Patent Description:
The invention relates generally to liquid chromatography systems. More particularly, the invention relates to liquid chromatography sample managers, and associated needle drive systems and methods.

Chromatography is a set of techniques for separating a mixture into its constituents. For instance, in a liquid chromatography system, a pump takes in and delivers a mixture of liquid solvents to a sample manager, where an injected sample awaits its arrival. In an isocratic chromatography system, the composition of the liquid solvents remains unchanged, whereas in a gradient chromatography system, the solvent composition varies over time. The mobile phase, comprised of a sample dissolved in a mixture of solvents, passes to a column, referred to as the stationary phase. By passing the mixture through the column, the various components in the sample separate from each other at different rates and thus elute from the column at different times. A detector receives the elution from the column and produces an output from which the identity and quantity of the analysis may be determined.

Prior to being provided into the liquid chromatography system, the sample may be provided to a sample manager. The sample manager may be configured to prevent the sample from degrading or becoming otherwise damaged while providing the sample into the liquid chromatography system. Sample managers are regularly interacted with by technicians and as such must be user friendly, dependable, accurate, reliable, serviceable, and cost effective. Improved sample managers, systems and methods, would be well received in the art.

<CIT> discloses an autosampler with a needle that has a capacity to retain a sample therein.

The present invention provides a liquid chromatography system comprising: a solvent delivery system; a sample manager having a thermal chamber, the thermal chamber including: a sampling mechanism mounted within the thermal chamber, the sampling mechanism including; a sample platter; a needle drive including: a base including a shaft configured to rotate about a vertical axis, the base attachable to an interior of a sample manager of the liquid chromatography system; a needle assembly attached to the base, the needle assembly including a sample needle and a drive system including a sample needle motor configured to impart vertical movement of the sample needle; and a sample delivery system in fluidic communication with solvent delivery system, the sample delivery system configured to transfer a first sample from a first sample vial carrier located in the sample platter into a chromatographic flow stream; a liquid chromatography column located downstream from the solvent delivery system and the sample delivery system; and a detector located downstream from the liquid chromatography column.

Additionally or alternatively, the needle assembly further includes a puncture needle, and wherein the drive system further includes a puncture needle motor configured to impart vertical movement on the puncture needle independently from the vertical movement of the sample needle, and wherein the needle assembly further includes a stripper foot movable in the vertical direction, wherein the stripper foot includes an opening through which the puncture needle is configured to extend during puncturing. Additionally or alternatively, the needle drive further including a sensor system, the sensor system including a flexible circuit board attached to the base and configured to bend with the rotation of the shaft about the vertical axis, the sensor system further comprising a stripper foot movement sensor configured to determine that the stripper foot has been moved in a vertical direction a predetermined distance, a sample needle movement sensor configured to determine that the sample needle has been moved in a vertical direction to a sample needle home position, and a puncture needle movement sensor configured to determine that the puncture needle has been moved in a vertical direction to a puncture needle home position.

Additionally or alternatively, the needle drive further includes: a shaft motor configured to impart rotation on the shaft about the vertical axis; and a magnetic encoder configured to maintain precise rotational position of the shaft of the base.

Additionally or alternatively, the base of the needle drive further includes needle arm housing supporting the shaft in at least two locations, the needle arm housing attached to an interior of the thermal chamber of the sample manager with a plurality of accessible bolts.

The needle assembly is attachably removable from the base of the needle drive with a plurality of accessible bolts. wherein the sample manager may further include a door providing a technician access to the thermal chamber when opened, wherein the needle drive is removable from the thermal chamber through the door.

The present invention provides a liquid chromatography sample manager comprising: a thermal chamber; a sample platter mounted in the thermal chamber; a needle drive including: a base including a shaft configured to rotate about a vertical axis, the base attachable to an interior of a sample manager of the liquid chromatography system; a needle assembly attached to the base, the needle assembly including a sample needle and a drive system including a sample needle motor configured to impart vertical movement of the sample needle; and a sample delivery system configured to transfer a first sample from a first sample vial carrier located in the sample platter into a chromatographic flow stream.

The needle assembly is attachably removable from the base of the needle drive with a plurality of accessible bolts, wherein the liquid chromatography sample manager may further comprise a door providing a technician access to the thermal chamber when opened, wherein the needle drive is removable from the thermal chamber through the door.

The present invention provides a needle drive for a liquid chromatography system comprising: a base including a shaft configured to rotate about a vertical axis, the base attachable to an interior of a sample manager of a liquid chromatography system; a needle assembly attached to the base, the needle assembly including a sample needle and a drive system including a sample needle motor configured to impart vertical movement of the sample needle.

Additionally or alternatively, the needle assembly further includes a puncture needle, and wherein the drive system further includes a puncture needle motor configured to impart vertical movement on the puncture needle independently from the vertical movement of the sample needle.

Additionally or alternatively, the needle assembly further includes a stripper foot movable in the vertical direction, wherein the stripper foot includes an opening through which the puncture needle is configured to extend during puncturing.

Additionally or alternatively, the needle assembly further comprises a sensor system, the sensor system including a flexible circuit board attached to the base and configured to bend with the rotation of the shaft about the vertical axis.

Additionally or alternatively, the sensor system further comprising a stripper foot movement sensor configured to determine that the stripper foot has been moved in a vertical direction a predetermined distance, a sample needle movement sensor configured to determine that the sample needle has been moved in a vertical direction to a sample needle home position, and a puncture needle movement sensor configured to determine that the puncture needle has been moved in a vertical direction to a puncture needle home position.

Additionally or alternatively, the needle drive includes a shaft motor configured to impart rotation on the shaft about the vertical axis.

Additionally or alternatively, the needle drive further includes a magnetic encoder configured to maintain precise rotational position of the shaft of the base.

Additionally or alternatively, the base further includes needle arm housing supporting the shaft in at least two locations, the needle arm housing attachable to the interior of the sample manager of the liquid chromatography system with a plurality of accessible bolts.

The needle assembly is attachably removable from the base with a plurality of accessible bolts.

The present teaching will now be described in more detail with reference to exemplary embodiments thereof as shown in the accompanying drawings.

As described herein, prior to performing a liquid chromatography run, a technician loads an array of vials containing samples onto a sample-vial carrier, places the sample-vial carrier onto a drawer, and slides the drawer into a bay within a sample platter of a thermal chamber of a sample manager system. The sample manager system includes a sample delivery system that is configured to transfer the sample from the sample-vial carrier into a chromatographic flow stream. The thermal chamber includes sampling mechanism which includes a rotating sample platter with improved sample capacity and sampling accuracy. A sampling needle as a part of the sampling mechanism is located on a rotating needle arm that, in combination with the rotating sample platter, provides complete needle coverage over the bays within the sample platter. The entirety of the needle arm is positioned and sized within the thermal chamber such that the needle arm is removable out a front door of the thermal chamber for ease of service. Encoders on the rotating needle arm and rotating sample platter maintain sufficient resolution for accurate sampling. These rotating needle arm may be calibrated using an accuracy-ensuring calibration process.

The features of the sample delivery system and sample manager thermal chamber described herein may be applicable to any liquid chromatography system configured to deliver samples into a chromatographic flow stream. As one example, <FIG> shows an embodiment of a liquid chromatography system <NUM> for separating a mixture into its constituents. The liquid chromatography system <NUM> includes a solvent delivery system <NUM> in fluidic communication with a sample manager <NUM> (also called an injector or an autosampler) through tubing <NUM>. The sample manager <NUM> is in fluidic communication with a chromatographic column <NUM>. A detector <NUM> for example, a mass spectrometer, is in fluidic communication with the column <NUM> to receive the elution.

The solvent delivery system <NUM> includes a pumping system <NUM> in fluidic communication with solvent reservoirs <NUM> from which the pumping system <NUM> draws solvents (liquid) through tubing <NUM>. In one embodiment, the pumping system <NUM> is embodied by a low-pressure mixing gradient pumping system having two pumps fluidically connected in series. In the low-pressure gradient pumping system, the mixing of solvents occurs before the pump, and the solvent delivery system <NUM> has a mixer <NUM> in fluidic communication with the solvent reservoirs <NUM> to receive various solvents in metered proportions. This mixing of solvents (mobile phase) composition that varies over time (i.e., the gradient).

The pumping system <NUM> is in fluidic communication with the mixer <NUM> to draw a continuous flow of gradient therefrom for delivery to the sample manager <NUM>. Examples of solvent delivery systems that can be used to implement the solvent delivery system <NUM> include, but are not limited to, the ACQUITY Binary Solvent Manager and the ACQUITY Quaternary Solvent Manager, manufactured by Waters Corp. of Milford, Mass.

The sample manager <NUM> may include an injector valve <NUM> having a sample loop <NUM>. The sample manager <NUM> operates in one of two states: a load state and an injection state. In the load state, the position of the injector valve <NUM> is such that the sample manager loads the sample <NUM> into the sample loop <NUM>. The sample <NUM> is drawn from a vial contained by a sample vial carrier. "Sample vial carrier" herein means any device configured to carry a sample vial such as a well plate, sample vial carrier, or the like. In the injection state, the position of the injector valve <NUM> changes so that the sample manager <NUM> introduces the sample in the sample loop <NUM> into the continuously flowing mobile phase from the solvent delivery system. The mobile phase thus carries the sample into the column <NUM>. In other embodiments, a flow through needle (FTN) may be utilized instead of a Fixed-Loop sample manager. Using an FTN approach, the sample may be pulled into the needle and then the needle may be moved into a seal. The valve may then be switched to make the needle in-line with the solvent delivery system.

The liquid chromatography system <NUM> further includes a data system <NUM> that is in signal communication with the solvent delivery system <NUM> and the sample manager <NUM>. The data system <NUM> has a processor <NUM> and a switch <NUM> (e.g. an Ethernet switch) for handling signal communication between the solvent delivery system <NUM> and sample manager <NUM>, as described herein. Signal communication among the various systems and instruments can be electrical or optical, using wireless or wired transmission. A host computing system <NUM> is in communication with the data system <NUM> by which a technician can download various parameters and profiles (e.g., an intake velocity profile) to the data system <NUM>.

<FIG> shows a perspective view of the liquid chromatography system <NUM> including the sample manager <NUM>, the detector <NUM>, the chromatographic column <NUM>, the solvent delivery system <NUM>, and the solvents <NUM>. Each of the sample manager <NUM>, the detector <NUM>, the chromatographic column <NUM>, the solvent delivery system <NUM> may include a housing or body within which the various features may be housed, such as the data system <NUM>, the sample loop <NUM> and injector valve <NUM>, the pumping system <NUM>, the mixer <NUM> and the tubing <NUM>. The various components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be interconnected with fluidic tubes and in signal communication to the data system <NUM> of the system. The liquid chromatography system <NUM> is shown with the solvent delivery system <NUM>, sample manager <NUM>, chromatographic column <NUM>, detector <NUM> and a tray for holding the solvents <NUM> stacked together.

<FIG> depicts a perspective view of the sampling mechanism <NUM> of the sample manager <NUM> of <FIG> and <FIG>, in accordance with one embodiment. As shown the sampling mechanism <NUM> includes a sample platter <NUM> attached to datum base <NUM>. A vertical frame <NUM> is attached and extends perpendicular from the datum base <NUM>. A needle arm <NUM> is attached to the vertical frame <NUM>. The needle arm <NUM> includes a puncture needle <NUM> (shown in <FIG>) and a sample needle (not shown) as part of a sample delivery system that is in fluidic communication with the solvent delivery system <NUM>.

The sample needle may be configured to obtain or otherwise draw the sample <NUM> from a sample vial <NUM> (shown in <FIG>). Thereafter, the sample delivery system of the liquid chromatography system <NUM> is configured to transfer the sample <NUM> into a chromatographic flow stream and to the column <NUM> located downstream from the sample delivery system, and then to the detector <NUM> located downstream from the column <NUM>. The sample vial <NUM> may be one of many vials located within up to four sample vial carriers (not shown), located on the sample platter <NUM>.

The sample platter <NUM> may be configured to rotate <NUM> degrees about a first vertical axis A1 while the needle arm <NUM> is configured to at least partially rotate about a second vertical axis A2. These two rotations may provide for sufficient coverage by the needle arm <NUM> across all the sample vial carriers <NUM> within the sample platter <NUM>. The rotating needle arm <NUM>, in combination with the rotation of the sample platter <NUM>, may thereby be configured to move the sample needle <NUM> into position to access any location on the sample platter <NUM> that holds a sample vial <NUM> within a sample vial carrier. As shown, the sample platter <NUM> includes a circular frame that includes four bays - a first carrier bay 126a, a second carrier bay 126b, a third carrier bay 126c, and a fourth carrier bay 126d. The carrier bays 126a, 126b, 126c, 126d are disposed equidistant about a perimeter of the circular sample platter <NUM>. In other words, the carrier bays, 126a, 126b, 126c, 126d are disposed circumferentially <NUM> degrees from each other about the circular sample platter <NUM>. As described above, the rotating needle arm <NUM>, in combination with the rotation of the sample platter <NUM>, is configured to move the sample needle <NUM> directly above any location covered by the respective perimeters of the respective carrier bays 126a, 126b, 126c, 126d. The platter can include four bays as shown but may also include three bays or extended to even more than four bays in other embodiments. The bays may be equidistant from each other or may be staggered in other manners about the circumference of the circular sample platter <NUM>.

Each of the carrier bays 126a, 126b, 126c, 126d is shown as a drawer that slides into and out of a bay drawer receiver 128a, 128b, 128c, 128d. The carrier bays 126a, 126b, 126c, 126d may be configured to be pulled from respective bay drawer receivers 128a, 128b, 128c, 128d radially outwardly in order to facilitate ease of loading of sample vial carriers into and out a front door <NUM> of the sample platter (shown in <FIG>). The integration of the carrier bays 126a, 126b, 126c, 126d and the respective bay drawer receivers 128a, 128b, 128c, 128d may be configured to stop the carrier bays 126a, 126b, 126c, 126d before the carrier bays 126a, 126b, 126c, 126d become fully disconnected from the bay drawer receivers 128a, 128b, 128c, 128d. Alternatively, the bezel of the sampling mechanism <NUM> may include a structure that prevents the carrier bays 126a, 126b, 126c, 126d from becoming fully disconnected from the bay drawer receivers 128a, 128b, 128c, 128d.

The carrier bays 126a, 126b, 126c, 126d are each configured for receiving sample vial carriers. The sample manager <NUM> may be configured to receive and process samples within all four carrier bays 126a, 126b, 126c, 126d. In addition to sliding in and out of the bay drawer receivers 128a, 128b, 128c, 128d via a track system, the carrier bays 126a, 126b, 126c, 126d may include magnets positioned underneath that are configured to magnetically retain the sample vial carriers into position within the carrier bays 126a, 126b, 126c, 126d. Corresponding magnets may be located a radially inward position within the carrier bays 126a, 126b, 126c, 126d to further ensure that the carrier bay 126a, 126b, 126c, 126d is in position properly (i.e. fully inserted) relative to the bay drawer receivers 128a, 128b, 128c, 128d. Leaf springs <NUM> may be configured to bias received sample platters toward the left most wall of the respective carrier bays 126a, 126b, 126c, 126d, while the magnetic structure retains the received sample platters against the radially inward wall of the respective carrier bays 126a, 126b, 126c, 126d.

The sample platter <NUM> includes a middle opening <NUM> for receiving a post <NUM> around which the sample platter <NUM> is configured to rotate about the vertical axis A1. The sample platter <NUM> further includes additional openings <NUM> disposed around the perimeter in between the carrier bays 126a, 126b, 126c, 126d configured to receive and hold larger single individual vials (not shown) or other samples. The needle arm <NUM> (and the needle thereof) may be configured to be positioned over each of the perimeter additional openings <NUM>.

The sample platter <NUM> is shown mounted to the datum base <NUM>. The datum base <NUM> may be a metallic plate that is mounted to a thermal chamber frame (not shown) within the sample manager <NUM>. The datum base <NUM> may include openings through which deflection limiting columns <NUM> extend. The deflection limiting columns <NUM> may be configured to prevent deflection of the sample platter <NUM> beyond a specific distance relative to the datum base <NUM> before being stopped. The deflection limiting columns <NUM> may be keyed to a channel in the bottom of the sample platter <NUM> and may act as bearings to allow rotation of the sample platter <NUM> about the datum base <NUM>. Rotation of the sample platter <NUM> about the datum base <NUM> may be created by a motor <NUM> disposed on the datum base <NUM> proximate the perimeter of the sample platter <NUM>. The datum base <NUM> further includes a plurality of threaded openings configured to receive bolts for attaching a right-angle bracket <NUM> thereto at each side. The right-angle brackets <NUM> may be configured to attach the vertical frame <NUM> to the datum base <NUM> in a perpendicular orientation. An encoder (not shown) may further be attached to the sample platter <NUM> to maintain positioning of the sample platter <NUM> relative to the datum base <NUM>.

The vertical frame <NUM> is attached to the datum base <NUM> such that the vertical frame <NUM> extends through the circumference of the sample platter <NUM>. To account for this location being over the sample platter <NUM>, the vertical frame <NUM> includes an opening <NUM> (shown in <FIG>) or cutout through which the sample platter <NUM> and any received sample vial carrier 124a, 124b, and any received sample vials <NUM>, are configured to pass. The opening <NUM> is dimensioned tall enough to receive the tall sample vial carriers 124b without causing interference. The vertical frame <NUM> creates a surface over the opening <NUM> upon which to mount the needle arm <NUM>.

The needle arm <NUM> is shown including a drive mechanism <NUM> and a motor <NUM>. The motor <NUM> is configured to rotate about an axis that rotates a belt <NUM>, which in turn rotates a pulley <NUM>. Rotation of the pulley <NUM> may be configured to impart rotation of the needle arm <NUM> about the second vertical axis A2. The rotation of the needle arm <NUM> may be independent rotation relative to the rotation of the sample platter <NUM>, and may be rotation about a different vertical axis A2 than the vertical axis A1 about which the sample platter <NUM> rotates.

Referring now to <FIG>, a perspective view of the interior of the sample manager <NUM> of <FIG> and <FIG> is shown in a first calibration position, in accordance with one embodiment. The first calibration position shown in <FIG> is a position where the needle arm <NUM> is rotated counter clockwise about the second vertical axis A2 relative to the position shown in <FIG>. As shown, a shaft <NUM> extends through the pulley <NUM> that is attached and configured to rotate with the pulley <NUM>. The shaft <NUM> is connected to a rotating plate <NUM> that is configured to rotate with the shaft <NUM> and impart rotation on a needle assembly <NUM>. The shaft <NUM> includes a biasing spring <NUM>. A removable needle arm housing <NUM> is attached to the vertical frame <NUM>. The removable needle arm housing <NUM> includes a horizontal plate <NUM> extending from just above the opening <NUM> in the vertical frame <NUM>. The horizontal plate <NUM> includes a bushing <NUM> configured to receive the base of the shaft <NUM> and maintain the shaft <NUM> in alignment with the second vertical axis A2. The needle arm housing <NUM> is removably attached to the vertical frame <NUM> with a plurality of accessible bolts <NUM>. The accessible bolts <NUM> are accessible through the door <NUM> of the sample manager <NUM>. This may allow the entirety of the vertical frame <NUM> and the needle arm <NUM> and all of the components thereof to be easily removable through the door <NUM> during maintenance or part replacement.

The needle arm <NUM> further includes a magnetic encoder <NUM>. The magnetic encoder <NUM> may be configured to determine rotational position of the needle arm <NUM> to whatever tolerance is necessary for accurate positioning of the sample needle <NUM>. Likewise, the motor <NUM> may be equipped with an encoder for determining the rotational position of the sample platter <NUM>. The two encoders in the system may be in communication with a control system (e.g. data system <NUM>) for calibrating and controlling movement of the needle arm <NUM> and the sample platter <NUM>. While magnetic encoders may be utilized, other encoders are contemplated, such as optical encoders.

The needle arm <NUM> is shown including two separate motors 164a, 164b configured to rotate two separate drive shafts. A first motor 164a is configured to rotate a first drive shaft <NUM> (shown in <FIG> and <FIG>) that enacts movement on the puncture needle <NUM>. A second motor 164b is configured to rotate a second drive shaft <NUM> (shown in <FIG> and <FIG>) that enacts movement on a sample needle (not shown). The first and second motors 164a, 164b may be attached to the needle arm <NUM> such that the motors 164a, 164b rotate with the needle arm <NUM>. The puncture needle <NUM> may operate in conjunction with the sample needle in order to puncture whatever material or membrane covers a sample vial. The two motors 164a, 164b may be configured to operate independently and may be controlled and programed by the control system and/or data system <NUM> for operational routines.

The needle assembly <NUM> of the needle arm includes a plate <NUM> having two accessible bolts <NUM> which are accessible by a technician that opens the door <NUM> of the sample manager <NUM>. Upon unbolting the accessible bolts <NUM>, the technician can remove the needle assembly <NUM> and the attached motors 164a, 164b from the needle mechanism base <NUM>. The needle assembly <NUM> and the motors 164a, 164b may be removable through the door <NUM> of the sample manager <NUM> without removing the needle mechanism base <NUM>. Similarly, the motors 164a, 164b may be easily removed from the needle arm <NUM> by removal of one or more accessible motor bolts <NUM> from the plate <NUM>. This may allow for the motors 164a, 164b to be easily replaced or removed for maintenance through the front door <NUM> of the sample manager <NUM> without removal of other components of the needle arm <NUM>.

The sample delivery system may further include a fluidic tube (not shown) located between the sample needle and the liquid chromatography column <NUM>. The fluidic tube may include a coiled portion configured to expand and contract during rotation of the needle arm <NUM> about the second vertical axis A2. The coiled portion may extend between the top of the needle arm <NUM> above the puncture needle <NUM> and to the vertical frame <NUM>. The coiled portion may uncoil when the needle arm <NUM> rotates away from the vertical frame <NUM> and recoils when the needle arm <NUM> rotates toward the vertical frame <NUM>. The coiled portion of the fluidic tube may be spiraled, bent, or otherwise curled in order to provide for lengthwise expansion and contraction in a predictable manner that does not interfere with the other movement of the various components within the sample manager <NUM>.

Referring back to <FIG>, the needle arm <NUM> is shown in this view having been rotated to a home position, whereby a projecting stop <NUM> that is connected to, coupled to, or integrated into, the vertical frame <NUM> is contacted with the needle assembly <NUM>. The home position may be a position that is rotated to a stopping point, past which the needle arm <NUM> may not be capable of rotating. As shown, at the home position the needle arm <NUM> is rotated in a clockwise direction to a point of maximum rotation whereby the needle arm <NUM> is stopped from further clockwise rotation by the projecting stop <NUM>.

Attached to the datum base <NUM> may be a needle wash system (not shown) extending from an opening <NUM> located in the datum base <NUM> near the home position or location. The needle wash system may include a plurality of liquid source tubes each configured to introduce water and/or other cleaning agent(s) to wash the sample needle <NUM> and/or the puncture needle when the needles are moved over the needle wash system. A wash process may include, for example, providing a first cleaning agent to the sample needle <NUM> from a first of the liquid source tubes, and then moving the sample needle <NUM> over the second of the liquid source tubes to be cleansed with water. Other wash processes and structure are contemplated as would be appropriate to wash needle(s) in the needle arm <NUM>.

The needle arm <NUM> may be configured to rotate about the rotating shaft <NUM> and the second axis A2 an amount that allows complete coverage of the needle assembly <NUM> over the entirety of the working portion of the sample platter <NUM>. The needle arm <NUM> may be configured to rotate more than <NUM> degrees but less than <NUM> degrees in the embodiment shown. Additional rotational movement than what is shown (i.e. equal to or greater than <NUM> degrees) is also contemplated in other embodiments. Referring to <FIG> and <FIG>, the interior of the sample manager <NUM> of <FIG> and <FIG> is shown with the needle arm <NUM> located in two calibration positions, in accordance with one embodiment. In various contemplated embodiments, various calibration systems are contemplated. <FIG> and <FIG> shown one exemplary calibration system in which the data system <NUM> and/or sample manager control system may be configured to calibrate the sampling mechanism <NUM> to use. One calibration process may include a first step, shown in <FIG>, of moving the sample platter <NUM> and the needle arm <NUM> to align the needle with the first opening <NUM> in the sample platter and then recording a first encoder position of each the sample platter <NUM> and the needle arm <NUM>. For example, the needle arm <NUM> may move counter-clockwise from the home position (shown in <FIG>) to the position shown in <FIG> so that the puncture needle <NUM> (or sample needle) is directly above the first opening <NUM>.

The calibration process may then include a second step of moving the sample platter <NUM> and the needle arm <NUM> to the position shown in <FIG>, in order to align the puncture needle <NUM> (or sample needle) with the second opening <NUM> in the sample platter. The calibration process may then include recording a second encoder position of each the sample platter <NUM> and the needle arm <NUM>. With the known first and second encoder positions, the data system <NUM> and/or sample manager control system may be configured to back-calculate the geometric parameters of the sampling mechanism <NUM> and thereby calibrate the movement and position of the sample platter <NUM> and the needle arm <NUM>. The positional accuracy may be more precise than a typical prior art calibration process, as the inventive process described above does not rely on assumed geometric qualities being within a certain level of tolerance.

<FIG> depicts a perspective view of the needle arm <NUM> detached from the interior of the sample manager <NUM>, in accordance with one embodiment. As shown, the needle arm <NUM> includes a base <NUM> that is removably attachable to the sample manager <NUM> of the liquid chromatography system <NUM>. The needle arm <NUM> further includes the needle assembly <NUM> that is removably attachable to the base <NUM>.

The removability of each of the base <NUM> from the sample manager <NUM> and the needle assembly <NUM> from the base <NUM> may be provided by accessible bolts, screws, pins or other easily accessible, engageable and/or disengageable coupling devices. The attachable removability of each of these components as described herein provides for ease of servicing and replacing components of the needle arm <NUM> through a front door of the sample manager <NUM>. Further, as described above, the needle arm <NUM> includes sufficient structure to provide for rotational movement of the arm about a vertical axis when the needle arm <NUM> is attached within a sample manager <NUM>.

<FIG> depicts a perspective view of the base <NUM> of the needle arm of <FIG> with the needle assembly <NUM> detached, in accordance with one embodiment. The base <NUM> includes the removable needle arm housing <NUM>. The removable needle arm housing <NUM> provides a frame for attaching the base <NUM> to the interior of the sample manager <NUM> of the liquid chromatography system <NUM>, such as by attachment of the removable needle arm housing <NUM> to the vertical frame <NUM>. The removable needle arm housing <NUM> includes a flat vertical surface configured to abut the flat vertical surface of the vertical frame <NUM>. As shown in <FIG>, a plurality of alignment pins <NUM> located on a back surface of the needle arm housing <NUM> act in cooperation with the accessible bolts <NUM> to attach the flat vertical surface of the needle arm housing <NUM> with the flat vertical surface of the vertical frame <NUM>. While not shown, the vertical frame <NUM> may include corresponding bores, or female receiving openings for receiving each of the accessible bolts <NUM> and alignment pins <NUM>.

As shown, the base <NUM> includes the shaft <NUM> that is configured to rotate about the vertical axis A2. The removable needle arm housing <NUM> is configured to hold the shaft <NUM> at both a top location and a bottom location, while allowing the shaft <NUM> to rotate about the removable needle arm housing <NUM>. Specifically, the removable needle arm housing <NUM> includes the lower horizontal plate <NUM> and an upper horizontal plate <NUM> extending from the flat vertical surface of the removable needle arm housing <NUM>. The bushing <NUM> is disposed with an opening at the lower horizontal plate <NUM> allowing the shaft <NUM> to rotate therein.

The base <NUM> further includes the motor <NUM>, the drive mechanism <NUM>, the belt <NUM>, the pulley <NUM>, and the rotating plate <NUM>. The drive mechanism <NUM> of the motor <NUM> may be a drive shaft, or the like, that the motor <NUM> is configured to cause to rotate. Rotation of the drive mechanism <NUM> further causes movement of the belt <NUM> and thereby rotation of the pulley <NUM> that is attached to the vertical shaft <NUM>. The rotating plate <NUM> is attached to the shaft <NUM>, and is configured to rotate with rotation of the shaft <NUM>.

<FIG> depicts a side view of the needle arm <NUM> in accordance with one embodiment including both the needle assembly <NUM> and the base <NUM>. Referring to both the perspective view of <FIG> and the side view of <FIG>, the base <NUM> is shown including each of the motor <NUM>, the magnetic encoder <NUM>, the housing <NUM> and the rotating plate <NUM>. The needle assembly <NUM> includes a housing <NUM> or other body upon which the components of the needle assembly <NUM> are attached. As shown, the plate <NUM> of the housing <NUM> of the needle assembly <NUM> is attached to the base <NUM>, and specifically to the rotating plate <NUM>.

The needle assembly <NUM> includes a drive system. The drive system includes a first motor having a first drive shaft <NUM> attached to a top of the plate <NUM> of the housing <NUM>. The needle assembly <NUM> further includes a second motor 164b having a second drive shaft <NUM> attached to a bottom of the plate <NUM> of the housing <NUM>. The first motor 164a and first drive shaft <NUM> are configured to impart vertical motion or movement on the puncture needle <NUM> via imparting vertical motion or movement on a puncture needle axis <NUM>. Likewise, the second motor 164b and the second drive shaft <NUM> are configured to impart vertical motion or movement on a sample needle <NUM> via imparting vertical motion or movement on a sample needle axis <NUM>.

Further, a stripper foot <NUM> is attached to a stripper foot axis <NUM> that includes a spring loaded end <NUM> having a spring mechanism. The spring mechanism may be configured to compress during downward movement of the stripper foot <NUM> and stripper foot axis <NUM>. In use, the stripper foot <NUM> may contact the top of a sample vial (not shown), after which the puncture needle <NUM> may be pushed through a protective membrane of the sample vial. After the puncture needle <NUM> has punctured this top protective membrane, the puncture needle <NUM> must be retracted from the sample vial and protective membrane. The stripper foot <NUM> may be configured to provide a downward force on the top of the sample vial so that the puncture needle <NUM> may be retracted properly without sticking to the protective membrane of the sample vial. The stripper foot <NUM> includes an opening through which the puncture needle <NUM> is configured to extend during puncturing.

As shown in <FIG>, the stripper foot axis <NUM> is movable relative to the puncture needle axis <NUM>, via two couplings <NUM>. The couplings <NUM> may include a top elongated vertical opening and a bottom elongated opening in the stripper foot axis <NUM> through which top and bottom respective pins extend. The top and bottom respective pins are attached to a puncture needle coupling surface <NUM> of the puncture needle axis <NUM>. The top and bottom elongated vertical openings cooperate with the pins so that the stripper foot axis <NUM> and the puncture needle axis <NUM> are connected or otherwise coupled in a manner that allows for vertical movement between the stripper foot axis <NUM> and the puncture needle axis <NUM>. The maximum vertical movement between the stripper foot axis <NUM> and the puncture needle axis <NUM> is defined by the vertical length of the top and bottom elongated vertical openings in the stripper foot axis <NUM>.

The sample needle <NUM> is located along the same vertical axis as the puncture needle <NUM>. The sample needle <NUM> may be a needle having a smaller diameter than the puncture needle <NUM> such that the sample needle <NUM> is configured to extend through the larger diameter opening of the puncture needle <NUM>. A needle holder <NUM> is located at a top of the sample needle axis <NUM>. The sample needle holder <NUM> may be configured to removably receive the sample needle <NUM> at a location that aligns the sample needle <NUM> with the puncture needle <NUM>. The sample needle holder <NUM> is attached to the sample needle axis <NUM> so that the sample needle holder <NUM>, and thereby the sample needle <NUM>, move when the sample needle axis <NUM> is driven or moved by the second motor 164b and the second drive shaft <NUM> thereof.

<FIG> depicts a top view of the needle arm <NUM>, in accordance with one embodiment. Referring to both the perspective view of <FIG> and the top view of <FIG>, a needle arm sensor system is shown. The sensor system includes a sample needle home sensor <NUM>, a puncture needle home sensor <NUM>, and a top sensor <NUM>. The sensor system may further include a printed circuit board <NUM> configured to provide power, control signals and/or communication signals to and from the various sensors <NUM>, <NUM>, <NUM> in the sensor system. The printed circuit board <NUM> may be a flexible circuit board configured to flex with rotation of the needle assembly <NUM> about the vertical shaft <NUM>. The printed circuit board <NUM> may be capable of performing its function without losing its signal and/or conductive integrity while being bent back and forth through the rotation of the needle assembly <NUM> about the vertical shaft <NUM> throughout the lifecycle of the needle arm <NUM>. The sensor system and/or printed circuit board <NUM> and the sensors <NUM>, <NUM>, <NUM> may be in operable communication with a control system such as the data system <NUM>, such that sensed information is provided to the data system <NUM> for processing.

The sample needle home sensor <NUM> is configured to sense movement of the sample needle axis <NUM> and/or determine when the sample needle axis <NUM> arrives in a home (top) position. The sample needle home sensor <NUM> may be configured to sense and/or determine that the sample needle <NUM> has been moved in a vertical direction a predetermined distance to a sample needle home position. The sample needle holder <NUM> is connected to the sample needle axis <NUM> and moves with the sample needle axis <NUM>. The sample needle holder <NUM> includes an extending projection <NUM> configured to move between the two prongs of the sample needle home sensor <NUM>. Thus, when the sample needle axis <NUM> moves to a top home position, the extending projection <NUM> is positioned between the two prongs of the sample needle home sensor <NUM>, which thereby senses that the sample needle axis <NUM> is in the home position. A connecting conductor <NUM> extends between the printed circuit board <NUM> and the sample needle home sensor <NUM> configured to provide power and/or other control or communication signals to and from the sample needle home sensor <NUM>.

The puncture needle home sensor <NUM> is configured to sense movement of the puncture needle axis <NUM> and/or determine when the puncture needle axis <NUM> arrives in a home (top) position. The puncture needle home sensor <NUM> may be configured to sense and/or determine that the puncture needle <NUM> has been moved in a vertical direction a predetermined distance to a puncture needle home position. The puncture needle axis <NUM>, and specifically the puncture needle coupling surface <NUM> thereof, includes an extending projection <NUM> configured to move between the two prongs of the puncture needle home sensor <NUM>. Thus, when the puncture needle axis <NUM> moves to a top home position, the extending projection <NUM> is positioned between the two prongs of the puncture needle home sensor <NUM>, which thereby senses that the puncture needle axis <NUM> is in the home position. A connecting conductor <NUM> extends between the printed circuit board <NUM> and the puncture needle home sensor <NUM> configured to provide power and/or other control or communication signals to and from the puncture needle home sensor <NUM>.

The top sensor <NUM> of the sensor system is configured to sense when the stripper foot <NUM> is compressed by a predetermined amount. This predetermined amount may correspond to a force acting on the stripper foot <NUM> by a top of the sample vial. A service loop <NUM> may extend from the printed circuit board <NUM> to the top sensor <NUM> for providing power and/or other control or communication signals to and from the top sensor <NUM>. The top sensor <NUM> may be a stripper foot movement sensor configured to determine that the stripper foot <NUM> has been moved in a vertical direction over a predetermined distance.

Claim 1:
A needle drive (<NUM>) for a liquid chromatography system (<NUM>) comprising:
a base (<NUM>, <NUM>) including a shaft (<NUM>) configured to rotate about a vertical axis, the base (<NUM>, <NUM>) attachable to an interior of a sample manager (<NUM>) of a liquid chromatography system (<NUM>); and
a needle assembly (<NUM>) attached to the base (<NUM>, <NUM>), the needle assembly (<NUM>) including a sample needle (<NUM>) and a drive system including a sample needle motor (164b) configured to impart vertical movement of the sample needle (<NUM>), wherein the needle assembly (<NUM>) is attachably removable from the base (<NUM>, <NUM>) with a plurality of accessible bolts (<NUM>).