constructed from, but is not limited to, a semi-rigid foam material that provides spring-like resistance to downward forces, and may have a thermal conductivity (κ) in the range of 0.02 to 0.15 W / (m·K). In various embodiments, the semi-rigid foam material may be a polyethylene foam blend, alternatively a polymer foam, or a laminate of foam materials. The insulating disk 810 includes a recess 812 in its upper surface that receives a contact disk 815 of the thermally conductive material. In one embodiment, the contact disk 815 may be made of copper, a copper alloy, silver, a silver alloy, aluminum, or an aluminum alloy, but is not limited thereto. In one embodiment, the contact disk 815 has a thermal conductivity of 150 watts per meter per Kelvin or greater (κ > 150 W / (m·K)). In one embodiment, the contact disk 815 may be plated with a coating such as nickel or gold to suppress corrosion of the contact disk 815. The thermocouple joint 820 is fixed to the underside of the contact disk 815, generally at the center of the contact disk 815. In one embodiment, the thermocouple joint 820 may be attached to the contact disk 815 by a solder joint 825. In one embodiment, a resistance temperature sensor may be used instead of the thermocouple joint. The thermocouple wire lead 830 exits from the underside of the insulating disk 810 through a channel 835. In one embodiment, the contact disk 815 may be bonded to the insulating disk 810 by adhesive bonding.

[0057] In the operation, the frozen freezing bag or sample container may be considered a thermal sink load. The thermal sink load is positioned on the lower heater plate 230 and in contact with the contact disk 815, thus forming a dynamic heat flux through the sensor system including the lower heater plate 230, the insulating disk 810, the contact disk 815, and the freezing bag container. Each of one or more thermal sensors (e.g., temperature sensor island 674) on the lower heater plate 230 may form such a sensor system as shown in Figure 4, and may be controlled individually or in combination based on the accumulation of measured sensor data. The insulating disk 810 may be formed from a material selected to have the lowest thermal conductivity of the sensor system, so that, under the conditions of the established temperature flux between the lower heater plate 230 and the freezing bag container, the maximum temperature drop in the heat path occurs across the insulating disk 810. As a result, the temperature of the contact disk 815 is closely coupled to the temperature of the freezing bag. In other words, temperature measurement is relatively more specialized in the portion of the freezing bag at each heat sensor in the lower heater plate 230.

[0058] As the temperature of the freezing bag container, positioned to be in contact with the lower heater plate 230, rises rapidly, the temperature difference between the lower heater plate 230 and the freezing bag container decreases, and the magnitude of the heat flux through each sensor system constantly changes, potentially having localized fluctuations as measured by each thermal sensor on the lower heater plate 230. As a result, the temperature of the contact disk 815 does not necessarily come into equilibrium with the freezing bag container, and the temperature of the contact disk 815 becomes a relative surrogate for the temperature of the freezing bag container in the area of ​​contact at the interface between the bag and the contact disk 815. As the temperature of the freezing bag container rises and the temperature difference between the lower heater plate 230 and the freezing bag container decreases, the temperature of the sensor contact disk 815 more closely represents the temperature of the freezing bag container at the point where the phase change of the contents of the freezing container is almost complete, and the temperature of the contact disk 815 correlates with the temperature recorded by the sensor attached to the inner wall of the bag with an accuracy of ±10%.

[0059] Therefore, the temperature of the sensor contact disk 815 may be used as an accurate and repeatable metric for the completion state of the phase change of the contents of the freezing bag container. Thus, the interpretation of the temperature profile derived from the sensor contact disk 815 may be used as the primary or exclusive data stream for the completion of the thawing algorithm that controls the thawing sequence in the device. The application of multiple sensor contacts to the freezing bag container (as shown in Figure 6) allows the temperature profile of the freezing bag container to be measurable at different locations in the container, enabling integration into more complex data processing algorithms that may compensate for temperature gradients within the container or within the heater plate, and in addition, provides a spare sensor as a guarantee of functionality in the event of a single sensor failure.

[0060] The various applications of the defrosting apparatus are evident from the drawings above and include, but are not limited to, illustrative sequences of operations described herein. The described sequence of events to follow is one of many possible specific sequences of events that may be applied to embodiments of the present invention and is not intended to limit in any way any sequence of states, stages, or events that may be associated with the use of the apparatus.

[0061] (IV. Computer Systems) Embodiments of this technology may include a defrosting system. The defrosting system may include a defrosting device which may be any of the defrosting devices described herein. The defrosting system may include a computer system which includes instructions and which, when the instructions are executed, controls the defrosting device to perform a defrosting method.

[0062] Any computer system described herein may use any appropriate number of subsystems. An example of such subsystems is shown in Figure 6 by computer system 10. In one embodiment, the computer system includes a single computer device, and the subsystems may be components of the computer device. In another embodiment, the computer system may include multiple computer devices, each of which is a subsystem having internal components. The computer system may include desktop and laptop computers, tablets, mobile phones, other mobile devices, and cloud-based systems.

[0063] The subsystems shown in Figure 6 are interconnected via a system bus 75. Additional subsystems are shown, such as a printer 74, a keyboard 78, a storage device 79, and a monitor 76 (e.g., an LED display screen) coupled to a display adapter 82. Peripheral and input / output (I / O) devices coupled to the I / O controller 71 may be connected to the computer system by any number of means known in the prior art, such as input / output (I / O) ports 77 (e.g., USB). For example, an I / O port 77 or an external interface 81 (e.g., Ethernet, Wi-Fi, etc.) may be used to connect the computer system 10 to a wide area network such as the Internet, a mouse input device, or a scanner. The interconnection via the system bus 75 allows the central processor 73 to communicate with each subsystem, control the execution of multiple instructions from the system memory 72 or storage device 79 (e.g., a hard disk or optical disk), and enable the exchange of information between subsystems. The system memory 72 and / or storage device 79 may be in the form of computer-readable media. Other subsystems include data acquisition devices 85 such as a camera, microphone, and accelerometer. Any data described herein may be output from one component to another, or to the user.

[0064] A computer system may include multiple identical components or subsystems connected to one another by, for example, an external interface 81, an internal interface, or a removable storage device that can be connected to and disconnected from one component to another. In one embodiment, the computer system, subsystem, or device can communicate over a network. In this case, one computer may be considered a client and another computer may be considered a server, and each may be part of the same computer system. The client and server may each include multiple systems, subsystems, or components.

[0065] Aspects of the embodiments may be implemented in the form of control theory using hardware circuits (e.g., application-specific integrated circuits or field-programmable gate arrays) and / or computer software having a modular or integrated generally programmable processor. As used herein, the processor may include a single-core processor, a multi-core processor, or multiple processing units on a single circuit board or network together with dedicated hardware on the same integrated chip. Based on the disclosures and teachings provided herein, those skilled in the art will know and recognize other means and / or methods of implementing embodiments of the invention using hardware and combinations of hardware and software.

[0066] Any software component or function described in this application may be implemented as software code executed by a processor using, for example, a suitable computer language such as Java, C, C++, C#, Objective-C, or Swift, or a scripting language such as Perl or Python, using, for example, the prior art or object-oriented techniques. The software code may be stored as a series of instructions or commands on a computer-readable medium for storage and / or transmission. Suitable non-temporary computer-readable media may include random access memory (RAM), read-only memory (ROM), magnetic media such as hard disks and floppy disks, optical media such as compact discs (CDs) and DVDs (digital multipurpose discs), Blu-ray discs, and flash memory. The computer-readable medium may be a combination of any of these storage or transmission devices.

[0067] Such programs may be encoded and transmitted using carrier signals adapted for transmission over wired, optical, and / or wireless networks compliant with various protocols, including the Internet. In this case, a computer-readable medium may be formed using the data signals encoded by such a program. The computer-readable medium encoding the program code may be packaged with a compatible device or provided separately from other devices (e.g., by internet download). Any such computer-readable medium may reside on or within a single computer product (e.g., a hard drive, CD, or an entire computer system), or on or within different computer products within a system or network. The computer system may include a monitor, printer, or other suitable display for providing the user with any of the results described herein.

[0068] Any of the methods described herein may be performed entirely or partially by a computer system including one or more processors which may be configured to perform the steps. Therefore, embodiments relating to a computer system configured to perform the steps of any of the methods described herein may have different components performing each step or each group of steps. Although indicated as numbered steps, the steps of the methods herein may be performed simultaneously, at different times, or in different orders. In addition, parts of these steps may be used in conjunction with other parts of other methods. All or part of the steps may be optional. In addition, any step of any of the methods may be performed using other means of modules, units, circuits, or systems for performing these steps.

[0069] Certain details of a particular embodiment may be combined in any suitable manner without departing from the spirit and scope of the embodiments of the present invention. However, other embodiments of the present invention may be directed to specific embodiments relating to each individual aspect or to specific combinations thereof.

[0070] The above description of exemplary embodiments of this disclosure is provided for illustrative and illustrative purposes only. It is not intended to be exhaustive or to limit the disclosure to any specific form described, and numerous modifications or variations are possible based on the teachings above.

[0071] Unless otherwise specified, the use of “a certain” or “one” is intended to mean “one or more.” Unless otherwise specified, the use of “or” is intended to mean “inclusive or,” and not “exclusive or.” A reference to a “first” part does not necessarily require that a second part be provided. Furthermore, unless otherwise specified, a reference to a “first” or “second” part does not limit the referenced part to a specific location. The term “based on” is intended to mean “based at least in part.”

[0072] Certain details of a particular embodiment may be combined in any suitable manner without departing from the spirit and scope of the embodiments of the present invention. However, other embodiments of the present invention may be directed to specific embodiments relating to each individual aspect or to specific combinations thereof.

[0073] The above description of exemplary embodiments of the present invention is provided for illustrative and explanatory purposes only. It is not intended to be exhaustive or to limit the disclosure to the exact embodiments described, and numerous modifications or variations are possible based on the teachings above.

[0074] In the preceding description, several details have been provided to give an understanding of various embodiments of the present technology for illustrative purposes. However, it will be apparent to those skilled in the art that certain embodiments may be carried out without some of these details or with additional details.

[0075] As various embodiments are described, it will be recognized by those skilled in the art that various modifications, alternative structures, and equivalents may be used without departing from the spirit of the invention. In addition, several well-known methods and elements are not described in order to avoid unnecessarily obscuring the invention. Furthermore, details of any particular embodiment may not always be present in variations of that embodiment, or may be added to other embodiments.

[0076] Where a range of values ​​is provided, each intervening value is understood to be specifically disclosed up to one-tenth of the lower limit unit, unless otherwise specified, between the upper and lower limits of the range. Within the stated range, each smaller range between any stated value or intervening value, and any other stated or intervening value within the stated range, are included. The upper and lower limits of these smaller ranges may, independently, be included in or excluded from the range, and each range in which one limit is included, neither limit is included, or both limits are included is included in the present invention and depends on any particularly excluded limit within the stated range. If a stated range includes one or both limits, it also includes ranges that exclude one or both included limits.

[0077] As used herein and in the appended claims, the singular forms “a” and “one” include the plural form unless the context makes it clear otherwise. Thus, for example, a reference to “method” includes multiple such methods, and a reference to “heater” includes one or more heaters and their equivalents known to those skilled in the art. The present invention has been described in detail for clarity and understanding. However, it is recognized that certain changes and modifications can be carried out within the scope of the appended claims.

[0078] All patents, patent applications, publications, and descriptions described herein are included by reference in their entirety for all purposes and none are considered prior art.

Claims

1. A method for thawing a frozen sample in a bag-type container, wherein the method is: Measuring multiple first temperatures of the bag-type container in contact with a first surface and a second surface, wherein each of the multiple first temperatures is measured by a different sensor of a plurality of sensors, and each of the plurality of sensors is configured to measure the temperature at a different location on the bag-type container, Comparing each of the aforementioned multiple first temperatures with a first threshold, Using the above comparison, identify a subset of the plurality of sensors, wherein each sensor in the subset of the plurality of sensors measures a first temperature below the first threshold, The frozen sample is heated using the first heater bank, and simultaneously the frozen sample is heated using the second heater bank. The plurality of second temperatures of the bag-type container are measured using the subset of the plurality of sensors, When the second temperature of the plurality of second temperatures exceeds a second threshold indicating the presence of a partially thawed sample in the bag-type container, Heating the partially thawed sample using the first heater bank, To terminate the heating of the partially thawed sample using the second heater bank, A method comprising heating the partially thawed sample using the first heater bank for a predetermined period of time, and then terminating the heating of the partially thawed sample using the first heater bank.

2. The method according to claim 1, wherein when heating of the partially thawed sample using the first heater bank is terminated, the majority of the partially thawed sample is an aqueous solution and a solid phase remains in the partially thawed sample.

3. The heating of the partially thawed sample is terminated at a predetermined time. The method according to claim 2, wherein the predetermined time is calculated using an empirically determined phase change period.

4. The method further includes measuring a plurality of third temperatures of the bag-type container using the subset of the plurality of sensors, The method according to claim 2, wherein heating of the partially thawed sample using the first heater bank is terminated when the third temperature of the plurality of third temperatures exceeds a third threshold.

5. The method according to claim 4, wherein the third threshold is determined empirically.

6. The plurality of third temperatures of the bag-type container are measured using the subset of the plurality of sensors, The method further includes comparing the plurality of third temperatures with a reference temperature profile, The method according to claim 1, wherein heating of the partially thawed sample using the first heater bank is terminated when the third temperature of the plurality of third temperatures deviates significantly from the reference temperature profile.

7. The method further includes arranging the bag-shaped container in contact with the first surface and the second surface, The port of the bag-shaped container is located near the first end of the first surface and near the first end of the second surface. The method according to claim 1, wherein the port of the bag-type container is located closer to the first heater bank than to the second heater bank.

8. The further includes arranging the aforementioned bag-shaped container, The bag-shaped container overlaps with the first surface in a first portion of the first surface, and does not overlap with the first surface in a second portion of the first surface. The bag-shaped container overlaps with the second surface in the first portion of the second surface, and does not overlap with the second surface in the second portion of the second surface. The first heater bank is positioned closer to the first portion of the first surface and the first portion of the second surface than to the second portion of the first surface and the second portion of the second surface, The second heater bank is positioned closer to the second portion of the first surface and the second portion of the second surface than to the first portion of the first surface and the first portion of the first surface, The bag-shaped container has a surface area smaller than the surface area of ​​the first surface, The method according to claim 1, wherein the bag-type container has a surface area smaller than the surface area of ​​the second surface.

9. The method according to claim 8, wherein the surface area of ​​the bag-shaped container is 30% or less of the surface area of ​​the first surface.

10. The further includes arranging the aforementioned bag-shaped container, The method according to claim 1, wherein the line perpendicular to the first surface extends through the second heater bank but not through the bag-shaped container.

11. Receiving user input to specify the size of the bag-type container, The method according to claim 1, further comprising excluding sensors from the subset of the plurality of sensors based on the size of the bag-shaped container.

12. The method according to claim 11, further comprising receiving user input that identifies the type of medium in the bag-type container.

13. The method according to claim 1, wherein measuring the plurality of first temperatures of the bag-shaped container in contact with the first surface and the second surface includes measuring the plurality of first temperatures at five locations that are non-uniformly distributed across the first surface and the second surface.

14. The method according to claim 1, wherein the subset of the plurality of sensors has fewer sensors than the plurality of sensors.

15. The aforementioned frozen sample is the first frozen sample, The bag-shaped container is a first bag-shaped container characterized by a first size, The aforementioned method, The method further includes thawing a second frozen sample in a second bag-type container that is in contact with the first surface and the second surface, The method according to claim 1, wherein the second bag-type container is characterized by a second size different from the first size.

16. The method according to claim 1, wherein the first threshold is lower than the temperature of the bag-type container measured when the bag-type container first comes into contact with the first surface and the second surface.

17. Heating the frozen sample using the first heater bank involves targeting a temperature setpoint in the range of 37°C to 45°C for the first heater bank. The method according to claim 1, wherein heating the frozen sample using the second heater bank is performed with a target temperature setpoint for the second heater bank.

18. The method according to claim 1, wherein heating the partially thawed sample using the first heater bank is targeted to a temperature setpoint in the range of 37°C to 45°C for the first heater bank.

19. The bag-shaped container is brought into contact with the first surface, The bag-shaped container is brought into contact with the second surface, The method according to claim 1, further comprising clamping the bag-shaped container between the first surface and the second surface.

20. Loading the bag-shaped container into the device's drawer, The method according to claim 19, further comprising removing the bag-shaped container from the apparatus after completing the heating of the partially thawed sample using the first heater bank.

21. It is a defrosting system, The first surface and, The second surface and Multiple sensors, The first heater bank and The second heater bank, A thawing device having, A defrosting system comprising: a computer system having instructions to control a defrosting device to perform the method described in claim 1 when executed.

22. The defrosting system according to claim 21, wherein the first surface is a first plate and the second surface is a second plate.

23. The defrosting system according to claim 21, wherein the plurality of sensors are non-uniformly distributed across the first surface and the second surface.

24. The defrosting system according to claim 21, wherein the first heater bank is positioned closer to the first end of the first surface and the first end of the second surface than the second heater bank is positioned between the first end of the first surface and the first end of the second surface.

25. A bag-type container containing a frozen sample is placed between the first surface and the second surface for thawing. The thawing system according to claim 21, wherein the lines perpendicular to the first surface extend through the second heater bank and not through the bag-shaped container.

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