NORRED EXHIBIT 2317 - Page 1
`Medtronic, Inc., Medtronic Vascular,
`Inc., & Medtronic Corevalve, LLC
`v. Troy R. Norred, M.D.
`Case No. IPR2014-00395
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`

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`U.S. Patent
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`0ct.3l,2000
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`Sheet 1 ofll
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`6,139,575
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`NORRED EXHIBIT 2317 - Page 2
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`U.S. Patent
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`Oct. 31, 20110
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`Sheet 2 of 11
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`6,139,575
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`U.S. Patent
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`Oct. 31, 2000
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`Sheet 3 of 11
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`U.S. Patent
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`Oct. 31,2000
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`Sheet 4 of 11
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`U.S. Patent
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`Oct. 31, 2000
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`U.S. Patent
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`Oct. 31, 2000
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`U.S. Patent
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`Oct. 31,2004}
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`Sheet 3 of 11
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`U.S. Patent
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`Oct. 31, 2000
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`U.S. Patent
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`Oct. 31, 2000
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`FIG.I4
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`U.S. Patent
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`Oct. 31, 2000
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`1
`HYBRID MIECIIANICAL HEART VALVE
`PROSTHESIS
`
`FIELD OF THE INVENTION
`
`'lhe present invention pertains to prosthetic mechanical
`heart valves and in particular, to bi-leaflet and tri-lcallel
`mechanical valves formed with rigid hinge mechanism and
`flexible leallets.
`
`BACKGROUND OF THE INVENTION
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`During each cardiac cycle, the natural heart valves alter-
`natively open to allow blood to [low llt rough them and then
`close.
`to block blood llow. During systole, the mitral and
`tricuspid valves close to prevent reverse blood flow from the
`ventricles to the atria. At
`the same time,
`the aortic and
`pulmonary valves open to allow blood flow into the aorta
`and pulmonary arteries. Conversely. during diastole,
`the
`aortic and pulmonary valves close to prevent reverse blood
`flow from the aorta and pulmonary arteries into the
`ventricles, and the mitral and tricuspid valves open to allow
`blood llow into the ventricles. The cardiac valves open and
`close passively in response to blood pressure changes oper-
`ating against thc valve leallet structure. Their valve leaflets
`close when forward pressure gradient reverses and urges
`blood llow backward and open when forward pressure
`gradient urges blood flow forward.
`In certain individuals, the performance of a natural heart
`valve is compromised due to a birth defect or becomes
`compromised due to various disease processes. Surgical
`repair or replacement of the natural heart valve is considered
`when the natural heart valve is impaired to an extent such
`that normal cardiac function cannot be maintained. The
`natural heart valve can be replaced by ltomograft valves
`obtained from the same species (c.g., human donor heart
`valves), heterograft valves acquired from different species,
`and prosthetic mechanical heart valves.
`The present
`invention is directed to improvements in
`prosthetic mechanical heart valves. Modern implantable
`mechanical heart valves are typically fortnecl of a relatively
`rigid, generally annular valve body defining a blood flow
`orifice and an annular valve seat and one or more occluders
`that are movable between a closed, seated position in the
`annular valve seat and an open position at an angle to the
`valve body axis. These components of mechanical heart
`valves are made of blood compatible, non-thrombogenic
`materials, e.g., pyrolytic carbon and titanium. A bio-
`compatible, fabric sewing ring is typically provided around
`the exterior of the valve body to provide an attachment site
`for suturing the valve prosthesis into a prepared valve
`annulus. The occluder{.s) is retained and a prescribed range
`of motion is defined by a cooperating hinge mechanism or
`other restraining mechanism. Such prosthetic heart valves
`function essentially as check valves in which the occluderts}
`responds to changes in the relative blood pressure in the
`forward and reverse directions as described above and move
`between their open and closed positions.
`Two approaches to mechanical heart valve design have
`been followed over the ye ars. In a first approach, the design
`of the rnecbattical heart valve structure has attempted to
`mimic natural heart valve structures in construction, appear-
`ance and function. For example, in U.S. Pat. No. 4,556,996,
`a valve design is proposed using molded elastomer, trian-
`gular flaps that extend inwardly into the annulus of a ring
`shaped valve body that appears to be intended to mimic
`tricuspid heart valves. The flaps and ring-shaped body are
`integrally formed of Dclrin or a similar hard plastic and
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`2
`covered with an elastomcr. The flaps are intended to bond
`between open and closed positions by integrally formed
`hinges at the junctions of the flaps and the ring shaped body.
`This approach has also led to a number of proposed
`designs to mimic the operation of a natural tricuspid valve
`employing flaps formed of thin plastic membranes attached
`to the valve body and to struts extending downstream from
`the valve body leaving the ttaps with free flap edges. In
`operation,
`the three flaps balloon outward in the open
`position to define a cylindrical annulus for blood llow. In the
`closed position, the free flap edges of the three flaps collapse
`against one another. A variety of such mechanical heart
`valve prostheses are described in US. Pat. Nos. 4,222,126,
`4,364,127, 5,500,016 and 5,562,729, incorporated herein by
`reference.
`
`The flexible valve leafieLs of the designs following this
`first approach have not been successfully clinically imple-
`mented in part because the leaflet materials and integral
`hinge mechanisms cannot be shown to be reliable and
`immune from fracture or tear over long term use. It is also
`well known that calcium mineral deposits on the flaps causes
`calcification of leaflets. The calcified leaflets become rigid
`and fail
`to open and close properly. Their durability are
`greatly reduced and valve failure always occurs at
`the
`calcilied location. Moreover, the integral hinge structures
`are in low blood llow regions and blood stagnation in those
`regions can contribute to the accretion of tltrombus forma-
`tion and also cause the failure of these valves.
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`In the second approach, less attention is paid to trying to
`mimic the appearance and function of natural heart valve
`llaps, and more attention is paid to tnaxiinizing reliability of
`operation and hemodynamic function. Such mechanical
`heart valve prostheses have employed other occludcrs and
`binge or occluder restraint mechanisms that do not resemble
`llaps and integral
`flap hinges. A wide variety of such
`mechanical heart valve designs have been proposed andfor
`clinically used in the past. For example, US. Pat. No.
`3,9]],SU2 describes mechanical heart valves employing at
`spherical ball in a cage tharmoves in the cage into and out
`of engagement with an annular valve body seat in response
`to the blood flow due to normal pumping action of the heart.
`The spherical ball was formed of a variety of materials
`including metals, plastics, and silicone rubber.
`Other early heart valve prostheses employed occludcrs in
`the form of a circular disc restrained within cage struts or by
`disk mounted struts for movcmcrtt between open and closed
`disk positions in response to blood pressure changes, as
`shown, for example in U.S. Pat. Nos. 3,722,004 and 3,306,
`409. In the ‘G04 patent, the disk is formed of a pyrolytic
`carbon or metal ring coated with silicone rubber except for
`the periphery 20. The periphery 20 contacts the sides of the
`struts to restrain movement of the disk between the disk
`open and disk closed positions. The silicone rubber strikes
`the ends of the struts to step movement of the disk in the disk
`open position, and the silicone rubber coating llexcs to
`reduce noise and shock.
`
`l-Ieart valve prostheses using such spherical ball or cir-
`cular disk occluders provide poor hemodynamic function
`since the major surfaces of each such occluder remain
`perpendicular to the blood llow when the occluder is in the
`open position and therefore they impede blood tiow. These
`types of valve designs created significant pressure drop and
`energy loss. Moreover, the cage and strut restraints project-
`ing from the annular valve body can interfere with heart
`tissue and make implantation difficult or impossible in
`certain valve replacement
`locations.
`In addition, such
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`to manufacture with the
`restraint structures are diflicult
`annular valve body in a manner that assures adequate
`mechanical reliability over years of implantation. Fractures
`have been reported to have occurred at junctions that were
`welded together.
`A wide variety of pivoting disk heart valve prostheses
`have been developed and clinically used wherein a single
`circular disk of pyrolytic carbon cooperates with strut and
`stop structures to pivot between a disk open position and a
`disk closed position. The Medtronic llall'”" mechanical
`heart valve employs a strut machined from the titanium
`block forming the annular heart valve body that is extended
`through a central opening in the disk to restrain its pivotal
`movement. Such a single pivoting disk mechanical valve
`design is reliable, but the opening angle of the disk in the
`disk open position is limited to less than 90°.
`More recently, clinically used, bi—leaflet heart valve pros-
`theses have been developed that employ a pair of semi-
`circular or semi-elliptical plates or leaflets that are coupled
`to the annular heart valve base or body through pivot hinge
`mechanisms that allow the leaflets to pivot on leaflet pivot
`axes between leaflet open and seated, closed positions. The
`valve body has an interior side wall defining a blood flow
`orifice having a central blood flow axis centrally located
`with respect to the interior surface. The valve body also has
`tirst and second pairs of valve body hinge elements, eg.
`recesses, and first and second valve body seat regions. The
`pairs of valve body hinge elements provide opposed pairs of
`hinge pivot points and a pivot axis that extends across the
`valve annulus and is offset from the central axis of the valve
`annulus.
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`means of a pair of rounded ears extending radially outwardly
`from opposed edges of the leaflets to fit within rounded
`hinge recesses in opposed flat surfaces ofthe valve body side
`wall. Such bi-leaflet valves are exemplified by the mitral
`valve depicted in US. Pat. No. 4,276,658 and the aortic
`heart valve depicted in U.S. Pat. No. 5,178,632, both incor-
`porated herein by reference.
`leaflet ears are
`More particularly,
`the conventional
`received within curved hinge recesses extending radially
`into opposed flat surfaces of thickened wall sections inside
`the annulus of the generally cylindrical or annular valve
`body. Each hinge recess is designed in at least one respect
`to match the shape of the leaflet ear and is bounded by sets
`of leaflet stop surfaces angled to define the extreme open and
`closed leaflet positions. In other words, where the ear is
`formed as a portion of a circle having a given radius, the
`counterpart hinge recess is formed as a semicircle having a
`slightly greater radius. An inverse arrangement of the ear
`and recess hinge mechanism is depicted in U.S. Pat. No.
`5,354,330, incorporated herein by reference, whereby the
`leaflet car is replaced by a leaflet recess, and the hinge recess
`is replaced by a complementary shaped hinge boss.
`To achieve the pivoting mechanism, the mating surfaces
`of the cars and recesses are precisely machined so as to
`provide a small but definite working clearance for the ears
`to pivot about the necked down pivot surface and be retained
`within the hinge recesses. During valve assembly, the annu-
`lar valve body is deformed or distended so that the leaflet
`ears may be inserted into the respective hinge recesses. Each
`manufactured heart valve is then lab tested "dry" to ensure
`that the leaflets are held tightly enough to be secure against
`falling out of their hinge recesses. but are not so tightly
`engaged so as to create a binding or restricted valve action.
`The range ofleallel motion is typically controlled by pins
`or ramps or opposed side strips of the hinge recesses or by
`hinge bosses in the valve body. In one format described in
`the above-incorporated ‘(S32 patent,
`the hinge recess is
`generally spherical and bounded by open and closed stop
`surfaces of a stop member projecting into the recess. In the
`other formats depicted in the above-incorporated,
`‘C158
`patent, each hinge recess has an elongated “bow—tie" or
`"butterfly" appearance created by the inward angulation of
`opposed side edges extending from inflow and outflow end
`edges and meeting at opposite disposed, necked down, pivot
`points or surfaces intermediate the end edges.
`A great deal of ellort has been devoted to controlling the
`range of movement and the acceleration of the leaflets
`between the open and closed positions to both control noise
`and decrease wear or the possibility of leaflet
`fracture.
`Hi-leaflet mechanical heart valves are known to be noisy, in
`the sense that patients can frequently hear the seating ofthe
`valve leaflet peripheral edges against the valve seats upon
`closure.
`It
`is desirable for patient comfort
`to provide a
`bi-leaflet design that minimizes the distraction of leaflet
`seating noise.
`It is also known that blood cells are extremely fragile and
`delicate and can be damaged andfor destroyed when trapped
`in the valve seat regions during closure of the valve leaflet
`or in the wiping area of the valve leaflet ears and hinge
`recesses or between the leaflet ears and the open and closed
`stop surfaces. The wiping areas of the hinge recesses have
`the highest potential of thrombus formation and emboli
`entrapment which can accumulate therein, impair the move-
`‘ ment of the valve leaflets. and result in valve failure requir-
`ing surgical intervention. To this time, no design has been
`successful
`in eradicating this problem. Consequently,
`
`In such bi-leaflet valve configurations, two mirror image
`leaflets are typically disposed in opposed or mirror image
`relation to one another for alternately blocking blood flow in
`an inflow direction when seated in a leaflet closed position _
`and then allowing the ttow of blood through said blood tlow
`orifice in an outflow direction when in a
`leaflet open
`position. Upon closure, each valve leaflet occludes or closes
`a half section of the annular valve orifice or valve annulus.
`Generally, each leaflet is generally semi-circular in shape
`and has generally opposed, inflow and outflow, leaflet major
`surfaces and a peripheral edge extending between the
`opposed leaflet major surfaces. A leaflet seat section of the
`peripheral edge is formed to seat against a valve body seat
`region when in the closed position. Each leaflet can rotate
`about a leallet pivot axis extending between a pair of leaflet
`hinge elements. e.g., outwardly projecting leaflet ears. that
`cooperate with a pair of valve body hinge elements, e.g.. the
`opposed pair of hinge recesses. The leaflets are typically
`planar in profile, but curved or elliptical leaflets have been
`propotsed.
`Such mechanical heart valves are typically designed in
`somewhat diflering profile conligu rations for replacement of
`different impaired natural heart valves. However. the basic
`in vivo operating principle is similar regardless of configu-
`ration. Using an aortic valve as an example, when blood
`pressure rises in response to left ventricle contraction or
`systole in each cardiac cycle, the leaflets of such a valve
`pivot from a closed position to an open position to permit
`blood flow past the leaflets in an outflow direction. Vt’hen the
`left ventricle contraction is complete, blood tends to flow in
`the opposite, inflow direction in diastole in response to the
`back pressure. The back pressure causes the aortic valve
`leaflets to close in order to maintain arterial pressure in the
`arterial system.
`’lhe most widely accepted type of bi—leaflet heart valve
`presently used mounts its leaflets for pivoting movement by
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`patients receiving current bi~lcaflet mechanical he art valves
`are prescribed continuous blood anticoagulation therapy to
`prevent
`thrombus formation and thrornboernboli.
`In our
`commonly assigned US. patent application Ser. No. 08_F898,
`144 liled Jul. 22, 1997‘, and entitled MECHANICAL
`HEART VALVE PROSTI-IESIS, we present an improved
`hinge design that is intended to optimize washing of the
`hinge regions and decrease these problems of conventional
`hinge mecltanisms of the type described above.
`In operation, the valve leaflets accelerate rapidly as the
`leaflets move from the leaflet open position to the leaflet
`closed position during the closing phase in response to a
`change of blood pressure.
`It
`is dificult to dcceleratc the
`leaflets before the arcuate seat section of the leaflet periph-
`eral edge strikes the corresponding arcuate seat region of the
`annular valve body. Since a conventional mechanical heart
`valve leallct (disk) utilized rigid material, c.g., pyrolytic
`carbon, the momentum of the rotating rigid leallet (disk) and
`its surrounding fluid creates a high impact force due to the
`sudden stop when the arcuate seat section of the leaflet
`peripheral edge contacts the corresponding arcuate seat
`region of the annular valve body. This high impact force
`damages all blood elements entrapped in the contact region
`of the leaflet peripheral edge because the impact force is far
`beyond the bearable limit of any blood element and the
`dimension of this contact region is two orders of magnitude
`larger than any blood element. Blood hcmolysis in clinical
`observation is one of the typical results from this high
`impact force.
`Moreover, the blood [low pressure at the inflow side of the .
`conventional mechanical heart valve leaflet peripheral edge
`can drop to near vacuum pressure due to a water hammer
`effect upon leaflet closure. At the instant of a leaflet closure,
`blood volume proximal to the leaflet peripheral edge at the
`inflow side tends to separate from the leaflet surface due to .
`the moving momentum of fluid column and the abruptly
`stopping of the rigid leaflet. This ilow separation can create
`a very low pressure in a very short time span, usually less
`than one milli-second. This very low pressure in the water
`hammer effect has the potential to generate cavitation which,
`from occurring to vanished, is less than 50 micron seconds.
`Material corrosion, pitting and degradation of a
`leaflet
`surface caused by cavitation has been observed in clinical
`use in a few mechanical heart valves. Should cavitation
`occur, the explosion force of cavitation bubble in a very
`short time duration can easily damage blood elements near
`cavitation sites. Even if no cavitation occurs, the low pres-
`sure lield at the inflow side of the leaflet peripheral edge can
`cause damage to blood elements by generating high surface
`tension on surface membranes of blood elements.
`Also, after the valve is closed, localized high speed blood
`flow leakage has been observed on all the current mechani-
`cal heart valves. Thc blood flow leakage jets occur at the
`gaps between leaflet and valve housing clue to the large
`transvalvular pressure gradient in the valve closing phase.
`'l'he reported shear stresses of leakage jets are beyond the
`surface tensile stress Iintits of any blood element surface
`membranes. Therefore, these leakage jeLs not only reduce
`the cfliciency of a passive mechanical lteart valve, but also
`damage blood elements in the leakage stream.
`SUMMARY OF THE INVENTION
`
`element is provided for cooperatively engaging with a valve
`body hinge element to enable movement of the valve leaflet
`between a leaflet open position allowing blood flow through
`the valve body blood flow orifice and a
`leaflet closed
`position for blocking blood flow through the blood flow
`orifice. The valve lcaflct has generally opposed, inflow and
`outflow, leaflet major surfaces bounded by a peripheral edge
`extending between the opposed leaflet major sttrfaces. The
`peripheral edge is formed at least in part to provide a leaflet
`seat for engaging against the valve body seat region.
`The valve leaflet
`is fomztcd in a hybrid manner of a
`relatively rigid valve leaflet skeleton or frame and a rela-
`tively flexible valve leaflet body adhered to the frame
`formed of an elastic, bio—compatible material. The valve
`body elastic material extends over and is adhered to about at
`least a portion of the valve leaflet frame and extends away
`from the valve leaflet frame to form at least a portion of the
`opposed leaflet major surfaces and the peripheral edge. The
`leaflet body material has a resilience and thickness that
`allows the leaflet seat to be defonrted into a contact band
`with the valve body scat region to absorb contact shock
`when the leaflet moves into the leaflet closed position. The
`valve leaflet frame is coupled with the valve leaflet hinge
`element and formed of
`a dimensionally rigid, bio-
`compatiblc, material providing dimensional rigidity to a
`portion of the valve lcaflct and the leaflet hi ngc element. The
`valve lcailet frame enables the cooperative engagement of
`the valve body hinge element with the valve lcallct hinge
`element and governs movement of the valve leaflet between
`the leaflet open and closed positions with respect to the
`blood flow orifice.
`The leaflet frame preferably extends in a leaflet pivot axis
`direction and comprises lirst and second valve leaflet hinge
`elements at the opposite ends of the leaflet pivot axis. The
`valve body is formed with first and second valve body hinge
`elements for receiving the first and second valve leaflet
`hinge elements, respectively, for allowing pivotal movement
`of the valve leaflet about the leaflet pivot axis between the
`leaflet open and leallct closed positions. The leaflet body
`further comprises a coating of the elastic, bio-compatible
`material extending over the icaflet frame and forming sub-
`stantially all of the opposed, leallet major surfaces.
`Preferably, the invention is implemented in it bi-leaflet
`valve having two such leaflets that are hinged for pivotal
`_ movement between leaflet open and leaflet closed positions
`with respect to first and second portions of the annular blood
`ilow orifice and first and second valve body seat regions.
`Preferably, each valve leaflet frame extends between a pair
`of leaflct hinge clcrncnts that cooperatively engage a pair of
`valve body hinge elements together defining a dimensionally
`stable pivot axis. 'lhc first and second valve leaflets have
`leaflet bodies extending over substantially all of the leaflet
`frames formed as described in the preceding paragraph to
`provide first and second respective leaflet occluding sections
`bounded by arcuate seal sections of the peripheral edges
`thereof that deform when scaled against respective first and
`second valve body seat regions in the leaflet closed position.
`This deformation of the resilient leaflet body blocks blood
`flow leakage and eliminates leakage jets through the arcuate
`scat sections of the peripheral edges.
`In such bi-leallct mechanical heart valves, each of the first
`and second valve leaflets preferably further comprise first
`and second respective abutting sections of the peripheral
`edge formed to abut against one another when the first and
`: second valve leaflets are in the leaflet closed positions. The
`contact of the abutting sections blocks the leakage flow of
`blood through any space between the first and second valve
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`invention to
`is therefore an object of the present
`It
`minimize these problems associated with existing pivoting
`leaflet, mechanical heart valves.
`feature of the present
`In accordance with the first
`invention, a valve leaflet having at least one leaflet hinge
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`leaflets and through the blood flow orifice. The abutting
`section of each valve leaflet is formed by the extension of the
`elastic, bio-compatible material away from the leaflet frame
`having a
`resilience and thickness that provides mutual
`deformation of the flrst and second abutting sections into a
`contact band with one another and absorption of contact
`shocl-t therebetween when the leaflets move into the leaflet
`closed positions. The mutual contact oflhe abutting sections
`also decreases tlte intensity of contact of the arcuate scat
`section against the respective valve body seat region.
`The leaflet body is also flexible in a region ol‘ the leaflet
`extending inwarrlly of the arcuate seat section and to the
`leaflet frame to allow the leaflet to flex in response to blood
`pressure changes in the flow lield. This flexibility of the
`leaflet allows the leaflet occluding section to elIectiveIy
`bend and close earlier than a rigid metal leaflet. The flex-
`ibility also decreases the closing velocity of the leaflet and
`diminishes the closing impact of the arcuate seat section
`against the respective valve body seat region. The reduced
`impact effect plus the deformability of the leaflet can greatly
`reduce or eliminate the propensity of potential cavitation at
`the inflow surface of the leaflet peripheral edge.
`In order to promote adherence of the valve leaflet body
`with the valve leaflet frame, the valve leaflet frame is formed
`with opposed, frame major surfaces with a plurality of
`openings extending through the valve leaflet frame between
`the opposed, major frame surfaces. The leaflet body further
`comprises a coating of the elastic. bio-compatible material
`extending over the leaflet frame and through the plurality of
`openings and forming substantially all of the opposed,
`leaflet major surfaces.
`The method of adhering the leaflet body to the leaflet
`frame preferably comprises pre-treatment of the relatively
`rigid leaflet frame and molding of the elastomeric material
`about the frame to form the leaflet body. The leaflet frame is
`preferably formed of pyrolytic carbon coated on a graphite
`substrate, even more preferably pyrolytic carbon that
`is
`treated with certain chemical solutions such as solutions
`based on silarle or siloxanc chemistrics. The leaflet body is
`preferably molded about
`the treated leallet
`frame from
`silicone rubber or other elastomers. Compounds may be
`added to silicone rubber before it
`is molded to provide
`radio-opacity. The polymeric surfaces of the leaflet may be
`modified or
`treated with anticoagulation andfor anti-
`calcilication agents to prevent any potential thrombus for-
`mation andlor leaflet calcification.
`The valve frame provides for the structural rigidity and
`support of the valve leaflet hinge elements and absorbs
`shocks to the valve leaflet
`incurred in the opening and
`closing phases. The valve body moderates shocks and pro-
`vides for the soft closure that reduces blood damage and
`mechanical deterioration of the valve leaflet structure. The
`resulting need for anti-coagulation drug therapy may he
`reduced.
`
`The hybrid valve leaflet allows the pivoting leaflet
`mechanical heart valve to enjoy the gentle and smooth
`closing behavior of a tissue valve while retaining the long
`life and reliability ofthc mechanical heart valve. Because of
`the large thickness and strength of this leaflet design, poten-
`tial calcification and structural deterioration as seen in
`conventional polymeric valves are minimized or eliminated.
`These principles of construction and operation can also be
`applied to multi-leaflet mechanical bean valve prostheses.
`particularly, tri-leaflet heart valves, and the resultant advan-
`tages can enjoyed in such multi-leaflet heart valves.
`BRIEF DESCRIPTION OF THE DRAWINGS
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`60
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`65
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`These and other objects. advantages and features of the
`present invention will be appreciated as the same becomes
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`8
`better understood by reference to the following detailed
`description of the preferred embodiment of the invention
`when considered in connection with the accontpanying
`drawings. in which like numbered reference numbers des-
`ignate like parts throughout the figures thereof, and wherein:
`FIG. 1 is an isometric view from the inilow side of a
`bi-leaflet mechanical heart valve in an aortic configuration
`incorporating the improved hybrid leaflet of the present
`invention;
`FIG. 2 is a plan view of an exemplary planar hybrid valve
`lcaflct in accordance with a lirst embodiment of the inven-
`tion viewed from the inflow surface thereof;
`FIG. 3 is a plan view of a variation of the hybrid valve
`leaflet of FIG. 2 viewed from the inflow surface thereof;
`FIG. 4 is a partial cross-section, isometric view of the
`hybrid valve leaflet of FIGS. 2 and 3 taken along lines 4—4
`of FIGS. 2 and 3;
`isometric view of the
`FIG. 5 is a partial cross—scction,
`hybrid valve leaflet of FIGS. 2 and 3 seated in the leaflet
`closed position against a valve body seat region;
`FIG. 6 is a side cross—section view taken along lines 6—6
`of FIG. I ofa pair ofthe hybrid valve leaflets of FIGS. 2 and
`3 seated in the leaflet closed position against one another in
`an abutting contact band and against first and second valve
`body seat regions in seat contact bands;
`FIG. 7 is a plan view of an exemplary planar hybrid valve
`leaflet
`in accordance with a second embodiment of the
`invention viewed from the inflow surface thereof;
`FIG. 8 is a plan view of a variation of the hybrid valve
`leaflet of FIG. 7 viewed from the inllow surface thereof;
`
`FIG. 9 is a partial cross—section, isometric view of the
`hybrid valve leaflet of FIGS. 7 and 8 taken along lines 9—9
`of FIGS. 7 and 8;
`FIG. 10 is a partial t:ro.~Ls-section, isometric view of the
`hybrid valve leaflet of FIGS. 7 and 8 seated in the leaflet
`closed position against a valve body seat region;
`FIG.
`]_1 is a side cross-section view taken along lines
`11—11 of FIG. 1 of it pair of the hybrid valve leaflets of
`FIGS. '7 and 8 seated in the leaflet closed position against
`one another in an abutting contact band and against first and
`second valve body seat regions in seat contact bands;
`FIG. 12 is a plan view ofa further variation ofthe hybrid
`valve lc aflet of FIG. 2 viewed from the inflow surface
`thereof;
`FIG. 13 is a side cross-section view taken along lines
`13—l3 of the valve leaflet of FIG. 12; and
`FIG. 14 is a modilication of FIG. 6 depicting the use of
`elastomeric coatings applied to sections of the interior side
`wall of the valve body in the first and second valve body scat
`regions.
`FIG. 15 is a schematic of an apparatus for use in a surface
`treatment method in accordance with the present invention.
`[)l:"l'/\Il.EI) l)l£SCRll"l‘lON OF TI-IE
`PREFERRED EMBODIMENTS OF TIIE
`INVENTION
`
`It will be understood that the present invention may be
`embodied in mechanical heart valves having occluders
`formed of at least one, two or conceivably three or more
`leaflets, wherein the leaflets are formed in a hybrid fashion
`from a leaflet frame and a leaflet body as summarized above
`and explained in detail below. FIG. 1 depicts at least one
`preferred form of stlch a bi—leaflet mechanical heart valve in
`an aortic valve configuration having a low, narrow profile
`
`
`
`NORRED EXHIBIT 2317 - Page 16
`
`

`
`6,139,575
`
`9
`that follows the general configuration of that disclosed in
`application Ser. No. 08t898,1-14, in which the present inven-
`tion may be implemented.
`It will be understood that
`the
`hybrid valve leaflets can be implemented in a wide variety
`of pivoting disk or leaflet mechanical heart valve designs
`having differing hinge mechanisms. It will also be under-
`stood that the hybrid valve leallets can he used in diflierent
`valve designs that have dilferent leallet or disk open and
`closing directions.
`In FIG. 1,
`the heart valve 10 includes four major
`components, that is, an annular valve body 12, an occluder
`comprising first and second leaflets 14 and 16, and a fabric
`sewing ring 18. The first and second leaflets 14 and 16 are
`depicted in the leaflet closed, seated position and the leaflet
`open position, respectively, simply to illustrate the range of
`motion of the leaflets between these extreme positions.
`When in the closed position, the generally semi-circular
`sections of the peripheral leaflet edges constitute leaflet seats
`that are seated in contact with respective valve. body seat
`regions extending around respective halves of the annular
`valve body 12. The relatively straight sections of the pcriph-
`eral edge extending between the opposed leaflet ears contact
`one another at the centerline of the valve annulus.
`The fabric sewing ring 18 (shown not necessarily to scale)
`may take any of the forms known in the art and is preferably
`rotatable about an outer sewing ring channel formed in the
`outer wall of the annular valve body 12 between exterior
`flanges of the annular, inflow and outflow rims 21 and 23.
`The details of the constructi