Patent Description:
Many existing and emergent cancer therapy modalities involve the removal of cancerous lesions by ablation or radiotherapy. Among these, a few techniques - such as cryotherapy, laser ablation, irreversible electroporation (IRE), and brachytherapy - involve the insertion of needles or needle-shaped devices such as probes and introducers (henceforth all referred to as 'needles' for simplicity) to the target area.

In such procedures, positional guidance of the needle is necessary in order to ensure that the cancerous lesion is targeted and removed, and that healthy tissues are largely preserved. This can be achieved by means of an externally positioned needle guide that determines the trajectory of the needle passing through.

Conventional methods to guide a needle have several drawbacks. For example, the widely used brachytherapy template grid provides a grid of parallel needle guide channels, spaced apart at regular intervals. This means it does not provide the option of adjusting the angle of each needle, and insertion positions are limited to discrete points. Another commercially available biopsy needle guide, on the other hand, permits full positional control as it is robotically controlled in <NUM> degrees of freedom. However, it does not allow the insertion of multiple needles in a single procedure, such that at a single instant there are multiple needles in the patient's body. This is because the single needle guide is a closed channel, so if a needle has been inserted through it, it cannot move to the next position. <CIT> discloses a positioning apparatus including a needle holder having a through hole for regulating needle placement and movement, a needle positioning unit, and an engagement member that fixes a position of the needle holder with respect to the needle positioning unit. The positioning apparatus may be designed to accommodate the placement of multiple needles. <CIT> discloses a system that comprises a gripping device for gripping the needle in order to perform robotic insertion steps, yet for releasing the grip between such insertion steps, until the next insertion step is initiated. The gripper can either fully disconnect from the needle, or can partially disconnect but constrain motion within limits.

A need therefore exists to provide a needle guide that can address at least one of the above problems.

An aspect of the present invention provides a needle guide assembly as defined in claim <NUM>. Further embodiments of the invention are recited in the dependent claims. The needle assembly comprises a needle guide body comprising at least two separable portions; and a controller communicatively coupled to the needle guide body; wherein the needle guide body is operable by the controller to actuate between a closed configuration and an open configuration, wherein in the closed configuration, the at least two portions combine to define a channel therethrough for receiving a needle, and wherein in the open configuration, the at least two portions separate to release the received needle from the channel.

The channel comprises a proximal end and a distal end, and the needle is configured to be received at the proximal end and inserted through the channel toward the distal end.

An axis of the channel is aligned in use with a needle insertion site adjacent the distal end, and the needle guide body is pivotable about distal end.

The needle guide body may be movable to a next needle insertion site based on at least one parameter determined by the controller. The at least one parameter may comprise at least one of relative positions between consecutive needle insertion sites and needle diameter.

The assembly may further comprise an articulated arm mechanically connected to the needle guide body and communicatively coupled to the controller, for displacing the needle guide body based on instructions from the controller.

The at least two portions may be configured to move angularly relative to each other between the open and closed configurations. Alternatively or in addition, the at least two portions may be configured to move translationally relative to each other between the open and closed configurations.

Another aspect of the present disclosure provides an automated method of operating a needle guide assembly, the method comprising identifying a needle insertion site; moving a needle guide body of the needle guide assembly to the needle insertion site, the needle guide body comprising at least two separable portions operable between an open configuration and closed configuration; actuating the at least two portions to the closed configuration, the at least two portions defining a channel therethrough in the closed configuration; aligning an axis of the channel with the needle insertion site such that the axis has a predetermined angular orientation; and upon completion of needle insertion, actuating the at least two portions to the open configuration.

Aligning an axis of the channel with the needle insertion site may comprise pivoting the needle guide body about the distal end.

The method may further comprise moving the needle guide body to a next needle insertion site. Moving the needle guide body to the next needle insertion site may comprise controlling the needle guide body based on at least one parameter of relative positions between consecutive needle insertion sites and needle diameter.

Actuating the at least two portions may comprise moving the at least two portions angularly relative to each other. Alternatively or in addition, actuating the at least two portions may comprise moving the at least two portions translationally relative to each other.

Displacement of the needle guide body may be effected using an articulated arm.

The inventors have noted that, to be effective in guiding needles for cancer therapy, the needle guide should preferably combine two characteristics. Firstly, it should provide the flexibility of having its position and angle independently controlled. This helps to permit higher resolution and accuracy in targeting the lesion, for example, in focal therapy where the index lesion which is typically targeted has a small volume of ><NUM> cc to <NUM> cc, and a margin of <NUM> - <NUM> around it is required. Secondly, the needle guide should facilitate the insertion of multiple needles per procedure, as is the case with cryotherapy, IRE and brachytherapy.

The present disclosure provides a robotically controlled needle guide that permits the release of needles inserted through it and facilitates positional control of multiple needles.

<FIG> shows a schematic diagram illustrating a needle guide body <NUM> of a needle guide assembly according to an example embodiment. The needle guide body <NUM> includes at least two separable portions which are operable between an open configuration and closed configuration. In <FIG>, two portions 102a, 102b are shown in the closed configuration but it will be appreciated that the needle guide body <NUM> can be made of more than two portions in alternate embodiments. Relative movement of the portions 102a, 102b between the open and closed configurations can be translational, angular, or a combination of both. For example, in one implementation, each portion 102a, 102b may be actuated by a respective motor (not shown in <FIG>) to open/close in a hinge-like motion. In the open configuration, a slot or opening is formed between the portions 102a, 102b.

As shown in <FIG>, in the closed configuration, the at least two portions 102a, 102b define a straight channel <NUM> running through the at least two portions 102a, 102b. For example, the channel <NUM> is formed by respective elongated grooves on the at least two portions 102a, 102b. The channel <NUM> has a proximal end <NUM> and a distal end <NUM>. In use, the proximal end <NUM> is configured to receive a needle <NUM> which can be inserted through the channel <NUM> toward the distal end <NUM> before exiting the channel <NUM> from the distal end <NUM>. In other words, the channel <NUM> serves to determine the trajectory of the needle <NUM> inserted through it.

For example, an axis of the channel <NUM> can be aligned with a needle insertion site <NUM> which is near or adjacent the distal end <NUM>. The needle <NUM> is then inserted through the channel <NUM> such that the needle <NUM> passes through a skin <NUM> at the needle insertion site <NUM> and strikes a target <NUM>. Further, the needle guide body <NUM> including the inserted needle <NUM> is pivotable about the distal end <NUM> to facilitate adjustment of the angular orientation of the needle <NUM> before or during the insertion procedure.

The cross-sectional size of the channel <NUM> in the example embodiments is configured to be slightly larger than the cross-sectional size of needle <NUM> to allow a relative smooth insertion of the needle <NUM> through the channel <NUM> while substantially constraining the angular orientation of the needle <NUM> to that of the channel <NUM>. For example, if the needle <NUM> has a circular cross-section, the channel <NUM> may also have a circular cross-section of slightly larger diameter when the at least two portions 102a, 102b are fully closed. When a larger needle is to be used, the cross-sectional size of the channel <NUM> can be adapted accordingly.

<FIG> shows a schematic diagram illustrating a needle guide assembly <NUM> including the needle guide body <NUM> of <FIG> according to an example embodiment. In this example, the needle guide body <NUM> is mechanically connected to a robotic or articulated arm <NUM> having multiple degrees of freedom such that displacement of the needle guide body <NUM> can be effected by the articulated arm <NUM>. The robotic or articulated arm <NUM> and needle guide body <NUM> are communicatively coupled to a controller <NUM> (or computer system) which receives input relating to the needle insertion procedure and controls the arm <NUM> and needle guide body <NUM> accordingly.

<FIG> show schematic diagrams illustrating example operations of the needle guide assembly <NUM> of <FIG>. During a needle insertion procedure, the needle guide body <NUM> is moved into position such that the needle tip will end up at the needle insertion site <NUM>, as described above with reference to <FIG>. The treatment needle <NUM> is then inserted by the doctor through the channel <NUM> of the body <NUM> (see <FIG>). After the needle <NUM> has been inserted to the desired position (e.g. through a predetermined insertion depth), the at least two portions 102a, 102b are actuated to the open configuration, forming a slot <NUM> larger than the diameter of the needle <NUM> (see <FIG>). The body <NUM> is then moved away, e.g. opposite to the direction of the slot <NUM>, such that the needle <NUM> passes through the slot <NUM> and is left behind (see <FIG>). For the next needle, the body <NUM> is closed and moved to the next position (see <FIG>). The process of needle insertion and release is then repeated.

In the above example of <FIG>, the needle guide body <NUM> is moved substantially laterally from one needle insertion site to the next needle insertion site based on a sequence or algorithm determined by the controller <NUM> (<FIG>). The sequence sequence is such that the amount of movement is minimised, or, but not forming part of the claimed invention, collision between the needle guide body <NUM> and inserted needles is avoided. However, it will be appreciated that different forms of movements can be applied in alternate non-claimed embodiments. For example, the body <NUM> can be drawn back to achieve clearance from the needle before being moved to the next needle insertion site. Parameters that may be considered to optimise the path of the body <NUM> between needle insertion sites include, but are not limited to, relative positions between consecutive needle insertion sites, and needle diameter.

<FIG> shows a detailed flow chart <NUM> illustrating operations of a needle guide assembly as described above with reference to <FIG>, according to a non-limiting implementation. The operations are divided mainly into a planning stage and a positioning stage. In the planning stage, step <NUM> involves a user (e.g. a urologist) choosing target points or needle insertion sites. Alternatively or in addition, this step may be performed with the help of artificial intelligence. Next, at step <NUM>, the sequence in which target points should be accessed is calculated, e.g. based on the requirement of minimum interference. If there are points outside of the mechanical limit of the articulated arm <NUM> and/or needle guide body <NUM>, at step <NUM>, the user is informed of the target points which are not valid so that the user can adjust the choices. Further, even if no points are out of the mechanical limit, if it is determined that there will be interference during movement, e.g. between robot parts or between robot and needles, the user is similarly informed of the target points which are not valid.

On the other hand, if there is no interference, the process moves to the positioning stage where, at step <NUM>, the needle guide body <NUM> is at the first needle insertion site and at the desired angular orientation, with the portions 102a, 102b forming the needle guide body <NUM> in the closed configuration. Next, at step <NUM>, the needle <NUM> is inserted by the user through the channel <NUM> such that the needle <NUM> travels by a predetermined insertion depth from the first needle insertion site. The portions 102a, 102b forming the needle guide body <NUM> are then opened, at step <NUM>, thereby forming a slot through which the needle can be released. Then, at step <NUM>, the body <NUM> moves in a direction away from the needle <NUM> such that the needle passes through the slot and is left behind.

Before moving to the next target position, which is aligned with the next needle insertion site, the needle guide body <NUM> simultaneously undergoes several motions at step <NUM>, including moving to a position a fixed distance away from the next target position, such that the slot to be formed by the portions 102a, 102b is facing and approximately parallel to the next target position, aligning with the next target position based on a desired angular orientation, and closing the portions 102a, 102b. Step <NUM> involves moving the body <NUM> in the direction the slot faces, to the next target position. There, the steps <NUM>-<NUM> as described above can be repeated.

In the example embodiments, the position of the slot (relative to the channel) is fixed for the needle guide body. For example, with reference to the top plan view in <FIG>, the slot is below the channel. As implemented, the position of the slot can be determined by how the needle guide body opens in its hinge-like motion. Hence, if the slot is formed at the bottom of the needle guide body, then the needle guide body will be moved to above the next target position. If the slot is at the right of the needle guide body, then the needle guide body will be moved to the left of the next target position.

As described above, many or all of the operations of needle guide assembly can be automated based on instructions from a controller or computer system, and performed by a robot. This can improve accuracy and repeatability. Also, the same needle guide assembly can be used for multiple needle insertions, in an efficient manner.

<FIG> shows a flow chart <NUM> illustrating an automated method of operating a needle guide assembly according to an example embodiment. At step <NUM>, a needle insertion site is identified. At step <NUM>, a needle guide body of the needle guide assembly is moved to the needle insertion site. The needle guide body includes at least two separable portions operable between an open configuration and closed configuration. At step <NUM>, the at least two portions are actuated to the closed configuration, the at least two portions defining a channel therethrough in the closed configuration. At step <NUM>, an axis of the channel is aligned with the needle insertion site such that the axis has a predetermined angular orientation. At step <NUM>, upon completion of needle insertion, the at least two portions are actuated to the open configuration.

Claim 1:
A needle guide assembly (<NUM>) comprising:
a needle guide body (<NUM>) comprising at least two separable portions (102a, 102b); and
a controller (<NUM>) communicatively coupled to the needle guide body (<NUM>);
wherein the needle guide body (<NUM>) is operable by the controller (<NUM>) to actuate between a closed configuration and an open configuration, wherein in the closed configuration, the at least two portions (202a, 202b) combine to define a channel (<NUM>) therethrough for receiving a needle (<NUM>), and wherein in the open configuration, the at least two portions (102a, 102b) separate to release the received needle (<NUM>) from the channel (<NUM>);
wherein the channel (<NUM>) comprises a proximal end (<NUM>) and a distal end (<NUM>), and wherein the needle (<NUM>) is configured to be received at the proximal end (<NUM>) and inserted through the channel (<NUM>) toward the distal end (<NUM>);
wherein an axis of the channel (<NUM>) is aligned in use with a needle insertion site (<NUM>) adjacent the distal end (<NUM>), and wherein the needle guide body (<NUM>) is pivotable about the distal end (<NUM>); and
characterized in that the needle guide body (<NUM>) is movable laterally to a next needle insertion site based on a sequence determined by the controller (<NUM>) that minimises movement.