BACKGROUND OF THE INVENTION
a. Field of the Invention
[0001] The instant invention relates to an optic-based sensing assembly. The instant invention
includes an optic-based catheter assembly and related system used to monitor or determine
contact between a catheter and the surrounding proximate environment, such as tissue.
Such a system may be used for visualization, mapping, ablation, and/or other methods
of diagnosis and treatment of tissue.
b. Background Art
[0002] US 6,113,590 A relates to a heart catheter with a probe disposed at the distal end of the catheter
for high frequency coagulation of tissue and a temperature sensor for measuring the
heating of the coagulation area during the procedure.
[0003] US 2007/060847 A1 relates to an apparatus for exploring and treating an organ that permits computation
of a multi-dimensional force vector resulting from contact between the distal extremity
of the apparatus and the tissue of the wall of the organ.
[0004] The visualization and treatment of organs and tissues has been advanced through the
increasing use of catheter systems. Catheter systems have been designed for the incorporation
of various components to treat and diagnose ailments, as accomplished through the
mapping of organs, sensing of thermal and electrical changes exhibited by a tissue
(e.g., heart), as well as the application of energizing sources (such as radiofrequency,
cryogenics, laser, and high frequency ultrasound) to tissue.
[0005] Catheter systems generally include a portion that contacts the tissue or organ, or
is inserted in an environment (e.g., heart chamber or vessel) to detect a number of
parameters, such as for example, location of the tissue, contact or pressure exerted
on the tissue, electrophysiological attributes of the tissue, or other type of parameters
that aid in the evaluation or treatment of the organ or tissue.
[0006] It is known that sufficient contact between a catheter, in particular an electrode
provided in connection with a catheter, and tissue during a procedure is generally
necessary to ensure that the procedures are effective and safe. Current techniques
of mapping, visualization and treatment using energizing sources, such as the use
of radiofrequency energy during ablation, rely on the placing of the electrode of
a catheter system in consistent mechanical contact with targeted tissue. Perforations
of the cardiac wall as well as lesion formation (such as lesions created by exposure
to radiofrequency) partially depends upon the direction of contact between the electrode
and tissue. In particular, for endocardial catheter applications, the point of electrode-tissue
contact is typically 150 cm away from the point of application of force applied by
the operator (whether manual or automated) of the catheter outside of the body. Coupled
with the fact that a beating heart is a dynamically moving wall, this gives rise to
some functional and theoretical challenges such as ensuring that the electrode is
in sufficiently constant mechanical contact with the myocardial wall.
[0007] Catheter systems having sensor assemblies, such as those mounted on the catheter
shaft proximal to the electrode or remotely in the handle set, leave the possibility,
however small, of obtaining false positive outcomes when detecting contact between
the electrode and the tissue. False positive outcomes may occur, for example, when
the catheter wall, and not the electrode, is in contact with the tissue. Such condition
may arise during the catheter manipulation in the heart when, for instance, the distal
portion of the catheter is curled inward so much as to lose electrode contact with
the tissue, while the distal portion of the catheter is in contact with the tissue.
When that happens, remotely placed sensors generate signals due to the deflection
of the catheter shaft, thereby falsely indicating contact between the electrode and
tissue. Accordingly, optic-based contact sensors coupled to the electrode can, among
other things, help reduce the possibility of obtaining false positive outcomes when
detecting contact between the electrode and the tissue.
BRIEF SUMMARY OF INVENTION
[0008] The invention is defined in claim 1.
[0009] For some applications, it is desirable to have an optic-based catheter system that
includes an optical sensor that detects changes in reflected energy, such as light,
from an optically interactive surface provided by an electrode. In an embodiment,
the electrode is subjected to a compressive force due to mechanical contact of the
electrode surface with another body or surface. The optical sensor of the present
invention can be used to measure contact of an electrode with a dynamically moving
wall, such as a beating heart.
[0010] In another embodiment, a contact sensing assembly for sensing contact with a target
(e.g., a tissue or other organ surface) is provided. The assembly includes an elongated
body having a distal section and a sensor connected to the distal section. The sensor
including a segment with a first interactive component, a tip positioned distally
from the segment, and a flexible coupling member separating the segment from the tip.
The tip includes an external surface and is positioned distally from the segment,
the tip further including a second interactive component that is adapted to interact
with the first interactive component. The flexible coupling member separates the segment
from the tip, such that the second interactive component can move relative to the
first interactive component when the external surface of the tip contacts the target.
[0011] Accordingly, the present invention is directed to a catheter comprising a contact
sensing assembly for detecting and measuring contact force. The inventive assembly
includes a catheter having a proximal end and distal end. In an embodiment, the inventive
assembly further includes an electrode having a tip portion and a base portion. The
electrode further includes an optically interactive surface. A portion of the electrode
may be connected to the distal end of the catheter. The inventive assembly may further
provide at least one optical sensor within the catheter for interacting with the optically
interactive surface provided in connection with the electrode.
[0012] The present invention is further directed to an optic-based catheter system. The
inventive system includes a catheter having a proximal end and distal end. The system
may further provide an electrode having a tip portion and a base portion wherein the
electrode further includes an optically interactive surface and at least a portion
of the electrode is connected to the distal end of the catheter. In an embodiment,
the system still further may include at least one optical sensor provided within the
catheter for interacting with the optically interactive surface provided by the electrode.
The system may further include a light source, a processor, a catheter mapping unit
for use in mapping and/or visualizing the catheter location; and a fiber assembly
for carrying optical energy, such as light, emitted and received from the optical
sensor.
[0013] A method of sensing contact force as provided by the contact sensing assembly and
system is described. The method includes directing optical energy from a source through
an optic fiber assembly within a catheter. In an embodiment, the method may further
include emitting the optical signal and/or energy from an optical sensor across a
spaced gap and/or into a refractive medium for interacting with an optical interactive
surface provided by an electrode. In an embodiment, the method includes receiving
reflected optic energy by the optical sensor, the reflected optic energy may be transmitted
along the fiber assembly and processed by a processor to determine a change between
the optical energy (i.e., signal) emitted from the optical sensor and the reflected
optical energy received by the optical sensor to calculate or determine the corresponding
force vector exerted by the electrode on a tissue. More particularly, the change in
reflective energy, for example, the change in optical intensity, is proportional to
the displacement or movement of the optically interactive surface of the electrode.
The change in reflective energy is therein proportional to the force exerted on the
electrode either axially, laterally or a combination of both.
[0014] The foregoing and other aspects, features, details, utilities, and advantages of
the present invention will be apparent from reading the following description and
claims, and from reviewing the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015]
Figure 1 is a partial perspective view of a catheter assembly in accordance with an
embodiment of the present invention;
Figure 2 is an enlarged partial perspective view of the catheter assembly shown in
Figure 1, wherein the electrode and portion of the optic-based sensing assembly is
shown in phantom;
Figures 3A and 3B are partial perspective views of portions of an optic-based sensing
assembly according to alternative embodiments of the present invention;
Figure 4 is a side elevation view of an alternate embodiment of the present invention;
Figures 5A and 5B are exploded perspective views of an assembly of the type shown
in Figure 4;
Figure 6 is a side cross-sectional view of an assembly of the type shown in Figure
4;
Figure 7 is a side cross-sectional view of an assembly in accordance with another
embodiment of the present invention;
Figure 8 is a cross-sectional view of an assembly in accordance with another embodiment
of the present invention;
Figures 9A-9F are alternate embodiments of a portion of the assembly of the type shown
in Figure 5B;
Figures 10A-10B are alternate embodiments of a portion of the assembly for incorporation
with the present invention; and
Figures 11A-11I are schematic overviews of the system in accordance with alternate
embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Referring now to the drawings wherein like reference numerals are used to identify
like components in the various views, Figures 1 and 2 illustrate an exemplary embodiment
of a contact sensing assembly 10 as provided by the present invention. In a general
form, the contact sensing assembly 10 includes a catheter 12, an electrode 14 connected
to the catheter, and an optical sensor 16 for optically interacting with a portion
of electrode 14. In another embodiment, the contact sensing assembly 10 may include
a first interactive component and a second interactive component. The contact sensing
assembly may be used in the diagnosis, visualization, and/or treatment of tissue (such
as endocardial tissue) in a body. Contact sensing assembly 10 may be used in a number
of diagnostic and therapeutic applications, such as for example, the recording of
electrograms in the heart, the performance of cardiac ablation procedures, and/or
various other applications. The catheter assembly can be used in connection with a
number of applications that involve humans, or other mammals, for tissue observation,
treatment, repair or other procedures. Moreover, the present invention is not limited
to one particular application, but rather may be employed by those of ordinary skill
in the art in any number of diagnostic and therapeutic applications.
[0017] Catheter 12 of the present invention includes a body 18 having a distal end 20 and
a proximal end 22. Body 18 of catheter 12 is generally tubular in shape, although
other configurations of the catheter may be used as known in the industry. Distal
end 20 of catheter 12 is connected to electrode 14, while body 18 of catheter 12 may
house optical sensor 16 and may house other components used in the diagnosis and/or
treatment of tissue. If desired, the outer portion of catheter 12 may have a braided
outer covering therein providing increased flexibility and strength. The catheter
of the present invention vary in length and are attached to a handle or other type
of control member that allows a surgeon or operator of the catheter to manipulate
the relative position of the catheter within the body from a remote location, as recognized
by one of ordinary skill in the art.
[0018] As generally shown in Figure 1, an embodiment of the present invention includes distal
end 20 of catheter 12 that includes at least a portion or segment that exhibits increased
flexibility relative to more proximal portions of the catheter 12. The increased flexibility
of at least a portion or segment associated with the distal end 20 may be achieved
through any number of methods, including but not limited to, the use of flexible materials,
the formation of a spring-like coupling portion, or any other type of connection that
allows for increased flexibility at a portion or segment of the distal end 20 of catheter
12.
[0019] Electrode 14 is connected to distal end 20 of catheter 12. Upon the exertion of external
contact force on the surface of electrode 14, at least a portion of distal end 20
of catheter 12 flexes and/or bends relative to electrode 14. The relative movement
(e.g., displacement either axially, laterally or a combination thereof) of distal
end 20 may be proportionate or correlated to the force exerted on electrode 14. Electrode
14 includes a tip portion 24 and a base portion 26. Electrode 14 may be configured
to include a means for irrigating. For example, without limitation, the incorporation
of at least one irrigation port 28 within electrode 14, therein providing an irrigated
electrode tip. An irrigated electrode tip allows for the cooling of electrode 14,
for instance, through the transporting of fluid through electrode 14 and around the
surface of the tissue. A number of different types of electrodes, irrigated and non-irrigated,
may be connected and incorporated for use an electrode 14 according to embodiments
of the invention depending on the type of procedures being done. Such irrigated electrodes
include, but are not limited to, those disclosed in
U.S. Patent Application Nos. 11/434,220 (filed May 16, 2006),
10/595,608 (filed April 28, 2006),
11/646,270 (filed December 28,2006)
11/647,346 (filed December 29,2006) and
60/828,955 (filed October 10, 2006).
[0020] Electrode 14 may include an optically interactive surface 30 (see, e.g., FIG. 5B),
described further below, that is provided on a portion of the electrode 14 that interacts
with the optical sensor 16 of the assembly 10. As shown in Figure 2, electrode 14
may further include an electrode cavity 36, as shown in phantom. Electrode cavity
36 may also be used to provide a number of different components and/or functions in
connection with the electrode. In one embodiment, electrode cavity 36 may further
provide the optically interactive surface therein enabling optical sensor 16 to interact
with the internal surface of electrode 14 provided by electrode cavity 36. In alternate
embodiments, electrode cavity 36 may serve as a lumen for transferring of irrigation
channels, electrical components, or any other type assembly components that need to
be transferred through electrode 14.
[0021] In general, an optically interactive surface 30 may be provided on or in connection
with a surface associated with electrode 14, such that the surface positioning, configuration,
and orientation of the interactive surface (which has a know position with respect
to the electrode) allows sufficient interaction and/or functional communication with
the optical sensor 16 such that a change in the communication (e.g., optical signal,
light intensity) can provide a means for determining the contact force and/or orientation
of the electrode with the tissue or surrounding area. In one embodiment, electrode
cavity 36 includes an optically interactive surface 30. In an alternate embodiment,
optically interactive surface 30 may be provided on or in connection with base portion
26 of electrode 14. The optically interactive surface may be comprised of any material
suitable for the intended environment that reflects or refracts light energy. For
example, without limitation, the interactive surface may comprise a reflective metal,
such as a polished metal. The interactive surface 30 may also comprise prisms or other
refractive media which may include a reflective surface. Depending on the design of
optically interactive surface 30, the interactive surface 30 may further include a
mirrored surface, filters positioned relative to surface 30 and/or other types of
refractive media in combination with opaque segments, as discussed in more detail
below.
Optical sensor 16 may be positioned within the distal end 20 of the catheter 12. Optical
sensor 16 may include at least one optic fiber that transmits and receives an optical
signal, such as light energy. The optical sensor may also be manufactured to transmit
and/or receive various types of signals including those associated with electromagnetic
radiation, lasers, x-rays, radiofrequency, etc. In an embodiment, optical sensor 16
may use light energy to determine the relative contact (e.g., force, stress, and/or
orientation) between electrode 14 and an external surface in operational contact with
the electrode - for example, tissues and surrounding environments, including organs,
heart chambers, and interior of vessels. In an embodiment, the optical sensor may
be adapted to measure one or more parameters, including, for example, intensity, wavelength,
phase, spectrum, speed, optical path, interference, transmission, absorption, reflection,
refraction, diffraction, polarization, and scattering.
[0022] In an embodiment, one or more force vectors may be used to determine the contact
force and/or orientation of the electrode in connection with the surrounding tissue
or other external surfaces. In particular, the change of intensity of the optical
signal received by optical sensor 16 may be correlated to the contact force exerted
on electrode 14 by an external surface. The intensity of the optical signals received
by optical sensor 16 is proportional to the structural displacement of distal end
20 of catheter 12. As discussed in more detail below, the displacement of distal end
20 is governed by a factor (k) (such as a spring constant) exhibited by the material
comprising a portion of distal end 20. Accordingly, the factor (k) may be equated
to the external force (F), either laterally or axially, exerted on electrode 14, divided
by the unit displacement (D) (either axially or laterally) of electrode, which may
be generally expressed as k = F/D. Since the change in intensity to the optical signals
is proportional to the displacement of the electrode, the external force exerted on
the electrode may be determined.
[0023] In order to determine light or optical intensity, optical sensor 16 includes a receiver
32 and an emitter 34 for receiving and emitting light energy, respectively. Receiver
32 and emitter 34 may be included in a single fiber optic cable or in two separate
fiber optic cables, such as shown in Figure 2. A number of optical sensors 16 may
be arranged within distal end 20 of catheter 12 to operatively (e.g., optically) interact
with an interactive surface 30 that is provided in connection with electrode 14. Moreover,
a number of receivers 32 and emitters 34 may be disposed within distal end 20 of catheter
12 in various configurations and combinations to assess contact and/or orientation
readings. Such positioning and combinations can be configured adapted to optimize
their operation for an intended application or environment. For example, without limitation,
as shown in Figures 3A-3B an equal number of emitters and receivers may be provided.
In alternate embodiments, an unequal number of emitters and receivers may be provided
in various combinations.
[0024] Referring to Figures 2-3B, various embodiments having alternate configurations of
optical sensors 16 are illustrated in connection with catheter 12. Each optical sensor
16 includes a receiver 32 and an emitter 34. In the illustrated embodiments, the optical
sensors 16 are provided by a fiber optic cable 38 , wherein sensors 16 are connected
to peripheral wall 40 surrounding a lumen 42 disposed within body 18 of catheter 12.
Lumen 42 is provided to carry various components for use in the catheter or contact
assembly or provides a passageway for fluids, such as those needed for an irrigated
electrode. Figure 3A further illustrates three optical sensors 16 connected to the
peripheral wall 40 in a paired configuration wherein receiver 32 and emitter 34 are
provided adjacent to one another. Each optical sensor 16 may be positioned relative
to one another circumferentially around peripheral wall 40 of lumen 42. In a particular
embodiment, as generally shown in Figure 3A, optical sensors 16 may be provided in
the paired configuration, wherein the pairs are separated about peripheral wall 40
of fiber optic cable 38. Each of the pairs may be separated by various degrees, such
as 120 degrees, as shown. Figure 3B illustrates an example of an alternate embodiment,
wherein a plurality of receivers 32 and emitters 34 are circumferentially disposed
within the body of the catheter along the peripheral wall 40 from one another. Receivers
32 and emitters 34 may be provided in various combinations, ratios, and relative positions
to one another depending on the design of the sensing assembly 10.
[0025] Figures 4-7 further illustrate an alternate embodiment of a contact sensing assembly
10. The assembly 10 includes catheter 12, electrode 14, and optical sensor 16, wherein
distal end 20 of catheter 12 includes a coupling member 50 for receiving a portion
of electrode 14 for connection with distal end 20 of catheter 12. The coupling member
50 includes a neck portion 52 and a mounting shaft 54.
[0026] As shown in the combination of Figures 5A and 5B, the neck portion 52 of the coupling
member 50 defines a receptacle of receiving portion 58 for receiving a portion of
electrode 14 for connection with catheter 12. Base portion 26 of electrode 14 can
be received by electrode receptacle or receiving portion 58 for connecting electrode
14 to coupling member 50. Neck portion 52 further includes elastic portion 60, that
provides increased flexibility. Elastic portion 60 may include a number of alternate
embodiments, such as a spring. Elastic portion 60 of neck portion 52 moves relative
to the external force exerted on tip portion 24 of electrode 14. Mounting shaft 54
of coupling member 50 is connected to catheter 12, therein forming a flexible distal
end 20. In some embodiments, mounting shaft 54 is more rigid than neck portion 52
of coupling member 50 and provides secure engagement with catheter 12. At least one
pull wire (not shown) may be attached to mounting shaft 54 for movement and deflection
of the catheter. Mounting shaft 54 further provides at least one recessed groove 62
for receiving and mounting optical sensor 16. The recessed groove 62 may position
optical sensor 16 so that the end of the optical sensor 16 is flush with mounting
shaft 54. Alternate embodiments may provide for optical sensors that extend into the
electrode. Overall, the optical sensors are positioned to interact with optically
interactive surface 30 as provided by electrode 14. Figure 5B provides an embodiment,
wherein optically interactive surface 30 is provided on or is a part of base portion
26 of electrode 14. Optically interactive surface 30 may, in another embodiment, be
provided as a coating or formed surface in connection with electrode 14.
[0027] Figures 9A-9F generally illustrate alternate configurations of base portion 26 in
accordance with alternate embodiments of the present invention. Although not shown,
in the provided Figures, base portion 26 can be connected to and/or may be an integrated
part of electrode 14, for example, as shown in Figure 5B. Figures 9A-9C provide alternate
embodiments of optically interactive surface 30 as provided by base portion 26, wherein
optically interactive surface 30 may be hemispherical in shape or provided in a more
angular/planar design. The design of optically interactive surface may vary depending
on the physical requirements of the optical system and the desired interaction with
the optical signal emitted and reflected by the associated optical sensor or sensors.
In alternate embodiments, as shown in Figures 9D-9F, refractive media 31 may be further
provided by base portion 26 to optically interact with the signal (i.e., light) generated
by optical senor 16 of the present invention. The media may be prismastic or plano-convex.
Moreover, optically interactive surface 30 may further be provided in connection with
the media 31. Media 31 may further include various lens, filters or other types of
structures generally know to interact with optical signals (i.e., light).
[0028] As generally illustrated in Figures 6-8, base portion 26 of electrode 14 is positioned
within neck portion 52 of the coupling member 50 so that a gap and/or area 64 is provided
between optical sensors 16 and optically interactive surface 30. As tip portion 24
of electrode 14 is exposed to external force through contact with tissue, neck portion
52 of coupling member 50 moves relative to tip 24 of electrode 14. Gap 64 may vary
in size depending on the size of the electrode, as well as the desired optical interaction
between the electrode and the optical sensor. The length (1) of gap 64 correlates
to the size of elastic coupling 60 as provided by neck portion 54 of coupling member
50.
[0029] An alternate embodiment, the volume of the area generally defined by gap 64 may also
be filled, in whole or in part, with a medium 33 that transmits/transfers light. Medium
33 may further allow for the optical interaction of optical sensor 16 with surface
30 associated with electrode 14. Accordingly, the optical signal emitted from optical
sensor 16 may be transmitted either through medium 33 or may directly interact with
optically interactive surface 30 depending on the position and/or orientation of catheter
12 and the design of the assembly. The interaction and orientation of the signal may
be correlated to determine an associated amount of external force exerted on electrode
14 disposed on catheter 12, and may provide information concerning the orientation
of the electrode 14. Moreover, the assembly may be calibrated to better ensure appropriate
correlation. The optical signal is then reflected or refracted after interacting with
optically interactive surface 30 and received by optical sensor 16. In an embodiment,
the optical signal (e.g., light energy) is emitted by emitter 34 and received by receiver
32 of optical sensor 16.
[0030] As can be seen in Figures 10A-10B, alternate configurations of medium 30 are shown.
In particular, medium 33 may be positioned within the optical assembly such that the
proximal surface of the medium 33 may be coupled to or in proximity with optical sensor
16, while the distal surface of medium 33 may be position in proximity to base portion
26 of electrode 14. Base portion 26 of electrode 14 may further include optically
interactive surface 30. In an alternate configuration, medium 33 is provided to optically
interact with the optical signal generated by optical sensor 16, in particular, emitter
34, therein refracting the optical signal for transmitting to receiver 32. Medium
33 may include air, gel, liquid or other types of compliant materials known in the
industry that are suitable for the environment and do not unacceptably interfere with
the operation of the electrode 14 or the optical sensor 16. In an embodiment, medium
33 may be encapsulated within a compliant retaining structure. Medium 33 may be compressible
such that the material is responsive to external force as exerted on electrode 14.
In an alternate embodiment, medium 33 may comprise a gel or liquid like material dispersed
with a solid or solid particulate such that light is dispersed or refracted (i.e.
scattered) by the particulate. An alternate embodiment may provide a liquid or gel-like
material that further includes suspended particles (i.e. air or liquid bubbles) that
would refract the optical signal provided by emitter 34 to receiver 32. Figure 10B
illustrates another embodiment, wherein opaque partitions 35 are positioned among
medium 33, such that the optical signals emitted by each optical sensor 16 essentially
cannot interfere with one another. Such a configuration can aid in reducing "cross-talk"
and/or interference among each of the optical sensors 16.
[0031] A fiber assembly is further provided by the present invention. The fiber assembly
includes a supply fiber and a return fiber. The supply fiber (not shown) is connected
to emitter 34 and carries light energy from a light source to emitter 34. The return
fiber (not shown) carries reflected light from receiver 32 back to a processor and
display unit. The light energy emitted by optical sensor 16 is compared to the light
received by optical sensor 16 and used to determine the relative force exerted on
electrode 14 based on the orientation of electrode 14 and in connection with catheter
12.
[0032] In another embodiment, catheter assembly 10 provides a first interactive component
and a second interactive component such the interactive components may include optical
sensors, optically interactive surfaces in various combinations. For example, in an
embodiment, that assembly does not necessarily include an electrode, but may provide
a sensor that includes a segment with an interactive component and a tip with another
interactive component adapted to interact with one another when an external surface
of the tip contacts a target.
[0033] Figure 7 illustrates an alternate embodiment of assembly 10 wherein least one lumen
66 is included for receiving various energizing or sensing components. Lumen 66 is
provided for receiving sensing components such as a thermal sensor, pressure sensor,
tissue sensor, electrogram sensor, or other type of sensors and combinations thereof
that are known by those of ordinary skill in the art. An additional lumen 68 extends
from catheter 12 through coupling member 50 and into electrode 14, therein providing
an energizing component, such as source for radiofrequency current, direct current,
high-intensity ultrasound, laser, cryogenics, or other type of energizing component
and combinations that are known by those of ordinary skill in the art. Additional
lumens may be provided by assembly 10 for communication with additional components
for the assembly, such as electrical components, fluid (i.e. saline) passageways,
or others known in the industry.
[0034] As can be seen in Figures 7 and 8, electrode 14 may have alternate tip configurations
depending on the type of procedure or use of the catheter assembly. As previously
suggested, electrode 14 may be provided having an irrigated electrode tip or a non-irrigated
electrode tip. Each of these may be used in connection with embodiments of the present
invention.
[0035] The present invention further discloses an optic-based catheter system 100, as shown
in Figures 11A-11F, that includes assembly 10 of the present invention connected to
a signal converter 110 (such as an analog to digital converter) and an operator interface
120, which may further include a computer and display, for processing the optical
signals received from assembly 10 in connection with positioning and contact with
tissue, such as myocardial tissue 105. This optic-based information is processed to
determine the contact force exerted on electrode 14 of assembly 10. A calibration
system 130 (i.e., calibration software) may be further provided to readily correlate
the amplitude or intensity of the received signal to the external force on the electrode.
A mapping system 140, such as the EnSite system, also known as NavX®, may be integrated
with system 100 to provide a visualization and mapping system for use in connection
with assembly 10 of the present invention. In an alternate embodiment, as shown in
Figures 11D-11F, the signal processor may be integrated with each of the receivers
provided by optical sensor 16, such that the optical signal is directly processed
and provided on the operator interface. Moreover, in another alternate embodiment,
as shown in Figures 11G-11I, the emitter and receiver may use the same optical fiber
for transmitting and receiving the optical signal. Accordingly a splitter 150, as
known by one of ordinary skill in the art, may be used to manage the transmission
and receiving of the optical signal for processing. Overall, each of these components
may be modified and/or integrated with one another depending on the design of the
optical system as recognized by one of ordinary skill in the art.
[0036] As previously described, the present invention provides a method of sensing contact
force and/or orientation as provided by the contact sensing assembly and system. The
inventive method includes directing light or energy from a source through an optical
sensor within a catheter; emitting light or energy from the optical sensor across
a spaced gap for interacting with an optically-interactive surface provided in connection
with an electrode; and receiving reflected light or energy by the optical sensor.
The reflected light or energy may be processed by a processor to determine a change
between the light or energy emitted from the optical sensor and the reflected light
energy correspondingly received by the optical sensor. The changes may be correlated
to, among other things, force vectors exerted by the electrode on a adjacent tissue.
[0037] In particular, under normal conditions of zero-contact force (i.e. when the electrode
is not subjected to external forces), the plane of reflection as provided by either
optically interactive surface 30, media 31 or medium 33, alone or in combination with
one another as the case may be, is generally parallel to the plane of emitters 34
as previously described. Accordingly, the amplitude or intensity of the optical signal
(i.e., light) received by receivers 32 is substantially the same or proportionally
constant depending on the properties of the interactive surface. When the electrode
contacts a surface, the contact force modifies the plane of reflection provided by
the respective interactive surface (30, 31, or 33). In particular, upon the exertion
of axial force (F
a) on the electrode, the plane of reflection is pushed closer to the place of emitters
due to the spring-like configuration and/or flexibility exhibited by distal end 20
of catheter 12. Similarly, upon the exertion of lateral force (F
1), the place of reflection is tilted with respect to the plane of emitters. The change
in amplitude or intensity of the reflected optical signal (i.e. light) received by
each of the receivers relative to one another results in the calculation of the lateral
force exerted on the external surface of the electrode. The change in amplitude or
intensity of the reflected light relative to the zero-axial-force condition can be
used to determine the axial force being exerted on the electrode. As a result, the
net contact force is given by the vector sum of the axial and lateral force, and the
direction relative to the axis may be calculated. Overall, the force, either axial,
lateral or a combination of both, is determined based on the change of intensity of
the optical signal received by the receivers which is proportional to the displacement
and/or movement of the distal end 20 of catheter 12.
[0038] Although a number of embodiments of this invention have been described above with
a certain degree of particularity, those skilled in the art could make numerous alterations
to the disclosed embodiments without departing from the scope of this invention. For
example, all joinder references (e.g., attached, coupled, connected, and the like)
are to be construed broadly and may include intermediate members between a connection
of elements and relative movement between elements. As such, joinder references do
not necessarily infer that two elements are directly connected and in fixed relation
to each other. It is intended that all matter contained in the above description or
shown in the accompanying drawings shall be interpreted as illustrative only and not
limiting. Changes in detail or structure may be made without departing from the the
invention as defined in the appended claims.
1. A catheter assembly comprising:
a contact sensing assembly (10) comprising
a catheter (12) including a body having a proximal end (22) and a distal end (20)
and housing an optical sensor (16);
an electrode (14) including a tip portion (24), an electrode cavity (36), and a base
portion (26); wherein the distal end (20) of the catheter includes
a coupling member (50) comprising a neck portion (52) and a mounting shaft (54), (52),
wherein the neck portion (52) comprises an elastic portion (60), wherein the base
portion (26) of the electrode (14) is configured to be received by the neck portion
(52), wherein a distal end of the optical sensor (16) is configured to be coupled
to the coupling member (50) and positioned proximal of the elastic portion (60) and
proximal of the base portion (26) of the electrode (14), the electrode (14) includes
an optically interactive surface (30) that is provided on a portion of the electrode
(14) that interacts with the optical sensor (16), wherein the elastic portion (60)
is adapted to move relative to an external force exerted on the electrode (14) such
that at least a portion of distal end (20) of catheter (12) flexes and/or bends relative
to electrode (14),
wherein the optical sensor (16) includes an emitter (34) and a receiver (32).
2. The catheter assembly
according to claim 1, wherein a plurality of optical sensors (16) are provided in
pairs separated about the peripheral wall of a fiber optic cable (38), such that each
emitter (34) operatively interacts with a corresponding receiver (32).
3. The catheter assembly according to claim 2, wherein the fiber optic cable (38) comprises
at least one lumen (42) and a peripheral wall (40) surrounding the lumen (42), wherein
the optical sensor is connected to the peripheral wall (40).
4. The catheter assembly of claim 3, wherein the electrode (14) comprises the lumen (42)
provided with an internal cavity of the electrode (14), the lumen (42) positioned
adjacent to the base portion (26) and tip portion (24) of the electrode (14).
5. The catheter assembly of any one of claims 1 to 4, wherein the interactive surface
(30) includes a refractive media.
6. The catheter assembly of claim 5, wherein the refractive media includes a mirrored
surface.
7. The catheter assembly of any one of claims 1 to 6, wherein the emitter (34) and receiver
(32) are adjacent to one another and are paired.
8. The catheter assembly of claim 1, comprising a lumen (66, 68) disposed within the
body of the catheter (12), at least a portion of the lumen (66, 68) extending into
the electrode (14) for receiving at least one sensing component and/or for receiving
at least one energizing component.
9. The catheter assembly of claim 8, wherein the sensing component is selected from a
thermal sensor, pressure sensor, tissue sensor, electrogram sensor, and combinations
thereof.
10. The catheter assembly of any one of the preceding claims, wherein the optical sensor
(16) is adapted to measure a parameter selected from the group consisting of intensity,
wavelength, phase, spectrum, speed, optical path, interference, transmission, absorption,
reflection, refraction, diffraction, polarization, and scattering.
11. An optically-based catheter system (100) comprising:
catheter of any one of the preceding claims,
a light or energy source;
a processor (110, 120),
a catheter mapping unit (140) for use in mapping or visualizing the catheter location;
and
a fiber assembly for carrying light energy that is emitted, is reflected by the optically-interactive
surface, and is received by the optical sensor.
1. Katheteranordnung, die aufweist:
eine Kontakterfassungsanordnung (10), mit
einem Katheter (12), der einen Körper mit einem proximalen Ende (22) und einem distalen
Ende (20) aufweist und einen optischen Sensor (16) beherbergt;
einer Elektrode (14), die einen Spitzenbereich (24), einen Elektrodenhohlraum (36)
und einen Basisbereich (26) aufweist, wobei das distale Ende (20) des Katheters
ein Kopplungselement (50) mit einem Halsbereich und einem Montageschaft (54) aufweist,
wobei der Halsbereich (52) einen elastischen Bereich (60) aufweist, und der Basisbereich
(26) der Elektrode (14) konfiguriert ist zum Aufnehmen des Halsbereichs (52), wobei
ein distales Ende des optischen Sensors (16) konfiguriert ist zur Kopplung mit dem
Kopplungselement (50) und zur Positionierung proximal zu dem elastischen Bereich (60)
und proximal zu dem Basisbereich (26) der Elektrode (14), wobei die Elektrode (14)
eine optisch interaktive Fläche (30) aufweist, die auf einem Bereich der Elektrode
(14) bereitgestellt ist, der mit dem optischen Sensor (16) interagiert, wobei der
elastische Bereich (60) angepasst ist zur relativen Bewegung zu einer externen Kraft,
die auf die Elektrode (14) ausgeübt wird, derart, dass mindestens ein Bereich des
distalen Endes (20) des Katheters (12) sich relativ zu der Elektrode (14) biegt und/oder
krümmt,
wobei der optische Sensor (16) einen Emitter (34) und einen Empfänger (32) aufweist.
2. Katheteranordnung nach Anspruch 1, bei der eine Mehrzahl von optischen Sensoren (16)
paarweise über eine Umfangswand eines Lichtwellenleiters (38) getrennt derart vorgesehen
sind, dass jeder Emitter (34) operativ mit einem entsprechenden Empfänger (32) interagiert.
3. Katheteranordnung nach Anspruch 2, bei der der Lichtwellenleiter (38) mindestens ein
Lumen (42) und eine das Lumen (42) umgebende Umfangswand (40) aufweist, wobei der
optische Sensor mit der Umfangswand (40) verbunden ist.
4. Katheteranordnung nach Anspruch 3, bei der die Elektrode (14) das Lumen (42) aufweist,
das durch einen inneren Hohlraum der Elektrode (14) bereitgestellt ist, wobei das
Lumen (42) benachbart zu dem Basisbereich (26) und dem Spitzenbereich (24) der Elektrode
(14) positioniert ist.
5. Katheteranordnung nach einem der Ansprüche 1 bis 4, bei der die interaktive Fläche
(30) ein lichtbrechendes Medium aufweist.
6. Katheteranordnung nach Anspruch 5, bei der das lichtbrechende Medium eine verspiegelte
Oberfläche aufweist.
7. Katheteranordnung nach einem der Ansprüche 1 bis 6, bei der der Emitter (34) und der
Empfänger (32) benachbart zueinander und paarweise ausgebildet sind.
8. Katheteranordnung nach Anspruch 1, mit einem Lumen (66, 68), das innerhalb des Körpers
des Katheters (12) vorgesehen ist, wobei mindestens ein Bereich des Lumens (66, 68)
sich in die Elektrode (14) erstreckt zum Aufnehmen von mindestens einer Erfassungskomponente
und/oder mindestens einer erregenden Komponente.
9. Katheteranordnung nach Anspruch 8, bei der die Erfassungskomponente ausgewählt ist
aus einem thermischen Sensor, einem Drucksensor, einem Gewebesensor, einem Elektrogrammsensor
und Kombinationen davon.
10. Katheteranordnung nach einem der vorangegangen Ansprüche, bei der der optische Sensor
(16) angepasst ist zum Messen eines Parameters, der ausgewählt ist aus der Gruppe:
Intensität, Wellenlänge, Phase, Spektrum, Geschwindigkeit, optischer Weg, Interferenz,
Übertragung, Absorption, Reflektion, Refraktion, Beugung, Polarisierung und Streuung.
11. Optisch basiertes Kathetersystem (100) mit:
einer Katheteranordnung gemäß einem der vorangegangenen Ansprüche,
einer Licht- oder Energiequelle;
einem Prozessor (110, 120),
einer Katheterabbildungseinheit (140) zur Verwendung bei der Abbildung oder Visualisierung
des Katheterorts; und
einer Faseranordnung zum Transportieren von Lichtenergie, die ausgesendet, durch die
optische interaktive Fläche reflektiert und von dem optischen Sensor empfangen wird.
1. Assemblage de cathéter comprenant :
un assemblage de détection de contact (10) comprenant
un cathéter (12) comprenant un corps ayant une extrémité proximale (22) et une extrémité
distale (20) et abritant un capteur optique (16) ;
une électrode (14) comprenant une partie de pointe (24), une cavité d'électrode (36)
et une partie de base (26) ; dans lequel l'extrémité distale (20) du cathéter comprend
un élément d'accouplement (50) comprenant une partie de col (52) et un arbre de montage
(54), (52), dans lequel la partie de col (52)
comprend une partie élastique (60), dans lequel la partie de base (26) de l'électrode
(14) est configurée pour être reçue par la partie de col (52), dans lequel une extrémité
distale du capteur optique (16) est configurée pour être couplée à l'élément d'accouplement
(50) et positionnée à proximité de la partie élastique (60) et à proximité de la partie
de base (26) de l'électrode (14), l'électrode (14) comprend
une surface optiquement interactive (30) qui est prévue sur une partie de l'électrode
(14) qui interagit avec le capteur optique (16), dans lequel la partie élastique (60)
est adaptée pour se déplacer par rapport à une force externe exercée sur l'électrode
(14) de telle sorte qu'au moins une partie de l'extrémité distale (20) de cathéter
(12) fléchit et/ou se plie par rapport à l'électrode (14),
dans lequel le capteur optique (16) comprend un émetteur (34) et un récepteur (32).
2. Assemblage de cathéter selon la revendication 1, dans lequel une pluralité de capteurs
optiques (16) sont fournis par paires séparées autour de la paroi périphérique d'un
câble à fibres optiques (38), de sorte que chaque émetteur (34) interagit de manière
opérationnelle avec un récepteur (32) correspondant.
3. Assemblage de cathéter selon la revendication 2, dans lequel le câble à fibres optiques
(38) comprend au moins une lumière (42) et une paroi périphérique (40) entourant la
lumière (42), dans lequel le capteur optique est connecté à la paroi périphérique
(40).
4. Assemblage de cathéter selon la revendication 3, dans lequel l'électrode (14) comprend
la lumière (42) pourvue d'une cavité interne de l'électrode (14), la lumière (42)
étant positionnée de manière adjacente à la partie de base (26) et à la partie de
pointe (24) de l'électrode (14).
5. Assemblage de cathéter selon l'une quelconque des revendications 1 à 4, dans lequel
la surface interactive (30) comprend un milieu réfractif.
6. Assemblage de cathéter selon la revendication 5, dans lequel le milieu réfractif comprend
une surface réfléchissante.
7. Assemblage de cathéter selon l'une quelconque des revendications 1 à 6, dans lequel
l'émetteur (34) et le récepteur (32) sont adjacents l'un à l'autre et sont appariés.
8. Assemblage de cathéter selon la revendication 1, comprenant une lumière (66, 68) disposée
dans le corps du cathéter (12), au moins une partie de la lumière (66, 68) s'étendant
dans l'électrode (14) pour recevoir au moins un composant de détection et/ou pour
recevoir au moins un composant d'excitation.
9. Assemblage de cathéter selon la revendication 8, dans lequel le composant de détection
est choisi parmi un capteur thermique, un capteur de pression, un capteur de tissu,
un capteur d'électrogramme et des combinaisons de ceux-ci.
10. Assemblage de cathéter selon l'une quelconque des revendications précédentes, dans
lequel le capteur optique (16) est adapté pour mesurer un paramètre choisi d'un groupe
constitué d'intensité, de longueur d'onde, de phase, de spectre, de vitesse, de chemin
optique, d'interférence, de transmission, d'absorption, de réflexion, de réfraction,
de diffraction, de polarisation et de diffusion.
11. Système de cathéter à base optique (100) comprenant :
un assemblage de cathéter selon l'une quelconque des revendications précédentes,
une source lumineuse ou d'énergie ;
un processeur (110, 120),
une unité de cartographie de cathéter (140) permettant de cartographier ou de visualiser
l'emplacement de cathéter ; et
un assemblage de fibres servant à transporter l'énergie lumineuse qui est émise, est
réfléchie par la surface optiquement interactive et est reçue par le capteur optique.