U.S. patent application number 17/751993 was filed with the patent office on 2022-09-08 for needle steering by shaft manipulation.
The applicant listed for this patent is TECHNION RESEARCH & DEVELOPMENT FOUNDATION LTD.. Invention is credited to Michael ARAD, Gonen DASKAL, Daniel GLOZMAN, Yoav PINSKY, Moshe SHOHAM.
Application Number | 20220280251 17/751993 |
Document ID | / |
Family ID | 1000006351505 |
Filed Date | 2022-09-08 |
United States Patent
Application |
20220280251 |
Kind Code |
A1 |
GLOZMAN; Daniel ; et
al. |
September 8, 2022 |
NEEDLE STEERING BY SHAFT MANIPULATION
Abstract
A method and apparatus for steering of a flexible needle into
tissue using a steering robotic platform for manipulation of the
needle shaft, and by use of a semi-active arm for locating and
orienting of the steering robot on the patient's body. As opposed
to other steering methods, the robot does not hold the base of the
needle, which is its proximal region, but rather grips the shaft of
the needle by means of a manipulatable needle gripping device, near
its distal end. The needle gripper attached to the robotic platform
may be equipped with a traction assembly to provide motion to the
needle in its longitudinal direction, such that it co-ordinates the
entry of the needle with the desired entry angle. The gripping of
the needle at its distal end, close to its insertion point,
provides the needle manipulator with a low profile, with
concomitant advantages.
Inventors: |
GLOZMAN; Daniel; (Kfar
Adummim, IL) ; DASKAL; Gonen; (Kefar Hanassi, IL)
; SHOHAM; Moshe; (Hoshaya, IL) ; ARAD;
Michael; (Tel Aviv, IL) ; PINSKY; Yoav; (Beit
Keshet, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TECHNION RESEARCH & DEVELOPMENT FOUNDATION LTD. |
Haifa |
|
IL |
|
|
Family ID: |
1000006351505 |
Appl. No.: |
17/751993 |
Filed: |
May 24, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16714840 |
Dec 16, 2019 |
11369444 |
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17751993 |
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15027438 |
Apr 6, 2016 |
10507067 |
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PCT/IL2014/050891 |
Oct 7, 2014 |
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16714840 |
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61887654 |
Oct 7, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 2090/374 20160201;
A61B 34/30 20160201; A61B 2090/3762 20160201; A61B 90/37 20160201;
A61B 2017/3409 20130101; A61B 90/11 20160201; A61B 2034/304
20160201 |
International
Class: |
A61B 34/30 20060101
A61B034/30; A61B 90/11 20060101 A61B090/11 |
Claims
1. A method for manipulating a needle insertable into a body of a
subject, the method comprising: providing a robotic platform having
a plurality of degrees of freedom; providing a needle gripper
configured to be attached to said robotic platform; using the
needle gripper to grip a shaft of said needle at a distal portion
thereof; and manipulating said needle gripper to provide said
needle with a desired pose.
2. The method according to claim 1, wherein said needle gripper
comprises a driving mechanism, and the method further comprises the
step of: activating said driving mechanism to provide motion to
said needle in the longitudinal direction of said needle.
3. The method according to claim 2, wherein the activating further
comprises the step of: coordinating activation between the robot
platform and the driving mechanism such that the robotic platform
adjusts the orientation angle of the needle inside a soft tissue of
the body during insertion motion of said needle into said subject,
such that said needle traverses a non-linear path within said soft
tissue of said subject.
4. The method according to claim 1, wherein said robotic platform
comprises an actuated platform and a base plate, and the method
further comprises the steps of: positioning the base plate on the
skin of the subject close to a point of insertion of the needle
into the body of the subject; and positioning and orienting said
actuated platform relative to said base plate to achieve said
desired pose of said needle.
5. The method according to claim 1, further comprising the step of:
releasing the grip of the needle gripper on the needle, to allow
said needle to move freely longitudinally.
6. The method according to claim 1, further comprising the step of:
rotating the needle about its axis, to allow free longitudinal
motion of the needle when an insertion step is actuated.
7. The method according to claim 1, further comprising the step of
detecting motion of the body of the subject by a sensor system.
8. The method according to claim 1, further comprising the step of
defining a breath cycle of the subject by a sensor system.
9. The method according to claim 1, further comprising the steps of
providing a support arm; and aligning said robotic platform close
to a point of insertion of said needle into the body of the
subject, using said support arm.
10. A method for manipulating a needle insertable into a body of a
subject, comprising: providing a robotic platform comprising an
actuated platform having a plurality of degrees of freedom;
providing a needle gripper configured to be attached to the
actuated platform; using the needle gripper to grip a shaft of said
needle at a distal portion thereof; and manipulating said needle
gripper to provide an insertion motion to the needle with a desired
pose.
11. The method according to claim 10, further comprising the step
of inserting said needle in the longitudinal direction of said
needle.
12. The method according to claim 11, wherein the activating
further comprises the steps of: coordinating activation between the
actuated platform and the needle gripper such that the actuated
platform adjusts the orientation angle of the needle inside a soft
tissue of the body during the insertion motion of said needle into
said subject, such that said needle traverses a non-linear path
within said soft tissue of said subject.
13. The method according to claim 10, wherein said robotic platform
further comprises a base plate, and the method further comprises
the steps of: positioning the base plate on the skin of the subject
close to a point of insertion of the needle into the body of the
subject; and positioning and orienting said actuated platform
relative to said base plate to achieve said desired pose of said
needle.
14. The method according to claim 10, further comprising the step
of releasing the grip of the needle gripper on the needle, to allow
said needle to move freely longitudinally.
15. The method according to claim 10, wherein said needle gripper
comprises a driving mechanism, and the method further comprises the
step of activating said driving mechanism to provide motion to said
needle in the longitudinal direction of said needle.
16. The method according to claim 15, further comprising the steps
of: attaching the needle gripper to the actuated platform; and
coupling the needle to the needle gripper such that the driving
mechanism is positioned at the distal portion of the needle shaft.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. patent
application Ser. No. 16/714,840 filed Dec. 16, 2019, which is a
Continuation of U.S. Pat. No. 15/027,438 filed Apr. 6, 2016, now
U.S. Pat. No. 10,507,067, issued Dec. 17, 2019, which is a U.S.
National Phase Application under 35 U.S.C. 371 of International
Application No. PCT/IL2014/050891, which has an international
filing date of Oct. 7, 2014, and which claims the benefit of
priority from U.S. Provisional Patent Application No. 61/887,654,
filed Oct. 7, 2013, the disclosures of which are incorporated
herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of devices for
needle steering and their use in image-guided robotic needle
steering.
BACKGROUND OF THE INVENTION
[0003] Many routine treatments employed in modem clinical practice
involve percutaneous insertion of needles and catheters for biopsy
and drug delivery and other therapies. The aim of a needle
insertion procedure is to place the tip of an appropriate needle
safely and accurately in a target region, which could be a lesion,
organ or vessel. Examples of treatments requiring needle insertions
include vaccinations, blood/fluid sampling, regional anesthesia,
tissue biopsy, catheter insertion, cryogenic ablation, electrolytic
ablation, brachytherapy, neurosurgery, deep brain stimulation and
various minimally invasive surgeries.
[0004] Guidance and steering of needles in soft tissue is a
complicated task that requires good 3-D coordination, knowledge of
the patient anatomy and a high level of experience. Therefore
robotic systems have been proposed for performing these functions.
Among such robotic systems are those described in U.S. Pat. No.
7,008,373 to D. Stoianovici, for "System and method for robot
targeting under fluoroscopy"; and in U.S. Pat. No. 5,572,999 to
Funda et al, for "Robotic system for positioning a surgical
instrument relative to a patient's body"; and in the product data
sheets on the Innomotion robot, as provided by Innomedic GmbH, of
Philippsburg-Rheinsheim, Germany.
[0005] All of these systems are guiding systems that help in
choosing the insertion point and in aligning the needle with the
target. The insertion is then done by the surgeon who pushes the
needle along the straight line. Such systems usually work with 3-D
data taken before the procedure, typically by CT or MM. The 3-D
reconstruction of the patient anatomy is done first. Then the
needle is registered to the 3-D anatomy and the robot can orient a
cannula so that it will be aligned with the target. Through that
cannula the doctor inserts a needle assuming that the needle will
not deviate from a straight line and that it will hit the target. A
problem with this method is that both needles and tissue are
flexible, and the needle therefore does not always proceed in a
straight line even in soft tissue. It may deviate from the planned
straight path, and methods are needed for ensuring that it does
reach the intended target region.
[0006] A method for needle steering which is based on the lateral
forces exerted on the tip of flexible beveled needle has been
described in published U.S. Patent Application US 2007/0016067 A1
to R.J. Webster III et al, for "Distal Bevel Tip Needle Control
Device and Algorithm". This application describes a needle driver
which grasps the base of the beveled needle and drives the needle
shaft by pushing it for longitudinal entry, and rotating it for
steering.
[0007] In PCT publication No. WO 2007/141784 to D. Glozman et al,
for "Controlled Steering of a Flexible Needle", there is described
another method in which the base of the needle is held by a robot,
and the needle is steered by manipulation of the needle base by the
robot.
[0008] However, all of the methods and systems described above use
needles gripped robotically or otherwise, at their proximal ends,
remote from the insertion point into the patient. This results in
the need for a large workspace, which may be especially problematic
in the realm of imaging systems, where headroom above the supine
patient is often limited. There therefore exists a need for a more
compact method of manipulating a needle during the insertion
process into a subject.
[0009] The disclosures of each of the publications mentioned in
this section and in other sections of the specification, are hereby
incorporated by reference, each in its entirety.
SUMMARY OF THE INVENTION
[0010] The present disclosure describes a method and apparatus for
steering of a flexible needle inside soft tissue by manipulation of
the needle shaft, and by use of a semi-active device for locating
and orienting of the steering robot on the patient's body. As
opposed to other steering methods, the robot does not hold the base
of the needle, or a proximal point close to the base of the needle,
but rather grips the shaft of the needle by its distal part, closer
to the insertion point into the patient, by means of a
manipulatable needle gripper. The combination of the needle gripper
and the robotic platform for manipulating the needle gripper is
called in this application, a robotic needle manipulator.
[0011] The robotic needle manipulator should be able to move with
at least 4 degrees of freedom. The minimal four degrees of freedom
enable orientation and positioning of the robotic needle
manipulator. Two degrees of freedom are needed for positioning the
entry point of the needle and two for orientation. Motion
perpendicular to the plane is not essential, since the insertion
motion of the needle may be provided by a pushing motion generated
within the robotic needle manipulator, as described below. Since
the robotic needle manipulator does not have to generate the motion
required for insertion of the full length of the needle, which
could be considerable, the workspace required by the system is
significantly smaller than that of prior art systems which do
perform the robotic insertion themselves. However, use of a robotic
platform with more than 4 degrees of freedom may also be
advantageous, though the use of the direction of freedom in the
direction parallel to the needle will not generally be used for
inserting the needle, because the large travel generally required
for inserting the needle may conflict with the need to maintain a
low profile workspace of the robotic needle manipulator.
[0012] Besides the needle orientation and positioning functions
generated by the robotic actuator, as described above, the robotic
needle manipulator should also be able to insert the needle by
means of a mechanism which moves the needle in its longitudinal
direction. This mechanism can be either a mechanical system
designed to grip the needle shaft and to move it inwards and
outwards, or alternatively, the "mechanism" could simply be a
manual operation by the medical personnel inserting the needle by
hand while the gripping action of the robotic needle manipulator is
released, or alternatively, not even fitted, with the needle held
freely in a cannula.
[0013] In addition, rotation of the needle may be useful for use
with beveled needle guidance systems, or, simply in order to keep
the bevel at 90 degrees to the imaging plane so that if lateral
forces develop during the insertion, the deviation generated
because of the beveled needle will be in the imaging plane, where
imaging is optimal for detection of such a deviation. The proposed
system can work with various medical image modes, such as CT, MRI,
PET or Ultrasound.
[0014] The needle may be inserted either continuously or step by
step, requiring operator approval for each step. A major innovative
aspect of this system is in the manipulation of the needle by means
of its distal portion.
[0015] One advantage of the systems described in this application
is that the workspace required for the robot is significantly
smaller than for prior art systems, where the robot manipulates the
base of the needle, which, for a long needle, can be 10 cm. or even
more from the entry point at the tip of the needle. The workspace
can be as little as the order of 10 millimeters as opposed to
several centimeters for the prior art systems. In the systems
described in this application, the longitudinal needle motion is
mechanically separated from the lateral manipulations of the
needle. A characteristic of these implementations of the devices of
this disclosure is that the needle driving mechanism is capable of
driving needles of variable lengths while the dimensions and
workspace of the driving mechanism does not depend on the length of
the needles. In prior art systems, the longitudinal needle
insertion is either not available robotically, or if available, it
requires the manipulator to have a range of motion at least as long
as the length of insertion of the needle.
[0016] Examples of needle base driving and needle shaft driving
will be shown below by a numerical simulation. A smaller workspace
allows the use of a smaller robot which is advantageous in such
medical applications. Such a workspace of only 10 millimeters or so
is advantageous from a safety point of view. The robot is then
incapable of accidentally moving significantly and of injuring
neighboring organs.
[0017] Because of their low profile, the robotic needle
manipulators described in this application can be easily placed on
the patient's body, which is also advantageous because this
compensates for patient motion during the procedure -- the robot
moves with the patient. The robot can be placed on the patient
directly and be connected with belts, or adhesives, thereby
affixing its lateral position on the patient's skin.
[0018] Furthermore, the low profile enables the robotic needle
manipulator to be used more readily in the limited space of a CT or
other three-dimensional imaging system.
[0019] According to an exemplary aspect of the present invention,
the robotic needle manipulator is supported by a semi-active
support arm whose purposes may be one or more of the following:
(i) to append the robotic needle manipulator to the patient's body
surface by applying a gentle force, and (ii) to track the robot
position in real-time.
[0020] The semi-active arm may have 3 or more degrees of freedom,
and preferably 6, in order to be able to laterally locate the robot
above the needle entry point and to orient the robot plane relative
to the patient's body. The semi-active arm may comprise a series of
links connected by joints, as in a serial robot. However, it is to
be understood that a parallel robot or a hybrid serial-parallel
robot may also be used in this application. For a serial robot,
each such semi-active joint should have an encoder which monitors
the rotation of the joint, so that the position and orientation of
the end effector can be calculated by solution of the forward
kinematics problem. The semi-active arm can, on the other hand,
alternatively be fully passive, meaning that there are no motors in
the joints and the joints can be rotated freely unlocked, or there
may be motors or springs operating on one or more joints so that
the angle of at least one joint can be controlled. Alternatively,
one or more joints can be locked and others passive. Regardless of
the actual configuration used, the encoders on the joints, if
fitted, can be used as the sensors for determining the position of
the semi-active arm relative to the patient's body, hence
determining the position and orientation of the robot, such as for
the purposes of the registration described herewithin.
[0021] Control of one or more joints is useful for solution of the
respiration gait problem (respiration compensation), where the
robot should move synchronously with movements of the patient's
body. An additional function of the semi-active arm may be to
monitor the respiration of the patient. The semi-active arm reduces
the need for placing external sensors on the patient's skin, as is
done in prior art methods, in order to monitor the stages of the
breath cycle of the patient. Since the robotic needle manipulator
maintains contact with the patient's chest, its sensors are able to
define the breath cycle of the patient.
[0022] A particularly useful configuration of the support arm is to
provide it with positive control in the direction perpendicular to
the patient's body surface, such as by use of a spring, such that
it exerts sufficient pressure that the robotic needle manipulator
remains in contact with the patient's skin, yet allows the robotic
needle manipulator to rise and fall with the patient's breathing
cycle. At the same time, the other directions of freedom of the
robotic needle manipulator control system may advantageously be
maintained sufficiently stiffly controlled that the robotic needle
manipulator remains nominally constrained by the support arm to its
predetermined position on the subject's body at the needle
insertion point, yet allows some level of freedom of movement
should the patient move laterally during the procedure due to
coughing or discomfort or the like.
[0023] Additionally, the need for sensors on the semi-active arm
may be dictated by the need to maintain registration of the robot
position with the CT coordinate system. The initial robotic
registration to establish correct co-ordinate transformation
between the robot and CT systems, becomes invalidated by the
patient's breathing motion, which also moves the robot. The sensors
in the semi-active arm are able to track the robot position, in
order to maintain the correct current co-ordinate transformation
from the initial registration procedure, even as the robot
moves.
[0024] An additional advantage of connecting the robot via a
semi-active arm is that the arm with the robot and the patient now
move together and it is possible to perform volume scans of the
patient with the needle inserted. In order to perform a volume
scan, the CT bed needs to move. When the needle is inside the
patient and the CT bed moves, the needle and the robot move with
the bed and the patient, so there is no relative movement between
the needle and the patient.
[0025] There is thus provided in accordance with an exemplary
implementation of the devices described in this disclosure, a
system for needle insertion into a subject, comprising:
(i) a robotic platform having a plurality of degrees of freedom
providing the needle with a desired pose, and (ii) a needle gripper
attached to the robotic platform, the needle gripper being
activated to provide motion to the needle in its longitudinal
direction, wherein the needle gripper grips the shaft of the needle
distally to the base of the needle.
[0026] Such a system may further comprise a positioning system for
positioning the robotic platform close to the point of insertion of
the needle into the subject. Furthermore, the needle gripper may
comprise at least a pair of rollers on either side of the needle,
such that co-ordinated rotation of the rollers causes the needle to
move in its longitudinal direction. Additionally, a needle rotation
mechanism may be incorporated, such that the needle can be rotated
about its axis. In yet other implementations, the needle gripper
may be adapted to release its grip on the needle, such that the
needle can move longitudinally freely.
[0027] In yet other implementations of the needle insertion systems
of the present application, the robotic platform may comprise a
base plate, such that the robotic platform can be positioned with
the base plate in juxtaposition to the skin of the subject.
Furthermore, the pose may be adjusted in co-ordination with
activation of the needle gripper such that the orientation of the
needle can be adjusted as the needle is inserted into the
subject.
[0028] Furthermore, in any of the above-described systems, gripping
of the needle shaft distally to the needle base is such that the
system can operate without any part thereof extending further from
the subject than the base of the needle. In some exemplary
implementations, the workspace of the system may not extend more
than 50 mm from the point of insertion of the needle, and in other
implementations not more than 30 mm. and in yet other
implementations, not more than 20 mm.
[0029] In any of the above-described systems, the robotic platform
may be a parallel, a serial or a hybrid robotic platform.
[0030] There is further provided in accordance with another
exemplary implementation of the devices described in this
disclosure, a system for needle insertion into a subject,
comprising:
(i) a robotic platform for aligning and inserting the needle into
the subject, (ii) a support arm for aligning the robotic platform
close to the point of insertion of the needle into the subject, and
(iii) a sensor system for detecting motion of the body of the
subject close to the point of insertion of the needle, wherein the
sensor system provides commands for the robotic platform, for
insertion of the needle in co-ordination with the detected motion
of the body of the subject.
[0031] The motion of the body of the subject mentioned hereinabove
in relation to such a system, may be breathing related motion.
Additionally, the support arm may be designed to apply pressure on
the robotic platform, such that the robotic platform remains in
contact with the subject's body, and the support arm may be such
that its motion is essentially unconstrained in a direction
perpendicular to the surface of the patient's body, such that the
robotic platform moves freely with motion of the subject's body.
Furthermore, the motion of the support arm may be partially
constrained in directions parallel to the surface of the patient's
body, such that the robotic platform is generally constrained by
the support arm to a predetermined position on the subject's
body.
[0032] Yet other implementations perform a method for insertion a
needle into a subject, comprising:
(i) providing a robotic platform having a plurality of degrees of
freedom to align the needle at its desired pose, (ii) providing a
needle gripper for attachment to the robotic platform, (iii) using
the needle gripper to grip the shaft of the needle distally from
the base of the needle, and (iv) activating the needle gripper to
provide motion to the needle in its longitudinal direction.
[0033] An additional exemplary method for inserting a needle into a
subject, may comprise:
(i) providing a robotic platform for aligning the needle for
insertion into the subject, (ii) providing a support arm for
aligning the robotic platform close to the point of insertion of
the needle into the subject, (iii) detecting motion of the body of
the subject close to the point of insertion of the needle, and (iv)
using the detected motion of the body to provide commands for the
robotic platform, such that the needle can be inserted in
co-ordination with the detected motion of the body of the
subject.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The present invention will be understood and appreciated
more fully from the following detailed description, taken in
conjunction with the drawings in which:
[0035] FIG. 1 shows overall view of a system of the present
disclosure, used to manipulate a needle under the guidance of a CT
imaging system;
[0036] FIG. 2 is a schematic view of the robotic needle manipulator
attached to the patient base plate for insertion into an imaging
system;
[0037] FIG. 3 is a schematic view of a complete robotic needle
manipulator shown holding a needle remotely from the needle
base;
[0038] FIG. 4 is another schematic view of the robotic needle
manipulator of FIG. 3;
[0039] FIGS. 5 and 6 show schematically a complete robotic needle
manipulator at two different insertion angles, incorporating a
needle driving mechanism employing rotation of two or more rollers,
such that the needle insertion can be performed under robotic
control;
[0040] FIG. 7 is a graphical representation of a prior art example
of needle steering by steering of the needle base; and
[0041] FIG. 8 is a graphical representation of an example of needle
steering using the distal shaft gripping method of the present
disclosure, showing the space saving advantages over the prior art
method shown in FIG. 7.
DETAILED DESCRIPTION
[0042] Reference is first made to FIGS. 1 and 2 which show the
overall view of a system used to manipulate the needle under the
guidance of an imaging system, such as CT or MRI guidance. However,
it is to be understood that the needle steering manipulation
technique and the needle manipulating robot is not limited to use
with CT or MRI imaging modality, but can be used with any existing
imaging modality such as Ultrasound, PET, or the like.
[0043] FIG. 1 shows an exemplary system mounted on a CT system. The
system does not need to be connected to the CT system directly. The
robotic needle manipulator 11 may be connected to the base element
plate 12 via a semi-active arm 13, which may be connected to the
base element via an arched support arm 21. The base element may be
placed on the imaging system bed 14 and moves together with the
imaging system bed. Alternatively, the support arch could be
mounted directly on the imaging system bed.
[0044] Reference is now made to FIG. 2 where the complete system is
shown without the CT. The miniature robot 11 is shown connected to
the base element 12 via a semi-active arm 13. The semi-active arm
is so-called because it has one or more actuators, but does not
generally need as many actuators as its number of degrees of
freedom, such that not all of the joints need to be controlled.
That would make the arm unnecessarily complex and costly for its
function, which is only to position the robotic needle manipulator
in the correct position relative to the needle entry point and the
patient's body pose. The base element, preferably having the shape
of the CT-bed, should be stiff enough so that the patient can lie
on it and firm enough that the connection of the arched support arm
21 to it will be rigid enough.
[0045] In the example shown, the semi-active arm has 5 degrees of
freedom, 3 for positioning of the base of the robotic needle
manipulator anywhere on the patient's body, and 2 for orienting of
the robotic needle manipulator to be generally parallel to the
patient's body, and advantageously in contact with the subject's
skin.
[0046] Reference is now made to FIG. 3 where a complete robotic
needle manipulator is shown. A robot 11 is shown holding the needle
31. For purposes of illustration, the robot is based on the
well-known Stewart-Gough platform, which was introduced in 1965,
though it is to be understood that this is just an exemplary
implementation, and any other suitable type of robot could be used.
The robot has 6 degrees-of-freedom and can position and orient the
needle cannula in space by appropriately positioning and orienting
the actuated platform 32 of the robot relative to its base plate
41. Inside the robotic needle manipulator, there is a needle
driving mechanism to be described in FIGS. 5 and 6. The base plate
41 of the robotic needle manipulator may be connected to the
semi-active arm 13 by spherical or U-joints enabling orientation of
the device on the skin of the patient.
[0047] Reference is now made to FIG. 4 where the modified
Stewart-Gough platform is shown in close up. The base plate 41 is
placed on the patient's skin. The base may have a soft pillow 42 to
conform to the body of the patient. Although FIGS. 4 and 5 show a
6-DOF modified Stewart-Gough robot, it is to be understood that the
robotic needle manipulator could utilize any suitable type of
robotic platform, whether parallel, such as the Stewart-Gough, or
serial, or hybrid.
[0048] The robotic needle manipulator shown in FIGS. 1 to 4 may be
used either as a simple robotic needle positioning and orientating
device, such as could be used by the physician for manual insertion
of the needle, or it could incorporate a needle driving mechanism,
such that the needle insertion too could be performed under robotic
control. Reference is now made to FIG. 5 and FIG. 6 where an
example of such a needle driving mechanism is shown in two
different insertion orientation angles, employing rotation of two
or more rollers 51. The driving force is created by non-sliding
friction between the needle shaft 31 and the rollers 51. After
passing the rollers the needle is traversed through a directing
cannula 53, which more precisely controls the direction of the
exiting needle. Also shown schematically in FIGS. 5 and 6 is a
needle rotation mechanism 54. This mechanism could be based on a
pair of friction rollers aligned with their axes in the plane
essentially parallel to the shaft of the needle, or on a single
driven pulley wheel in that plane, with the needle shaft passing
through a friction clutch at its center, such that application of
the clutch and rotation of the pulley wheel will rotate the needle,
or by any other of the known mechanisms for providing such
selectable rotation motion. Any such rotation mechanism must allow
free longitudinal motion of the needle when an insertion step is
actuated.
[0049] Reference is now made to FIG. 7 where a spatial simulation
of a prior art example of needle steering by steering of the needle
base is shown. The simulation is based on the system described in
PCT published application WO 2007/141784 A2. The axes, which
represent the longitudinal and lateral views of the needle
environment, are marked in cm. The needle holder 71 holds the base
34 of the needle 31 and manipulates the base of the needle as
shown. It can be seen that the workspace required for the robot
manipulator to insert the needle has to be at least the height of
the needle. For instance, to insert the needle 6 cm into the
subject's body, the workspace of the robot manipulator has to be at
least 6 cm in length and, for the orientation manipulations shown
in the simulation of FIG. 7, about 5-6 cm in width, which is the
extent of lateral travel of the needle base 34. In medical
applications, a robot having a large workspace is disadvantageous
because of safety issues. Large workspace means that the robot can
move accidently to the wrong place.
[0050] Reference is now made to FIG. 8 where there is shown an
example of needle steering by manipulation of its shaft using the
robotic needle manipulator of the present application. The needle
is required to realize the same trajectory as in FIG. 7, but it can
be seen that the robot manipulator workspace required is much
smaller, because the manipulator is very close to the skin. In the
example shown the workspace is seen to be only 2 cm. high, and the
width approximately 3 cm. The height is dependent on the type of
robot used, but typical robots of height even up to 5 cm. still
show a workspace advantage over the prior art methods of robotic
needle insertion. Robots made for such a small workspace have a
significant advantage relating to safety since the manipulator is
physically constrained to small area and cannot harm the nearby
areas. Furthermore, the decoupling of the position and orientation
manipulation mechanisms from the pushing mechanism also contributes
to increased safety. Additionally, the workspace of the robot is
flat or planar and doesn't depend on the needle length. The same
robot can accommodate needles of effectively any practically used
length. Furthermore, the robot can be more easily accommodated in
the limited confines of a tomographic imaging system.
[0051] It is appreciated by persons skilled in the art that the
present invention is not limited by what has been particularly
shown and described hereinabove. Rather the scope of the present
invention includes both combinations and subcombinations of various
features described hereinabove as well as variations and
modifications thereto which would occur to a person of skill in the
art upon reading the above description and which are not in the
prior art.
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