Engagement portion for a sample container holder

Abstract

Apparatus for securely engaging a payload such as a sample container rack, allowing for transport by automated sample handling systems used in high throughput analytical laboratory settings. Mass measuring means may be provided to determine a payload mass and / or a payload mass distribution.

Description

ENGAGEMENT PORTION FOR A SAMPLE CONTAINER HOLDERFIELD

[0001] The present disclosure relates to mechanisms for securely engaging a sample container rack, allowing for a rack to be moved in an automated sample handling system such as those used in analytical laboratory settings. The disclosure is applicable at least to equipment of the type used in high throughput analytical laboratories, and also equipment used in small scale applications.BACKGROUND

[0002] Automation has revolutionized the operation of analytical and research laboratories. By integrating advanced robotics, instrumentation, and software, laboratory automation optimizes workflows, enhances process reproducibility, as well as reducing labor costs

[0003] At its core, laboratory automation aims to streamline experimental workflows by replacing manual tasks with automated processes. This involves the integration of robotic systems capable of performing a wide array of tasks, ranging from sample preparation and handling, sample analysis, output data analysis and storage.

[0004] Laboratory automation encompasses a diverse array of methodologies tailored to specific process requirements. Liquid handling robots, equipped with precision pipetting systems, enable accurate dispensing of reagents and samples, facilitating high-throughput screening and assay development. Integrated robotic workstations automate sample preparation workflows, including DNA extraction, purification, and amplification, revolutionizing genomics and molecular biology research. High-content imaging systems coupled with automated analysis software enable rapid acquisition and analysis of large-scale image datasets, empowering researchers in drug discovery and cell biology.

[0005] Automation is especially prevalent in high throughput analytical laboratories of the type used to analyze samples of clinical, environmental and industrial origin. Such laboratories are tasked with performing analysis on hundreds or thousands of individual samples per day, and automation is absolutely essential to operations.

[0006] Sample handling is also a feature of non-automated systems, such as in small-scale diagnostic laboratories and research environments.

[0007] Some processes in sample handling systems are carried out manually, or semi-manually with machine assistance.

[0008] Some sample handling systems rely on a robot or other means to transport sample containers (such as tubes) between locations across the system. The sample containers may be held in a container rack. Conventionally, stepper motor-driven gripper fingers may be used to grip and release objects in robot-based systems. Such arrangements are contraindicated for handling potentially infectious samples (such as pathology samples) given the potential for the samples to be dropped, thereby creating infectious spill and aerosols. Particularly, a power failure may result in the stepper motor opening the gripping fingers. Alternatively, the samples may be knocked from between the gripper fingers. Moreover, the need for a stepper motor adds to weight and expense.

[0009] In addition or as an alternative the problems discussed above, a second problem arises where a sample handling robot is intended to pick up payloads of variable mass, such as a full sample rack compared to a half-empty sample rack. Moreover, different payloads have varying centers of gravity depending on where the sample containers are disposed in the rack being transported. For example, sample containers may be grouped together toward an end of the rack, or be grouped in the center of the rack. A specific issue arises in that a Proportional-Integral- Derivative (PID) controller of a collaborative robot may have multiple values that should be tuned to within 10% accuracy in order to avoid the motion controller falling into an error state or performing erratically.

[0010] It is an aspect of the present disclosure to provide an improvement in prior art means for handling a sample container rack. It is a further aspect of the present disclosure to provide a useful alternative to prior art means for handling a sample container rack.

[0011] The discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the present disclosure. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each provisional claim of this application.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The foregoing aspects and other features of the disclosed embodiment are explained in the following description, taken in connection with the accompanying drawings, wherein:

[0013] FIG. 1 illustrates in upper perspective view an exemplary engagement portion of a sample handling workstation, the engagement portion configured to engage with a tube rack carrier.

[0014] FIG. 2A illustrates diagrammatically and in lateral view the engagement portion of FIG. 1 alongside a payload (tube rack, tubes in the tube rack, and tube rack carrier). The tube rack carrier is configured to engage with the engagement portion of FIG. 1. The engagement portion and tube rack carrier are disposed on a surface, and are disengaged as would be the case before instigation of any program by the sample handling workstation.

[0015] FIG. 2B follows chronologically from FIG. 2A, showing the engagement portion having been moved to located below a complimentary formation of tube rack carrier.

[0016] FIG. 2C follows chronologically from FIG. 2B, showing the engagement portion having been moved upwardly by a motor of the workstation such that a cavity of the engaging portion engages with a complimentary formation of tube rack carrier.

[0017] FIG. 2D follows chronologically from FIG. 2C, showing the engagement portion having been moved further upwardly by a motor of the workstation such that the tube rack carrier is lifted from the surface.

[0018] FIG. 3 A and FIG. 3B illustrate diagrammatically and in upper perspective view the engagement portion of FIG. 1 and a solenoid-driven locking mechanism configured to lock the complimentary formation of the tube rack to the engaging portion. The locking mechanism may be actuated before the tube rack carrier is lifted (i.e. at the time point shown in FIG. 2C). FIG. 3 A illustrates the mechanism in the unlocked state, while FIG. 3B illustrates the locked state. The complimentary formation is not drawn for clarity.

[0019] FIG. 4A (diagrammatic lateral view) and FIG. 4B (lateral perspective view) illustrate the engaging portion of FIG. 1 connected to a member fitted with a strain gauge configured to determine the mass of the payload (tube rack, tubes in the tube rack, and tube rack carrier).

[0020] FIG. 5A (diagrammatic lateral view) and FIG. 5B (lateral perspective view) illustrate the engaging portion of FIG. 1 connected to a lever mechanism configured to determine the center of gravity of the payload (tube rack, tubes in the tube rack, and tube rack carrier).

[0021] FIG. 6 is a block diagram illustrating communication of output from an engaging portion first and second strain gauges to a processor, the processor communicating with a motor controller, and the motor controller in turn communicating with a motor which moves the engaging portion.

[0022] The drawings are not necessarily prepared to any particular scale or dimension and are not presented as being a completely accurate presentation of the various embodiments.SUMMARY

[0023] In a first aspect, but not necessarily the broadest aspect, there is provided a sample handling apparatus for engaging a sample container holder or a sample container holder carrier payload, theapparatus comprising an engaging portion configured to engage with a payload, wherein the engaging portion comprises a support surface configured to receive a generally downward force exerted by the payload due to gravity.

[0024] In one embodiment of the first aspect, the engaging portion comprises one or more cavities or formations configured to mate with a respective complimentary formation or cavity of the payload.

[0025] In one embodiment of the first aspect, the engaging portion is not reliant on any moving part to engage the payload under a lifting force.

[0026] In one embodiment of the first aspect, the apparatus comprises a locking arrangement, optionally comprising a locking structure configured to adopt a first position whereby the payload is permitted to disengage from the engaging portion, and a second position whereby the payload is prevented from disengaging from the engaging portion.

[0027] In one embodiment of the first aspect, the locking structure extends through or from the engaging portion.

[0028] In one embodiment of the first aspect, the apparatus comprises a solenoid or functional equivalent thereof configured to move the locking structure between the first and second positions.

[0029] In one embodiment of the first aspect, the apparatus comprises one or more mass measuring means associated with the engaging portion, wherein the one or more mass measuring means are configured to determine a payload mass and / or a mass distribution of a payload mass.

[0030] In one embodiment of the first aspect, one of the one or more mass measuring means is connected in series with the engaging portion such that the apparatus is capable of determining a mass of the payload.

[0031] In one embodiment of the first aspect, the one or more mass measuring means is associated with a flexible member, the flexible member being connected to a fixed point of the apparatus at a first end, and to the engaging portion at a second end such that increasing payload mass causes greater flexion of the flexible member which in turn causes the mass measuring means to determine a greater mass.

[0032] In one embodiment of the first aspect, one of the one or more mass measuring means is connected to the engaging means by a lever arrangement such that the apparatus is capable of determining a center of gravity of the payload.

[0033] In one embodiment of the first aspect, the one or more mass measuring means is connected to a lever member at a first end, and to the engaging portion at a second end such that increasing payload mass causes the second lever member end to move a greater distance downwardly and therefore the first lever member end to move a greater distance upwardly.

[0034] In one embodiment of the first aspect, the apparatus is configured to sample an output of the one or more mass measuring means substantially immediately upon lifting of a payload by the engaging portion and to determine the payload mass and / or the mass distribution of the payload mass by reference to the output.

[0035] In one embodiment of the first aspect, the output is regularly sampled for the period that the engaging portion maintains the payload in a lifted position.

[0036] In one embodiment of the first aspect, the apparatus comprises one or more motors configured to move the engaging portion, the one or more motors being adjustable by a controller incorporating a control loop feedback mechanism, the controller configured to receive an output of the one or more mass measuring means.

[0037] In one embodiment of the first aspect, the controller is a PID (proportional integral derivative) controller.

[0038] In one embodiment of the first aspect, the apparatus comprises a sample container holder carrier configured to mate with the engaging portion.

[0039] In one embodiment of the first aspect, the apparatus is configured as a component of a sample container handling robot configured to move a sample container from a first position to a second position in a sample processing workflow of an analytical laboratory.

[0040] In a second aspect there is provided a sample container handling robot configured to move a sample container from a first position to a second position in a sample processing workflow of an analytical laboratory, the sample container handling robot being collaborative with a human and comprising the apparatus of any embodiment of the first aspect.

[0041] In a third aspect there is provided a method of moving a sample container in a sample processing workflow of an analytical laboratory, the method comprising causing or allowing the apparatus of any embodiment of the first aspect to engage with a payload and to move the payload from a first position to a second position.DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS

[0042] After considering this description it will be apparent to one skilled in the art how the invention is implemented in various alternative embodiments and alternative applications.However, although various embodiments of the present invention will be described herein, it is understood that these embodiments are presented by way of example only, and not limitation. As such, this description of various alternative embodiments should not be construed to limit the scope or breadth of the present invention. Furthermore, statements of advantages or other aspects apply to specific exemplary embodiments, and not necessarily to all embodiments, or indeed any embodiment covered by the claims.

[0043] Throughout the description and the claims of this specification the word "comprise" and variations of the word, such as "comprising" and "comprises" is not intended to exclude other additives, components, integers or steps.

[0044] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may.

[0045] The term “payload” includes a carrier for a sample container holder, such as a carrier for a sample tube rack. The term may also be used to refer to a sample container holder per se.

[0046] The term “collaborative” in the context of a robot, includes a robot designed to work safely alongside humans in a shared workspace. A collaborative robot may comprise safety features such as speed limitations, force sensors, and collision detection to ensure it can work safely alongside humans without requiring physical barriers.

[0047] The term "sample container holder" includes any means for releasably holding a plurality of sample containers, preferably sample containers used to hold a sample for analysis in an automated sample handling system of an analytical laboratory. Each sample container may bedisposed in a separate cavity or space of the holder, and may be removed by a substantially vertical movement. Generally sample containers are held in a line, a grid, an array, or some other regular arrangement. Typically a sample container holder is dedicated to the purpose of holding sample containers. A sample container holder may not be a part of any item of laboratory equipment, or be an adapter allowing for multi-apparatus use, or any other contrivance that may otherwise be capable of, or used for, holding sample containers.

[0048] A sample container holder may be of substantially solid constructed and in the form of a block having cavities formed therein. Alternatively, it may be a tray having upwardly extending fingers with a sample container being retained upright between two or more fingers. As another option, the rack may be fabricated from wire, and therefore be of a generally open construction.

[0049] A sample container holder may be configured to hold at least about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 40, 50, 60, 70, 80, 90 or 100 sample containers.

[0050] A sample container holder may be configured to hold very small containers such as reaction tubes of milliliter capacity, slender test tubes having a capacity of 10-15 mL, and higher capacity tubes of more squat proportions such as 50 mL tubes. The containers may be primary tubes such as those used in pathology sample collection such as blood tubes, sputum jars, urine jars; PCR tubes; or secondary containers used for sample storage, sample aliquotting. A container may be compatible for use with a certain item of laboratory equipment such as a biochemistry analysis machine.

[0051] As used herein, the term "sample container holder carrier" includes any contrivance that is capable of carrying a sample container holder. Typically, the sample container holder carrier includes a portion for contacting a surface of sample container holder, and some means of preventing lateral movement of the sample container holder relative to that portion. In exemplaryform, the sample container holder carrier comprises a floor portion upon which the sample container holder may be disposed, and one or more walls extending upwardly from the floor portion so as to prevent lateral movement of sample container holder relative to the floor portion.

[0052] Any positional terms used herein (such as "lateral", "across", "above", "below", "higher", "lower", "upward", "downward", "vertical" "horizontal", "plan view") are to be considered with reference to a sample handling apparatus orientated so as to maintain a sample container in an upright position.

[0053] In a first aspect, there is provided a sample handling apparatus for engaging a sample container holder or a sample container holder carrier payload, the apparatus comprising an engaging portion configured to engage with a payload, wherein the engaging portion comprises a support surface configured to receive a generally downward force exerted by the payload due to gravity.

[0054] The present apparatus is a significant departure from prior art sample handling robots in terms of the means by which a payload (such as a sample container rack carrier) is engaged. Prior art contrivances typically exploit a gripping mechanism such as opposed “fingers” which pinch together to engage with a payload, or suction mechanisms reliant on a vacuum-based engagement. The present apparatus comprises an engaging portion without moving parts, any need for power or a motor and is not reliant on any vacuum system. Given the avoidance of any complexities, the present engaging portion is expected to function reliably and without the need for maintenance or repairs for extended periods of time.

[0055] The present engaging portion functions to lift a payload from beneath, such that the weight of the payload bears on a generally upwardly facing surface of the engaging portion. In some ways, the engaging portion is akin to a crane hook with the upwardly facing surface of the hook contacting a downwardly facing surface of a structure such as a sling eye. In another analogy theengaging portion may be considered to function similarly to the forks of a forklift, with the upwardly facing surfaces of the forks engaging with downwardly facing surfaces of a pallet.

[0056] To increase the level of engagement between the engaging portion and the payload, the engaging portion may have a cavity, such as a pocket or a depression, that receives a complimentary formation of the payload. In such an arrangement, the payload may comprise a downwardly directed formation which accepts an upwardly directed cavity. The downwardly direct formation may be configured to be disposed above the surface on which the payload is disposed, such that the cavity of the engaging portion may be moved laterally into a position beneath the formation, with lifting of the engaging portion leading to engagement of the cavity with the formation. With further lifting, the formation eventually contacts a floor of the cavity, such that further upward movement of the engaging portion acts to lift the entre payload.

[0057] As will be readily appreciated, the arrangement described above may be reversed, with the payload having the cavity and the engaging portion having the complimentary formation.

[0058] The conventional approach to designing a gripping mechanism in prior art sample handling robots is to use a stepper motor to actuate fingers to pinch the payload. The motor may fail or the power supply cut in which case the sample containers may be dropped. This is less of an issue for light payloads or consistent payloads. However, many applications involve relatively heavy payloads. For example where a payload is a tube rack holding 24 tubes, with each tube holding 15 ml; a total mass of 360 g must be lifted. Moreover, it is not uncommon for a robot to then handle a partially loaded rack, which may have a weight of as little as 20 g. Such variability in payload causes difficulty in designing a gripping mechanism having the capability of handling heavy payloads without dropping, while not using excessive force to grip lighter payloads.

[0059] Conventional gripping arrangements may dispose the center of gravity of the payload somewhat distally to the gripper, or a supporting structure of the gripper. Such distal dispositionmay cause material stresses, or excessive loads being placed on motors. The present engaging portion may be block-like and therefore amenable to being positioned proximal to any support, or any motor. The block-like geometry further facilitates centering the payload along the center-line of the engaging portion leading to a generally increase in stability.

[0060] In the life sciences industry where the risk of dropping an infectious sample is severe, even a rare instance of a tube being dropped by a robot is unacceptable. The present engaging means, with its hook-like or fork-like mode of engagement, and having any moving parts, is not reliant on any motor, power or vacuum to maintain engagement with the payload and is therefore distinctly advantageous over the prior art.

[0061] To improve the security of engagement, and to prevent any inadvertent disengagement, the present apparatus may comprise some mechanism for selectively locking the payload to the engaging portion. The mechanism may comprise a structure (such as a member) which is moved so as to insert into a cavity of the pay load, or a member which moves so as to compress the payload against a surface of the engaging portion, or two members which sandwich the payload therebetween, so as to lock the payload to the engaging means. Typically, the member is a part or, or at least proximal to, the engaging means. The member is preferably moved by non-motor means so as to reduce complexity and cost. The member may be moved by the action of a solenoid, for example.

[0062] In a different approach, the locking arrangement is an inflatable chamber such as a bellowslike arrangement which, when inflated by a pressurized air source, the outer surfaces move outwardly such that the locking structure wedges tightly between a surface of the engaging portion and a surface of the payload.

[0063] Movement of the locking structure is typically processor-controlled so as to synchronize with various functions of the robot. For example, when the robot has parked the payload on asurface the locking structure may be withdrawn so as to allow a human to deliberately remove the payload, and optionally load a new payload. In that state, the processor (by way of program instructions) may cause the solenoid to be energized so as to keep the locking structure away from the payload. Conversely, when the robot is under instruction to move a payload, the processor may de-energize the solenoid thereby allowing a spring to urge the locking structure toward the payload. The payload is therefore locked in position while being moved, and therefore invulnerable to being dropped.

[0064] The locking structure may function to prevent or limit the movement of the payload relative to the engaging portion, thereby limiting any opportunity for slippage and therefore dropping.

[0065] The apparatus may be configured to sense or infer the state (i.e. locked or unlocked or indeterminate) of the locking arrangement. A sensed or inferred state may be utilized by a processor of the apparatus to conditionally block any movement of the engaging portion where the sensed state is unlocked or indeterminant. For example, where the locking arrangement comprises a locking structure, a position of the locking structure may be sensed or inferred. The sensed or inferred position may be indicative of the payload being locked to, or unlocked from, the engaging portion. Position of the locking structure may be sensed by any suitable means including a contact sensor, a proximity sensor, a magnetic sensor, a Hall effect sensor, a reed switch, an inductive sensor, a capacitive sensor, an electrical conductivity sensor, a mechanical sensor, a potentiometric sensor, an electrical switch, an optical sensor, a camera, or an ultrasonic sensor. Alternatively, the position of the locking structure may be inferred. For example, the energized / non-energized state of a solenoid that moves the locking structure may be polled to infer the position of a locking pin.

[0066] It may be considered that any lesser security of engagement resulting from the avoidance of using a conventional stepper motor-enabled gripping mechanism may be effectively addressed by the locking arrangement.

[0067] Movement of even a securely engaged payload may nevertheless cause problems when the payload is moved by the robot. Problems arise where payloads of highly variable masses and / or center of gravity are encountered at first instance (depending on the number, size, and distribution of tubes in a rack holder as first loaded), or where the mass and / or center of gravity changes in the course of a workflow (when tubes are added to, or removed from, a tube rack). Particularly, control of the motor(s) involved in moving the payload can respond to processor-generated instructions erratically, or not at all.

[0068] Sample handling robots typically comprise some type of electronic feedback mechanism to control the motor(s) involved in moving a payload. One example is a PID controller which automatically and regularly compares a desired target value (setpoint or SP) with the actual value of the system (process variable or PV). The difference between these two values is called the error value. The controller applies corrective actions automatically to bring the PV to the same value as the SP using three methods: The proportional (P) component responds to a current error value by producing an output that is directly proportional to the magnitude of the error. This provides immediate correction based on how far the system is from the desired setpoint. The integral (I) component, in turn, considers the cumulative sum of past errors to address any residual steadystate errors that persist over time, eliminating lingering discrepancies. Lastly, the derivative (D) component predicts future error by assessing the rate of change of the error, which helps to mitigate overshoot and enhance system stability, particularly when the system undergoes rapid changes. The PID output signal can directly control motors through voltage, current, or other modulation methods, depending on the application.

[0069] The present apparatus may be configured to provide information required by a PID controller (or other similar controller) such as mass and center of gravity of the payload. Such information may be provided by way of payload mass measurements obtained via the engaging portion, and continuously fed to the controller. Thus, the motor(s) and therefore movements ofthe robot may be tuned on the fly to more accurately position the engagement portion with reference to a point in space such as a payload, a position about a payload, or a surface.

[0070] In one embodiment, a purely mechanical arrangement is provided so as to provide one or both of payload mass and center of gravity. Preferably, the arrangement provides both parameters. Particularly, simple strain gauges may be connected directly or indirectly to the engaging portion such that weight forces are transferred from the payload via the engaging portion, to the strain gauge(s).

[0071] Strain gauge (410) output (whether analog or digital) may be input into a processor of the apparatus, and processed into information useful to a PID controller. Processor-executable instructions may direct the manipulation or transformation of strain gauge (410) output according to program instructions. A calculation may be performed in accordance with a mathematical relationship, such as defined by a formula or a calibration curve. Alternatively, the program instructions encode or otherwise have access to a lookup table allowing or a mass value to be read off the table, having regard to an output value. It will be understood that any determination of mass may be inferred, estimated, or approximated.

[0072] As an alternative to a strain gauge, mass may be determined by a piezoresistive sensor or any other suitable means.

[0073] A further alternative may be in the form of an angle measuring contrivance, such as an IMU. Increasing mass may increase an angle of inclination of a member in mechanical connection to the payload in a cantilever or lever arrangement.

[0074] The present disclosure will now be more fully explained by reference to the non-limiting embodiment illustrated in the accompanying drawings.

[0075] Reference is made to FIG. 1A illustrating a preferred engaging portion (10) of the present apparatus. The engaging portion (10) comprises an elongate cavity (15) divided by a central crossmember (20). A vertical stop surface (25) is formed on the end of the engaging portion (10). In the context of the overall apparatus (an example being a sample handling workstation) the engaging portion (10) is typically movable upwardly and downwardly (z direction) by motor means. The apparatus may also be configured to move the engaging portion (10) laterally (x, y direction). The particular means of moving the engaging portion (10) is not material to the disclosure and accordingly no detailed disclosure is provided.

[0076] FIG. 2A through FIG. 2D illustrates the sequence of events involved in engaging and lifting a tube rack (100), and moving the tube rack (100) laterally to another location. Referring firstly to FIG. 2A, the engaging portion (10) is advanced by the apparatus in the direction marked “A” toward the tube rack carrier (200). The tube rack carrier (200) carries a tube rack (100) holding a number of tubes (105). The engaging portion (10) is designed to engage with the tube rack carrier (300) rather than the tube rack (100) per se.

[0077] The engaging portion (10) is advanced until the stop surface (25) contacts the end wall (205) of the tube carrier (200). At that juncture (See FIG. IB), the upward facing opening of the cavity (15) is located directly below the complimentary formation (205) of the tube rack carrier (200).

[0078] The engaging portion (10) is moved by the apparatus in direction B until the complimentary formation (205) seats in the cavity (15). The complimentary formation (210) comprises a central notch (not visible in the lateral views of FIG. 1) to accommodate the central crossmember (20) of the engaging portion (10). At that juncture (FIG. 1C), the engaging portion (10) is fully engaged with the tube rack carrier (200).

[0079] Further movement of the engaging portion (10) in direction B lifts the tube rack carrier (200) clear of the surface (300) as shown in FIG. ID. Lateral movement of the tube rack carrier (200) in direction C is therefore allowed.

[0080] FIG. 3 A and FIG. 3B show a locking mechanism of the engaging portion (10). The locking mechanism comprises a locking pin (400) movable axially by the solenoid (405) through the aperture (410).

[0081] In FIG. 3 A, the locking pin (400) is drawn in the retracted position so as to remain outside the cavity (15) of the engaging portion (10). The locking pin (400) is retained in the retracted position and against the bias of spring (415) by the powered solenoid (405). When the locking pin (400) is retracted, the complementary formation of the tube rack carrier (200) is free to enter and exit the cavity (15) of the engaging portion (10), such as required for transition from the arrangement illustrated in FIG. 2B to that of FIG. 2C.

[0082] As illustrated in FIG. 3B, the solenoid (405) has been de-energized under instruction from a processor (not drawn) such that the locking pin (400) is free to move axially. The bias of spring (415) urges the locking pin (400) into the cavity (15). The complimentary formation (205) of the tube rack carrier (200) comprises an aperture sized to receive the locking in (400). When in that aperture, the complimentary formation (205) (and therefore the tube rack carrier (200)) is effectively locked to the engaging portion (10). It would be impossible for the tube rack carrier (200) to be dislodged by a force acting in any direction (x, y or z). The position of the locking pin (400) is sensed by the apparatus so as to determine whether it is inside or outside the cavity (15). Program instructions accessible by a processor of the apparatus prevent movement of the engaging portion (10) unless the locking pin (400) is sensed to be inside the cavity (15).

[0083] Biasing of the locking pin (400) to the extended position (FIG. 3B) ensures that in the event of a power outage or other system failure, the locking mechanism defaults to locking the tube rackcarrier (200) to the engaging portion (10), that being the safest configuration. In that circumstance, an operator may manually move the locking pin (400) to the retracted position so as to release the tube rack carrier (200).

[0084] The position of the solenoid (405) may be reported by a Hall sensor. The sensor provides an analog signal which is used to determine the solenoid positions relating to status, as follows:Position StatusFully retracted Solenoid pin retracted correctlyFully inserted Lock not engaged properly.Partially inserted Rack carrier correctly locked in placePartially retracted Pin stuck. Could not release lock.All others Error

[0085] Further description will now be provided in relation to the determination of mass and center of gravity of the payload lifted by the engaging portion (10), the payload being the combination of the tube rack carrier (200), the tube rack (100) and any tubes (105) therein. It will be appreciated that any variability in mass will arise predominantly or exclusively by the number and / or the mass of sample in the tubes (105). Any variability in center of gravity will arise predominantly or exclusively by the variable positioning of tubes (105) in the tube rack (100) and / or the variable mass of sample in each of the tubes (105).

[0086] Reference is made to FIG. 4A illustrating a preferred arrangement for determining the mass of a payload (100, 105, 200, 205) engaged with the engaging portion (10). The apparatus provides an anchor structure (600) from which a connecting arm (400) extends. The terminus of the connecting arm (400b) is fixed to the engaging portion (10). The connecting arm (400) is not fixed to the anchor structure (400), although another structure (not drawn) involved in center of gravitydetermination (as discussed below for FIG. 5A and FIG. 5B) bears downwardly on the region (400b) so as to maintain the connecting arm (200) in the generally horizontal orientation as drawn.

[0087] The connecting arm (400) is intended to rock on the fulcrum formed at the external corner (600a) to a very minor extent. Such rocking is for the purposes of determining the payload center of gravity only (as discussed infra), and is not a requirement for simple payload mass determination as being presently discussed.

[0088] The connection arm (400) flexes to a very minor extent. Flexion is proportional to the payload mass. Flexion may be detected by the use of a strain gauge (410) applied to the upper face of the connecting arm (400). Under flexion, the upper face is placed into tension which is detectable by the strain gauge (410).

[0089] The following discussion is in relation to the determination of center of gravity of a payload engaged by the engaging portion (10) by a lever mechanism. Reference is made to FIG. 5 A and FIG. 5B. The connecting arm (400) is configured to flex under the payload to only a very minor extent (as required for the measurement of mass discussed in relation to FIG. 4A and FIG. 4B), and therefore maintains sufficient rigidity to function as a beam in a lever mechanism. The connecting arm (400) rocks on the fulcrum formed by the external corner (600a). The effort in the lever mechanism is the downward force on the connecting arm (400a) arising from the payload (100, 105, 200). The downward force on connecting arm end (400a) causes upward movement of the opposite end (400b). The connecting arm end (400b) bears on the lower face of pivoting element (500). The pivoting element (500) has a pivot (505) which comprises a bearing about a bolt. The pivot (505) is fixed in terms of position, and the upward force applied by connecting arm end (400b) is therefore transferred to the lower surface of member (510) and the end (510a). The member (510) is fixed by screws to the anchor structure (600) at the end (510b), such that upward force at the end (510a) leads to flexion of the member (510) in its central region. A strain gauge (515) is applied to the lower surface of the member (500) with flexion placing the lowersurface into tension. The stain gauge (515) detects the flexion, with the output being useful in determining the payload (100, 105, 200) center of gravity.

[0090] Where the tubes (105) are concentrated at the right end (as drawn) of the of the tube holder (100), the payload center of gravity is more so toward the right. In that circumstance, payload mass is concentrated distal to the fulcrum (600a), and the lever mechanism therefore amplifies the effort (i.e. the payload mass) to a greater degree as compared to the circumstance where the tubes (100) are concentrated at the left end of the tube holder (100). It will be appreciated that the tube holder carrier (200) functions as an extension of connecting arm (400) thereby forming part of the beam component of the lever mechanism.

[0091] Payload concentrated to the right provides a center of gravity toward the right, and vice versa for the left. A rightward center of gravity is detected by relatively high flexion of the member (500) as reflective in strain gauge (515) output.

[0092] Strain gauge (515) output (whether analog or digital) may be input into a processor of the apparatus, and processed into information useful to a PID controller. Processor executable program instructions may direct the manipulation or transformation of the strain gauge (515) output according to program instructions. A calculation may be performed in accordance with a mathematical relationship, such as defined by a formula or a calibration curve. Alternatively, the program instructions encode or otherwise have access to a lookup table allowing for a center of gravity value to be read off the table, having regard to the output value. It will be understood that any determination of center of gravity may be inferred, estimated, or approximated.

[0093] It should be noted that pivoting element (500) and member (510) together perform a function in the context of the mass determination mechanism illustrated in FIG. 4A and FIG. 4B. Particularly, pivoting element (500) and member (510) function to significantly limit movement of connecting arm end (400b) thereby almost (but not completely) fixing the connecting arm end(400b) to the anchor structure (600). The significant restriction in movement of connecting arm end (400b) allows the connecting arm (400) to nevertheless flex in response to payload mass.

[0094] It should be noted that the present apparatus is capable of measuring mass (by the mechanism illustrated in FIG. 4A and FIG. 4B) and center of gravity (by the mechanism of FIG. 5A and FIG. 5B) contemporaneously, and by way of a single component as illustrated in the drawings.

[0095] Reference is made to FIG. 6, illustrating the communication of strain gauge (410, 515) output to a processor (800), the processor having access to program instructions stored in electronic memory (805). The program instructions are executed by the processor (800). The program instructions receive the strain gauge (410, 515) output and transform the output from strain gauge (410) into a pay load mass value, and output form strain gauge (515) into a payload center of gravity value. Both values are communicated to motor controller (710) which may be a PID controller. The controller (710) in turn controls the motor (715). The motor (715) is a motor of a robot of a sample handling workstation, the robot being responsible for engaging, lifting and moving a tube holder carrier via the engaging portion (10). The controller is provided with continuously updated mass and center of gravity values in real time for the payload carried by the engaging portion. The operation of the motor (and therefore the robot) may be appropriately controlled in light of the changing mass and / or center of gravity that occurs where tubes are removed from or loaded onto the a tube holder being moved by the robot.

[0096] In the event of a catastrophic power failure when the robot is moving a rack of biohazards in open tubes the robot will not stop moving. Momentum will keep the robot moving on a rail and requires electrical intervention to stop motion. In this scenario, the pinching fingers approach would rely on the compression of the springs to keep the samples from being knocked out of the gripper. Using a solenoid as we do in this new design ensures that the samples will not get knocked out of the gripper because the solenoid pin is inserted in its default powered off state. This pinimpales the rack carrier and can only be retracted by one of either two methods: (i) the operator manually pulls the pin back to release the payload, or (ii) the software sends a signal to the controller to electronically retract the solenoid.

[0097] As a further advantage the present disclosure may detect both locking and alignment is correct which is only available with heavier pinching fingers which have position feedback.

[0098] The present disclosure may be embodied as a generic interface that is suitable to pick up, transport and safely move racks containing biohazards around a laboratory. It is designed with safety as a main consideration, and risk assessment has identified that existing gripper technologies would not be as safe under certain scenarios such as extreme knocks, power loss, or vacuum interruption (for suction-reliant payload engagement).

[0099] The present disclosure may eliminate the need for a heavy stepper motor, linear bearings or lengthy fingers which deducts from the robots overall payload. This may enable carriage of up to 17% more payload when used with a 3kg capacity collaborative robot.

[0100] The present disclosure may be embodied in the form of program instructions executable by a processor of the present apparatus. The instructions may take the form of software or firmware or both. The program instructions may be configured to execute any method disclosed herein, including any steps of inputting information relating to a position of a sample container holder or a sample container holder carrier on the apparatus surface, triggering application of current to a selected electromagnet based on the positional information and / or operating state of the robotic gripper, halting current application to an electromagnet based on the operating state of the robotic gripper some error detection system. The program instructions may be stored on a physical medium such as solid state storage means, magnetic storage means, or optical storage means.

[0101] It will be understood that the foregoing description is only illustrative of the aspects of the present disclosure. Various alternatives and modifications can be devised by those skilled in the art without departing from the aspects of the present disclosure. Accordingly, the aspects of the present disclosure are intended to embrace all such alternatives, modifications and variances that fall within the scope of any claims appended hereto. Further, the mere fact that different features are recited in mutually different dependent or independent claims does not indicate that a combination of these features cannot be advantageously used, such a combination remaining within the scope of the aspects of the present disclosure.

[0102] Any single feature or combination of features described herein may be implemented not only with the preferred embodiments disclosed herein, but also any other embodiment falling within the ambit of the present disclosure.

Claims

CLAIMS:

1. A sample handling apparatus for engaging a sample container holder or a sample container holder carrier payload, the apparatus comprising an engaging portion configured to engage with a payload, wherein the engaging portion comprises a support surface configured to receive a generally downward force exerted by the payload due to gravity.

2. The apparatus of claim 1, wherein the engaging portion comprises one or more cavities or formations configured to mate with a respective complimentary formation or cavity of the payload.

3. The apparatus of claim 1 or claim 2, wherein the engaging portion is not reliant on any moving part to engage the payload under a lifting force.

4. The apparatus of any one of claims 1 to 3 comprising a locking arrangement configured to alternately lock and unlock the payload to and from the engaging portion.

5. The apparatus of any one of claims 1 to 4, comprising a locking structure configured to adopt a first position whereby the payload is permitted to disengage from the engaging portion, and a second position whereby the payload is prevented from disengaging from the engaging portion.

6. The apparatus of claim 5 or claim 6, wherein the locking structure extends through or from the engaging portion.

7. The apparatus of claim 5 or claim 6, comprising a solenoid or functional equivalent thereof configured to move the locking structure between the first and second positions.

8. The apparatus of any one of claims 1 to 7 comprising one or more mass measuring means associated with the engaging portion, wherein the one or more mass measuring means are configured to determine a payload mass and / or a mass distribution of a payload mass.

9. The apparatus of claim 8, wherein one of the one or more mass measuring means is connected in series with the engaging portion such that the apparatus is capable of determining a mass of the payload.

10. The apparatus of claim 9, wherein the one or more mass measuring means is associated with a flexible member, the flexible member being connected to a fixed point of the apparatus at a first end, and to the engaging portion at a second end such that increasing payload mass causes greater flexion of the flexible member which in turn causes the mass measuring means to determine a greater mass.

11. The apparatus of claim 8 or claim 9, wherein one of the one or more mass measuring means is connected to the engaging means by a lever arrangement such that the apparatus is capable of determining a center of gravity of the payload.

12. The apparatus of claim 11, wherein the one or more mass measuring means is connected to a lever member at a first end, and to the engaging portion at a second end such that increasing payload mass causes the second lever member end to move a greater distance downwardly and therefore the first lever member end to move a greater distance upwardly.

13. The apparatus of any one of claims 8 to 10, configured to sample an output of the one or more mass measuring means substantially immediately upon lifting of a payload by the engaging portion and to determine the payload mass and / or the mass distribution of the payload mass by reference to the output.

14. The apparatus of claim 13, wherein the output is regularly sampled for the period that the engaging portion maintains the payload in a lifted position.

15. The apparatus of any one claims 1 to 14 comprising one or more motors configured to move the engaging portion, the one or more motors being adjustable by a controller incorporating a control loop feedback mechanism, the controller configured to receive an output of the one or more mass measuring means.

16. The apparatus of claim 15, wherein the controller is a PID (proportional integral derivative) controller.

17. The apparatus of any one of claims 1 to 16 comprising a sample container holder carrier configured to mate with the engaging portion.

18. The apparatus of any one of claims 1 to 17, configured as a component of a sample container handling robot configured to move a sample container from a first position to a second position in a sample processing workflow of an analytical laboratory.

19. A sample container handling robot configured to move a sample container from a first position to a second position in a sample processing workflow of an analytical laboratory, the sample container handling robot being collaborative with a human and comprising the apparatus of any one of claims 1 to 17.

20. A method of moving a sample container in a sample processing workflow of an analytical laboratory, the method comprising causing or allowing the apparatus of any one of claims 1 to 18 to engage with a payload and to move the payload from a first position to a second position.

Images