U.S. patent application number 11/196811 was filed with the patent office on 2005-12-08 for injectable snoring implant.
This patent application is currently assigned to Restore Medical, Inc.. Invention is credited to Conrad, Timothy R., Griffin, Jerry C., Knudson, Mark B..
Application Number | 20050268922 11/196811 |
Document ID | / |
Family ID | 23577668 |
Filed Date | 2005-12-08 |
United States Patent
Application |
20050268922 |
Kind Code |
A1 |
Conrad, Timothy R. ; et
al. |
December 8, 2005 |
Injectable snoring implant
Abstract
A method and apparatus for treating snoring of a patient
includes providing an implant for altering a dynamic response of a
soft palate of the patient to airflow past the soft palate. The
implant is embedded in the soft palate to alter the dynamic
response. For example, the implant has a mass, stiffness or
dampening sufficient to alter the dynamic response following the
implantation without substantially impairing a function of the soft
palate to close a nasal passage of the patient during
swallowing.
Inventors: |
Conrad, Timothy R.; (Eden
Prairie, MN) ; Knudson, Mark B.; (Shoreview, MN)
; Griffin, Jerry C.; (Chicago, IL) |
Correspondence
Address: |
Timothy R. Conrad
MERCHANT & GOULD P.C.
P.O. Box 2903
Minneapolis
MN
55402-0903
US
|
Assignee: |
Restore Medical, Inc.
St. Paul
MN
|
Family ID: |
23577668 |
Appl. No.: |
11/196811 |
Filed: |
August 3, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11196811 |
Aug 3, 2005 |
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10938255 |
Sep 9, 2004 |
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10938255 |
Sep 9, 2004 |
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10629490 |
Jul 29, 2003 |
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10629490 |
Jul 29, 2003 |
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09872545 |
Jun 1, 2001 |
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6626181 |
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09872545 |
Jun 1, 2001 |
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09398991 |
Sep 17, 1999 |
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6250307 |
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Current U.S.
Class: |
128/898 ;
623/23.72 |
Current CPC
Class: |
A61F 5/566 20130101 |
Class at
Publication: |
128/898 ;
623/023.72 |
International
Class: |
A61F 002/02; A61B
019/00 |
Claims
1-13. (canceled)
14. An apparatus to brace or fixate tissue in targeted pharyngeal
structures and/or individual anatomic components within the
pharyngeal conduit comprising a material including one or more
liquid components that is injected into tissue as a liquid or
slurry and that sets in situ to create a non-liquid mechanical
implant structure.
15. A system comprising at least two apparatuses, at least one of
the apparatuses comprising an apparatus as defined in claim 14.
15. A method for implanting an apparatus in targeted pharyngeal
structures and/or individual anatomic components within the
pharyngeal conduit comprising the steps of providing at least one
apparatus as defined in claim 14, and injecting the apparatus in
targeted pharyngeal structures and/or individual anatomic
components within the pharyngeal conduit.
Description
[0001] This application is a continuation of U.S. patent
application Ser. No. 10/629,490 filed Jul. 29, 2003; which is a
continuation of U.S. patent application Ser. No. 09/872,545 filed
Jun. 1, 2001, now U.S. Pat. No. 6,626,181; which is a continuation
of U.S. patent application Ser. No. 09/398,991 filed Sep. 17, 1999,
now U.S. Pat. No. 6,250,307; which applications are incorporated
herein by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention is directed to methods and apparatuses for
treating snoring.
[0004] 2. Description of the Prior Art
[0005] Snoring has received increased scientific and academic
attention. One publication estimates that up to 20% of the adult
population snores habitually. Huang, et al., "Biomechanics of
Snoring", Endeavour, p. 96-100, Vol. 19, No. 3 (1995). Snoring can
be a serious cause of marital discord. In addition, snoring can
present a serious health risk to the snorer. In 10% of habitual
snorers, collapse of the airway during sleep can lead to
obstructive sleep apnea syndrome. Id.
[0006] Notwithstanding numerous efforts to address snoring,
effective treatment of snoring has been elusive. Such treatment may
include mouth guards or other appliances worn by the snorer during
sleep. However, patients find such appliances uncomfortable and
frequently discontinue use (presumably adding to marital
stress).
[0007] Electrical stimulation of the soft palate has been suggested
to treat snoring and obstructive sleep apnea. See, e.g., Schwartz,
et al., "Effects of electrical stimulation to the soft palate on
snoring and obstructive sleep apnea", J. Prosthetic Dentistry, pp.
273-281 (1996). Devices to apply such stimulation are described in
U.S. Pat. Nos. 5,284,161 and 5,792,067. Such devices are appliances
requiring patient adherence to a regimen of use as well as
subjecting the patient to discomfort during sleep. Electrical
stimulation to treat sleep apnea is discussed in Wiltfang, et al.,
"First results on daytime submandibular electrostimulation of
suprahyoidal muscles to prevent night-time hypopharyngeal collapse
in obstructive sleep apnea syndrome", International Journal of Oral
& Maxillofacial Surgery, pp. 21-25 (1999).
[0008] Surgical treatments have been employed. One such treatment
is uvulopalatopharyngoplasty. In this procedure, so-called laser
ablation is used to remove about 2 cm of the trailing edge of the
soft palate thereby reducing the soft palate's ability to flutter
between the tongue and the pharyngeal wall of the throat. The
procedure is frequently effective to abate snoring but is painful
and frequently results in undesirable side effects. Namely, removal
of the soft palate trailing edge comprises the soft palate's
ability to seal off nasal passages during swallowing and speech. In
an estimated 25% of uvulopalatopharyngoplasty patients, fluid
escapes from the mouth into the nose while drinking. Huang, et al.,
supra at 99. Uvulopalatopharyngoplasty (UPPP) is also described in
Harries, et al., "The Surgical treatment of snoring", Journal of
Laryngology and Otology, pp. 1105-1106 (1996) which describes
removal of up to 1.5 cm of the soft palate. Assessment of snoring
treatment is discussed in Cole, et al., "Snoring: A review and a
Reassessment", Journal of Otolaryngoloy, pp. 303-306 (1995).
[0009] Huang, et al., supra, describe the soft palate and palatal
snoring as an oscillating system which responds to airflow over the
soft palate. Resulting flutter of the soft palate (rapidly opening
and closing air passages) is a dynamic response generating sounds
associated with snoring. Huang, et al., propose an alternative to
uvulopalatopharyngoplas- ty. The proposal includes using a surgical
laser to create scar tissue on the surface of the soft palate. The
scar is to reduce flexibility of the soft palate to reduce palatal
flutter. Huang, et al., report initial results of complete or
near-complete reduction in snoring and reduced side effects.
[0010] Surgical procedures such as uvulopalatopharyngoplasty and
those proposed by Huang, et al., continue to have problems. The
area of surgical treatment (i.e., removal of palatal tissue or
scarring of palatal tissue) may be more than is necessary to treat
the patient's condition. Surgical lasers are expensive. The
proposed procedures are painful with drawn out and uncomfortable
healing periods. The procedures have complications and side effects
and variable efficacy (e.g., Huang, et al., report promising
results in 75% of patients suggesting a full quarter of patients
are not effectively treated after painful surgery). The procedures
may involve lasting discomfort. For example, scar tissue on the
soft palate may present a continuing irritant to the patient.
Importantly, the procedures are not reversible in the event they
happen to induce adverse side effects not justified by the benefits
of the surgery.
SUMMARY OF THE INVENTION
[0011] According to a preferred embodiment of the present
invention, methods and apparatuses are disclosed for treating
snoring of a patient. The invention includes providing an implant
for altering a dynamic response of a soft palate of the patient to
airflow past the soft palate. The implant is embedded in the soft
palate to alter the dynamic response. For example, the implant has
a mass, stiffness or dampening sufficient to alter the dynamic
response following the implantation without substantially impairing
a function of the soft palate to close a nasal passage of the
patient during swallowing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a side sectional view of a portion of a human head
showing a soft palate in a relaxed state and in relation in
adjacent anatomical features;
[0013] FIG. 2 is a portion of the view of FIG. 1 showing the soft
palate in a flexed state;
[0014] FIG. 3 is a front view of an interior of the mouth shown in
FIG. 1 and showing an area to be ablated according to a first prior
art surgical procedure;
[0015] FIG. 4 is the view of FIG. 3 and showing an area to be
scarred according to a second prior art surgical procedure;
[0016] FIG. 5 is a schematic representation of a spring-mass system
model of the soft palate;
[0017] FIG. 6 is the view of FIG. 1 with the soft palate containing
an implant according to a first embodiment of the present
invention;
[0018] FIG. 7 is the view of FIG. 3 showing the embodiment of FIG.
6;
[0019] FIG. 8 is a cross-sectional view of the implant of FIG.
6;
[0020] FIG. 9 is a first modification of the implant of FIG. 8
having a tissue in-growth layer;
[0021] FIG. 10 is a second modification of the implant of FIG. 8
having a smooth outer layer;
[0022] FIG. 11 is the view of FIG. 6 with the soft palate
containing an implant according to a second embodiment of the
present invention;
[0023] FIG. 12 is the view of FIG. 7 showing the embodiment of FIG.
11;
[0024] FIG. 13 is a perspective view of the implant of FIG. 11;
[0025] FIG. 14 is a cross-sectional view of the implant of FIG.
13;
[0026] FIG. 15 is a view of the implant of FIG. 14 with the implant
pre-formed to assume the shape of a soft palate in a relaxed
state;
[0027] FIG. 16 is the view of FIG. 14 with the implant constructed
to have greater flexion in a downward direction;
[0028] FIG. 17 is an exploded perspective view of first
modification of the implant of FIG. 13;
[0029] FIG. 18 is a perspective view of a modification of a housing
of the embodiment of FIG. 17;
[0030] FIG. 19 is a side section view of a second modification of
the implant of FIG. 13;
[0031] FIG. 20 is a cross-sectional view of an implant that is
another embodiment of the present invention, the implant is shown
in a flattened orientation;
[0032] FIG. 21 is a cross-sectional view of the implant of FIG. 20
in an expanded orientation;
[0033] FIG. 22 shows the implant of FIG. 20 in the flattened
orientation and implanted in the soft palate; and
[0034] FIG. 23 shows the implant in FIG. 21 in the expanded
orientation and implanted in the soft palate.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0035] For ease of understanding the present invention, the
dynamics of snoring are explained with reference to FIGS. 1-4. The
hard palate HP overlies the tongue T and forms the roof of the
mouth M. The hard palate HP includes a bone support B and does not
materially deform during breathing. The soft palate SP is soft and
is made up of mucous membrane, fibrous and muscle tissue extending
rearward from the hard palate HP. A leading end LE of the soft
palate SP is anchored to the trailing end of the hard palate HP. A
trailing end TE of the soft palate SP is unattached. Since the soft
palate SP is not structurally supported by bone or hard cartilage,
the soft palate SP droops down from the plane of the hard palate HP
in an arcuate geometry of repose.
[0036] The pharyngeal airway passes air from the mouth M and the
nasal passages N into the trachea TR. The portion of the pharyngeal
airway defined between opposing surfaces of the upper surface of
the soft palate SP and the wall of the throat is the nasopharynx
NP.
[0037] During normal breathing, the soft palate SP is in the
relaxed state shown in FIG. 1 with the nasopharynx NP unobstructed
and with air free to flow into the trachea TR from both the mouth M
and the nostrils N.
[0038] During swallowing, the soft palate SP flexes and extends (as
shown in FIG. 2) to close the nasopharynx NP thereby preventing
fluid flow from the mouth M to the nasal passages N.
Simultaneously, the epiglottis EP closes the trachea TR so that
food and drink pass only into the esophagus ES and not the trachea
TR. The soft palate SP is a valve to prevent regurgitation of food
into the nose N. The soft palate SP also regulates airflow through
the nose N while talking. Since the soft palate SP performs such
important functions, prior art techniques for surgically altering
the soft palate SP can compromise these functions.
[0039] The majority of snoring is caused by the soft palate SP
flapping back and forth. If breathing is solely through the nose N
with the mouth closed, the trailing edge TE of the soft palate SP
is sucked into the nasopharyngeal space NP obstructing the airway
and subsequently falls opening the airway in a repeating cycle.
When the mouth is open, air flows over the upper and lower surfaces
of the soft palate SP causing the soft palate SP to flap up and
down alternating in obstructing the oral and nasal passageways M,
N. The snoring sound is generated by impulses caused by rapid
obstruction and opening of airways. Huang, et al., state the airway
passage opening and closing occurs 50 times per second during a
snore. Huang, et al., utilize a spring-mass model (FIG. 5) to
illustrate oscillation of the soft palate in response to airflow
(where the soft palate is the ball B of mass depending by a spring
S from a fixed anchor A).
[0040] Huang, et al., analogize the shortening of the soft palate
SP in uvulopalatopharyngoplasty as effectively raising the critical
air flow speed at which soft palate flutter will occur. The shaded
area SA in FIG. 3 shows the area of the trailing end TE of the soft
palate SP to be removed during this procedure. The alternative
procedure proposed by Huang, et al., reduces the flexibility of the
soft palate SP through surface scarring which is asserted as
effecting the critical flow speed. The shaded area SA' in FIG. 4
shows the area to be scarred by this alternate procedure. In FIG.
4, dashed line L shows the demarcation between the soft and hard
palates.
[0041] Using the spring-mass model of FIG. 5 as a convenient model
of the soft palate SP, the present invention is directed to a
surgical implant into the soft palate SP to alter the elements of
the model and thereby alter the dynamic response of the soft palate
SP to airflow. The implant can alter the mass of the model (the
ball B of FIG. 5), the spring constant of the spring S, the
dampening of the spring S or any combination of these elements.
Unlike the prior art surgical techniques, the implants that will be
described are easy to insert in a small incision resulting in
reduced patient discomfort and are not exposed to the interior of
the mouth (such as the surface scarring of Huang, et al.) as a
patient irritant. Also, as will be described, the degree of dynamic
remodeling can be fine tuned avoiding the need for excessive
anatomical modification and are reversible in the event of adverse
consequences.
[0042] FIGS. 6-7 illustrate a first embodiment of the present
invention where individual units 10 of mass (in the form of
implantable modular devices such as spheres or implants of other
geometry) are imbedded in the soft palate SP in close proximity to
the trailing end TE. With reference to the model of FIG. 5, the
spheres add mass to the mass-spring system thereby altering dynamic
response to airflow and adding resistance to displacement and
accelerating. The placement of the units 10 of mass also alter the
location of the soft palate's center of mass further altering the
model and dynamic response.
[0043] The embodiment of FIGS. 6-10 is tunable to a particular
patient in that multiple modules 10 can be implanted (as
illustrated in FIG. 7). This permits the surgeon to progressively
increase the number of implanted modules 10 until the altered
dynamic response is such that snoring inducing oscillation is
abated at normal airflow. The individual modules 10 may be placed
into the soft palate SP through small individual incisions closed
by sutures which is much less traumatic than the gross anatomical
destruction of uvulopalatopharyngoplasty or the large surface area
scarring proposed by Huang, et al.
[0044] Preferably, such modules 10 of mass are solid modules such
as spheres of biocompatible material which are radiopaque (or
radio-marked) and compatible with magnetic resonance imaging (MRI).
Titanium is such a material. By way of non-limiting example, the
modules 10 of mass may be about 2-4 mm in diameter. In the case of
pure, non-sintered titanium, each such sphere 10 would add
0.15-1.22 gm of mass to the trailing end TE of the soft palate SP
and contribute to re-modeling the mass distribution of the soft
palate SP. An example of an alternative material is any
biocompatible ceramic.
[0045] As shown in FIG. 9, the spheres (labeled 10' to distinguish
from the version 10 of FIG. 8) may be sintered throughout or
otherwise provided with tissue growth inducing material 12 on their
outer surface. Such material may be a sintered outer layer or a
coating or covering such as a polyester fabric jacket. Such
material permits and encourages tissue in-growth to secure the
implant 10' in place. Also, placement of an implant 10 or 10' will
induce a fibrotic response acting to stiffen the soft palate SP
(and further alter the dynamic response and resistance to
displacement and acceleration). A sintered or coated sphere 10'
will enhance the fibrotic response and resulting stiffening.
[0046] While tissue in-growth and enhanced fibrotic response have
the benefits described above, such embodiments may make the implant
10' more difficult to remove in the event reversal of the procedure
is desired. Therefore, as shown in FIG. 10 as an alternative, the
spheres (labeled 10" to distinguish from the implants 10, 10') may
be coated with smooth coating 14 (such as parylene or PTFE) to
reduce fibrosis.
[0047] The embodiments of FIGS. 6-10 add to and relocate the mass
of the spring-mass system of FIG. 5 to remodel the dynamic
response. The amount of mass is selected to alter the dynamic
response but not preclude the soft palate SP being moved to close
off nasal passages N during swallowing. Through fibrotic response
and incision healing, the spring S of the model is stiffened.
[0048] In addition to modifying the mass profile of the spring-mass
system, the spring component S of FIG. 5 can be modified (alone or
in combination with mass modification) to alter dynamic response.
FIG. 11-16 illustrate an implant 20 in the form of a flexible strip
for placement in the soft palate. The use of the term "strip"
herein is not intended to be limited to long, narrow implants but
can also include plates or other geometries implanted to alter the
dynamic model of the soft palate SP. Elongated strips are presently
anticipated as a preferred geometry to facilitate ease of
implant.
[0049] The strip 20 has a transverse dimension less than a
longitudinal dimension. By way of non-limiting example, the strip
may have a length L.sub.S of about 20-30 mm, a thickness T.sub.S of
about 2-4 mm and a width W.sub.S of 5-10 mm. As shown in FIG. 11,
the strip 20 is embedded in the soft palate SP with the
longitudinal dimension L.sub.S extending from adjacent the hard
palate HP toward the trailing end TE of the soft palate SP. As
shown in FIG. 12, multiple strips 20 may be embedded in the soft
palate SP extending either straight rearward or angled to the sides
while extending rearward. The strips 20 may be formed straight
(FIG. 14) or pre-shaped (FIG. 15) to have a rest shape approximate
to the side-cross section shape of the soft palate in a relaxed
state.
[0050] The strips 20 may be any flexible, biocompatible material
and are preferably radiopaque or radio-marked as well as MRI
compatible. The strips 20 need not be elastic and having a material
spring constant biasing them to their original shape. Such strips
20 could simply be flexible, plastically deformable strips which
are stiffer than the soft palate SP to reinforce the soft palate SP
and assist the soft palate SP in resisting deflection due to
airflow. Such stiffening of the soft palate SP stiffens and dampens
the spring S in the spring-mass system of FIG. 5 and alters the
dynamic response of the soft palate SP. The strip 20 may be a
spring having a spring constant to further resist deflection of the
soft palate SP as well as urging the soft palate SP to the relaxed
state of FIG. 5. The stiffness of the strip 20, a spring constant
of the strip 20, and the number of strips 20, are selected to avoid
preclusion of closure of the soft palate SP during swallowing.
Examples of suitable materials include titanium and nitinol (a
well-known nickel-titanium alloy). As with the examples of FIGS. 9
and 10, the strips 20 may be provided with tissue in-growth
surfaces or may be coated as desired. Also, the strips may be
structurally modified to control their flexibility. In FIG. 16, the
bottom 22 of the strip 20 (facing the tongue after placement) is
provided with transverse notches 24 to enhance downward flexion of
the strip 20 relative to upward flexion of the strip 20 following
placement.
[0051] FIG. 17 provides an alternative to the strips 20 of FIG. 13.
In FIG. 17, the strip 20' includes a housing 26 having an interior
space 28 with an access opening 25. The interior space 28 extends
in the longitudinal dimension of the housing 26. The strip 20'
further includes a longitudinal insert 32 sized to be passed
through the access opening 25 and into the space 28. By way of
non-limiting example, the housing 26 could be silicone rubber (with
radio-markers, not shown, to indicate placement) and the inserts 32
could be titanium rods or other flexible member. With the
embodiment of FIG. 17, the housing 26 (without an insert) may be
embedded in the soft palate SP. The housing 26 acts independently
as a stiffening strip to add stiffness to the soft palate SP to
alter the soft palate's dynamic response. In the event further
stiffening or a spring action is desired, the implant 20' can be
selectively tuned to the patient's unique dynamic model by placing
the insert 32 into the space 28 at the time of initial surgery or
during a subsequent procedure. The embodiment of FIG. 17, permits
selection of an insert 32 from a wide variety of materials and
construction so that an insert 32 of desired characteristics (e.g.,
stiffness and spring action) can be selected to be inserted in the
space 28 and alter the dynamic response as desired. The embodiment
of FIG. 17 also permits later removal of the insert 32 and
replacement with a different insert 32 of different properties for
post-surgery modification of the soft palate's dynamic
response.
[0052] The embodiment of FIG. 18 is similar to that of FIG. 17. The
housing 26' is provided with multiple, parallel-aligned interior
spaces 28' and access openings 25'. In addition to the function and
benefits of the embodiment of FIG. 17, the number of inserts 32 may
be varied to alter and adjust the dynamic response of the soft
palate SP.
[0053] FIG. 19 illustrates a still further embodiment of the strip
implant. In FIG. 19, the strip 20'" is a bladder having a housing
26" in the form of a completely sealed envelope of flexible
synthetic material defining an interior space 28". The envelope 26"
is preferably self-sealing following needle injection. Fluid is
injected into the housing 26" (e.g., through hypodermic needle 40
injection) to stiffen the strip 20'". Addition of fluid further
stiffens the strip 20'" and further alters the dynamic response of
the soft palate SP. Removal of fluid increases the flexibility.
Unlike the embodiments of FIG. 17 (where inserts 32 are most
effectively replaced post-operatively through incision to alter
flexibility), the embodiment of FIG. 19 permits selectively varying
flexibility of the soft palate SP through needle injection. An
alternative to FIG. 19 is to fill the space 28" with a so-called
phase change polymer and inject a stiffening agent into the space
28" to alter the flexibility of the polymer.
[0054] FIGS. 20-23 illustrate a still further embodiment of the
present invention. In the foregoing embodiments, the spring-mass
system of FIG. 5 is altered by altering the mass of the soft palate
SP or the spring characteristics of the soft palate SP. The dynamic
response can also be altered by altering the force acting on the
spring-mass system. Namely, the force acting on the soft palate SP
is generated by airflow over the surface of the soft palate. The
soft palate acts as an airfoil which generates lift in response to
such airflow. By modifying the longitudinal (i.e., anterior to
posterior) cross-sectional geometry of the soft palate SP, the
aerodynamic response and, accordingly, the dynamic response are
altered.
[0055] In the embodiments of FIGS. 20-23, the implant 30 is
inserted into the soft palate SP through an incision. The implant
30 has an oval shape to cause deformation of the geometry of the
soft palate SP. Prior to implantation, the implant 30 is preferably
formed as a flat oval (FIGS. 20 and 22) for ease of insertion.
After implantation, the implant 30 expands to an enlarged oval
(FIGS. 21 and 23). While such expansion could be accomplished
mechanically (i.e., through balloon expansion), the implant 30 is
preferably formed as a shape-memory alloy (such as nitinol) which
expands to the enlarged shape in response to the warmth of the
body. In addition to changing the aerodynamics of the soft palate
SP, the implant 30 can be constructed with a mass and stiffness as
desired to alter the spring and mass components of the spring-mass
system of FIG. 5.
[0056] The foregoing describes numerous embodiments of an invention
for an implant for the soft palate to alter a dynamic response of
the soft palate. The invention is much less traumatic than prior
surgical treatments. Further, the invention permits use of
reversible procedures as well as procedures which can be
selectively tuned both during surgery and post-operatively. Having
described the invention, alternatives and embodiments may occur to
one of skill in the art. For example, the strips of FIG. 13 may be
encased coiled springs which may be tightened to further stiffen
the strips. Such strips may also be hinged segments. It is intended
that such modifications and equivalents shall be included within
the scope of the following claims.
* * * * *