Patent Description:
To perform a molecular analysis of a tumor, for the purposes of oncology diagnostics, a certain amount and concentration of tumor cells must be present in the sample to be analyzed. Tumor tissue is heterogenous and contains other tissue and cell types. Therefore, a region of interest (ROI) is typically defined as the sample to be dissected from a thin section of tissue disposed on a microscope slide. Manual methods of dissection are most common, in which a lab technician scrapes material from the ROI using e.g. a scalpel blade and transfers the scraped material into a collection tube.

An example of an automated device for extracting material from a biological sample via milling is disclosed in <CIT>. The device comprises a head assembly and a stage that can accommodate and collect samples from several tissue slides and enables automated filling and uploading of several milling tips into a plurality of corresponding sample collection vials. The stage includes a plurality of receptacles adapted to receive a corresponding number of spring-loaded milling tip holders, which are used for automatic loading of the milling tips by the head assembly. The stage further accommodates a fill station for filling the milling tips with a buffer solution. In an embodiment, the stage supports a tray into which receptacles are formed for receiving the spring-loaded milling tip holders and sample collection vials. When a milling tip is securely seated in the corresponding holder, a threaded section of the milling tip can be threaded to the head assembly and automatically moved to the fill station for filling with buffer solution. After dissection, the used milling tip can then be reloaded into a holder or discarded to avoid cross-contamination.

A further example of such an automated device having an interchangeable milling tip is known from <CIT>.

In the field of liquid handling devices, in which a single pipette tip or an array of pipette tips is attached to a plunger mechanism for dispensing a metered amount of liquid into e.g. a microwell plate, automated methods of pick-up and detachment are generally applied. <CIT>, for example, discloses a device with an array of attachments that extend through an ejector plate. The device is configured to pick up a corresponding array of disposable tips by pressing the attachments into an opening in the pipette tip. After use, the ejector plate is driven by a mechanical actuator and is moved downward to push off the attached tips.

<CIT> discloses a device in which a lever is activated in order to push off a single pipette. The device is equipped with an electromagnet that is energized in order to pull up one end of the lever arm.

There is still room for improvement in terms of defining an apparatus for automated dissection of biological material that allows a dissection tool to be attached and detached from a movable head in a straightforward automated manner.

In a first aspect, the invention relates to an apparatus according to claim <NUM> for automated dissection of biological material from a tissue sample disposed on e.g. a glass slide, which comprises an interface for releasable attachment of a disposable dissection tool. The tool is attachable to the interface via at least one push fitting and is rotatable about a vertical rotation axis.

To permit disengagement of the tool, the interface is equipped with one or more lever arms, each pivotably connected to a housing of the interface about a horizontal pivot axis and arranged at a radially outer location relative to the at least one push fitting. Each lever arm has first and second engagement surfaces at first and second ends thereof, whereby the first engagement surface is generally located at a greater radial distance from the vertical rotation axis than the second engagement surface. The tool has an upper collar, which in attached condition preferably bears against an underside of the interface housing. According to the invention, the tool upper collar and the one or more lever arms are configured such that when the tool is in attached condition, the first engagement surface of each lever arm lies radially outside of the outer collar, and such that the second engagement surface will make contact with and exert a disengaging force on an upper surface of the tool collar when the first end of each lever arm is displaced in upward direction by a sufficient amount.

Furthermore, the apparatus is configured to detach the tool simply by lowering the interface relative to a surface that surrounds an opening of sufficient depth to receive a main body of the tool. The upward displacement of each lever arm is effected by contact between said surrounding surface and each lever first engagement surface. An apparatus in accordance with the invention therefore enables automated detachment in a straightforward manner, via the application of relatively low force.

In order to perform high-precision dissection, it important for the tool to be attached with precise alignment. The attachment between the tool and the interface therefore preferably comprises one or more conical connections. The interface may comprise a number of conical pins that engage in corresponding conical recesses provided at an upper end of the tool. Alternatively, the tool may comprise a number of conical pins that engage in corresponding conical recesses in the housing.

The push fitting that provides a locking force between the tool and the interface may be achieved via an interference fit between the one or more conical connections. In other embodiments, the locking force is mainly provided via a snap-fit connection.

In a preferred embodiment, the interface comprises one central conical protrusion that extends from an underside of the interface housing and the tool comprises a central conical recess that is surrounded by the upper collar. The tool may be provided with a number of snap-fit joints arranged at an entrance to the conical recess and the interface protrusion may be provided with an annular ridge that engages in the snap-fit joints when the protrusion is pushed into the recess.

As will be understood, the one or more lever arms on the interface are adapted to exert a force that is greater than the locking force between the tool and the interface.

To ensure sufficient lever force, the interface may be provided with at least two lever arms arranged with an even angular spacing relative to the vertical rotation axis. In a preferred embodiment, the interface comprises three lever arms.

Suitably, the pivot axis of each lever arm is located farther from the first end than the second end, to maximise the effective length of the lever. Furthermore, when each lever arm is in a rest position, the first engagement surface preferably lies in a first horizontal plane that is lower than a generally horizontal plane of the housing underside. In a preferred embodiment, the first end of each lever arm comprises a vertical extension and the housing underside comprises a suitable opening through which it extends. When the tool is attached, the vertical extension and first engagement surface then lies below the upper surface of the tool collar.

The corresponding second engagement surface of each lever arm is located in a second horizontal plane, which preferably lies relatively higher than the first when the lever arm is in a non-activated position. The second engagement surface may lie in the same plane as the underside of the housing, or somewhat higher. To permit the second engagement surface of each lever arm to extend beneath the housing underside when the first end of the lever is activated, a further opening is provided, or a longitudinal slot may be provided in the underside that permits both ends of the relevant lever to protrude.

As mentioned above, activation of the levers is possible via a downward movement of the tool and the application of a relatively low force. The downward movement can also be used to pick up a tool.

The apparatus of the invention suitably comprises an assembly of actuators that are used to move the tool from a tool docking and undocking station to a dissection station, where the slides comprising e.g. thin sections of paraffin-embedded tumour tissue are located, and to perform the X- and Y-translations and rotational movements needed to dissect material from an identified region of interest. To enable high-speed and high-precision dissection, it is advantageous to minimise the weight of the actuator assembly. The tool interface of the invention permits the use of a lightweight and compact actuator for performing the movements needed to dock and undock a dissection tool. Suitably, the interface is fixed connection with a rotary actuator that enables the interface and attached tool to be rotated about the vertical rotation axis and with a linear actuator that permits movement of the interface and tool in vertical direction. The rotary actuator and the linear actuator are also used during dissection to control an orientation of the blade and to bring the scraping blade into contact with the glass slide with a controlled downward force.

A stack of linear actuators may be used, which are in connection with each other, comprising an x-stage, a y-stage for the translational motions during dissection and a z-stage for the vertical motions. In a preferred embodiment, the rotary actuator is connected to the z-stage. The rotary actuator may comprise a stepper motor or a linear drive motor with a hollow axis for allowing a pneumatic connection with the interface and tool, such that suction may be applied during dissection. The z-stage may comprise a hinge bearing for position control, to ensure a constant and precise downward force during dissection. Alternatively, the z-stage may be equipped with a force feedback control to maintain the downward force at a desired level.

The apparatus comprises a tool carrier having a main recess that is shaped to receive a dissection tool as described above. The main recess is surrounded by an upper surface which contains a number of relatively higher portions and a number of relatively lower portions, at least equal to the number of lever arms of the tool interface. When the tool interface is in a first angular position, being a pick-up position, the position of the relatively lower portions coincides with the position of the first engagement surface of each lever arm. In one example, the relatively higher portions of the carrier surface are formed by essentially flat sections and the relatively lower portions are formed by indentations in alignment with each first engagement surface.

Preferably, the apparatus comprises a tray containing a plurality of such tool carriers for receiving a plurality of dissection tools. In an embodiment, the apparatus comprises a number of such trays arranged on moveable carriers for automated insertion and removal of the trays.

Consequently, a tool can be picked up by lowering the interface relative to a tool held in a tool carrier by an amount sufficient to engage the at least one push fitting, without engaging the first end of each lever arm.

After dissection, the tool may be disposed of in a separate receptacle with an opening of suitable diameter such that the first end each lever arm is activated when the tool is lowered into the opening and makes contact with the surrounding surface.

In a preferred embodiment, the apparatus is configured to deposit a used tool back into the same carrier. To enable this, the actuator rotates the interface to a second angular position, being a position in which the first end of each lever arm is in alignment with the aforementioned relatively higher portions of the carrier surface, such that lowering the tool into the shaped recess of the carrier brings the first end of each lever arm into contact therewith, causing it to pivot and displace the second end, which releases the tool from the interface.

Thus, docking and undocking of a dissection tool can be performed in an automated manner that requires the application of minimal force.

In a preferred embodiment, an apparatus for dissection according to the invention is configured for use in conjunction with suction. The tool then comprises an internal passageway that extends through the tool in vertical direction and has an orifice at one end where a scraping blade is arranged. The scraping blade is preferably made of a metal having a high yield stress. An air-permeable filter element is arranged in the internal passageway and a section of the internal passageway between the filter element and the orifice serves as a suction nozzle.

The interface housing is similarly provided with an internal passageway that extends in vertical direction through the interface and which connects with the tool internal passage in an airtight manner when the tool is in attached condition. In the preferred embodiment where the interface comprises a central conical protrusion and the tool comprises a central conical recess, the housing internal passageway extends through the conical protrusion and engagement with the tool conical recess provides the airtight connection. In other embodiments, a seal may be provided at the connection between the interface internal passageway and the tool internal passageway.

The internal passageway of the interface is connectable via suitable tubing and optional valves to a vacuum generator, such that during dissection, an underpressure is generated an attachment end of the dissection tool. This creates an uplifting airstream at the tool orifice, which suctions material dissected by the scraping blade into the nozzle, where it is held at an underside of the filter element.

The apparatus may suitably comprise a further station where collection tubes are held. After use, the dissected material can be ejected straight into a collection tube, by applying a pressure pulse, thereby minimising the risk of contamination. The tool is then disposed of into a waste receptacle or is returned to the docking/undocking station where it is deposited in a tool carrier and a fresh tool is picked up in the manner described above.

In a further aspect, the interface comprises:.

In a preferred embodiment, the first engagement surface of each lever arm generally lies in a first horizonal plane, and the corresponding second engagement surface is generally arranged in a second horizonal plane which lies upward of the first horizonal plane.

In an advantageous further development, the means for enabling a push fitting and the means for enabling an airtight connection with the tool comprise a hollow, central conical protrusion that extends from an underside of the housing. As described above, an outer surface of the central conical protrusion may comprise an annular ridge, at a location between the underside of the housing and a conically shaped end portion of the protrusion. The annular ridge forms part of the push fitting and is adapted for snap-fit engagement with the tool.

In a still further aspect, the invention relates to a method of detaching a dissection tool from an apparatus according to claim <NUM>, the apparatus comprising a tool interface as defined above, whereby the tool is attached to the interface via at least one push fitting. The method of attachment includes a step of:.

The method of detachment includes a step of:.

In an embodiment, the method of detachment comprises returning a tool to the same tool carrier and includes a further step of:.

The invention will now be further elucidated with reference to the embodiments described hereinafter. In the drawings,.

It should be noted that items which have the same reference numbers in different figures, have the same structural features and the same functions.

<FIG> schematically shows a cut view of a dissection tool <NUM> attached to a tool interface <NUM> which form part of a dissection apparatus according to an embodiment of the invention. A first end of the dissection tool comprises a blade <NUM> for scraping off biological material from a tissue sample disposed on a slide. The apparatus further comprises an actuator <NUM> to which the tool interface <NUM> is fixed, which forms part of an assembly of actuators which are suitably controlled and moved in order to bring the scraping blade <NUM> into contact with a slide surface and detach biological material from an identified region of interest ROI of a tissue sample. The actuator <NUM> is movable in vertical direction and permits rotation about a vertical axis <NUM> and is used both during dissection and for automated attachment and detachment of the dissection tool, which will be explained in detail later.

The depicted dissection tool is adapted to work in combination with suction. The tool thus comprises a nozzle <NUM> having an orifice where the blade <NUM> is arranged and an internal passageway that extends through the tool and connects with an internal passageway <NUM> through the tool interface <NUM>. The internal passageways are connectable to a vacuum generator <NUM>, via suitable tubing <NUM>, so that during use of the tool, biological material dissected by the blade <NUM> is suctioned into the nozzle <NUM>, where it is caught at the underside of an air-permeable filter element <NUM> arranged to span the tool internal passageway. The tool <NUM> is designed for single use.

At the end of the dissection process, the tool <NUM> must be detached from the interface <NUM>. To enable high-resolution and high-precision dissection at relatively high speed, it is important that the actuator <NUM> is lightweight and compact. To facilitate efficient automated processing of multiple tissue samples, it is advantageous if the tool <NUM> can be detached from the interface <NUM> and a new tool attached in an automated manner that does not add to the complexity and the weight of the assembly of actuators. The attachment interface <NUM> of the invention is thus designed to enable precise, stable and airtight attachment of the tool <NUM>, followed by detachment, in a straightforward, automated manner that requires the actuator <NUM> to exert minimal force.

This will be explained also with reference to <FIG>, which shows a perspective view of the underside of the inventive tool interface <NUM> and <FIG>, which shows a cross-sectional view of the dissection tool <NUM>.

The interface <NUM> comprises a housing <NUM> which has a generally planar underside <NUM> from which a central conical protrusion <NUM> extends. The protrusion <NUM> is hollow and forms part of the internal passageway <NUM> explained above. A body <NUM> of the tool comprises a corresponding conical recess <NUM>. The conical protrusion <NUM> and the conical recess <NUM> have a common centre axis, which coincides with the vertical rotation axis <NUM> (refer <FIG>). This provides a self-aligning, airtight connection between the tool and the interface. Additionally, the interface may comprise an alignment pin <NUM> that fits into a corresponding hole that extends into the tool body <NUM>. The geometry of the interface and the tool thus enables the tool to be attached with a precise location, which is necessary to enable the blade <NUM> to perform high-precision dissection.

In some embodiments, the locking force between the tool and the interface is realized via a press fit between the conical protrusion <NUM> and the conical recess <NUM>. Alternatively, the locking force may be provided via a snap-fit connection. The conical protrusion <NUM> may comprise an annular ridge (not shown) which engages with snap-fit joints on the tool.

As shown in <FIG>, the tool <NUM> comprises an upper collar <NUM> having an essentially flat upper surface <NUM>, which surrounds an entrance to the conical recess <NUM>. A number of snap-fit joints <NUM> - three in the depicted embodiment - are provided at the entrance to the conical recess, which engage with the annular ridge on the conical protrusion <NUM> when the interface protrusion is pushed into the tool recess. In the depicted example, the snap-fit joints are cantilever arms that extend within a corresponding indentation <NUM> in the tool body <NUM> at the entrance to the conical recess <NUM>. A gap between each arm <NUM> and a radially outer wall of the indentation <NUM> permits flexure of the arm needed for engagement and disengagement with the annular ridge on the interface conical protrusion <NUM>. Suitably, the snap fit joints <NUM> are arranged at even angular intervals around the entrance to the conical recess <NUM> and are adapted to provide a stable locking force that is sufficiently large to enable precise dissection using the tool, yet small enough to permit relatively low-force disengagement.

To enable detachment of the tool, the interface is provided with at least one lever arm that is pivotably connected to the interface <NUM> about a horizontal pivot axis and is moveable within the interface housing <NUM>. In a preferred embodiment, the interface comprises three lever arms <NUM> which are arranged within the housing, at a radially outer location relative to the conical protrusion <NUM>. A first end of each lever arm has a first engagement surface <NUM> that extends beyond the generally planar underside <NUM> of the housing <NUM>. A second end of each lever arm has a second engagement surface (not visible in <FIG>) which can extend beyond the housing underside <NUM> when the lever arm is pivoted. As shown, the housing underside may comprise slots <NUM> that permit protrusion of the first and second engagement surface of each lever arm beyond the housing underside.

The process of tool detachment will be explained further with reference to <FIG>, which shows a side view of the tool <NUM> attached to the interface <NUM>, whereby part of the housing <NUM> is cut away to show one of the three lever arms <NUM>. The lever arm is pivotable about pivot axis <NUM>, which axis is located closer to the second end of the lever arm than the first end. Furthermore, the first end of the lever arm has a vertical extension <NUM>, which is generally located at a radial distance x, relative to the centre axis <NUM> of the interface conical protrusion, whereby x is larger than an outer radius of the tool upper collar <NUM>. The vertical extension <NUM> thus lies radially outside of the tool upper collar <NUM> such the first engagement surface <NUM> makes no contact with the tool. Suitably, the vertical extension <NUM> is sufficiently long to extend beyond an underside of the tool collar <NUM>.

The second end of the pivot arm is generally located at a shorter radial distance y relative to the centre axis <NUM> than the first end of the lever arm. The distance y is such that when the tool is in attached condition, the second engagement surface <NUM> of the lever arm <NUM> lies above the upper surface <NUM> of the upper collar <NUM>. The second engagement surface may be in contact with the collar upper surface or there may be a small gap. Displacement of the first engagement surface <NUM> of the lever arm <NUM> in an upward direction brings the second engagement surface <NUM> into contact with the collar upper surface <NUM> and exerts a force on the tool. Suitably the lever force exerted by the three lever arms is sufficient to overcome the locking force between the tool and the interface. In the embodiment where the tool is secured to the interface via snap fit joints, the combined lever force pushes the tool out of the engaged locking position.

In an embodiment, the tool is deposited into a tool carrier tray <NUM>, an example of which is shown in <FIG>. The tray comprises a number of tool carriers each of which comprises a recess <NUM> that is shaped to receive a tool body. Preferably, a tool is picked up from a tool carrier and replaced in the same carrier after use.

<FIG> shows a top view of two adjacent tool carriers <NUM>, <NUM> in the carrier tray <NUM>. Each tool carrier comprises an identically shaped main recess <NUM> for accommodating a tool. In the depicted example, each carrier is shaped such that when a tool is held therein, the upper surface <NUM> of the tool upper collar does not protrude beyond an upper surface <NUM> of the tray. Each carrier further comprises three indentations <NUM>, <NUM>, <NUM> relative to the tray upper surface <NUM>, which are located radially outwards of the main recess <NUM> and which are adapted to the receive the first engagement surface <NUM> of each lever arm <NUM> of the tool interface <NUM>. Let us assume that the interface will pick up a tool arranged in the first carrier <NUM>.

The actuator lowers the conical protrusion of the interface into the first carrier <NUM>, when the interface <NUM> is in a first angular position, being a pickup position in which the first engagement surface <NUM> of each lever arm is in alignment with the corresponding indentations <NUM>, <NUM>, <NUM> in the carrier.

<FIG> shows the tool interface <NUM> after it has been lowered into the first carrier <NUM> for picking up a tool. The conical protrusion of the tool interface <NUM> can be lowered into the first carrier <NUM> without engagement of the lever arm <NUM> because the first engagement surface <NUM> is in alignment with the first indentation <NUM> of the first carrier <NUM>. Similarly, the first engagement surface of the second and third lever arms are in alignment with the second and third indentations <NUM>, <NUM> respectively. As will be understood, the indentations have a sufficient depth to enable the conical protrusion <NUM> to be lowered until the annular ridge engages with the snap joints <NUM> at the entrance to the tool conical recess <NUM>. Downward movement of the actuator and the application of a relatively small force is thus sufficient to mechanically connect the tool to the interface. Preferably, the tray of carriers is able to flex somewhat, such that the tool can be displaced in the X-Y plane while being held in the recess <NUM>, to enhance alignment.

After dissection using the tool, it may be deposited back into the first carrier <NUM>. The actuator rotates the interface <NUM> about the vertical axis <NUM> to a second angular position, in which the first engagement surface of each lever arm is out of alignment with the indentations and will make contact with the upper surface <NUM> of the tray. In the depicted embodiment, the second angular position is a half turn from the first angular position, given that the tool body, and shaped recess <NUM>, has two degrees of rotational symmetry. Other configurations are of course possible.

The detachment process is evident from <FIG>, which show the tool being lowered into the first tool carrier <NUM> of the tool carrier tray <NUM>. After rotation to the second angular position, the actuator moves the interface <NUM> and tool <NUM> downward towards the tray, which is now positioned relative to the tool such that the tool body <NUM> is inserted into the shaped recess of the tool carrier <NUM> and the first engagement surface <NUM> of the lever arm <NUM> now makes contact with the tray upper surface <NUM>, as shown in <FIG>. Further downward movement causes the first end of the lever arm to be displaced upwards within the interface housing <NUM> as shown in <FIG> and the second engagement surface <NUM> of the lever arm is displaced to exert a releasing force on the tool collar <NUM>, which disengages the snap-fit connection as explained above. When the tool has been released, the actuator raises the interface <NUM> until the conical protrusion <NUM> is above the tray and can be moved to pick up a new tool that is arranged in an adjacent tool carrier of the carrier tray.

Thus, the only necessary actions of the actuator <NUM> to perform automated tool pickup and depositing are rotation about a vertical axis, free from load, and downward movement involving the application of low force. This can be achieved using a compact and lightweight actuator.

Examples, embodiments or optional features, whether indicated as non-limiting or not, are not to be understood as limiting the invention as claimed.

Claim 1:
Apparatus for dissecting biological material from a sample disposed on a planar substrate, comprising a tool interface (<NUM>) for releasable attachment of a dissection tool (<NUM>) that is connectable to the interface via at least one push fitting (<NUM>, <NUM>) and is rotatable about a vertical rotation axis (<NUM>), further comprising an actuator (<NUM>) in fixed connection with the interface (<NUM>), wherein the actuator (<NUM>) is moveable in vertical direction and is rotatable between a first angular position and a second angular position about the vertical rotation axis (<NUM>); characterised in that the interface (<NUM>) further comprises one or more lever arms (<NUM>) each pivotably connected to a housing (<NUM>) of the interface via a horizontal pivot axis (<NUM>), whereby:
• each lever arm (<NUM>) is arranged at a radially outer location relative to the at least one push fitting and has first and second ends with respective first and second engagement surfaces (<NUM>, <NUM>), the first engagement surface (<NUM>) being arranged at a greater radial distance from the vertical axis (<NUM>) than the second engagement surface (<NUM>); and
• the tool (<NUM>) has an upper collar (<NUM>) which is dimensioned such that when the tool is attached to the interface (<NUM>), the first engagement surface (<NUM>) of each lever arm (<NUM>) lies outside of an outer dimension of the upper collar and makes no contact therewith, and is further dimensioned such that the second engagement surface (<NUM>) of each lever arm will make contact with an upper surface (<NUM>) of the collar when the first end of the lever am is displaced in upward direction;
and in that
• the apparatus further comprises a receptacle (<NUM>) having an opening (<NUM>) of sufficient depth to accommodate a main body (<NUM>) of the tool, and is configured to detach the tool by lowering the interface (<NUM>) towards the opening until the first engagement surface (<NUM>) of each lever arm makes contact with a surface (<NUM>) that surrounds the opening and is displaced in upward direction, causing each lever arm to pivot such that the corresponding second engagement surface (<NUM>) is displaced against the upper surface (<NUM>) of the tool and exerts a force on the collar (<NUM>) that disengages the at least one push fitting.