- 4IUIITY
`
`FILING DATE CLASS
`
`RtAC.NUMBER
`
`1865,7O3 O5/21/6 24
`RULE O
`JA$ES E. JERVIS, ATF1ERTON, CA.
`
`F'1TENT
`NUMBER
`GROUP ART UNIT
`
`SUBCLASS
`
`: \f
`
`—
`
`\ L:.
`
`EXAMINER
`
`//
`
`jr*CONTINUING DATA*********************
`THIS APPLN IS A CON OF
`VERIFIED
`
`*FOREIGN1PCT kPPLICATIONS************
`ERIFIED
`
`7z//—
`
`o9-/73-3 -3
`
`I
`
`,
`
`-
`
`OREIGN FILING LICENSE GRANTED O6/23/?
`
`I
`S119cpndItIofls met
`U3u and Rckflowiedged xmlner'sinltIis I "'*
`IRA D,. BLECKER
`RHEM-çORP.,
`5O CONSTITUTION DRIVE
`ENL PARK. CA 94025
`
`.
`
`STATE OR
`COUNTRY DRWGS.
`
`CLAIMS
`
`CLAIMS
`
`C A
`
`1
`
`1 0
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`1
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`f
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`RECEIVED
`74 00
`-/
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`2
`
`DOCKET NO.
`
`MOØ S 4 —J 52
`
`MEDICAL DEVICES INCORPORATING SIM ALtO'! FLEMFNTS
`
`kt. E--
`
`US. DEPT. of COMM..Pat. & TM Office— PTQ.436L (rev. 1048)
`/
`- 7
`;/'2—/ / .t-
`
`.1 f, /
`
`-
`
`PARTS OF APPLICATION FILED SEPARATELY
`
`.
`
`FIGURES CLAIMS
`DRWGS.
`
`AT ALLOWANCE
`CLSS
`
`/2
`
`/
`
`SUBCLASS
`
`/
`L Y,A'A
`
`(Assistant Examiner)
`EXAMINED,AND PASSED
`
`(Docket Clerk)
`FOR ISSUE
`
`/-- 7 PREPARED FOR ISSUE/O/
`C
`' C. FRED RQ1A1JM
`L&wF
`
`Estimate f lrTntdd DaOOS
`Drawings)
`
`(Art Unht
`Issue lee due (esi 1
`
`,NTOH tABEt.
`
`-
`
`Notice of allowance and issue fee due (eSt)
`Date paid
`Oats mailed
`
`I j/)
`
`—
`
`COOK
`Exhibit 1004-0001
`
`

`

`CONTENTS
`1. Applications
`papers.
`2._Qr(tO
`3.Pr at±
`••'* ti-
`
`A(R
`
`(1
`
`6.
`
`:
`
`——.
`I;" I
`
`_J, f.
`
`5..
`
`'
`
`\
`
`.—
`
`!2.
`
`4.
`25.
`
`26.
`27.
`28.
`29.
`
`f
`
`--
`
`_(J I
`
`--
`
`—
`
`_______••
`
`4
`
`COOK
`Exhibit 1004-0002
`
`

`

`L
`
`SYMaOLS
`
`STATU$
`
`Rejectetj
`Allowed
`—(Through flumeräl)Canceted
`ROStrIj requremenP
`Nonelected nverto.) or spe
`Interference
`Appeal
`
`N
`
`COOK
`Exhibit 1004-0003
`
`

`

`PATENT APPLICATION SERIAL NO.
`
`365703
`
`U.S. DEPARTMENT OF COMMERCE
`PATENT AND TRADENARK OFFICE
`FEE RECORD SHEET
`
`P 30134 05/28/86 865703
`P 30135 05/28/86 865703
`
`18-0560 030 101
`18-0560 030 102
`
`340.OOCH
`34.OOCH
`
`COOK
`Exhibit 1004-0004
`
`

`

`'
`
`LJO4
`
`7Q3
`
`MP 08 84—U Si
`
`MEDICAL DEVICES INCORPORATING
`SIM ALLOY ELEMENTS
`
`James E. Jervis
`
`ABSTRACT OF THE DISCLOSURE
`
`Medical devices which are currently proposed to use
`e1ementsmade from shape memory alloys may be improved by
`the use of stress—induced martensite alloy elements instead.
`The use of stress—induced martensite decreases the temperature
`sensitivity of the devices, thereby making them easier to
`install and/or remove.
`
`5
`
`B352 484 36
`
`Diane Browning
`
`COOK
`Exhibit 1004-0005
`
`

`

`a2
`
`'. \ t.
`
`—2—
`
`,PO884—US1
`
`2
`
`BACKGROUND OF THE INVENT ION
`
`Field of the Invention
`
`This invention relates to medical devices incorporating
`
`shape memory alloys, and to improvements therein.
`
`I 5
`
`Introduction to the Invention
`
`Materials, both organic and metallic, capable
`of possessing shape memory are well known. An article
`made of such materials can be deformed from an original,
`
`heat—stable configuration-to a second, heat—unstable
`10 configuration. The article is said to have shape
`memory for the reason that, upon the application of
`eat alone, it can be caused to revert, or to attempt
`to revert, from its heat—unstable configuration to its
`orij-inal, heat—stable configuration, i.e. it "remembers"
`15 its original shape.
`
`Among metallic alloys, the ability to possess shape
`memory is a result of the fact that the alloy undergoes
`a reversible transformation from an austenitic state to
`a martensitic state with a change in temperature. This
`20 transformation is sometimes referred to as a thermoelastic
`martensitic transformation. An article made from such an
`alloy, for example a hollow sleeve, is easily deformed from
`its -6riginal configuration to a new configuration when
`cooled below the temperature at which the alloy is trans—
`formed from the austenitic state to the martensitic state.
`
`25
`
`COOK
`Exhibit 1004-0006
`
`

`

`a3
`
`P0884—US1
`
`—3—
`
`The temperature at which this transformation begins is
`usually referred to as H5 and the temperoture at which it
`finishes Hf. When an article thus deformed is warmed to
`the temperature at which the alloy starts to revert back to
`
`austenite, referred to as A (Af being the temperature
`at which the reversion is complete) the deformed object will
`begin to return to its original configuration.
`
`Many shape memory alloys (SMAs) are known to display
`stress—induced martensite (SIN). When an SMA sample exhibit—
`ing stress—induced martensite is stressed ata temperature
`above H (so that the austenitic state is initially
`stable), but below Nd (the maximum temperature at which
`martensite formation can occur even under stress) it first
`deforms elastically and then, at a critical stress, begins
`to transform by the formation of stress—induced martensite.
`Depending on whether the temperature is above or below A5,
`the.behav.ior when the deforming stress is released differs.
`If the temperature is below A5, the stress—induced martensite
`is stable; but if the temperature is above A, the martensite
`is unstable and transforms back to austenite, with the
`
`sample returning (or attempting to return) to its original
`The effect is seen in almost all alloys which
`shape.
`exhibit a thermoelastic martensitic transformation, a1on
`with the shape memory effect. However, the extent of the
`temperature range over which SIM is seen and the stress and
`strain ranges for the effect vary greatly with the alloy.
`
`In copending and commonly assigned U.S. Patent Applic—
`to Quin, the disclosure of
`which is incorporated herein by reference, a nickel/titanium/
`vanadium alloy having SIM over a wide temperature range is
`disclosed.
`
`5
`
`10
`
`15
`
`20
`
`25
`
`30
`
`1
`
`COOK
`Exhibit 1004-0007
`
`

`

`a4
`
`MP0884—U51
`
`—4-
`
`Shape memory alloys have found use in recent years in,
`for example, pipe couplings (such as are described in U.S.
`Pat. Nos. 4,035,007 and 4,198,081 to Harrison and Jervis),
`electrical connectors (such as are described in u.S. Pat. No
`Fischer), switches (such as are described
`3,740,839 to Otte
`in U.S.
`
`No. 4,205,293), actuators, etc.
`
`--
`
`Various proposals have also been made to employ shape
`For example, U.S. Pat.
`memory alloys in the medical field.
`No. 3,620,212 to Fannon et al. proposes the ue of an SMA
`10 intrauterine contraceptive device, U.S. Pat. No. 3,786,806
`to Johnson et al. proposes the use of an SMA bone plate,
`U.S. Pat. No. 3,890,977 tâ Wilson proposes the use of an SMA
`element to bend a catheter or cannula, etc.
`
`These medical SMA devices rely on the property of shape
`15 memory to achieve their desired effects. That is to say,
`che(rely on the fact that when an SMA element is cooled to
`its martensitic state and is subsequently deformed, it will
`retain its new shape; but when it is warmed to its austenitic
`state, the original shape will be recovered.
`
`20
`
`However, the use of the shape memory effect in medical
`applications is attended with two principal disadvantages.
`First, it is difficult to control the transformation temper-
`
`atures of shape memory alloys with accuracy as they are
`
`usually extremely composition—sensitive, although various
`25 teniques have been proposed (including the blending by
`$o-e-r metallurgy of already—made alloys of differing trans—
`formation temperatures: see U.S. Pat. No. 4,310,354 to
`Fountain et al.). Second, in many shape memory alloys there
`
`COOK
`Exhibit 1004-0008
`
`

`

`85
`
`—5—
`
`MP084-U51
`
`is a large hysteresis as the alloy is transformed between
`austenitic and martensitic states, so that reversing of the
`state of an SMA element may require a temperature excursion
`of several tens of degrees Celsius. The combination of these
`factors with.the limitation that (a) it is inconvenient to
`have to engage in
`any temerature manipulation, and (b)
`human tissue cannot be heated or cooled beyond certain
`relatively narrow limits (approximately 00 - 60°C for short
`periods) without suffering
`temporary or permanent damage is
`expected to limit the use that can be made of SMA medical
`devices. It would thus be desirable to develop a way in
`which the advantageous
`property of shape memory alloys,
`i.e. their ability to return to an original shape after
`relatively substantial deformation, could be used in medical
`devices without requiring the delicacy of alloying control
`and/or the temperature Control of placement or removal
`needed by present shape memory alloy devices.
`
`DESCRIPTION OF THE INVENTION
`
`Summary of the Invention
`
`I have discovered that if, in a medical device
`containing
`a shape memory alloy element which uses the shape memory
`property of that alloy, an element which shows the property
`of stress_induced martensite is used instead, an improved device
`
`resul.ts.
`
`Accordingly, this invention provides a medicol device
`intended for use within
`a mammalian body, or in such proximity
`to a mammalian body that the device is
`substantially at body
`temperature, which device
`comprises a shape memory alloy
`element, the improvement in which comprises the substtutjon
`of an alloy element which
`displays stress_induced martensite
`at said body temperature for the shape memory alloy element.
`
`10
`
`15
`
`25
`
`COOK
`Exhibit 1004-0009
`
`

`

`a6
`
`—6—
`
`MP0884—US1
`
`Brief Description of the Drawing
`
`Eigures 1 and 2 illustrate the stress—strain behavior
`of an alloy which exhibits constant stress versus strain
`behavior due, to stress—induced martensite.
`
`5
`
`Detailed Description of the Preferred Embodiments
`
`The invention will be discussed first by introducing
`the concept of stress—induced martensite and the effect
`achievable by its use, and then by examples showing how SIM
`alloy elements can be substituted for conventional SMA
`elements in medical devices to achieve the beneficial effect
`of the invention.
`
`The Figures illustrate the phenomenon of stress—
`induced martensite by means of stress—strain curves. In
`both gure 1 and g,ure 2, the alloy is at a temperature
`betwee?M5 and Md sä that it is initially austenitic;
`and it will be assumed for the puposes of this discussion
`that M is equal to Hf, and A equal to Af. Figure
`1 shows the case when the temperature is below A, so that
`any martensite formed by the applied stress is stable; while
`Figure 2 shows the case where the temperature is above A5,
`so that austenite is the only stable phase at zero stress.
`
`In Figure 1, when a stress is applied to the alloy,
`it deforms elastically along the line OA.
`At a critical
`./ applied stress, a.r, the austenitic alloy begins to trans—
`form to (stress—induced) martensite. This transformation
`
`10
`
`.15
`
`20
`
`25
`
`COOK
`Exhibit 1004-0010
`
`

`

`a7
`
`MP0884—LJS1
`
`—7—
`
`--
`
`takes place at essentially constant stress until the alloy
`becomes fully martensitic at point B. From that point on,
`as further stress is applied, the martensite yields first
`elastically and then plastically (only elastic deformation
`is shown at point C). When the stress is released, the
`martensite recovers elastically to point D, at which there
`is zero residual stress, but a non—zero residual strain.
`Because the alloy is below A5, the deformation is not
`recoverable until heating above A results in a reversion
`to austenite. At that point, if the sample is unrestrained,
`the original shape will be essentially completely recovered:
`if not, it will be recovered to the extent permitted by the
`restraint, However, if the material is then allowed to
`re—cool to the original temperature at which it was deformed
`(or a temperature where SIM behavior of this type is seen),
`the stress produced in the sample will be constant regardless
`of the strain provided that the strain lies within the
`"plateau" region of the stress—strain curve. That is, for a
`and 4,, the tin will be
`strain between
`This
`20 (means that a known, constant force (calculable from aM) can
`be applied over a wide (up to 5% or more for certain Ni/Ti
`alloys) strain range. Thus, though this resembles the
`conventional shape memory effect, because the alloy shows SIM
`and is below A a constant force can be achieved.
`
`15
`
`25
`
`In Figure 2, when a stress is applied to the alloy,
`it deforms elastically along line OA, then by SIM along line
`AB, and by deformation of the martensite to point C, just as
`in Figure 1.
`However, the stress—strain behavior on unloading
`is significantly different, since the alloy is above
`
`COOK
`Exhibit 1004-0011
`
`

`

`aS
`
`MP0884—US1
`
`—8--
`
`As the stress
`and the stable phase is therefore austenite.
`is removed, the alloy recovers elastically from C to D;
`( then, at a critical stress,
`the alloy reverts to
`A'
`austenite without requiring a change in temperature. Thus
`reversion occurs at essentially constant stress. Finally if
`the stress is removed from the reverted austenite, it
`recovers elastically along line EO. The recoverable deform-
`ation associated with the formation and reversion of stress—
`induced marténsite has been referred to as pseudoelasticity.
`While °M may be comparatively high, e.g. 50 ksi, c is
`usually substantially lower, e.g. less than 10 ksi; thereby
`creating a constant—force spring with an effective working
`The shape change available
`range of about 5% (cB Ep).
`in the SMA is thus mechanically, rather than thermally,
`actuated and controlled, permitting a greater control over a
`device incorporating it. -
`
`•
`
`Suitable alloy for this invention i.e. those displaying
`stress—induced martensite at temperatures near mammalian
`body temperature (35c_400C), may be selected from known SMAs
`by those of ordinary skill inheart, having regard to this
`disclosure bytstng for the existence of the SIM effect at
`the desired temperature. A particularly preferred alloy is
`the nickel/titanium/vanadium alLoy of U.S. Patent Application
`(Docket No. MP0873—US1), reférred to previously.
`
`The inventi'on will now be discussed in detail by some
`Examples of the use of an SIM alloy.
`
`( Example L L-Heart Valves
`
`Akins, in U.S. \Patent No. 4,233,690, the disclosure of
`which is incorporated herein by reference, describes the use
`of a shape memory alloy ring to hold a sewing cuff to the
`body of an artifical heart valve. The ring is made in the
`austenstic phase, cooled to the martensitic phase, deformed,
`placed around the valve body, and heated or allowed to warm
`to cause reversion to the austenitic phase and recovery of
`the ring into engagement with the valve body.
`
`5
`
`--
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`COOK
`Exhibit 1004-0012
`
`

`

`a9
`
`MP0884—US1
`
`—9—
`
`However, this technique has not found commercial
`acceptance. Present medical technique requires that the
`valve body be capable of being rotated relative to the cuff,
`thereby enabling the surgeon to set the rotational orientation
`of the valve after it has been sewn into place. This is
`desirable because the techniques used make it difficult to
`
`visualize or accomplish optimal orientation during initial
`
`placement.
`
`10
`
`In order to accomplish the desired torque control to
`permit the desired rotation and yet ensure a firm hold of
`the cuff on the valve body, precise control of the pressure
`exerted on the valve body by the ring is needed. This is
`difficult because there are substantial manufacturing
`tolerances in the valve body which may be made, for example,
`of pyrolytic graphite or ceramics, etc. Because the austenite
`stress—strain curve is extremely steep, it is not considered
`practical to use the simple shape memory technique proposed
`by Akins. Indeed, Akins does not even address the. issue of
`rotation.of the cuff with respect to the valve body.
`
`20
`
`However, if an SIM alloy is used instead of conventional
`
`shape memory, the process may be considerably simplified.
`
`First, if the alloy has a stress—strain curve like that
`
`25
`
`of Figure 1, the alloy ring may be made just as for Akins.
`The ring is then expanded from its initial austenitic state
`When the ring is placed about the
`by the formation of SIM.
`valve body, it needs only to be heated above Af and
`allowed to cool to its original temperature for the ring to
`
`COOK
`Exhibit 1004-0013
`
`

`

`alO
`
`MP0884—US1
`
`—10—
`
`engage the valve body with a constant force, even if the
`valve body has a deviation from the specified size.
`The
`torque may thus be controlled to the desired level despite
`
`manufacturing tolerances.
`
`Second, if the alloy has a stress—strain curve like
`that of Figure 2, the ring may be expanded, placed over the
`valve body, and the stress released all at the same temperature.
`Because the austenitic phase is stable, the stress—induced
`martensite spontaneously reverts to austenite until recovery
`is restrained by the ring engaging the valve body. Because
`the reversion to austenite takes place at constant stress, a
`constant force (and hence constant torque) may be obtained
`regardless of manufacturing tolerances. Close temperature
`control is not required, either; and the fact that the
`patient in a heart valve replacement operation is convention—
`ally cooled as much as 15°C or so below normal body temperature
`does not affect the operation of the ring.
`
`To control the torque at a sufficiently low level,
`it may be desirable for the alloy ring to be other than a
`solid ring, such as, for example, a continuous helical spring,
`a flat zigzag spring, etc. Such variations permit the
`achievement of a greater range of movement with constant
`force and a reduction in the force exerted by the ring on
`the value body, since the ring recovers in a bending mode
`rather than in tension.
`
`10
`
`15
`
`20
`
`25
`
`/
`
`COOK
`Exhibit 1004-0014
`
`

`

`all
`
`MP0884—USl
`
`—11—
`
`Example II. Catheters And Cannulas
`
`Wilson, in U.S. Patent No. 3,890,977, the disclosure
`/
`of which is incorporated herein by reference, discloses a
`catheter or cannula (both being included hereinafter in the
`word "catheter") made of, .or containing, an SMA element to
`cause all or a portion of the catheter to deploy in a useful
`form once introduced into a living body.
`
`10
`
`15
`
`20
`
`25
`
`However, again this device has not been commercialized.
`Possible defects of the device which have prevented commercial—
`ization include (i) the inability to slowly emplace the
`catheter in a desired pos±tion when the transition temperature
`of the alloy is below body temperature (since the SMA
`element will attempt to revert to its original shape as it
`reaches body temperature), thus limiting the ability of the
`physician to place the device carefully and precisely; or
`alternatively, if the transition temperature of the alloy is
`above body temperature, the requirement that the device,-by
`heated to a temperature above body temperature to cause
`recovery and that the device be placed so as not to change
`shape again when it re—cools (since the body temperature is
`below the transition temperature); (ii) the inability to
`remove the device easily; and (iii) the need for controlled
`
`temperature storage to prevent premature reversion to
`austenite of the SMA, with consequent shape change.
`
`The issue of removal of a catheter is especially
`significant, and not addressed by Wilson. Consider, for
`example, a tracheal puncture catheter. This should be
`
`COOK
`Exhibit 1004-0015
`
`

`

`a12
`
`.
`
`MP0884—US1
`
`—12—
`
`straight for easy insertion into the trachea through a
`puncture into the front of the neck, but should curve after
`insertion so that the flow of air or oxygen through the
`catheter passes axially down the trachea rather than impinging
`If a shape
`on the surface of the trachea and damaging it.
`memory catheter is used s contemplated by Wilson, it would
`presumably become austenitic and bend after insertion (see
`Figures la and ib, and corresponding text, of Wilson). But
`removal would require either cooling to below the transition
`temperature (which could easily mean cooling to so low a
`temperature that the tracheal tissue is damaged), removal in
`the bent shape (presumably damaging tissue), or forcing the
`austenitic SMA to straighten to permit direct removal (unlikely
`to be satisfactory since the austenitic alloys e.g. of Ni/Ti
`may have yield strengths of 100 ksi or more, and force
`sufficient to cause plastic deformation would be required).
`
`If an SIM element is used instead, however, removal can
`be accomplished almost as easily as insertion. If.the
`
`catheter is made in a bent shape (as in Wilson) , it can be
`
`straightened by insertion of a straight pin down the catheter
`axis, the catheter deforming by the formation of stress—induced
`martensite. Insertion of the catheter into the trachea is
`accomplished while the catheter is straight, at whatever
`
`rate is desired (permitting easy and accurate placement),
`and the pin is gradually withdrawn to permit the catheter to
`take up its desired shape as the martensite reverts to
`austenite. [It is assumed here that the stress—strain curve
`of the alloy at the temperature of use is of the form of
`Figure 2, so spontaneous reversion occurs on removal of the
`stress induced by the pin]. When removal is desired, it may
`be achieved simply by the 'gradual insertion of the pin,
`straightening the catheter and permitting easy withdrawal.
`Insertion of the catheter into the body and pin removal may,
`of course, take place simultaneously if desired, as may pin
`reinsertion and removal of the catheter from the body.
`
`5
`
`V
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`COOK
`Exhibit 1004-0016
`
`

`

`a13
`
`•1P0884—US1
`
`—13—
`
`Example III. . IUDS
`
`Fannon et al., in U.S. Patent No. 3,620,212, the
`disclosure of which is incorporated herein by reference,
`discloses an intrauterine contraceptive device (an IuD)
`proposed to be formed of a shape memory alloy. The device
`is suggested to be deformed in the martensitic phase (the
`transition temperature being below the temperature of the
`uterus), and the deformed device insulated with, e.g. wax
`Removal is contemplated only by using two
`and inserted it.
`SMA elements in opposition, the higher temperature one being
`
`martensitic at body temperature but strong enough so that,
`if heated, it will overcome the lower temperature element
`and deform the IUD back to a removable shape. The heating
`contemplated is electrical. The storage problem discussed
`in Example II also exists here, so that the device must be
`stored below its transition temperature.
`
`By the use of an SIM element, however, these dis-
`advantages may be overcome. Again, assume that thealloy is
`SIM psuedoelastic, i.e. that it has the stress—strain curve of
`Figure 2.
`Then an IUD may be formed into the desired shape
`in the austenitic state, and deformed by compression into a
`tubular placement device (the deformation being such that
`the strain levels lie within the "plateau" of the stress—
`strain curve). When the placement device is inserted into
`the uterus, the IUD may be deployed by extrusion of the IUD
`from the placement device. Deployment is then controlled but
`immediate, so that the physician may satisfy himself with
`placement. Removal is the reversal of placement: the
`placement device is inserted into the uterus, the IUD deformed
`by withdrawal into the placement device, and the placement
`device withdrawn. Temperature control is not required.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`COOK
`Exhibit 1004-0017
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`

`

`al 4
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`MP0884—US1
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`—14—
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`Example IV. Bone Plates
`
`Johnson et al., in U.S. eatent No. 3,786,806, the
`f
`disclosure of which is incorporated herein by reference,
`propose the use of Ni/Ti. SMA bone plates in fracture
`fixation. The plate is deformed in its rnartensitic state,
`screwed to the two ends of the bone it is desired to compress
`together, and warmed (or allowed to warm) to the austenitic
`state, when the plate contracts, compressing the bone ends
`together.
`
`Because of the high elastic moduli of the austenitic
`shape memory allo's, it will be difficult to control the
`amount of force
`h ma)i be applied by a bone plate of the
`type proposed by Johnson et al., and precision placement of
`the bone ends and elongation of the plate will be required.
`
`If, however, an SIM pseudoelastic bone plate is used,
`itwill be easily possible to elongate the plate and fasten
`it to the bone ends without requiring high precision.
`Because of the comparatively large (e.g. 5%) strain range
`at essentially constant stress, the force which will be put
`on the bone ends to compress them will be readily adjustable
`(by the size of the plate, for example) and will be insensitive
`to precise placement of the bone ends and/or elongation of
`the plate. Also, the recovery of the plate, since it is
`controlled by mechanical restraint, may be as gradual as
`desired, achieving excellent force and time control, and
`pernitting the surgeon to make adjustments as desired.
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`COOK
`Exhibit 1004-0018
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`

`

`a15
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`1PO884—USl
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`—15—
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`Example V.: Marrow Nails
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`Baumyart et al., in U.S. \Patent No. 4,170,990, the
`)
`disclosure of which is incorporated herein by reference,
`discloses the use of the two—way shape memory effect (where
`an SMA element exhibits a first shape in the austenitic
`state and a second in the martensitic state, and spontaneously
`changes between the two shapes with a change in temperature)
`in, inter alia, marrow nails (see Figures la through le, and
`corresponding text, of Baumgart et al.).
`
`The method proposed, however, requires the use of a
`wide temperature range in order to cause the phase change
`which is the origin of the two—way shape memory effect (5°C
`to 60°C for the water used to cool or heat the nail). In
`addition, it requires the manufacture of two—way shape
`memory elements, which is generally more complex than the
`manufacture of conventional shape memory elements; and
`•precise control of the tranisition temperature is required.
`
`However, if an SIM pseudoelastic alloy element is employed,
`If internal tangs, which
`these disadvantages may be overcome.
`may be gripped by an inserted tool, are provided within a
`marrow nail of the type shown in Figure 1a of Baumgart et
`al. , then the nail may be radially compressed by the application
`of stress by such a tool. When the nail is released by the
`tool, it will expand to fill the bone channel with a constant
`force (not readily available by Baumgart et al.); and it may
`be withdrawn by the reverse procedure.
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`COOK
`Exhibit 1004-0019
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`

`

`a16
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`0884—US1
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`—16—
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`Example VI Dental Arch Wire
`
`J Andreasen, in U.S. Patent No. 4,037,324, the disclosure
`of which is incorporated herein by reference, proposes the
`use of dental arch wires made of Ni/Ti alloys instead of
`conventional 18—8 stainless steel wires. The wires are
`stated to be of lower elastic modulus and higher elastic
`limit than stainless steel, which is stated to be advantageous.
`Heat recovery of an SMA wire, is also suggested as a technique
`for orthodonture.
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`The technique of using the conventional shape memory
`effect is not believed to have found clinical application,
`possibly because such a technique would require rapid
`placement of the wire in its martensitic state to avoid
`premature recovery, and would result in rapid recovery with
`extremely high forces, which would be painful for the patient.
`
`.The use of a wire which displays lower elastic modulus
`and higher elastic limit than stainless steel has found some
`application, however. Otsuka et al. in Metals Forum, v. 4,
`pp. 142—52, (1981) have suggested that this behavior may be
`the result of elasticity enhanced by cold working and
`martensite—to—martensite psuedoelasticity in an alloy which
`has a transition temperature below body temperature. The
`alloy, then, is martensitic rather than austenitic in its
`undeformed state.
`
`While the use of an enhanced elasticity wire may offer
`some advantages over the more usual stainless steel wire, it
`remains the situation that the amount of motion in the teeth
`that may be produced by an arch wire without further adjustment
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`COOK
`Exhibit 1004-0020
`
`

`

`a17
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`P0884—US1
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`—17—
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`is largely limited by the pain tolerance of the patient
`(since the force applied by the arch wire is proportional to
`the deformation of the wire). However, if an SIM pseudoelastic
`wire is used, it can exert a relatively constant force
`(chosen by the dentist to be sufficient to cause tooth
`movement but, not painful) over a strain range of up to 5%.
`The load may be applied mechanically, and is thus more
`readily established, and no precise temperature control of
`the alloy is needed as would be required for the shape
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`memory effect.
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`Example VII. Coil Stents and Filters
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`The use of tubular coiled wire stent grafts has been
`dis'cused in the medical literature since 1969. Although
`the coils helped maintain patency of the vessels in which
`they were placed, they were difficult of insertion unless
`narrow enough to significantly narrow the lumen of the
`vessel. Recently it has been proposed, see Radiology, v.
`147, pp. 259—60 and pp. 261—3 (1983), the disclosures of
`which are-incorporated herein by reference, to use SMA wire
`to form these tubular coils. The wire, which has a trans-
`formation temperature below body temperature, is introduced
`through a catheter after being straightened in its martensitic
`state. When the wire is heated, the coil re—forms.
`
`Because of the difficulty of controlling the trans—
`formation temperature accurately, it has proved necessary
`to cool the straightened wire during insertion and/or to
`heat the wire to form the coil after insertion. These
`procedures add to the complexity of the operation.
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`COOK
`Exhibit 1004-0021
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`

`

`a18
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`P0884—USI
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`—18—
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`If an SIM pseuddelastic wire is used to form the
`coil, which is then isothermally deformed by loading into
`catheter, then the need, for temperature control is avoided.
`The wire remains straight when in the catheter, but re—forms
`the coil spontaneously when it is extruded from the catheter.
`Accurate placement is thus readily obtainable, since there
`is no urgency as might be-required with a conventional shape
`memory effect element.
`
`It has similarly been proposed to use SMA wire to form
`a filter for emplacement by catheter in the vena cava to
`trap blood clots.
`The filter is formed in the austenitic
`state, the wire straightened in the martensitic state and
`inserted, and the filterre—forms on warming. Just as for
`the coil stents discussed above, the use of an SIM pseudo—
`elastic wire would greatly simplify manufacture and insertion
`of such a vena cava filter, permitting accurate placement
`with no need for urgency or temperature manipulation.
`( z..
`Example VIII.' -Bone Staples, Clips, etc.
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`-
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`Bone staples are frequently used to hold fragments of
`fractured bone together when the fracture is fixed, and may
`be used in some cases as a replacement for bone plates in
`the same situation. Sometimes the staples are inserted into
`drilled holes, sometimes merely driven into the bone directly.
`
`It would be desirable to have a bone staple which provided
`a cntrolled force between the tines which would tend to hold
`
`the staple in place. Shape memory alloys have been proposed
`for this application, but again the problem of accurate place—
`ment while operating quickly enough to prevent the shape
`change associated with the martensite—to—austenite transition
`and/or the need for temperature control complicate their use.
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`COOK
`Exhibit 1004-0022
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`

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`a19
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`1P0884—USl
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`—19—
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`5
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`If an SIM alloy is used, these disadvantages may be
`If the alloy is below A9, it may be
`readily overcome.
`emplaced in the martensitic state. Brief heating will then
`be required to cause it to become austenitic, but on re—
`cooling to body temperature, a constant force can be achieved.
`If the alloy is above A5, the staple can be held deformed
`by a moderate force, then released after insertion to also
`In either event, removal
`provide an accurately—known force.
`is easier than if the alloy is purely austenitic, as discussed
`above for Examples II and V, for example.
`
`Similarly, SIM alloy (especially alloy which is
`pseudoelastic, above A at its utilizstion temperature)
`may be used to manufacture vascular clips, etc.
`The alloy
`element here acts as a constant force spring over a wide
`strain range (greater than conventional elastic metals),
`resulting in ease of use.
`
`From the foregoing, it is clear that, in a situation
`where narrow temperature differences are available or
`preferable, as often is the case in medical applications,
`mechanically constrained shape change is a much more useful
`solution than heat actuated shape change. It offers a
`degree of control heat actuation does not, it offers easier
`alloy composition control, it eases mating part tolerance
`requirements, and it offers simple mechanical reversal at
`minimal stress levels, all without heating, cooling or
`insul ation complications.
`
`It will be obvious to those skilled in the art, having
`regard to this disclosure, that other variations on this
`
`invention beyond those specifically exemplified here, and
`other medical devices making use of stress—induced martensite,
`may be made. Such variations are, however, to be considered
`as coming within the scope of this invention as limited
`
`solely by the following claims.
`
`COOK
`Exhibit 1004-0023
`
`

`

`bi
`
`MP0884—US1
`
`—20—
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`•
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`I claim:
`
`In a medical device intended for use within a
`1.
`mammalian body, or in such proximity to a mammalian body
`that the device is substantially at body temperature, which
`
`device comprises a shape memory alloy element, the improvement
`which comp