U.S. patent application number 10/001560 was filed with the patent office on 2002-06-06 for imaging scope.
Invention is credited to Gravenstein, Dietrich, Lampotang, Samsun, Melker, Richard.
Application Number | 20020068851 10/001560 |
Document ID | / |
Family ID | 21728936 |
Filed Date | 2002-06-06 |
United States Patent
Application |
20020068851 |
Kind Code |
A1 |
Gravenstein, Dietrich ; et
al. |
June 6, 2002 |
Imaging scope
Abstract
The subject invention pertains to a system for imaging the human
airway having highly advantageous optical, mechanical, ergonomical
and physical characteristics. In a specific embodiment, the human
airway can be imaged during the intubation procedure. The subject
imaging scopes can incorporate a malleable stylet which its shape
when bent, in order to facilitate intubation of a patient. In a
preferred embodiment, a solid metal stylet, for example, a
conventional endotracheal tube stylet, can be utilized. In a
specific embodiment the subject intubation scope allows for a user
to utilize conventional techniques for the insertion of an
endotracheal tube, reducing the training needed for use of the
subject intubation scope. Preferably, the subject imaging scopes
also incorporate at least one illumination fiber to convey light to
the distal tip of the subject imaging scopes, for illumination of
the objects to be imaged.
Inventors: |
Gravenstein, Dietrich;
(Gainesville, FL) ; Lampotang, Samsun;
(Gainesville, FL) ; Melker, Richard; (Gainesville,
FL) |
Correspondence
Address: |
SALIWANCHIK LLOYD & SALIWANCHIK
A PROFESSIONAL ASSOCIATION
2421 N.W. 41ST STREET
SUITE A-1
GAINESVILLE
FL
326066669
|
Family ID: |
21728936 |
Appl. No.: |
10/001560 |
Filed: |
October 23, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10001560 |
Oct 23, 2001 |
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09007939 |
Jan 16, 1998 |
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09007939 |
Jan 16, 1998 |
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PCT/US97/17954 |
Oct 6, 1997 |
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PCT/US97/17954 |
Oct 6, 1997 |
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08725779 |
Oct 4, 1996 |
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Current U.S.
Class: |
600/121 ;
600/146 |
Current CPC
Class: |
A61B 1/05 20130101; A61B
1/07 20130101; A61B 1/00165 20130101; A61B 1/042 20130101; A61B
1/2676 20130101 |
Class at
Publication: |
600/121 ;
600/146 |
International
Class: |
A61B 001/00 |
Claims
We claim:
1. An imaging stylet comprising: a malleable stylet having a
longitudinal axis and a proximal end and a distal end; a flexible
image guide having a longitudinal axis and a proximal end and a
distal end, said image guide being connected to said stylet such
that a portion of said image guide runs parallel to a portion of
said stylet along the longitudinal axis of said stylet and such
that the distal end of said image guide is co-extensive with the
distal end of said stylet; means for viewing an image, said viewing
means being connected to the proximal end of said image guide; at
least one flexible illumination fiber having a proximal end and a
distal end, said illumination fiber being connected to said stylet
such that a portion of said illumination fiber runs parallel to a
portion of said stylet along the longitudinal axis of said stylet
and such that the distal end of said illumination fiber is
co-extensive with the distal end of said stylet; and a removable
sheath having a longitudinal axis and at least one open end, said
sheath disposed around the distal ends of said stylet, said image
guide, and said illumination fiber such that the longitudinal axis
of said sheath substantially coincides with or is parallel with the
longitudinal axis of said stylet.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of co-pending patent
application Ser. No. 09/007,939, filed Jan. 16, 1998; which is a
continuation-in-part of co-pending patent application Ser. No.
PCT/US97/17954, filed Oct. 6, 1997; which is a continuation of
patent application Ser. No. 08/725,779filed Oct. 4, 1996.
BACKGROUND OF THE INVENTION
[0002] This invention relates to fiber optic imaging scopes and, in
a particular embodiment, to intubation scopes. The subject
intubation scopes can incorporate a malleable stylet, which can
retain its shape when bent, to facilitate intubation.
Advantageously, this invention can utilize plastic optical fibers
to enhance the safety and efficacy of procedures performed with
these novel fiber optic scopes, while simultaneously reducing the
costs. Additionally, the scopes of the subject invention can,
optionally, utilize a sheath which can reduce the amount of
cleaning, i.e., sterilization, required between uses and thereby
reduce the costs of use.
[0003] It is frequently necessary in medical procedures to insert
an endotracheal tube into the trachea of a patient for the purpose
of performing diagnostic tests or for the introduction of some
means of ventilation, oxygenation, and/or airway protection. Even
in the best situations, intubation is often difficult and can give
rise to complications. In many patients, establishment of the
airway is particularly difficult due to morphologic anomalies such
as a large tongue, excessive pharyngeal or laryngeal soft tissue,
or tracheal displacement, as well as physiologic events such as
laryngospasm, regurgitation of gastric materials, bleeding, or
foreign bodies aspiration. These morphologic anomalies and/or
events make it difficult to visualize the posterior pharyngeal area
and larynx with conventional laryngoscopic maneuvers. In emergency
situations, attempts to intubate such patients are difficult and
time consuming. Inability to expeditiously intubate the patient and
protect the airway can lead to significant hypoxemia, myocardial
ischemia, and brain injury. Cases of death have also been related
to complications caused by the inability to quickly and clearly see
the larynx and trachea.
[0004] Proper intubation requires positioning the tip of the
tracheal tube within the trachea, midway between the patient's
vocal cords and carina. Direct laryngoscopy in many instances is
sufficient to intubate the patient, but does not permit the precise
confirmation of tip location or tracheal inspection.
[0005] If the tracheal tube is not inserted far enough past the
vocal cords, the tube may become dislodged and prove to be
ineffective in supporting adequate artificial ventilation. Further,
the tube may inadvertently end up in the esophagus. Esophageal
intubations, resulting from either dislodgement or incorrect
initial placement have led to severe morbidity and even death. At
the other extreme, if inserted too far and beyond the carina, the
tube may only permit ventilation of one lung (as opposed to both
lungs). Thus, correct tube placement is essential in order to
properly ventilate the patient.
[0006] Even the most skilled anesthesiologist may encounter what is
commonly referred to as a "difficult" airway. This occurs in about
5% of all operating room intubations, with an even higher incidence
of an inability to fully visualize the glottic opening. The
incidence level is significantly higher in other areas of the
hospital and prehospital environment. Although presurgical
examination of the jaw, teeth, mouth opening and neck motion
assists in gauging the degree of difficulty likely to be
encountered at intubation, not all difficult intubations can be
identified in advance. There is always the unexpected difficult
airway, discovered only at the time of intubation. In emergency
situations, there is little if any time to perform an airway
assessment prior to attempting intubation. Thus, all emergency
intubations are considered "difficult" intubations.
[0007] There are a number of techniques used to assist in difficult
intubations. These include laryngoscopy, with or without axial
cervical stabilization, fiberoptic bronchoscopy, with or without a
transtracheal retrograde wire guide, blind nasal and the lighted
stylet techniques.
[0008] Fiberoptic bronchoscopy is considered by many as the "gold
standard" for viewing the airway and properly positioning a
tracheal tube. The complexity of operating and cost of buying,
maintaining, cleaning, and repairing existing glass fiberoptic
systems, which are fragile, are major factors preventing greater
usage of bronchoscopy.
[0009] The retrograde wire technique involves placing a needle into
the cricothyroid space and advancing a guide wire through the
needle and upward through the glottic opening between the vocal
cords and pharynx until it emerges from the nose or mouth. After
the wire is localized, a fiberoptic bronchoscope or tracheal tube
is advanced over the wire into the larynx. This technique is not
recommended in emergency situations. Major negative concerns
associated with this technique are its invasive nature and the risk
for bleeding and infection in the trachea. The wire can also cause
injury to the tracheal tissue and/or vocal cords.
[0010] A lighted stylet is essentially a standard stylet with a
bright light at the distal end. This technique provides only
indirect transcutaneous illumination of the trachea. Direct
visualization is not possible when using a lighted stylet.
[0011] Fiberoptic intubating scopes with cameras and/or eyepieces
for viewing that which is illuminated by the fiber optic system
have previously been described. See, for example, U. S. Pat. Nos.
3,776,222; 4,742,819; 4,846,153 and 5,363,838. Current fiber optic
scopes, for example, intubation scopes and associated systems for
imaging the human airways, typically use glass optical fibers.
Unfortunately, these intubation scopes and associated systems
utilizing glass optical fibers are expensive to purchase, clean,
and store. Additionally, the glass optical fibers within these
scopes are prone to breaking thereby shortening the life of the
scopes.
BRIEF SUMMARY OF THE INVENTION
[0012] The subject invention pertains to a system for imaging the
human airway having highly advantageous optical, mechanical,
ergonomical and physical characteristics. The subject system allows
for a user to utilize conventional techniques for the insertion of
an endotracheal tube while using the subject imaging scope. The
excellent characteristics of the imaging system of the subject
invention result, in part, from the use of plastic optical fibers.
Plastic optical fibers are more robust than the glass optical
fibers used in currently available imaging systems, and are
therefore capable of being bent and/or twisted with virtually no
concern of breakage. In addition, the lower costs of plastic
optical fibers enables scopes of the subject invention, in a
specific embodiment, to be manufactured for single patient use
thereby eliminating the requirement for cleaning, special care, the
maintenance of expensive inventory, and most importantly
eliminating the opportunity for cross contamination between
patients. A further aspect of the subject invention concerns a
novel sheath which can cover all or a portion of the parts of the
imaging system which enter the patient. This sheath can reduce the
need for expensive sterilization of the subject intubation scope
after use.
[0013] An embodiment of the subject imaging system utilizing
plastic optical fiber is highly advantageous because of its longer
life, increased ruggedness, greater flexibility, comparable image
quality, optional disposability, and lower cost, compared to glass
scopes. These scopes are useful, for example, for observing the
bronchi of the lungs, locating the tracheal opening to allow
insertion of an endotracheal tube into the trachea for intubation,
and visually locating the endotracheal tube tip. Specifically,
using a scope of the subject invention, a practitioner can easily
and precisely identify the exact location of the distal end of the
tracheal tube, as well as the various anatomical airway landmarks.
Currently, this degree of precision is only possible with an
expensive glass fiberoptic bronchoscope. In addition, the scopes of
this invention are particularly advantageous for use in
anesthesiology.
[0014] In a specific embodiment, the subject imaging system can
incorporate a malleable stylet which can retain its shape when
bent. This embodiment can be used as an intubation scope. During an
intubation, an anesthesiologist can insert the subject intubation
scope into an endotracheal tube to be inserted into a patient. Once
the intubation scope is inserted into the endotracheal tube, the
anesthesiologist can bend the intubation scope-endotracheal tube
combination into a shape, essentially any shape, which facilitates
insertion into the patient. Advantageously, the anesthesiologist
can then hold the scope-tube combination in one hand, with a
conventional grip, for example in a pen-like fashion, and easily
maneuver the scope-tube combination during insertion into the
patient.
[0015] While prior art scopes have required the anesthesiologist to
change the standard procedure for inserting an endotracheal tube,
for example by holding on to the scope and/or manipulating a handle
on the scope to direct the tip of the scope, an anesthesiologist
using the subject scope can hold the endotracheal tube in the
conventional manner during intubation. This is an important
improvement over the prior art because anaesthesiologists are not
necessarily trained in endoscopy and without such additional
training, would not normally be adept with the techniques for use
of such prior scopes. The subject technology can therefore be
referred to as a transparent technology, due to the minimal
instruction needed before use thereof. Specifically, the subject
invention allows an anaesthesiologist to hold the scope-tube
combination with one hand during intubation and, for example, use a
laryngoscope with the other hand, if necessary. In addition, the
subject intubation scopes can be removed from the endotracheal
tube, after insertion, with only one hand, thus freeing the
anaesthesiologist's other hand. This is in contrast to many prior
art scopes which require two hands for use, for example due to a
twist motion needed to unlock the scope from the endotracheal
tube.
[0016] In a specific embodiment, the subject invention pertains to
a plastic optical fiber imaging scope, having an optional sheath,
for intubation. This intubation scope can be used for intubation of
patients under general and/or local anesthesia. The intubation
scope of this embodiment can be disposable, sterilizable for reuse,
or enclosed within a disposable sheath for reuse without expensive
sterilization. Due to lower cost for the plastic optical fiber
scopes, the scopes of the subject invention are particularly
advantageous for situations calling for disposable scopes, and can
be less expensive than the cleaning and sterilization costs for
existing glass scopes.
[0017] Imaging scopes with varying components and corresponding
performance capabilities can be manufactured with this new
technology. By way of these multiple embodiments, the subject
invention can be used for imaging essentially all of the airway
system of humans and animals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 shows an embodiment of the intubation scope of the
subject invention.
[0019] FIGS. 2A and 2D illustrate a longitudinal cross section and
a transverse cross section, respectively, of the distal end of a
sheath designed to fit over a plastic optical fiber image
guide.
[0020] FIGS. 2B and 2E illustrate a longitudinal cross section and
a transverse cross section, respectively, of the distal end of a
sheath designed to fit over a plastic optical fiber image guide,
wherein the sheath comprises an illumination fiber.
[0021] FIGS. 2C and 2F illustrate a longitudinal cross section and
a transverse cross section, respectively, of the distal end of a
sheath designed to fit over a stylet incorporated with a plastic
optical fiber image guide, wherein the sheath comprises an
illumination fiber.
[0022] FIG. 3 illustrates markings and a hollow channel for
ventilation, suction, and/or irrigation, in accordance with the
subject invention.
[0023] FIGS. 4A and 4D illustrate a longitudinal cross section and
a transverse cross section, respectively, of the distal end of an
embodiment of the subject invention comprising a stylet, an image
guide, at least one illumination fiber, and rings to hold the
components together.
[0024] FIGS. 4B and 4E illustrate a longitudinal cross section and
a transverse cross section, respectively, of the distal end of an
embodiment of the subject invention comprising a stylet, an image
guide, at least one illumination fiber, and an outer covering to
hold the components together.
[0025] FIGS. 4C and 4F illustrate a longitudinal cross section and
a transverse cross section, respectively, of the distal end of a
flexible embodiment of the subject invention comprising an image
guide, at least one illumination fiber, and an outer covering to
hold the components together.
[0026] FIG. 5 illustrates a specific embodiment of the subject
invention comprising an image guide, at least one illumination
fiber, and a stylet made of multiple wire strands.
[0027] FIG. 6 illustrates an embodiment of the subject invention
wherein an image guide, an illumination fiber(s), and a hollow
channel are housed within a malleable stylet.
[0028] FIG. 7 illustrates a preferred embodiment of the subject
invention incorporating an image guide, an illumination fiber(s),
and a malleable stylet, held together by an outer covering.
DETAILED DISCLOSURE OF THE INVENTION
[0029] The subject invention utilizes optical fiber to produce
fiber optic scopes, and in a particular embodiment, intubation
scopes, for use in imaging the human airway. In a preferred
embodiment, the subject invention utilizes plastic optical fiber.
The device of the subject invention can assist practitioners in
properly introducing and confirming the position of tracheal tubes.
Although the device has application in "difficult" intubations, use
in all intubations is envisioned for confirming optimal tracheal
tube advancement between the vocal cords and positioning within the
trachea. This can only be achieved with direct tracheal
visualization. The plastic fiberoptic device of the subject
invention makes this possible while also being highly cost
effective.
[0030] The device of the subject invention has application for
intubating patients undergoing general, intravenous and local
anesthesia and in emergency situations. Thus, the device can be
used in surgical procedures as well as in intensive care units,
emergency departments and the prehospital settings.
[0031] The device of the subject invention can incorporate plastic
fiberoptic technologies, enabling direct visualization of the
pharynx, glottic opening, larynx and trachea and thus, facilitate
accurate tracheal tube placement and periodic verification of
tracheal tube tip location. Further, the subject device can easily
be steered, simplifying proper tube placement. Traditional reusable
glass fiber bronchoscopes are expensive to purchase and maintain.
Effectively cleaning the bronchoscope is difficult. It is also
recognized that sterility of existing reusable glass fiber
bronchoscopes is often not achieved after use with a patient.
[0032] The subject invention achieves substantial improvements in
performance compared to existing glass fiber scopes, including: (1)
longer life; (2) increased ruggedness; (3) greater flexibility; (4)
optional disposability; (5) greater ease of use; and (6) less
expense. By varying the components of the intubation scopes
utilizing the teachings of the subject invention, these performance
characteristics can be optimized, to facilitate the use of these
scopes for imaging a vast portion of the human airways and in a
variety of situations. Thus, the scopes of the subject invention
can be used, for example, for observing the bronchi of the lungs,
locating the tracheal opening to allow insertion of an endotracheal
tube into the trachea for intubation, and locating the endotracheal
tube tip. In particular, an anesthesiologist can, using the scope
of the subject invention, stand behind the head of a patient while
performing an intubation. Additionally, this device will reduce the
force necessary for laryngoscopy. Reduced force leads to less
tissue trauma, hemodynamic changes, and post-operative sore throat
complications. Advantageously, the scopes of the subject invention
are more cost effective in situations requiring a disposable scope
and/or can be used with an optional disposable sheath to enclose
the portion of the scope entering the body to reduce cleaning and
sterilization costs.
[0033] In one embodiment the light source can be derived from a
standard laryngoscope. In a second embodiment, one or more optical
fiber(s) can transmit the light required to illuminate the airway.
The source of the light can be, for example, a laryngoscope or an
inexpensive separate light source.
[0034] Image guides used in conjunction with intubation, for
example, bronchoscopes, are typically made with step index glass
optical fiber. Plastic optical fiber can also be fabricated with a
step index of refraction. Both plastic and glass step index fibers
are constructed with a core of refractive index n.sub.1, and a
cladding of refractive index n.sub.2 where n.sub.1>n.sub.2. A
second type of fiber is known as gradient index or graded index
fiber and can also be made with plastic or glass. Since flexibility
is an important characteristic for the scopes of the subject
invention, plastic gradient index optical fibers are preferred over
glass gradient index optical fibers for the subject image
guides.
[0035] In comparing the step index structure with the gradient
index structure, it is noted that there are different trajectories
of light rays in these two fiber structures. Within step index
fiber, the light travels in straight lines, and is reflected at the
core-cladding interface. While in gradient index fiber, the light
travels in a curved trajectory always being refracted back towards
the axis of the fiber. As a consequence, an image can be conveyed
within a single gradient index fiber, while an image cannot be
conveyed within a single step index fiber. Although, when conveying
an image in a single gradient index fiber, some correction may be
required to correct aberrations in the output image, for example,
by using one or more negative gradient index lens attached to one
or both ends of the single gradient index fiber.
[0036] Referring to FIG. 1, the intubation scope of the subject
invention comprises an image guide 1, which conveys optical images
from inside the body, for example from inside the human airways, to
outside of the body for viewing by a medical caregiver. In a
specific embodiment, this image guide 1 can comprise a single
gradient index plastic optical fiber. In a specific embodiment,
this single fiber can have a diameter, for example, of about 0.5 to
2.0 mm. A focusing lens 2 can optionally be used to focus the
desired image into the distal tip 7 of the single fiber, the distal
tip 7 entering the body, generally through the mouth or nose. This
lens 2 can be attached by, for example, optical glue, and can act
as a bi-convex lens to focus the desired image onto the distal tip
of the single fiber. In this single fiber embodiment, a negative
gradient rod lens, made of glass or plastic, can be attached to the
proximal end of the single fiber image guide 1 and used to correct
for aberrations resulting from the use of a single gradient index
plastic optical fiber to carry the image.
[0037] In an alternative embodiment, this image guide 1 can
comprise a bundle of plastic optical fibers. This plastic fiber
optic image guide 1 can be made of a plurality of individual
plastic optical fibers which have been fused together. In a
specific embodiment, this bundle can comprise approximately 10,000
individual plastic optical fibers, wherein the bundle is
approximately 1.0 millimeter in diameter. This bundle can comprise
gradient index plastic optical fibers and, in a preferred
embodiment, this bundle can comprise step-index plastic optical
fibers. Each end of the bundle can be polished to allow high
resolution imaging. A focusing lens 2 can be used to focus the
desired image onto the distal tip 7 of the bundle, the distal tip 7
entering the human body, generally through the mouth or nose. This
lens 2 can be attached at the distal tip 7 of the bundle, for
example, by optical glue 4. This lens 2 can act like a bi-convex
lens to focus the image onto the distal tip of the fiber optic
bundle. In a preferred embodiment, the lens 2 can be a
gradient-index glass rod lens. In a more preferred embodiment, the
lens 2 can be a gradient-index plastic rod lens.
[0038] An optical system can transmit the image from the proximal
end of the fiberoptic image guide 1 onto a charge coupled device
(CCD). The CCD can be used to convert the image into an electrical
signal which can be displayed on a monitor. Alternatively, camera
equipment available to the physician can be used. In a specific
embodiment, the proximal tip 8 of the image guide 1 is arranged so
that the image from inside the patient is focused directly onto an
imaging eyepiece 6. The imaging eyepiece 6 can be connected to a
camera for viewing the image, or the image can be viewed directly
by the medical caregiver through the imaging eyepiece 6.
[0039] In an alternative embodiment, when a camera is not to be
used for viewing the image, a second lens 3 can be attached, for
example, by optical glue 5, to the proximal tip 8 of the image
guide 1, the proximal tip remaining outside of the body. This lens
can be, for example, a mini plastic lens microscope connected
directly to the proximal end of the fiber scope for direct viewing
by the caregiver, i.e., by placing an eye to the microscope lens.
In a specific embodiment, the fiberoptic image guide can be
lengthened and mini plastic lens microscope can be mounted on a
caregiver's head, for example, by a mounting means such as a pair
of glasses or goggles. This allows the caregiver to have both hands
free to perform, for example, an intubation, while being able to
view the patient and the image from the scope without having to
turn his or her head.
[0040] Manufacturing the subject invention without a camera can be
done to reduce costs or to meet the needs of certain medical
situations. However, when the eyepiece is connected to a camera,
the image can be displayed via, for example, a television monitor.
This monitor can be, for example, placed out of the sterile field
for viewing.
[0041] In a specific embodiment, the visualization system scope of
the subject invention can be inserted into a plastic tube (sheath),
which can have a transparent end plate. This combination can then
be used for imaging the airway. The image viewed through the end
plate is unimpaired by the sheath or end plate. The advantage of
this sheath is that it is disposable and allows the intubation
scope to be reused with minimal sterilization.
[0042] In a preferred embodiment, the sheath can have at least one
internal, or external, illuminating optical fiber(s) which
transmits light to illuminate the internal body structure to be
imaged. Additionally, it is preferred but not essential, that there
be no transparent end plate at the distal end of the illuminating
optical fiber(s) to avoid the illuminating light reflecting at such
a plate and impairing the quality of the image. A longitudinal
cross section and a transverse cross section of a sheath comprising
an external illumination fiber are shown in FIGS. 2B and 2E,
respectively.
[0043] When performing, for example, an intubation, a malleable
stylet, typically made of metal, is often used in conjunction with
an endotracheal tube to facilitate the placement of the tube into
the body. In a specific embodiment, the subject intubation scope
can incorporate a stylet, wherein the stylet can be bent into the
shape which the caregiver believes will facilitate the easiest and
safest placement of the endotracheal tube, and then the
endotracheal tube, which typically surrounds the stylet and scope,
can be inserted into the patient. A longitudinal cross section and
a transverse cross section of a sheath comprising an external
illumination fiber, where the sheath is designed to fit over a
stylet incorporated with a plastic optical fiber image guide, are
shown in FIGS. 2C and 2F, respectively. In this case, the sheath
and illuminating fiber could be regarded as disposable after a
single use.
[0044] Accordingly, the intubation scope and/or sheath of the
subject invention can comprise such a stylet, such that many
combinations of scope, stylet, illuminating fiber(s), and sheath
are possible. In accordance with the subject invention, the
combination of an image guide and a malleable stylet, which retains
its shape when bent, facilitates the placement of an endotracheal
tube into a patient. In a preferred embodiment, a solid metal
stylet, for example a conventional endotracheal tube stylet, can be
utilized. The image guide can be attached to the stylet such that
the image guide takes essentially the same shape as the stylet when
the stylet is bent. In a specific embodiment, referring to FIG. 6,
the image guide can be incorporated into the stylet. Accordingly,
the stylet-image guide combination, i.e., the intubation scope, can
be inserted into an endotracheal tube which is to be inserted into
a patient. In a more preferable embodiment, the intubation scope
can also comprise an illumination fiber, for example also attached
to the stylet. Once the intubation scope is inserted into the
endotracheal tube, a caregiver can bend the endotracheal tube into
the shape, essentially any shape, which the caregiver believes will
facilitate the easiest and safest insertion of the endotracheal
tube. In fact, a caregiver can insert the tube-scope combination
into a patient using one hand to hold and maneuver the tube-scope
combination. Once the tube-scope combination is in place in the
patient, a caregiver can, again with one hand, remove the subject
intubation scope from the endotracheal tube.
[0045] A variety of attachment means can be utilized in accordance
with the subject invention to attach the stylet, image guide,
and/or illuminating fiber. It is preferred that the relative
position of the distal tip of the image guide and the distal tip of
the illumination fiber remain fixed, both in angular orientation
and axial translation, in order to enhance the quality of the
image. In addition, it is preferred that the relative position of
the distal end of the stylet also remain fixed with respect to the
distal tip of the image guide.
[0046] Referring to FIGS. 4A and 4D, a specific embodiment of the
subject invention is shown where the distal ends of a stylet, an
image guide, and an illumination fiber are securely attached to
each other via an attachment means, for example with glue or a
clip. This embodiment also includes rings, for example made of an
appropriate elastic material, which hold the various components
together along the length of the intubation scope. These rings can
allow for slippage of the various components, for example during
the bending of the intubation scope, while maintaining the relative
positions of the distal ends of the various components.
[0047] Alternatively, referring to FIGS. 4B and 4E, an outer
covering can be used to hold the various components together. This
outer covering can be made of a material, for example a polymer,
which can alter, either increase or reduce, the friction between
the subject intubation scope and the inside of an endotracheal
tube. For example, reduced friction can facilitate the removal of
the subject intubation scope after intubation of a patient. Again,
it is preferred that the relative positions of the distal ends of
the various components remain constant. In an additional
embodiment, a transparent end covering can be utilized to cover the
distal tip of the intubation scope.
[0048] FIGS. 4C and 4F show an embodiment of the subject invention
which can be referred to as a noodle. This embodiment does not
incorporate a stylet and, therefore, can be useful, for example,
for nasal intubations. This embodiment can also be used, for
example, to check the position of the distal tip of an endotracheal
tube which is in place in a patient.
[0049] Stylets of various cross-sectional shapes can be used in
accordance with the subject invention. A variety of materials for
producing the stylet are also envisioned within the scope of the
subject invention, for example polymers, metals, or other materials
having the proper physical characteristics. It is important for the
stylet to be malleable such that the stylet can be bent and will
retain its shape when bent. Preferably, the subject stylet can be
bent easily by a user into essentially any shape which will
facilitate the insertion.
[0050] In addition, the subject intubation scopes can have a
coating, for example a polymer coating. In a specific embodiment,
this coating can be placed around a solid cylindrical rod made of a
malleable metal. The coating can be used to modify friction between
the endotracheal tube and the subject scope so as to optimize
movement of the scope within the tube. For example, a low friction
coating may decrease friction between the scope and the
endotracheal tube so as to ease withdrawal of the scope from the
tube. Various cross-sectional shapes for the subject intubation
scopes are also possible. For example, referring to FIG. 5, the
subject scope can incorporate a stylet comprising multiple, thinner
rods which can be positioned circumferentially around the image
guide. If illumination fibers are utilized, these illumination
fibers can also be positioned circumferentially around the image
guide, for example interspaced with the multiple rods of the
stylet. In addition, a coating and/or an outer covering can be
applied to the outside of the intubation scope to assist in holding
the multiple stylets and multiple illumination fibers to the side
of the image guide. This coating may allow for reuse of the subject
scope, for example after cleaning.
[0051] In an additional embodiment, referring to FIG. 6, an outer
covering around the subject image guide can act as a stylet, for
example if the outer coating is malleable and retains its shape
when bent. The embodiment shown in FIG. 6 comprises a malleable
stylet having hollow channels where an image guide and illumination
fiber(s) can reside. This stylet can, for example, be extruded such
as to have these channels. As also shown in FIG. 6, an additional
channel can be provided for injection, ventilation, suction, and/or
irrigation. In a preferred embodiment, the subject imaging scopes
have no moving parts other than that resulting from bending of the
stylet, image guide, any illumination fibers, and other lumens.
[0052] Preferably, during insertion of an endotracheal tube into a
patient, the distal tip of the image guide can reside near the
distal tip of the endotracheal tube such that a caregiver receives
images from near the distal tip of the endotracheal tube, so as to
facilitate proper placement of the tube. In addition, it is
preferable that the distal tip of the stylet and image guide do not
extend from the distal tip of the tube where they may injure the
trachea or other areas during the insertion of the tube. To prevent
the distal tips of the stylet and image guide from traveling past
the distal tip of the tube, the stylet can be bent near the
proximal end of the tube, for example bent over the proximal end of
the tube. The image guide can be bent as well, for example if
attached to the stylet of the scope at the proximal end of the
tube, or can move independently from the stylet.
[0053] In a preferred embodiment of an intubation scope in
accordance with the subject invention, as illustrated in FIG. 7,
the proximal end of the stylet can terminate, for example in a
loop, at a length slightly longer than an endotracheal tube into
which it is to be inserted. Such a loop can allow a caregiver to
easily grasp the stylet end to bend the stylet end over the
proximal end of the tube. In addition, a looped proximal end of the
stylet can assist in removal of the scope from the tube. For
example, a user can hold the end of the tube with one hand and use
the thumb on the same hand to move the scope out of the tube by
hooking the loop with the thumb. Advantageously, due to the
lightweight image guide and illumination fiber(s), the center of
gravity of the endotracheal tube-intubation scope combination can
be located in essentially the same location along the endotracheal
tube as with a conventional stylet inserted in an endotracheal
tube, such as to provide good balance in the user's hand during
intubation. This allows the center of balance of the tube-scope
combination in a user's hand to remain in essentially the same
position as for a conventional endotracheal tube-stylet
combination.
[0054] In accordance with the subject invention, the ability of a
caregiver to hold the endotracheal tube itself during insertion
into a patient has many advantages. By holding the tube with a
conventional, or pen-like, grip a caregiver can twist or rotate the
tube, as well as move it translationally, with more leverage than
if held by, for example, a scope inserted into the tube. During the
insertion, a caregiver can view the image from the image guide on,
for example, a monitor, without the need to view the patient
directly.
[0055] In addition, the ability to bend the scope-tube combination
in essentially any shape prior to insertion of the tube into a
patient can reduce the risk of injury to a patient whose anatomy
may require a tailored bend. Advantageously, insertion of the tube
can then be performed on a patient in the neutral position. Prior
art devices have required the patient to be in a "sniffing"
position or to have the head tilted back to create a straighter
insertion channel, due in part to the stiffness and limited range
of motion of the prior devices. Insertion of the tube while a
patient is in the neutral position, as opposed to the sniffing or
head-tilted-back positions, results in reduced increases in blood
pressure, heart rate, and reduced injury to the treachea. In
addition, the ability to bend the scope-tube combination in
essentially any shape allows the tube to be preformed to a shape
tailored specifically to a patient, prior to insertion of the tube.
This allows insertion of the scope-tube combination while a patient
is in the neutral position, and can thus eliminate the need for a
laryngoscope to elevate tissues. If preferred, a laryngoscope can
be used to move the tongue out of the way such that the tube-scope
combination can be inserted. However, there is no need to use the
laryngoscope to further elevate tissues, for example to see the
larynx. The subject tube-scope is preferably rigid enough so that a
laryngoscope is not necessary. The scope can sweep the tongue away,
eliminating the need for a laryngoscope, thus reducing
complications, such as chipped teeth. In addition, less force can
be applied, reducing injuries. This allows intubation to be
performed while a patient is awake or asleep, in an elective or
emergency situation. In addition, the ability to intubate a patient
in the neutral position can prevent further injury to a patient
with, for example, known or possible neck or spine injuries.
Patients with known or possible cervical spine instability or
fused/fixed spine can be intubated and/or examined without having
to be moved.
[0056] In a specific embodiment in accordance with the subject
invention, an intubation scope can have a removable stylet. The
stylet can be removed to perform, for example, nasal intubation or
stoma/tracheotomy. In addition, this embodiment can allow for
insertion of an endotracheal tube, utilizing the intubation scope
with the stylet attached, and the subsequent verification of the
tube's position, utilizing the intubation scope with the stylet
removed. In another embodiment, the subject scope can have no
stylet. This embodiment can be useful for confirmation of the
endotracheal tube location and inspection of patients' tissues and
structures, for example to reduce the need for x-rays. FIGS. 4C and
4F illustrate one such embodiment.
[0057] In a specific embodiment of the subject intubation scope, a
charge-coupled device (CCD) can be mounted at the distal tip of the
stylet, which can eliminate the necessity for an optical fiber
image guide. The signal generated from the CCD can be carried, for
example via wires, to a camera external to the endotracheal tube.
This camera can be located in any position which allows a caregiver
to conveniently view the camera during intubation of the patient.
In a further embodiment, the CCD and camera can be located at the
proximal end of the stylet, such that an image is carried from the
distal tip of the endotracheal tube to the CCD by an image guide
during intubation.
[0058] Once the subject intubation scope is inserted into an
endotracheal tube and secured in place, for example by bending the
proximal end of the stylet over the proximal end of the
endotracheal tube, the image carried from the distal tip of the
image guide to the proximal end of the image guide needs to be
viewed by the caregiver. In a preferred embodiment, the proximal
end of the image guide can terminate with a quick-connect connector
such that the proximal end of the image guide can easily plug into
a device for receiving and displaying the image. Quick-connect
connectors are particularly advantageous when a plastic optical
fiber image guide and plastic optical fiber illumination fibers are
utilized, due to greater misalignment tolerances than with glass
optical fiber. The proximal end of any illumination fibers can also
terminate with quick-connect connectors such that easy connection
to an illuminating light source is possible. In a specific
embodiment, slide and lock quick-connect connectors may be
utilized. The use of quick-connect connectors allows for a free
flexible tail and a lightweight intubation scope. The use of slide
and lock quick-connect connectors can assist a caregiver in
maintaining proper orientation of the image being viewed and
prevent the connector from coming loose during operation, thus
enhancing performance.
[0059] A preferred embodiment of an intubation scope in accordance
with the subject invention is illustrated in FIG. 7. The proximal
ends of the illumination fiber and image guide can form a free
flexible tail which is lightweight. Accordingly, after insertion of
the subject intubation scope into an endotracheal tube, the
scope-tube combination can be maneuvered easily and has the same
feel in a user's hand as the conventional tube with a conventional
stylet inserted. The quick-connect connectors can be connected just
before placement of the scope-tube combination into the patient,
allowing the caregiver considerable freedom of maneuverability
while inserting the intubation scope into the endotracheal
tube.
[0060] The intubation scope and method of tracheal tube placement
verification of the subject invention represents a significant cost
saving for the hospital. Rather than having to periodically x-ray
the patient to verify tube position, the hospital staff can use the
subject invention to not only confirm proper tube placement but to
also evaluate the airway for obstruction and/or erosion, which is
not possible with x-rays. Advantageously, the use of the subject
technology can reduce a patients exposure to x-rays.
[0061] The device of the subject invention is easily connected to
bronchoscope imaging equipment, without incurring the cost of
buying and sterilization processing of the bronchoscope. In another
embodiment, an off the shelf LCD device similar to a Sony
"WATCHMAN" can be utilized for imaging.
[0062] Following are examples which illustrate procedures for
practicing the invention. These examples should not be construed as
limiting.
[0063] Example 1
[0064] The device of the subject invention not only makes
intubation easier and more accurate, but also reduces the potential
for inflicting injury with the laryngoscope blade. Using the device
of the subject invention, the practitioner only needs to use the
laryngoscope blade to control the position of the patient's tongue.
The device can also be used without a laryngoscope and for
nasotracheal intubation.
[0065] The device of the subject invention can comprise a bundle of
10,000 individual plastic optical fibers (bundle is approximately
1.0 millimeter in diameter). The resolution of the image is
comparable to an existing glass fiberoptic bronchoscope, providing
good visualization of the patient's airway.
[0066] The manufacturing process places the bundle integral to a
standard malleable stylet. An additional fiber may be used for
illuminating purposes. Suctioning and insufflation can be added by
adding an additional channel if desired.
[0067] A focusing lens (i.e., gradient refractive index lens) is
placed at the distal tip of the optical fibers and acts like a
bi-convex lens to focus the image onto the distal tip of the fiber
optic bundle. An optical system transmits the image from the
proximal end of the fiberoptic bundle onto a charge coupled device
(CCD). The CCD is used to convert the image into an electrical
signal which can be displayed on a monitor. Alternatively, camera
equipment available to the physician may be used.
[0068] Example 2
[0069] Referring to FIGS. 2A, 2B, 2C, 2D, 2E, and 2F, this example
provides three illustrative combinations of image guide,
illuminating fiber, stylet, and/or sheath. FIGS. 2A and 2D
illustrate a longitudinal cross section and a transverse cross
section, respectively, of the distal end of a sheath designed to
fit over a plastic optical fiber image guide. The sheath covers the
distal tip of the image guide with a transparent end plate. In this
case, any illuminating fibers and/or stylets would not be enclosed
within this sheath, although they could have their own sheaths.
[0070] FIG. 2B and 2E illustrate a longitudinal cross section and a
transverse cross section, respectively, of the distal end of a
sheath designed to fit over a plastic optical fiber image guide,
wherein the sheath comprises an illumination fiber. The distal end
of the illumination fiber is not covered by the sheath, in this
example, so as to not impair the image. Accordingly, the
illuminating fiber can be disposed of with the sheath. In this
embodiment, the sheath acts to attach and position the illumination
fiber with respect to the image guide.
[0071] FIGS. 2C and 2F illustrate a longitudinal cross section and
a transverse cross section, respectively, of the distal end of a
sheath designed to fit over a stylet incorporated with a plastic
optical fiber image guide, wherein the sheath comprises an
illumination fiber. The distal end of the illumination fiber is not
covered by the sheath, but the distal end of the image guide plus
stylet is covered. In this embodiment, the stylet can be reused
along with the image guide. Other geometrical arrangements of the
stylet, image guide, and illumination fiber are obviously
possible.
[0072] Example 3
[0073] It is sometimes necessary to replace an endotracheal tube in
a patient, for example when the tube no longer provides an adequate
airway. In a specific embodiment, the subject invention can permit
the easy removal of one endotracheal tube and its replacement with
a new one.
[0074] A device in accordance with the subject invention can be
inserted into the patient's trachea, generally through an existing
tracheal tube, until the distal tip is at or near the tip of the
tube. Oxygen for ventilation, suction or irrigation can also be
applied in succession via, for example, quick fit connectors to the
proximal end if desired. Once the anatomy is visualized, the light
source, camera or eyepiece, and oxygen/suction/irrigation can all
be disconnected from the proximal end of the subject device. The
endotracheal tube can then be completely removed by sliding it out
of the trachea, along, and off the proximal end of the subject
device. The connectors of the subject device can be of a suitable
diameter and located at different positions relative to the
proximal end to permit their passage through the tracheal tube. The
new tracheal tube can be loaded onto the subject device and the
illumination and visualization equipment reconnected. The tracheal
tube can be advanced down into the trachea while observing the
airway anatomy via the subject device. Preferably, the subject
device can be rigid enough to maintain its location in the trachea
as it guides a replacement endotracheal tube into the trachea.
[0075] Alternatively, the image guide and illumination fiber(s) can
remain connected until the endotracheal tube to be replaced has
been slid out of the trachea. This allows continuous monitoring of
the location of the distal tip of the tube exchanger, reducing the
risk of the tube exchanger being dislodged during removal of the
endotracheal tube. Once the tube is completely out of the patient,
the proximal ends of the image guide and illumination fiber(s) can
be disconnected to slide the tube off of the exchanger and slide a
new tube onto the exchanger. The image guide and illumination fiber
can then be reconnected to confirm the position of the exchanger
before and during the placement of the new tube into the
patient.
[0076] In order to utilize the subject invention during the
exchange of an endotracheal tube, the fiber optic bundle can,
preferably, be approximately the same length as a commercially
available endotracheal tube exchanger, for example about 80-100 cm.
In addition, referring to FIG. 3, markings can be provided on its
wall indicating, for example in 5 cm increments, the length from
its distal end to any given mark. This can allow the clinician to
better gauge whether the distal tip is likely to be in the
oropharynx, trachea, bronchus or beyond and can therefore improve
patient safety.
[0077] Example 4
[0078] Referring to FIG. 3, the subject invention, for example the
devices disclosed in the previous examples, can have a hollow
channel of sufficient caliber to provide adequate jet ventilation,
suction and/or irrigation, if desired. Accordingly, if mucus plugs
are visualized they can be suctioned and if secretions obstruct
vision, the lens can be cleaned with irrigation through the hollow
channel. Advantageously, ventilation can be provided through the
hollow channel during the exchanging of endotracheal tubes.
[0079] The subject invention can also incorporate deflection, for
example of about 0-60.degree., between about 1-10 cm from the
distal tip, to allow a clinician to direct the subject device down
either bronchus, towards a mucus plug, or away from the tracheal
wall, simply by rotating the device along its length. This
deflection may be incorporated into a device such that the distal
tip of the subject scope conforms to the shape of an endotracheal
tube while within the tube. When the distal end of the scope is
advanced past the distal end of tube, the tip can assume a
predefined deflection, for example due to memory in the stylet.
[0080] It should be understood that the examples and embodiments
described herein are for illustrative purposes only and that
various modifications or changes in light thereof will be suggested
to persons skilled in the art and are to be included within the
spirit and purview of this application and the scope of the
appended claims.
* * * * *