U.S. patent application number 16/043691 was filed with the patent office on 2018-12-06 for systems and methods for navigation and control of an implant positioning device.
The applicant listed for this patent is Smith & Nephew, Inc.. Invention is credited to Branislav JARAMAZ, Benjamin Oliver MCCANDLESS, Constantinos NIKOU.
Application Number | 20180344414 16/043691 |
Document ID | / |
Family ID | 49679603 |
Filed Date | 2018-12-06 |
United States Patent
Application |
20180344414 |
Kind Code |
A1 |
NIKOU; Constantinos ; et
al. |
December 6, 2018 |
SYSTEMS AND METHODS FOR NAVIGATION AND CONTROL OF AN IMPLANT
POSITIONING DEVICE
Abstract
Systems and methods for navigation and control of an implant
positioning device are discussed. For example, a method can include
operations for accessing an implant plan, establishing a 3-D
coordinate system, receiving tracking information, generating
control signals, and sending the control signals to the implant
positioning device. The implant plan can include location and
orientation data describing an ideal implant location and
orientation in reference to an implant host. The 3-D coordinate
system can provide spatial orientation for the implant positioning
device and the implant host. The tracking information can identify
current location and orientation data within the 3-D coordinate
system for the implant positioning device and implant host during a
procedure. The control signals can control operation of the implant
positioning device to assist a surgeon in positioning the implant
according to the implant plan.
Inventors: |
NIKOU; Constantinos;
(Monroeville, PA) ; JARAMAZ; Branislav;
(Pittsburgh, PA) ; MCCANDLESS; Benjamin Oliver;
(Pittsburgh, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Smith & Nephew, Inc. |
Memphis |
TN |
US |
|
|
Family ID: |
49679603 |
Appl. No.: |
16/043691 |
Filed: |
July 24, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14073999 |
Nov 7, 2013 |
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16043691 |
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61724601 |
Nov 9, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 2002/4627 20130101;
A61B 2034/104 20160201; A61F 2/4603 20130101; A61F 2/4609 20130101;
A61B 34/30 20160201; A61F 2002/4688 20130101; A61B 34/20 20160201;
A61F 2002/4633 20130101; A61B 34/32 20160201; A61F 2002/4681
20130101; A61F 2/46 20130101; A61B 34/10 20160201; A61F 2002/30538
20130101; A61F 2002/4628 20130101; A61F 2002/4632 20130101; A61B
34/70 20160201; A61B 2034/2055 20160201; A61B 34/00 20160201; A61B
2034/2046 20160201; A61B 2034/301 20160201; A61F 2002/4625
20130101 |
International
Class: |
A61B 34/30 20060101
A61B034/30; A61B 34/10 20060101 A61B034/10 |
Claims
1-20. (canceled)
21. An implant positioning device comprising: an end effector
configured to contact an implant component during a surgical
procedure; a motor configured to cause one or more impacts to be
produced at the end effector, thereby imparting the impact force to
the implant component; and a control circuit coupled to the motor
and configured to: generate at least one motor control signal,
transfer the at least one motor control signal to the motor, and as
a result of the at least one motor control signal, cause the motor
to move the end effector to produce one or more impacts.
22. The device of claim 21, wherein the end effector comprises a
retention device configured to retain the implant component in a
fixed position relative to the end effector during insertion.
23. The device of claim 21, further comprising a tracking marker
configured to be tracked by a tracking system, thereby providing
for monitoring of a position of the implant positioning device
during the surgical procedure.
24. The device of claim 21, further comprising an actuator operably
connected to the end effector and the motor and configured to
impart an impact force to at least a portion of the implant
component during the surgical procedure.
25. The device of claim 24, wherein the actuator comprises a
plurality of actuators positioned about an exterior periphery of
the end effector.
26. The device of claim 25, wherein the plurality of actuators are
configured to induce a rotation on the implant component during
insertion.
27. The device of claim 24, further comprising a telescoping
positioning arm, wherein the actuator is affixed to a distal end of
the telescoping positioning arm.
28. The device of claim 27, wherein the motor is further configured
to control extension of the telescoping positioning arm.
29. The device of claim 21, further comprising a communication
device configured to: establish a communication link with a
surgical control system; and receive system control signals from
the surgical control system, the system control signals for
controlling the insertion of the implant component.
30. The device of claim 29, wherein the system control signals
comprise an impact frequency indication defining how frequently the
implant positioning device is to impart an impact force to the
implant component.
31. The device of claim 21, wherein the surgical procedure
comprises a hip replacement surgery.
32. The device of claim 31, wherein the implant component comprises
a prosthetic acetabular cup.
33. An implant positioning device comprising: an end effector
configured to contact an implant component during a surgical
procedure; a motor configured to cause one or more impacts to be
produced at the end effector, thereby imparting the impact force to
the implant component; and a control circuit coupled to the motor
and configured to: establish a communication link with a surgical
control system, receive at least one motor control signal from the
surgical control system, transfer the at least one motor control
signal to the motor, and as a result of the at least one motor
control signal, cause the motor to move the end effector to produce
one or more impacts.
34. The device of claim 33, wherein the end effector comprises a
retention device configured to retain the implant component in a
fixed position relative to the end effector during insertion.
35. The device of claim 33, further comprising a tracking marker
configured to be tracked by a tracking system, thereby providing
for monitoring of a position of the implant positioning device
during the surgical procedure.
36. The device of claim 33, further comprising an actuator operably
connected to the end effector and the motor and configured to
impart an impact force to at least a portion of the implant
component during the surgical procedure.
37. The device of claim 36, wherein the actuator comprises a
plurality of actuators positioned about an exterior periphery of
the end effector.
38. The device of claim 37, wherein the plurality of actuators are
configured to induce a rotation on the implant component during
insertion.
39. An implant positioning device comprising: an end effector
configured to contact an implant component during a surgical
procedure; a motor configured to cause one or more impacts to be
produced at the end effector, thereby imparting the impact force to
the implant component; and a control circuit coupled to the motor
and configured to: determine one or more parameters for the implant
positioning device, generate at least one motor control signal
based on the one or more parameters, transfer the at least one
motor control signal to the motor, and as a result of the at least
one motor control signal, cause the motor to move the end effector
to produce one or more impacts.
40. The device of claim 39, wherein the one or more parameters
comprise at least one of an amplitude of impact, a frequency of
impact, and a duration of impact.
41. The device of claim 39, wherein the one or more parameters
comprise extension parameters comprising at least a distance to
extend an end effector of the implant positioning device.
42. The device of claim 39, wherein the one or more parameters
comprise at least one of a location and an angle at which the
implant positioning device is directed to impact the implant
component.
43. The device of claim 39, wherein the one or more parameters
comprise release parameters for the implant positioning device.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/724,601, titled "Systems and Method for
Navigation and Control of an Implant Positioning Device," filed
Nov. 9, 2012, which is incorporated herein by reference in its
entirety.
TECHNICAL FIELD
[0002] This application relates generally to semi-active surgical
robotics, and more specifically to systems and methods to provide
computer-aided navigation and control of an implant positioning
device.
BACKGROUND
[0003] The use of computers, robotics, and imaging to aid
orthopedic surgery is well known in the art. There has been a great
deal of study and development of computer-aided navigation and
robotics systems used to guide surgical procedures. Two general
types of semi-active surgical robotics have emerged and have been
applied to orthopedic procedures, such as joint arthroplasty. The
first type of semi-active robotics attach the surgical tool to a
robotic arm that resists movements by the surgeon that deviate from
a planned procedure, such as a bone resection. This first type
often goes by the term haptic or haptics, which is derived from the
Greek word for touch. The second type of semi-active robotics is
focused on controlling aspects of the surgical tool, such as speed
of a cutting bit. This second type of semi-active robotics is
sometimes referred to as free-hand robotics, as a robotic arm does
not restrict the surgeon.
[0004] Both types of surgical robotics utilize navigation or
tracking systems to closely monitor the surgical tool and the
patient during a procedure. The navigation system can be used to
establish a virtual three dimensional (3-D) coordinate system,
within which both the patient and the surgical device will be
tracked.
[0005] Hip replacement is an area where the use of surgical
robotics, advanced imaging, and computer-aided navigation are
gaining acceptance. Total hip replacement (THR) or arthroplasty
(THA) operations have been performed since the early 1960s to
repair the acetabulum and the region surrounding it and to replace
the hip components, such as the femoral head, that have
degenerated. Currently, approximately 200,000 THR operations are
performed annually in the United States alone, of which
approximately 40,000 are redo procedures, otherwise known as
revisions. The revisions become necessary due to a number of
problems that may arise during the lifetime of the implanted
components, such as dislocation, component wear and degradation,
and loosening of the implant from the bone.
[0006] Dislocation of the femoral head from the acetabular
component, or cup, is considered one of the most frequent early
problems associated with THR, because of the sudden physical and
emotional hardship brought on by the dislocation. The incidence of
dislocation following the primary THR surgery is approximately 2-6%
and the percentage is even higher for revisions. While dislocations
can result from a variety of causes, such as soft tissue laxity and
loosening of the implant, the most common cause is impingement of
the femoral neck with either the rim of an acetabular cup implant,
or the soft tissue or bone surrounding the implant. Impingement
most frequently occurs as a result of mis-positioning of the
acetabular cup component within the pelvis.
[0007] Some clinicians and researchers have found incidence of
impingement and dislocations can be lessened if the cup is oriented
specifically to provide for approximately 15.degree. of anteversion
and 45.degree. of abduction; however, this incidence is also
related to the surgical approach. For example, McCollum et al.
cited a comparison of THAs reported in the orthopaedic literature
that revealed a much higher incidence of dislocation in patients
who had THAs with a posterolateral approach. McCollum, D. E. and W.
J. Gray, "Dislocation after total hip arthroplasty (causes and
prevention)", Clinical Orthopaedics and Related Research, Vol. 261,
p. 159-170 (1990). McCollum's data showed that when the patient is
placed in the lateral position for a posterolateral THA approach,
the lumbar lordotic curve is flattened and the pelvis may be flexed
as much as 35.degree.. If the cup was oriented at
15.degree.-20.degree. of flexion with respect to the longitudinal
axis of the body, when the patient stood up and the postoperative
lumbar lordosis was regained, the cup could be retroverted as much
as 10.degree.-15.degree. resulting in an unstable cup placement.
Lewinnek et al. performed a study taking into account the surgical
approach utilized and found that the cases falling in the zone of
15.degree..+-.10.degree. of anteversion and
40.degree..+-.10.degree. of abduction have an instability rate of
1.5%, compared with a 6% instability rate for the cases falling
outside this zone. Lewinnek G. E., et al., "Dislocation after total
hip-replacement arthroplasties", Journal of Bone and Joint Surgery,
Vol. 60-A, No. 2, p. 217-220 (March 1978). The Lewinnek work
essentially verifies that dislocations can be correlated with the
extent of malpositioning, as would be expected. The study does not
address other variables, such as implant design and the anatomy of
the individual, both of which are known to greatly affect the
performance of the implant.
[0008] The design of the implant significantly affects stability as
well. A number of researchers have found that the head-to-neck
ratio of the femoral component is the key factor of the implant
impingement, see Amstutz H. C., et al., "Range of Motion Studies
for Total Hip Replacements", Clinical Orthopaedics and Related
Research Vol. 111, p. 124-130 (September 1975). Krushell et al.
additionally found that certain long and extra long neck designs of
modular implants can have an adverse effect on the range of motion.
Krushell, R. J., Burke D. W., and Harris W. H., "Range of motion in
contemporary total hip arthroplasty (the impact of modular
head-neck components)", The Journal of Arthroplasty, Vol. 6, p.
97-101 (February 1991). Krushell et al. also found that an
optimally oriented elevated-rim liner in an acetabular cup implant
may improve the joint stability with respect to implant
impingement. Krushell, R. J., Burke D. W., and Harris W. H.,
"Elevated-rim acetabular components: Effect on range of motion and
stability in total hip arthroplasty", The Journal of Arthroplasty,
Vol. 6 Supplement, p. 1-6, (October 1991). Cobb et al. have shown a
statistically significant reduction of dislocations in the case of
elevated-rim liners, compared to standard liners. Cobb T. K.,
Morrey B. F., Ilstrup D. M., "The elevated-rim acetabular liner in
total hip arthroplasty: Relationship to postoperative dislocation",
Journal of Bone and Joint Surgery, Vol 78-A, No. 1, p. 80-86,
(January 1996). The two-year probability of dislocation was 2.19%
for the elevated liner, compared with 3.85% for standard liner.
Initial studies by Maxian et al. using a finite element model
indicate that the contact stresses and therefore the polyethylene
wear are not significantly increased for elevated rim liners;
however, points of impingement and subsequent angles of dislocation
for different liner designs are different, as would be expected.
Maxian T. A., et al. "Femoral head containment in total hip
arthroplasty: Standard vs. extended lip liners", 42nd Annual
meeting, Orthopaedic Research society, p. 420, Atlanta, Ga. (Feb.
19-22, 1996); and Maxian T. A., et al. "Finite element modeling of
dislocation propensity in total hip arthroplasty", 42nd Annual
meeting, Orthopaedic Research society, p. 259-64, Atlanta, Ga.
(Feb. 19-22, 1996).
[0009] An equally important concern in evaluating the dislocation
propensity of an implant is variations in individual anatomies. As
a result of anatomical variations, there is no single optimal
design and orientation of hip replacement components and surgical
procedure to minimize the dislocation propensity of the implant.
For example, the pelvis can assume different positions and
orientations depending on whether an individual is lying supine (as
during a CT-scan or routine X-rays), in the lateral decubitis
position (as during surgery) or in critical positions during
activities of normal daily living (like bending over to tie shoes
or during normal gait). The relative position of the pelvis and leg
when defining a "neutral" plane from which the angles of movement,
anteversion, abduction, etc., are calculated will significantly
influence the measured amount of motion permitted before
impingement and dislocation occurs. Therefore, it is necessary to
uniquely define both the neutral orientation of the femur relative
to the pelvis for relevant positions and activities, and the
relationship of the femur with respect to the pelvis of the patient
during each segment of leg motion.
[0010] Currently, most planning for acetabular implant placement
and size selection is performed using acetate templates and a
single anterior-posterior x-ray of the pelvis. Acetabular
templating is most useful for determining the approximate size of
the acetabular component; however, it is only of limited utility
for positioning of the implant because the x-rays provide only a
two dimensional image of the pelvis. Also, the variations in pelvic
orientation cannot be more fully considered as discussed above.
[0011] Intra-operative positioning devices currently used by
surgeons attempt to align the acetabular component with respect to
the sagittal and coronal planes of the patient. B. F. Money,
editor, "Reconstructive Surgery of the Joints", chapter Joint
Replacement Arthroplasty, pages 605-608, Churchill Livingston,
1996. These devices assume that the patient's pelvis and trunk are
aligned in a known orientation, and do not take into account
individual variations in a patient's anatomy or pelvic position on
the operating room table. These types of positioners can lead to a
wide discrepancy between the desired and actual implant placement,
possibly resulting in reduced range of motion, impingement and
subsequent dislocation.
[0012] Several attempts have been made to more precisely prepare
the acetabular region for the implant components. U.S. Pat. No.
5,007,936 issued to Woolson is directed to establishing a reference
plane through which the acetabulum can be reamed and generally
prepared to receive the acetabular cup implant. The method provides
for establishing the reference plane based on selecting three
reference points, preferably the 12 o'clock position on the
superior rim of the acetabulum and two other reference points, such
as a point in the posterior rim and the inner wall, which are known
distances from the superior rim. The location of the superior rim
is determined by performing a series of computed tomography (CT)
scans that are concentrated near the superior rim and other
reference locations in the acetabular region.
[0013] In the Woolson method, calculations are then performed to
determine a plane in which the rim of the acetabular cup should be
positioned to allow for a predetermined rotation of the femoral
head in the cup. The distances between the points and the plane are
calculated and an orientation jig is calibrated to define the plane
when the jig is mounted on the reference points. During the
surgical procedure, the surgeon must identify the 12 o'clock
orientation of the superior rim and the reference points. In the
preferred mode, the jig is fixed to the acetabulum by drilling a
hole through the reference point on the inner wall of the
acetabulum and affixing the jig to the acetabulum. The jig
incorporates a drill guide to provide for reaming of the acetabulum
in the selected plane.
[0014] A number of difficulties exist with the Woolson method. For
example, the preferred method requires drilling a hole in the
acetabulum. Also, visual recognition of the reference points must
be required and precision placement of the jig on reference points
is performed in a surgical setting. In addition, proper alignment
of the reaming device does not ensure that the implant will be
properly positioned, thereby establishing a more lengthy and costly
procedure with no guarantee of better results. These problems may
be a reason why the Woolson method has not gained widespread
acceptance in the medical community.
[0015] In U.S. Pat. Nos. 5,251,127 and 5,305,203 issued to Raab, a
computer-aided surgery apparatus is disclosed in which a reference
jig is attached to a double self indexing screw, previously
attached to the patient, to provide for a more consistent alignment
of the cutting instruments similar to that of Woolson. However,
unlike Woolson, Raab et al. employ a digitizer and a computer to
determine and relate the orientation of the reference jig and the
patient during surgery with the skeletal shapes determined by
tomography.
[0016] Similarly, U.S. Pat. Nos. 5,086,401, 5,299,288 and 5,408,409
issued to Glassman et al. disclose an image directed surgical
robotic system for reaming a human femur to accept a femoral stem
and head implant using a robot cutter system. In the system, at
least three locating pins are inserted in the femur and CT scans of
the femur in the region containing the locating pins are performed.
During the implanting procedure, the locating pins are identified
on the patient, as discussed in col. 9, lines 19-68 of Glassman's
'401 patent. The location of the pins during the surgery are used
by a computer to transform CT scan coordinates into the robot
cutter coordinates, which are used to guide the robot cutter during
reaming operations.
[0017] While the Woolson, Raab and Glassman patents provide methods
and apparatuses that further offer the potential for increased
accuracy and consistency in the preparation of the acetabular
region to receive implant components, none of these references
provide minimally invasive assistance during the implant
procedure.
[0018] In addition, both the Raab and Glassman methods and
apparatuses require that fiducial markers be attached to the
patient prior to performing tomography of the patients. Following
the tomography, the markers must either remain attached to the
patient until the surgical procedure is performed or the markers
must be reattached at the precise locations to allow the
transformation of the tomographic data to the robotic coordinate
system, either of which is undesirable and/or difficult in
practice.
[0019] Thus, in addition to a continued need to provide improved
systems and methods to provide proper placement plans and joint
preparation techniques to ensure optimal outcomes in terms of range
of motion and usage, there exists a need for improved
intra-operative implant placement systems and methods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Some embodiments are illustrated by way of example and not
limitation in the figures of the accompanying drawings in
which:
[0021] FIG. 1 is a block diagram depicting a system for providing
navigation and control to an implant positioning device, according
to an example embodiment.
[0022] FIG. 2 is a diagram illustrating an environment for
operating a system for navigation and control of an implant
positioning device, according to an example embodiment.
[0023] FIG. 3 is a flowchart illustrating a method for navigation
and control of an implant positioning device, according to an
example embodiment.
[0024] FIG. 4 is a flowchart illustrating a method for establishing
a three dimensional coordinate system, according to an example
embodiment.
[0025] FIG. 5 is a flowchart illustrating a method for generating
control signals to control an implant positioning device, according
to an example embodiment.
[0026] FIG. 6 is a flowchart illustrating a method for providing
assistance to a surgeon operating an implant positioning device,
according to an example embodiment.
[0027] FIG. 7 is a diagram illustrating an implant positioning
device, according to an example embodiment.
[0028] FIGS. 8A-8B are block diagrams illustrating an alternative
end effector for the implant positioning device, according to an
example embodiment.
[0029] FIG. 9 is a block diagram illustrating another alternative
arrangement for circumferential actuators, according to an example
embodiment.
[0030] FIGS. 10A-10B are block diagrams illustrating an
articulating portion of the powered impactor, according to an
example embodiment.
[0031] FIG. 11 is a diagrammatic representation of a machine in the
example form of a computer system within which a set of
instructions for causing the machine to perform any one or more of
the methodologies discussed herein may be executed.
DEFINITIONS
[0032] Implant--For the purposes of this specification and the
associated claims, the term "implant" is used to refer to a
prosthetic device or structure manufactured to replace or enhance a
biological structure. For example, in a total hip replacement
procedure a prosthetic acetabular cup (implant) is used to replace
or enhance a patients worn or damaged acetabulum. While the term
"implant" is generally considered to denote a man-made structure
(as contrasted with a transplant), for the purposes of this
specification an implant can include a biological tissue or
material transplanted to replace or enhance a biological
structure.
[0033] Implant host--For the purposes of this specification and the
associated claims, the term "implant host" is used to refer to a
patient. In certain instances the term implant host may also be
used to refer, more specifically, to a particular joint or location
of the intended implant within a particular patient's anatomy. For
example, in a total hip replacement procedure the implant host may
refer to the hip joint of the patient being replaced or
repaired.
[0034] Real-time--For the purposes of this specification and the
associated claims, the term "real-time" is used to refer to
calculations or operations performed on-the-fly as events occur or
input is received by the operable system. However, the use of the
term "real-time" is not intended to preclude operations that cause
some latency between input and response, so long as the latency is
an unintended consequence induced by the performance
characteristics of the machine.
DETAILED DESCRIPTION
[0035] Example systems and methods for providing and using a
navigated and computer controlled implant positioning device are
described. In some example embodiments, the systems and methods for
computer-aided navigation and control of an implant positioning
device can involve a computer-controllable powered impactor. In an
example, the computer-controllable powered impactor can be used by
a surgeon to insert a prosthetic acetabular cup into the acetabulum
of an implant host (e.g., a patient). In other examples, an
alternative implant positioning device can be used to assist in a
similar arthroplasty procedure, such as a total knee replacement.
In the following description, for purposes of explanation, numerous
specific details are set forth in order to provide a thorough
understanding of example embodiments. It will be evident, however,
to one skilled in the art, that the present invention may be
practiced without these specific details. It will also be evident
that a computer controlled implant positioning system is not
limited to the examples provided and may include other scenarios
not specifically discussed.
[0036] In an example, the discussed system includes an acetabular
positioning device outfitted with additional impaction devices. The
positioning device can be tracked in at least 2 degrees of rotation
by a tracking system connected to a computer. Programs running on a
control system can communicate with the tracking system to monitor
the orientation and optionally the position of the acetabular
implant as the user orients it relative to the patient's body
(which is also tracked by the tracking system) in order to achieve
an intended preoperative plan, which is stored in the control
system's memory. The control system also can include a display that
gives the user (e.g., surgeon) information regarding the current
position and/or orientation relative to the body position, and/or
relative to the preoperative plan. The control system can also
communicate with the impaction device(s). A variety of algorithms
may be used to calculate which and how impact devices should be
activated. The simplest algorithm could be that the impact devices
activate when the user aligns the acetabular implant coincident to
the preoperative plan. Furthermore, this actuation could be
dependent on secondary input from the user, like a trigger, foot
pedal signal, or voice command.
[0037] The impaction devices may be mounted to the acetabular
positioner such that the impactions apply forces or torques to the
implant in a known way, and the computer algorithms may use robotic
path planning techniques to optimize a sequence of impactions to
push the acetabular component in an optimized pattern toward the
final preoperative plan.
[0038] Additional sensors can be deployed on the positioning tool
in order to give feedback on forces and torques applied to the
positioning tool, or to measure the force and torque applied to a
partially or fully fixed acetabular implant by the positioning
device, which could affect the result of the impaction patterns
that are employed.
Example System
[0039] FIG. 1 is a block diagram depicting a system 100 for
providing navigation and control to an implant positioning device
130, according to an example embodiment. In an example, the system
100 can include a control system 110, a tracking system 120, and an
implant positioning device 130. Optionally, the system 100 can also
include a display device 140 and a database 150. In an example,
these components can be combined to provide navigation and control
of the implant positioning device 130 during an orthopedic (or
similar) prosthetic implant surgery.
[0040] The control system 110 can include one or more computing
devices configured to coordinate information received from the
tracking system 120 and provide control to the implant positioning
device 130. In an example, the control system 110 can include a
planning module 112, a navigation module 114, a control module 116,
and a communication interface 118. The planning module 112 can
provide pre-operative planning services that allow clinicians the
ability to virtually plan a procedure prior to entering the
operating room. The background discusses a variety of pre-operative
planning procedures used in total hip replacement (total hip
arthroplasty (THA)) that may be used in surgical robotic assisted
joint replacement procedures. Additionally, U.S. Pat. No. 6,205,411
titled "Computer-assisted Surgery Planner and Intra-Operative
Guidance System," to Digioia et al., discusses yet another approach
to pre-operative planning U.S. Pat. No. 6,205,411 is hereby
incorporated by reference in its entirety.
[0041] In an example, such as THA, the planning module 112 can be
used to manipulate a virtual model of the implant in reference to a
virtual implant host model. The implant host model can be
constructed from actual scans of the target patient, such as
computed tomography (CT), magnetic resonance imaging (MRI),
positron emission tomographic (PET), or ultrasound scanning of the
joint and surround structure. Alternatively, the pre-operative
planning can be performed by selecting a predefined implant host
model from a group of models based on patient measurements or other
clinician selected inputs. In certain examples, pre-operative
planning is refined intra-operatively by measuring the patient's
(target implant host's) actual anatomy. In an example, a point
probe connected to the tracking system 120 can be used to measure
the target implant host's actual anatomy.
[0042] In an example, the navigation module 114 can coordinate
tracking the location and orientation of the implant, the implant
host, and the implant positioning device 130. In certain examples,
the navigation module 114 may also coordinate tracking of the
virtual models used during pre-operative planning within the
planning module 112. Tracking the virtual models can include
operations such as alignment of the virtual models with the implant
host through data obtained via the tracking system 120. In these
examples, the navigation module 114 receives input from the
tracking system 120 regarding the physical location and orientation
of the implant positioning device 130 and an implant host. Tracking
of the implant host may include tracking multiple individual bone
structures. For example, during a total knee replacement procedure
the tracking system 120 may individually track the femur and the
tibia using tracking devices anchored to the individual bones.
[0043] In an example, the control module 116 can process
information provided by the navigation module 114 to generate
control signals for controlling the implant positioning device 130.
In certain examples, the control module 116 can also work with the
navigation module 114 to produce visual animations to assist the
surgeon during an operative procedure. Visual animations can be
displayed via a display device, such as display device 140. In an
example, the visual animations can include real-time 3-D
representations of the implant, the implant host, and the implant
positioning device 130, among other things. In certain examples,
the visual animations are color-coded to further assist the surgeon
with positioning and orientation of the implant.
[0044] In an example, the communication interface 118 facilitates
communication between the control system 110 and external systems
and devices. The communication interface 118 can include both wired
and wireless communication interfaces, such as Ethernet, IEEE
802.11 wireless, or Bluetooth, among others. As illustrated in FIG.
1, in this example, the primary external systems connected via the
communication interface 118 include the tracking system 120 and the
implant positioning device 130. Although not shown, the database
150 and the display device 140, among other devices, can also be
connected to the control system 110 via the communication interface
118. In an example, the communication interface 118 communicates
over an internal bus to other modules and hardware systems within
the control system 110.
[0045] In an example, the tracking system 120 provides location and
orientation information for surgical devices and parts of an
implant host's anatomy to assist in navigation and control of
semi-active robotic surgical devices. The tracking system 120 can
include a tracker that includes or otherwise provides tracking data
based on at least three positions and at least three angles. The
tracker can include one or more first tracking markers associated
with the implant host, and one or more second markers associated
with the surgical device (e.g., an implant positioning device 130).
The markers or some of the markers can be one or more of infrared
sources, Radio Frequency (RF) sources, ultrasound sources, and/or
transmitters. The tracking system 120 can thus be an infrared
tracking system, an optical tracking system, an ultrasound tracking
system, an inertial tracking system, a wired system, and/or a RF
tracking system. One illustrative tracking system can be the
OPTOTRAK.RTM. 3-D motion and position measurement and tracking
system described herein, although those of ordinary skill in the
art will recognize that other tracking systems of other accuracies
and/or resolutions can be used.
[0046] U.S. Pat. No. 6,757,582, titled "Methods and Systems to
Control a Shaping Tool," to Brisson et al., provides additional
detail regarding the use of tracking systems, such as tracking
system 120, within a surgical environment. U.S. Pat. No. 6,757,582
(the '582 patent) is hereby incorporated by reference in it's
entirely.
[0047] In an example, a surgeon can use the implant positioning
device 130 to assist in inserting an implant within an implant host
during a surgical procedure. For example, within THA a surgeon will
often insert a prosthetic acetabular cup into the implant host's
acetabulum. Inserting a prosthetic acetabular cup often involves a
manual or powered impaction device. When a manual impactor is used,
the surgeon will hammer on the end of the impactor with a mallet to
seat the artificial acetabular cup (e.g., implant) into the proper
position. While some manual impaction devices have been coupled
with tracking systems, such as tracking system 120, the assistance
provided to the surgeon is limited to alignment of the manual
impaction device. The systems currently available lack the ability
to provide navigated control of an impaction device to assist the
surgeon in getting the implant into the ideal implant location (as
determined via pre-operative and intra-operative planning)
Additional details on an example navigated implant positioning
device, such as implant positioning device 130, are provided below
in reference to FIG. 7.
Example Operating Environment
[0048] FIG. 2 is a diagram illustrating an environment for
operating a system 200 for navigation and control of an implant
positioning device 130, according to an example embodiment. In an
example, the system 200 can include components similar to those
discussed above in reference to system 100. For example, the system
200 can include a control system 110, a tracking system 120, an
implant positioning device 130, and one or more display devices,
such as display device 140A and 140B. The system 200 also
illustrates an implant host 10, tracking markers 160, 162, and 164,
as well as a foot control 170.
[0049] In an example, the tracking markers 160, 162, and 164 can be
used by the tracking system 120 to track location and orientation
of the implant host 10, the implant positioning device 130, and a
reference, such as an operating table (tracking marker 164). In
this example, the tracking system 120 uses optical tracking to
monitor the location and orientation of tracking markers 160, 162,
and 164. Each of the tracking markers (160, 162, and 164) includes
three or more tracking spheres that provide easily processed
targets to determine location and orientation in up to six degrees
of freedom. The tracking system 120 can be calibrated to provide a
localized 3-D coordinate system within which the implant host 10
and the implant positioning device 130 (and by reference the
implant) can be spatially tracked. For example, as long as the
tracking system 120 can image three of the tracking spheres on a
tracking marker, such as tracking marker 160, the tracking system
120 can utilize image processing algorithms to generate points
within the 3-D coordinate system. Subsequently, the tracking system
120 (or the navigation module 114 (FIG. 1) within the control
system 110) can use the 3 points to triangulate an accurate 3-D
position and orientation associated with the device the tracking
marker is affixed to, such as the implant host 10 or the implant
positioning device 130. Once the precise location and orientation
of the implant positioning device 130 is known, the system 200 can
use the known properties of the implant positioning device 130 to
accurately calculate a position and orientation associated with the
implant (without the tracking system 120 being able to visualize
the implant, which may be within the implant host 10 and not
visible to the surgeon or the tracking system 120).
[0050] Operations and capabilities of the systems 100 (FIG. 1) and
200 are discussed further below in reference to FIGS. 3-6.
Example Methods
[0051] FIG. 3 is a flowchart illustrating a method 300 for
navigation and control of an implant positioning device 130 (FIG.
2), according to an example embodiment. In an example, the method
300 can include operations for: accessing an implant plan at 310,
establishing a 3-D coordinate system at 320, receiving tracking
information at 330, determining implant position and orientation at
335, determining if a planned location has been reached at 340,
generating control signals at 345, and transmitting control signals
at 350. Optionally, the method 300 can also include operations such
as creating an implant plan at 305, initializing a communication
link at 315, and providing feedback to a surgeon at 355. In
general, the operations discussed in reference to method 300 are
performed within the control system 100 (FIG. 1). However, in
certain examples, some of the operations may be performed within
other components of systems 100 or 200, such as the tracking system
120 (FIG. 2). Additionally, in some examples, some of the recited
operations may not be required to provide navigation and control to
an implant positioning device 130 (FIG. 2).
[0052] In an example, the method 300 can optionally begin at 305
with the planning module 112 (FIG. 1) assisting a clinician in
creating an implant plan. Creating an implant plan can include
generating a virtual implant host model from CT, MRI, or similar
medical scans of the appropriate anatomy of the implant host 10
(FIG. 2). Creating an implant plan can also include manipulation of
a virtual implant model in reference to a virtual implant host
model. Further, creating an implant plan can include planning bone
shaping procedures to be performed prior to implant insertion
within the implant host 10. In an example, the implant plan created
in this operation can provide detailed location and orientation
data regarding the ideal implant location within an implant host,
such as implant host 10.
[0053] At 310, the method 300 can continue with the control system
110 (FIG. 1) accessing an implant plan, such as the implant plan
created in operation 305. Alternatively, the control system 110 may
access an implant plan stored in database 150 (FIG. 1). In an
example, data regarding the implant, the desired (ideal) implant
location, and the implant host 10 within the implant plan can be
made available to the navigation module 114 and control module 116
as necessary to provide navigation and control to an implant
positioning device, such as implant positioning device 130 (FIG.
2).
[0054] At 315, the method 300 can optionally continue with the
control system 110, via the communication interface 118,
initializing a communication link with the implant positioning
device 130 and/or the tracking system 120 (FIG. 1). Initializing
the communication link can, in certain examples, include verifying
control capabilities of the implant positioning device 130. For
example, the systems 100 and 200 (FIGS. 1 & 2) may be suitable
for use with a computer-controlled powered impactor with or without
extension capabilities, which provides a controllable telescoping
extension for assisting with implant insertion. Initializing the
communication link with the implant positioning device 130 can
determine whether the connected device includes a powered extension
capability.
[0055] At 320, the method 300 can continue with the control system
110 establishing a 3-D coordinate system to track the surgical
instruments and implant host 10 (FIG. 2) during the procedure. In
an example, the control system 110 works in conjunction with the
tracking system 120 (FIG. 2) to establish a localized 3-D
coordinate system. In certain examples, the control system 110 can
step a clinician through alignment and calibration operations
involving tracking markers, such as tracking markers 160, 162, and
164 (FIG. 2), to establish the 3-D coordinate system. Establishing
the 3-D coordinate system may also involve use of a point probe
associated with the tracking system 120. Further details regarding
operation 320 are discussed below in reference to FIG. 4.
[0056] At 330, the method 300 can continue with the control system
110 receiving tracking information from the tracking system 120
(FIG. 1). In this example, at operation 330 the method 300 enters
the intra-operative phase. Within the intra-operative phase
surgical instruments, the implant host 10 (FIG. 2), and the implant
can be tracked to assist a clinician in performing the surgical
procedure. The tracking information received in operation 330 can
include location and orientation information for components of the
systems 100 or 200, such as the implant host 10 and the implant
positioning device 130 (FIGS. 1 & 2). In other examples, the
tracking information received in operation 330 can consist merely
of reference points detected for each tracked component, such as
identified locations of the tracking spheres on tracking marker 160
(FIG. 2). In these examples, the navigation module 114 (FIG. 1) can
use the reference points to calculate location and orientation data
associated with the tracked component.
[0057] In an example, at 335, the method 300 can continue with the
navigation module 114 (FIG. 1) determining implant position and
orientation. In certain other examples, determining implant
position and orientation may be done within the tracking system 120
(FIG. 2). In an example, the implant position and orientation is
calculated based on the known location and orientation of the
implant positioning device 130 (FIG. 2) and the known relationship
between the implant positioning device 130 and the implant. For
example, the tracking system 120 can provide a point location and
orientation within the 3-D coordinate system associated with the
implant positioning device 130. Pre-operative calibration of the
implant positioning device 130 can determine the relative position
of an end effector of the implant positioning device 130, which
allows a location and orientation of an implant affixed to the end
effector to be determined. Calibrating this relationship allows for
the navigation module 114 to track the precise location of the
implant via receiving the tracked location of the implant
positioning device 130.
[0058] At 340, the method 300 can continue with the control system
110 determining whether the implant has reached the planned (e.g.,
ideal) location in reference to the implant host 10 (FIG. 2). If
the ideal implant location has been achieved, the method 300 can
conclude. If the implant has not reached the ideal implant
location, then at 345 the method 300 can continue with the control
module 116 (FIG. 1) generating control signals to navigate and
control the implant positioning device 130 (FIG. 2). Additional
detail regarding control signal generation is discussed below in
reference to FIG. 5.
[0059] At 350, the method 300 continues with the control module 116
transmitting, over the communication interface 118, the control
signals to the implant positioning device 130 (FIG. 1). The process
of receiving tracking information, determining implant location,
generating control signals, and transmitting the control signals
represented by operations 330 through 350 can occur as often as
every few milliseconds, allowing the control system 110 (FIG. 2) to
rapidly alter the control parameters sent to the implant
positioning device 130. Cycles times provided herein are merely
exemplary and may be altered by application of specialized
processing hardware or optimized algorithms. Additionally, physical
constraints such as vibration settling time may also affect the
timing of control cycles in operation. The ability to rapidly alter
the control parameters allows for accurate control over the
placement and orientation of the implant within the implant host 10
(FIG. 2).
[0060] At 355, the method can optionally continue with the control
system 110 (FIG. 2) providing feedback to the surgeon to further
assist in positioning the implant. As discussed in greater detail
below in reference to FIG. 6, the feedback provided to the surgeon
can be visual, audible, and tactile.
[0061] As noted above, the method 300 can loop through operations
330-355 until it is determined, at operation 340, that the implant
has reached the ideal location and orientation. In an example, the
method 300 can also be halted or paused by a clinician during the
implant procedure. If paused, the control system 110 (FIG. 2) can
allow the clinician to continue the implant procedure. If the
method 300 is halted, the clinician can be provided options for
withdrawing the implant or leaving the implant in the position
reached prior to halting the navigation and control method. In
certain examples, the implant positioning device 130 (FIG. 2) can
include a trigger actuator that can be configured to start and
subsequently pause the operations discussed in reference to FIG.
3.
[0062] The following methods provide additional detail regarding
operations introduced above in reference to FIG. 3. The operations
discussed in the following methods are optional and may be
performed in a different order or on different systems than those
discussed in the following examples. Additionally, the operations
discussed above in reference to FIG. 3 may not all be necessary to
provide navigation and control to an implant positioning device,
such as implant positioning device 130 (FIG. 2). Further, the order
of operations discussed above is merely exemplary, the discussed
operations may be performed in different orders and on different
systems than discussed above.
[0063] FIG. 4 is a flowchart illustrating a method 320 for
establishing a three dimensional (3-D) coordinate system, according
to an example embodiment. In an example, the method 320 can include
operations such as: system calibration at 410, registration of an
implant host 10 at 420, registration of an implant positioning
device 130 at 430, aligning an implant host model with an implant
host 10 at 440, and aligning an implant model with an implant host
10 (FIG. 2) at 450. The method 320 corresponds to the operation 320
introduced is FIG. 3. The operations discussed in reference to
method 320 represent an example embodiment of operation 320.
[0064] The method 320 can begin at operation 410 with the control
system 110 and the tracking system 120 (FIG. 2) performing a system
calibration. Calibration of the tracking system 120 enables precise
tracking of tracking markers within the field of view of the
tracking system 120. In an example, the tracking system 120 can
include a point probe and a calibration fixture for calibrating the
tracking system 120. The tracking system 120, or the control system
110 in conjunction with the tracking system 120, can step a
clinician through calibration of a point probe using a calibration
fixture. The calibration fixture can provide precise orientation of
a 3-D coordinate system and the point probe can then be used to
register (e.g., calibrate) other components to be tracked, such as
an implant host 10 and an implant positioning device 130 (FIG. 2).
The tracking system 120, or the control system 110 in conjunction
with the tracking system 120, can step a clinician through
calibration of a point probe optionally using a calibration
fixture. The calibration process defines precise position and
orientation of a 3-D coordinate system related to the point probe
(especially at its tip). The probe can then be used to register
(e.g., calibrate) other components to be tracked, such as an
implant host 10 and an implant positioning device 130.
[0065] At 420, the method 320 can continue with the control system
110 facilitating registration of the implant host 10 with the
tracking system 120 (FIG. 2). In an example, a tracking marker,
such as tracking marker 162 (FIG. 2) can be affixed to the implant
host 10. With the tracking marker affixed, the clinician can use a
calibrated point probe to locate landmarks on the implant host 10
to register the critical anatomy with the tracking system 120.
Registration provides the control system 110 and/or the tracking
system 120 the information necessary to translate the position of
the tracking marker 162 into location and orientations relative to
the anatomy of the implant host 10 that will be involved in the
surgical procedure. For example, in THA the registration procedure
may locate relative locations of the implant host 10's
acetabulum.
[0066] At 430, the method 320 can continue with the control system
110 and/or tracking system 120 facilitating registration of the
implant positioning device 130 within the 3-D coordinate system
established by the tracking system 120 (FIG. 2). In an example,
registration of the implant positioning device 130 can include
using a point probe calibrated to the 3-D coordinate system to
locate landmark locations on the implant positioning device 130.
Tracking system 120 uses location information for the tracking
marker 160 (FIG. 2) attached to the implant positioning device 130
in conjunction with the landmark points identified by the point
probe to register the critical dimensions and relative locations on
the implant positioning device 130.
[0067] At 440, the method 320 can continue with the control system
110 aligning a virtual implant host model with the implant host 10
(FIG. 2). As discussed above, an implant plan can include a virtual
implant host model, which can be used for pre-operative planning of
implant location and orientation. In certain examples, the virtual
implant host model can be aligned within the 3-D coordinate system
established by the tracking system 120 to assist in navigation and
control of the implant positioning device 130 (FIG. 2). Alignment
of the virtual implant host model can be done from the landmark
locations gathered on the implant host 10 during registration of
the implant host 10. The aligned virtual implant host model can be
used to assist the surgeon in visualizing the implant location
through 3-D visualizations on a display device, such as display
device 140 (FIG. 2).
[0068] At 450, the method 320 can continue with the control system
110 aligning a virtual implant model with the implant host 10 (FIG.
2). Similar to the virtual implant host model, the virtual implant
model can be used during pre-operative planning to identify an
ideal location for the implant within an implant host, such as
implant host 10. In order to properly navigate and control the
implant positioning device 130, the virtual implant model used for
planning can be aligned within the 3-D coordinate system
established by the tracking system 120 (FIG. 2) in the ideal
location identified during planning. In certain examples, the
virtual implant model can also be used to assist the surgeon in
visualizing the implant location during the insertion
procedure.
[0069] FIG. 5 is a flowchart illustrating a method 345 for
generating control signals to control an implant positioning device
130 (FIG. 2), according to an example embodiment. In an example,
the method 345 can include operations such as: determining an
amplitude of impact at 510, determining a frequency of impact at
520, determining a duration of impact at 530, determining extension
or retraction parameters at 540, determining orientation parameters
at 550, and determining release parameters and timing at 560. The
control signal generation operations illustrated in FIG. 5 are
directed towards a computer-controlled powered impaction device,
such as the one described below in reference to FIG. 7. In examples
using a different type of implant positioning device, a different
set of control signal generation operations may be applicable.
[0070] In this example, the method 345 can begin at 510 with the
control module 116 (FIG. 1) determining the amplitude of impact
based on parameters such as current implant location and
orientation in reference to the ideal implant location. Amplitude
of impact is used here to refer to the magnitude of force applied
by the implant positioning device 130 (FIG. 2) to the implant. At
520, the method 345 can continue with the control module 116
determining a frequency of impact to be sent to the implant
positioning device 130. Frequency of impact is used here to refer
to how often the implant positioning device 130 delivers an impact
at the planned amplitude.
[0071] At 530, the method 345 can continue with the control module
116 (FIG. 1) determining duration of the impacts to be delivered
with the current amplitude and frequency parameters. In another
example, duration may be calculated to assist the clinician in
determining how long a particular orientation of the implant
positioning device 130 (FIG. 2) should be maintained. In certain
examples, the control system 110 can utilize a
pulse-measure-pulse-measure control scheme with varying durations
related to the amplitude and frequencies being applied. In yet
other examples, set impact durations may be used to keep the
surgeon engaged in the alignment process and allow time to check
progress between autonomous motions.
[0072] In certain examples, the implant positioning device 130
(FIG. 2) may include the ability to extent and/or retract a portion
of the device. In these examples, the method 345 may include an
operation 540. At 540, the method 345 can continue with the control
module 116 (FIG. 1) determining extension or retraction parameters
to send to the implant positioning device 130. For example, during
insertion of a prosthetic acetabular cup with a computer-controlled
powered impaction device, the device may be designed to allow the
clinician to merely maintain a proper alignment, while the device
extends an impaction head (e.g., end effector) with the implant
into the proper location.
[0073] At 550, the method 345 can continue with the control module
116 determining orientation parameters to be sent to the implant
positioning device 130 (FIG. 1). In certain examples, the implant
positioning device 130 may have the ability to control orientation
of the implant on the end effector. Such as in the example of a
prosthetic acetabular cup, the end effector may be configured to
allow impacts to be directed to localized portions on the
circumference of the implant. Localizing impacts to a small portion
of the circumference can induce a rotation force on the implant. In
other examples, the end effector of the implant positioning device
130 may be able to pivot or rotate to facilitate other orientation
adjustments.
[0074] Finally, at 560, the method 345 can conclude with the
control module 116 (FIG. 1) determining release parameters and
timing. In an example, the implant positioning device 130 (FIG. 2)
can include a mechanism to release the implant once it has reached
the ideal location. Release parameters can include parameters to
instruct the implant positioning device 130 to release an implant
retaining mechanism or trigger a release actuator to remove the
implant from the end effector. In an example, a release actuator
can include a simple air or electrically actuated cylinder within
the end effector to release the implant.
[0075] FIG. 6 is a flowchart illustrating a method 350 for
providing assistance to a surgeon operating an implant positioning
device 130 (FIG. 2), according to an example embodiment. In an
example, the method 350 can include operations such as: determining
location and orientation of the implant positioning device 130 at
610, determining alignment and orientation of implant host 10 (FIG.
2) at 615, generating 3-D representations at 620, displaying
cross-hair alignment guides at 625, displaying 3-D representations
at 630, displaying ideal implant location at 635, displaying an
implant host model at 640, producing audible alignment indicators
at 645, and generating haptic control signals at 650. The following
operations highlight one of the many potential benefits of
computer-aided navigation and control, the ability to assist a
clinician by visualizing aspects of an implant host 10's anatomy
and the implant during a procedure where both may be partially or
completely obstructed from view.
[0076] In an example, the method 350 can begin at 610 with the
navigation module 114 determining location and orientation of the
implant positioning device 130 (FIG. 1). In certain examples, the
location and orientation of the implant positioning device 130 will
have already been calculated to determine the location and
orientation of the implant (see operation 335 in FIG. 3). At 615,
the method 350 can continue with the navigation module 114
determining, if necessary, a location and orientation of the
implant host 10 (FIG. 2). Like operation 610, operation 615 may
have been performed previously to determine the implant location
relative to the implant host 10.
[0077] At 620, the method 350 can continue with the control system
110 generating 3-D representations of components such as the
implant and the implant positioning device 130 as well as the
implant host 10 (FIG. 2). The representations generated may be used
to present real-time visualizations to the surgeon. At 625, the
method 350 can continue with the control system 110 generating and
displaying cross-hair alignment guides to assist the surgeon in
aligning the implant positioning device 130. In an example,
information including the current implant location, the ideal
(planned) implant location, location and orientation of the implant
positioning device 130, and location orientation of the implant
host 10 can be used to generate the cross-hair alignment guides. In
an example, two (2) dimensions (e.g., x and y) on a cross-hair
alignment display can correspond to the azimuth and elevation of
the implant positioning device 130 in a spherical coordinate system
aligned to the implant plan. The center of the XY plot corresponds
to the implant plan, and the XY coordinates of the implant
positioning device 130 are the azimuth and elevation differences
between the implant positioning device 130 and implant plan. In
certain scenarios, this definition may lead to a non-intuitive
correlation between motion of the implant positioning device 130
and movement of the cross-hair on the screen. Therefore, angular
reference planes may be aligned to global references, such as
gravity or the user's facing direction. These references allow for
the user's left to correspond to leftward motion on the screen, and
motion in the upward direction (relative to gravity) of the implant
positioning device 130 handle to upward motion of the cross-hair.
Transformations of the reference coordinates in this manner are
evident to those skilled in the art of robotics or surgical
navigation.
[0078] At 625, the method 350 can continue with the control system
110 displaying 3-D representations on a display device, such as
display device 140 (FIG. 2). In an example, the 3-D representations
generated in operation 620 can be displayed to assist the surgeon
in visualizing implant location and orientation of the implant
positioning device 130 (FIG. 2), among other things. In some
examples, the 3-D visualizations can be color-coded to provide
additional feedback to the surgeon. For example, each different
component, such as the implant, the implant host 10 (FIG. 2), and
the implant positioning device 130, can be represented as a
different color. In another example, the implant can be color-coded
to indicate alignment in reference to the implant host 10. In this
example, the color-coding can change from red to green (with
various shades in between) to indicate where the implant is or is
not properly aligned. At 635, the method 350 can continue with the
control system 110 displaying the ideal implant location in
reference to the various other 3-D representations, such as the
implant host 10, the actual implant, and the implant positioning
device 130. At 640, the method 350 can continue with the control
system 110 adding a 3-D visualization of the implant host model to
the display. In an example, the nature of the 3-D visualization
displayed on the display device 140 can be controlled via foot
control 170 (FIG. 2) by the surgeon. Controlling the display can
enable the surgeon to scroll through various perspectives or
control which components are displayed at a given time.
[0079] At 645, the method 350 can continue with the control system
110 (FIG. 2) generating audible alignment indicators. The audible
alignment indicators can indicate implant alignment or implant
positioning device 130 (FIG. 2) alignment according to the implant
plan. Finally, at 650, the method 350 can conclude with the control
system 110 generating haptic control signals to transmit to the
implant positioning device 130. The haptic control signals can
instruct the implant positioning device 130 to produce a vibration
to provide tactile feedback to the surgeon. In an example, haptic
tactile feedback may be used to indicate a particularly bad
alignment of the implant positioning device 130 relative to the
implant plan. Alternatively, haptic tactile feedback can be used to
indicate a successful placement of the implant.
Example Implant Positioning Device
[0080] FIG. 7 is a diagram illustrating an implant positioning
device 130, according to an example embodiment. In an example, the
implant positioning device 130 can include components such as: a
body 705, a handle 710, a battery 715, a chuck 720, a telescoping
positioning arm 730, a stabilizing handle 735, an end effector 740,
an implant retention device 745, a trigger 750, a tracking marker
760, a manual impact surface 770, and a communication link 780. The
example implant positioning device 130 illustrated in FIG. 7 is a
cordless computer-controlled impactor that can be used in THA
procedures. Other implant positioning devices designed for other
procedures may include similar components to those described in
this example.
[0081] In this example, the primary components of the implant
positioning device 130 include a main body 705, a handle 710, a
battery (e.g., power supply) 715, a chuck 720, and a trigger 750.
The main body 705 contains a motor and other control circuitry
required to produce the desired impacts on the end effector 740.
The chuck 720 can be configured to allow for inter-changeable
positioning arms, such as telescoping positioning arm 730. In
certain examples, the trigger 750 provides a manual override
allowing the clinician to control the implantation process even
while the implant positioning device 130 is receiving control
signals from the control system 110.
[0082] In this example, the implant positioning device 130 includes
a telescoping positioning arm 730. The telescoping positioning arm
730 includes a proximal fixed portion 732 and a distal moveable
portion 734. In some examples, a stabilizing handle 735 can be
affixed to the proximal fixed portion 732 of the telescoping
positioning arm 730. The distal moveable portion 734 includes an
end effector 740 affixed to the distal end. The end effector 740
can be configured to mate with an implant to reduce any potential
damage to the implant during insertion. The end effector 740 can
include a retention device 745 that can be configured to retain the
implant in a fixed position relative to the end effector 740 during
insertion.
[0083] The implant positioning device 130 can include a tracking
marker 760 that allows the location and orientation of the implant
positioning device 130 to be tracked by the tracking system 120
(FIG. 2). In an example, the tracking marker 760 can include three
or more tracking spheres 765A . . . 765N (collectively referred to
as tracking sphere 765 or tracking spheres 765). The tracking
spheres 765 can be active or passive devices. For example, active
tracking spheres can include infrared LEDs enabling a tracking
system, such as the commercially available OPTOTRAK.RTM. 3-D motion
and position measurement and tracking system to track the implant
positioning device 130 using infrared sensors. Other tracking
systems may use cameras responsive to other wavelengths, which
would indicate the use of tracking spheres emitting compatible
wavelengths (or which reflect light in compatible wavelengths).
[0084] In this example, the implant positioning device 130 can
include a manual impact surface 770. The manual impact surface 770
enables a surgeon to revert to manual impaction in situations where
the computer-aided navigation and control is not functioning
properly.
[0085] Finally, the implant positioning device 130 can include a
communication link 780. In this example, the communication link 780
is illustrated as a wired connection. However, in other examples,
the communication link 780 can be implemented over any suitable
wireless protocol, such as IEEE 802.11 or Bluetooth, among
others.
[0086] FIGS. 8A-8B are block diagrams illustrating an alternative
end effector 800 for the implant positioning device 130, according
to an example embodiment. The alternative end effector 800 can
include a series of actuators 815A-815C (collectively referred to
as actuators 815) positioned between the distal moveable portion
734 and the end effector 740. The actuators 815 can induce forces
(e.g., impacts) on localized portions along the outer circumference
of the end effector 740. As discussed above, actuators position to
direct forces around the circumference of the end effector 740 can
induce a desired rotation on the implant during impaction. FIG. 8B
illustrates a section view of how actuators 815 can be arranged
around end effector 740.
[0087] FIG. 9 is a block diagram illustrating another alternative
arrangement for circumferential actuators 915A-915C, according to
an example embodiment. In this example, the circumferential
actuators 915A-915C are arranged between the distal moveable
portion 734 and the proximal fixed portion 732.
[0088] FIGS. 10A-10B are block diagrams illustrating an
articulating portion of the powered impactor, according to an
example embodiment. In this example, a portion of the telescoping
positioning arm 730 can include an articulating joint 905. The
illustrated example includes the articulating joint within the
distal moveable portion 734 of the telescoping positioning arm 730.
In another example, the articulating joint 905 can be included
within the proximal fixed portion 732 of the telescoping
positioning arm 730. The articulation joint 905 can be powered or
manually manipulated to assist in positioning the implant during
surgery.
Modules, Components and Logic
[0089] Certain embodiments of the computer systems described herein
may include logic or a number of components, modules, or
mechanisms. Modules may constitute either software modules (e.g.,
code embodied on a machine-readable medium or in a transmission
signal) or hardware modules. A hardware module is a tangible unit
capable of performing certain operations and may be configured or
arranged in a certain manner. In example embodiments, one or more
computer systems (e.g., a standalone, client or server computer
system) or one or more hardware modules of a computer system (e.g.,
a processor or a group of processors) may be configured by software
(e.g., an application or application portion) as a hardware module
that operates to perform certain operations as described
herein.
[0090] In various embodiments, a hardware module may be implemented
mechanically or electronically. For example, a hardware module may
comprise dedicated circuitry or logic that is permanently
configured (e.g., as a special-purpose processor, such as a field
programmable gate array (FPGA) or an application-specific
integrated circuit (ASIC)) to perform certain operations. A
hardware module may also comprise programmable logic or circuitry
(e.g., as encompassed within a general-purpose processor or other
programmable processor) that is temporarily configured by software
to perform certain operations. It will be appreciated that the
decision to implement a hardware module mechanically, in dedicated
and permanently configured circuitry, or in temporarily configured
circuitry (e.g., configured by software) may be driven by cost and
time considerations.
[0091] Accordingly, the term "hardware module" should be understood
to encompass a tangible entity, be that an entity that is
physically constructed, permanently configured (e.g., hardwired) or
temporarily configured (e.g., programmed) to operate in a certain
manner and/or to perform certain operations described herein.
Considering embodiments in which hardware modules are temporarily
configured (e.g., programmed), each of the hardware modules need
not be configured or instantiated at any one instance in time. For
example, where the hardware modules comprise a general-purpose
processor configured using software, the general-purpose processor
may be configured as respective different hardware modules at
different times. Software may accordingly configure a processor,
for example, to constitute a particular hardware module at one
instance of time and to constitute a different hardware module at a
different instance of time.
[0092] Hardware modules can provide information to, and receive
information from, other hardware modules. Accordingly, the
described hardware modules may be regarded as being communicatively
coupled. Where multiple such hardware modules exist
contemporaneously, communications may be achieved through signal
transmission (e.g., over appropriate circuits and buses) that
connect the hardware modules. In embodiments in which multiple
hardware modules are configured or instantiated at different times,
communications between such hardware modules may be achieved, for
example, through the storage and retrieval of information in memory
structures to which the multiple hardware modules have access. For
example, one hardware module may perform an operation and store the
output of that operation in a memory device to which it is
communicatively coupled. A further hardware module may then, at a
later time, access the memory device to retrieve and process the
stored output. Hardware modules may also initiate communications
with input or output devices, and can operate on a resource (e.g.,
a collection of information).
[0093] The various operations of example methods described herein
may be performed, at least partially, by one or more processors
that are temporarily configured (e.g., by software) or permanently
configured to perform the relevant operations. Whether temporarily
or permanently configured, such processors may constitute
processor-implemented modules that operate to perform one or more
operations or functions. The modules referred to herein may, in
some example embodiments, comprise processor-implemented
modules.
[0094] Similarly, the methods described herein may be at least
partially processor-implemented. For example, at least some of the
operations of a method may be performed by one or processors or
processor-implemented modules. The performance of certain of the
operations may be distributed among the one or more processors, not
only residing within a single machine, but deployed across a number
of machines. In some example embodiments, the processor or
processors may be located in a single location (e.g., within a home
environment, an office environment or as a server farm), while in
other embodiments the processors may be distributed across a number
of locations.
[0095] The one or more processors may also operate to support
performance of the relevant operations in a "cloud computing"
environment or as a "software as a service" (SaaS). For example, at
least some of the operations may be performed by a group of
computers (as examples of machines including processors), with
these operations being accessible via a network (e.g., the
Internet) and via one or more appropriate interfaces (e.g.,
APIs).
Electronic Apparatus and System
[0096] Example embodiments may be implemented in digital electronic
circuitry, or in computer hardware, firmware, software, or in
combinations of them. Example embodiments may be implemented using
a computer program product, for example, a computer program
tangibly embodied in an information carrier, for example, in a
machine-readable medium for execution by, or to control the
operation of, data processing apparatus, for example, a
programmable processor, a computer, or multiple computers. Certain
example embodiments of an implant positioning device 130 (FIG. 7)
can include a machine-readable medium storing executable
instructions to be performed by the implant positioning device
130.
[0097] A computer program can be written in any form of programming
language, including compiled or interpreted languages, and it can
be deployed in any form, including as a stand-alone program or as a
module, subroutine, or other unit suitable for use in a computing
environment. A computer program can be deployed to be executed on
one computer or on multiple computers at one site or distributed
across multiple sites and interconnected by a communication
network.
[0098] In example embodiments, operations may be performed by one
or more programmable processors executing a computer program to
perform functions by operating on input data and generating output.
Method operations can also be performed by, and apparatus of
example embodiments may be implemented as, special purpose logic
circuitry (e.g., a FPGA or an ASIC).
[0099] The computing system can include clients and servers. A
client and server are generally remote from each other and
typically interact through a communication network. The
relationship of client and server arises by virtue of computer
programs running on the respective computers and having a
client-server relationship to each other. In embodiments deploying
a programmable computing system, it will be appreciated that both
hardware and software architectures require consideration.
Specifically, it will be appreciated that the choice of whether to
implement certain functionality in permanently configured hardware
(e.g., an ASIC), in temporarily configured hardware (e.g., a
combination of software and a programmable processor), or a
combination of permanently and temporarily configured hardware may
be a design choice. Below are set out hardware (e.g., machine) and
software architectures that may be deployed, in various example
embodiments.
Example Machine Architecture and Machine-Readable Medium
[0100] FIG. 11 is a block diagram of machine in the example form of
a computer system 1100 within which instructions, for causing the
machine to perform any one or more of the methodologies discussed
herein, may be executed. In alternative embodiments, the machine
operates as a standalone device or may be connected (e.g.,
networked) to other machines. In a networked deployment, the
machine may operate in the capacity of a server or a client machine
in server-client network environment, or as a peer machine in a
peer-to-peer (or distributed) network environment. The machine may
be a personal computer (PC), a tablet PC, a set-top box (STB), a
PDA, a cellular telephone, a web appliance, a network router,
switch or bridge, or any machine capable of executing instructions
(sequential or otherwise) that specify actions to be taken by that
machine. Further, while only a single machine is illustrated, the
term "machine" shall also be taken to include any collection of
machines that individually or jointly execute a set (or multiple
sets) of instructions to perform any one or more of the
methodologies discussed herein.
[0101] The example computer system 1100 includes a processor 1102
(e.g., a central processing unit (CPU), a graphics processing unit
(GPU) or both), a main memory 1104 and a static memory 1106, which
communicate with each other via a bus 1108. The computer system
1100 may further include a video display unit 1110 (e.g., a liquid
crystal display (LCD) or a cathode ray tube (CRT)). The computer
system 1100 also includes an alphanumeric input device 1112 (e.g.,
a keyboard), a user interface (UI) navigation device (or cursor
control device) 1114 (e.g., a mouse), a disk drive unit 1116, a
signal generation device 1118 (e.g., a speaker) and a network
interface device 1120.
Machine-Readable Medium
[0102] The disk drive unit 1116 includes a machine-readable medium
1122 on which is stored one or more sets of instructions and data
structures (e.g., software) 1124 embodying or used by any one or
more of the methodologies or functions described herein. The
instructions 1124 may also reside, completely or at least
partially, within the main memory 1104, static memory 1106, and/or
within the processor 1102 during execution thereof by the computer
system 1100, the main memory 1104 and the processor 1102 also
constituting machine-readable media.
[0103] While the machine-readable medium 1122 is shown in an
example embodiment to be a single medium, the term
"machine-readable medium" may include a single medium or multiple
media (e.g., a centralized or distributed database, and/or
associated caches and servers) that store the one or more
instructions or data structures. The term "machine-readable medium"
shall also be taken to include any tangible medium that is capable
of storing, encoding or carrying instructions for execution by the
machine and that cause the machine to perform any one or more of
the methodologies of the present invention, or that is capable of
storing, encoding or carrying data structures used by or associated
with such instructions. The term "machine-readable medium" shall
accordingly be taken to include, but not be limited to, solid-state
memories, and optical and magnetic media. Specific examples of
machine-readable media include non-volatile memory, including by
way of example, semiconductor memory devices (e.g., erasable
programmable read-only memory (EPROM), electrically erasable
programmable read-only memory (EEPROM)) and flash memory devices;
magnetic disks such as internal hard disks and removable disks;
magneto-optical disks; and CD-ROM and DVD-ROM disks. A
"machine-readable storage medium" shall also include devices that
may be interpreted as transitory, such as register memory,
processor cache, and RAM, among others. The definitions provided
herein of machine-readable medium and machine-readable storage
medium are applicable even if the machine-readable medium is
further characterized as being "non-transitory." For example, any
addition of "non-transitory," such as non-transitory
machine-readable storage medium, is intended to continue to
encompass register memory, processor cache and RAM, among other
memory devices.
Transmission Medium
[0104] The instructions 1124 may further be transmitted or received
over a communications network 1126 using a transmission medium. The
instructions 1124 may be transmitted using the network interface
device 1120 and any one of a number of well-known transfer
protocols (e.g., HTTP). Examples of communication networks include
a LAN, a WAN, the Internet, mobile telephone networks, plain old
telephone (POTS) networks, and wireless data networks (e.g., WiFi
and WiMax networks). The term "transmission medium" shall be taken
to include any intangible medium that is capable of storing,
encoding or carrying instructions for execution by the machine, and
includes digital or analog communications signals or other
intangible media to facilitate communication of such software.
[0105] Thus, methods and systems for navigation and control of an
implant positioning device have been described. Although the
present invention has been described with reference to specific
example embodiments, it will be evident that various modifications
and changes may be made to these embodiments without departing from
the broader spirit and scope of the invention. Accordingly, the
specification and drawings are to be regarded in an illustrative
rather than a restrictive sense.
[0106] Although an embodiment has been described with reference to
specific example embodiments, it will be evident that various
modifications and changes may be made to these embodiments without
departing from the broader spirit and scope of the invention.
Accordingly, the specification and drawings are to be regarded in
an illustrative rather than a restrictive sense. The accompanying
drawings that form a part hereof, show by way of illustration, and
not of limitation, specific embodiments in which the subject matter
may be practiced. The embodiments illustrated are described in
sufficient detail to enable those skilled in the art to practice
the teachings disclosed herein. Other embodiments may be used and
derived therefrom, such that structural and logical substitutions
and changes may be made without departing from the scope of this
disclosure. This Detailed Description, therefore, is not to be
taken in a limiting sense, and the scope of various embodiments is
defined only by the appended claims, along with the full range of
equivalents to which such claims are entitled.
[0107] Such embodiments of the inventive subject matter may be
referred to herein, individually and/or collectively, by the term
"invention" merely for convenience and without intending to
voluntarily limit the scope of this application to any single
invention or inventive concept if more than one is in fact
disclosed. Thus, although specific embodiments or examples have
been illustrated and described herein, it should be appreciated
that any arrangement calculated to achieve the same purpose may be
substituted for the specific embodiments shown. This disclosure is
intended to cover any and all adaptations or variations of various
embodiments. Combinations of the above embodiments, and other
embodiments not specifically described herein, will be apparent to
those of skill in the art upon reviewing the above description.
[0108] All publications, patents, and patent documents referred to
in this document are incorporated by reference herein in their
entirety, as though individually incorporated by reference. In the
event of inconsistent usages between this document and those
documents so incorporated by reference, the usage in the
incorporated reference(s) should be considered supplementary to
that of this document; for irreconcilable inconsistencies, the
usage in this document controls.
[0109] In this document, the terms "a" or "an" are used, as is
common in patent documents, to include one or more than one,
independent of any other instances or usages of "at least one" or
"one or more." In this document, the term "or" is used to refer to
a nonexclusive or, such that "A or B" includes "A but not B," "B
but not A," and "A and B," unless otherwise indicated. In the
appended claims, the terms "including" and "in which" are used as
the plain-English equivalents of the respective terms "comprising"
and "wherein." Also, in the following claims, the terms "including"
and "comprising" are open-ended; that is, a system, device,
article, or process that includes elements in addition to those
listed after such a term in a claim are still deemed to fall within
the scope of that claim. Moreover, in the following claims, the
terms "first," "second," "third," and so forth are used merely as
labels, and are not intended to impose numerical requirements on
their objects.
[0110] The Abstract of the Disclosure is provided to comply with 37
C.F.R. .sctn. 1.72(b), requiring an abstract that will allow the
reader to quickly ascertain the nature of the technical disclosure.
It is submitted with the understanding that it will not be used to
interpret or limit the scope or meaning of the claims. In addition,
in the foregoing Detailed Description, it can be seen that various
features are grouped together in a single embodiment for the
purpose of streamlining the disclosure. This method of disclosure
is not to be interpreted as reflecting an intention that the
claimed embodiments require more features than are expressly
recited in each claim. Rather, as the following claims reflect,
inventive subject matter lies in less than all features of a single
disclosed embodiment. Thus the following claims are hereby
incorporated into the Detailed Description, with each claim
standing on its own as a separate embodiment.
* * * * *