United States Patent
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`["1 3,620,212
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`[72] Inventors
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`Robert D. Fannon, Jr.
`Columbus;
`Brenton R. Lower, Columbus. Ohio;
`Leonard E. Lauie, I206 lnverness Ave.,
`Pittsburgh, Pa. 15207
`[2]] Appl. No. 46,419
`[22] Filed
`June 15, 1970
`[45] Patented
`Nov. 16, I971
`[73] Assignee
`said Laufe, by said Fannon and said Lower
`
`[56]
`
`References Cited
`UNITED STATES PATENTS
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`2.063.202 l2/l93b Spicer.
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`3,467,089
`9/1969 Hasson
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`128/130
`l28/l 30
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`1507274 4/l970 Soichet, . . .
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`2/l97l Zipper ..................... .‘
`3,563,235
`Primary Examiner-Lawrence Charles
`Armrney-Parmelee, Utzler & Welsh
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`l28/l 30 X
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`(54] INTRAUTERINE CONTRACEPTIVE DEVICE
`8 Claims, 8 Drawing Figs.
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`[52] U.S.Cl .................... ..,
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`128/130
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`[51] lnt.Cl ........... ..
`[50] FieldofSeareh...
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`ABSTRACT: An intrauterine contraceptive device formed, in
`part at least. ofa nickel-titanium alloy which has a mechanical
`memory The device is formed initially in the desired free
`shape it will take in the uterine cavity. heat-treated with the
`free shape being mechanically constrained. and then plasti
`cally deformed to a compact, elongated shape for easy inser
`tion through a cervical canal into a uterine cavity The device
`will gradually resume its free shape as it is heated to tempera
`ture near the human body temperature.
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`Edwards Exhibit 1007, p. 1
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`

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`PATENTEDuuv 1s 197l
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`3,620,212
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`
`INVENTORS
`LEONARD E, LAUFE',
`ROBERT D. FA/VNOIV,./R.6 BRENTONR LOWER
`
`3”WW (MW/M
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`A Home]:
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`Edwards Exhibit 1007, p. 2
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`Edwards Exhibit 1007, p. 2
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`

`

`1
`INTRAUTERINE CONTRACEPTIVE DEVICE
`This invention relates to intrauterine contraceptive devices
`formed from material having a mechanical memory, whereby
`the device is plastically deformed from its free shape to a com
`pact shape for easy and painless insertion through a cervical
`canal into a uterine cavity and is gradually restored to its free
`shape as the device heats up to around body temperature .
`Intrauterine contraceptive devices of various shapes have
`become known in recent years and their use is becoming in
`creasingly widespread. The more popular devices are ring or
`loop shaped, and are formed usually of a plastic material.
`These devices have proved to be effective in preventing con
`ception, with the reason for their effectiveness not being con
`clusively understood. The most commonly accepted theory is
`that the device irritates the interoceptors in the endometrium
`of the uterus and thereby prevents a fertilized ovum from ad
`hering to the lining ofthe uterus. Placement of the devices in
`the uterus is often accomplished by use of a cannula which is
`simply a thin elongated tube having an internal plunger. The
`contraceptive devices are ?exible enough so that they can be
`either straightened to a strand or compressed to a compact
`shape and then placed in the cannula. The cannula is then in
`sorted through the cervical canal into the uterus where the
`device is pushed out of the cannula. The device will im
`mediately spring into its original shape.
`The commonly used intrauterine devices are not without
`their problems. Some of the devices have been found to dis
`play a high-ejection rate where the device is ejected from the
`uterus. This may lead to pregnancy when the woman in
`unaware of the ejection and falsely relies on its presence.
`Another serious problem is uterine perforation and infection
`when an end of the device penetrates the uterine wall. Both
`the ejection and the perforation problems are felt to be at
`tributable to the material used in fabricating the devices. It is
`considered that most materials used are not stiff enough and
`that when pulsations of the uterus wall occur, as during the
`menstrual periods, the pulsation waves cause the device to flex
`to an extent where it is pushed downwards and in many cases
`expelled. In the case of uterus perforation, it has been ob
`served that some materials used for the device have a steady
`creep and in time will grow to a point where a free end, if not
`properly placed, will penetrate the wall of the uterus.
`Another problem in the commonly used devices is the need
`to remove and replace them because of premature malforma
`tion or breakage. The material again is the cause of this
`problem. Most often the material is not strong enough and will
`exhibit stress relaxation or stress cracking which will lead to
`the malformation and breakage.
`The most common material used for intrauterine devices is
`polyethylene, which is ?exible enough so that the device may
`be straightened or compressed for inclusion within a cannula.
`Other plastics may also be used, such as polypropylene,
`polytetra?uoroethylene, polyethylene glycol terephthalate,
`tri?uorochloroethylene, polyvinyls and others. All of these
`plastics also exhibit the proper elasticity to reform when the
`device is inserted from the cannula into the uterus. However,
`all of the plastics have an innate characteristic to creep, and
`all, to a certain degree, will develop stress relaxation and stress
`cracking while in a uterus. In addition, some of the plastics will
`not provide the necessary stiffness to the device to avoid ejec
`tion from the uterus.
`-
`We overcome the aforementioned problems by providing
`an intrauterine device formed basically of a material which is
`stronger, stiffer, and has a lower creep rate \than any of the
`materials currently being used. In addition, our intrauterine
`device has a mechanical memory which is characterized by a
`return by the device to a preformed shape after the device is
`plastically deformed as when it is straightened or compressed
`to ?t in a cannula. Moreover, our device will gradually reform
`within the uterus as the material is heated therein, rather than
`reform abruptly with force as is the case with polyethylene
`type devices which are not plastically deformed but are elasti
`cally deformed. More specifically, we provide an intrauterine
`device which comprises an elongated strand shaped in a con
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`3,620,212
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`?guration lying substantially in one plane to ?t within a
`uterine cavity; the strand being composed at least partially
`throughout the length thereof of an alloy comprising
`53.5-56.5 weight percent nickel, the remainder being essen
`tially titanium. The desired shape of the device is ?rst formed
`and the device then heat-treated while the shape is mechani
`cally constrained. After heat treating, the device may be
`plastically deformed to a compact shape. The nature of the
`alloy used is such that the original shape will be restored when
`the alloy is heated to a temperature below the heat-treating
`temperature and in our application that temperature would be
`somewhere near human body temperature. Thus, our device
`has a mechanical memory.
`Other details and advantages of this invention will become
`apparent as the following description proceeds.
`In the accompanying drawings we illustrate various intrau
`terine devices formed in accordance with this invention, in
`which:
`FIGS. 1 through 3 illustrate intrauterine devices-of well
`known shape fabricated in accordance with the present inven
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`tion;
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`3
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`7
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`FIG. 4 is a sectional view along the line 4—4 of FIG. I and
`illustrating a solid nickel-titanium alloy construction of the
`device;
`FIG. 5 is a sectional view along the line 5—5 of FIG. 2 and
`illustrates a solid core of nickel-titanium alloy surrounded by a
`plastic sheath construction of the device;
`FIG. 6 is a view partly in section of an intrauterine device
`showing a wire core surrounded by plastic construction;
`FIG. 7 is a view of yet another intrauterine device of the
`present invention as initially formed; and
`'_
`FIG. 8 is the same device as illustrated in FIG. 7 but plasti
`cally deformed in a compact elongated form and surrounded
`by a gelatinous jacket.
`This invention is illustrated in the drawings as having several
`alternative forms. It should be understood that the intrau
`terine devices shown are merely examples of many shapes
`which can be taken by the device of this invention.
`The intrauterine devices shown in the drawings are all
`shaped in familiar con?gurations for placement within a
`uterine cavity. Each of the devices includes an elongated
`strand having a generally circular cross section. The devices
`are all formed with their strands composed entirely or partly
`of an alloy comprising 53.5-56.5 weight percent nickel and
`the remainder essentially titanium. The device I0 of FIG. I is
`composed entirely of the alloy; the device 20 of FIG. 2 has a
`solid core 22 of the alloy surrounded by a sheath 25 of molded
`plastic material such as polyethylene; and the device 30 of
`FIG. 6 has four wires 32-35 formed from the alloy with the
`wires being embedded in a sheath 40 of molded plastic materi
`al, such as polyethylene.
`The nickel-titanium alloys used in this invention are unique
`among engineering alloys in that they have mechanical memo
`ries. When items formed from these alloys are heat-treated
`above a certain temperature while mechanically constrained
`in a particular shape, they will return to that shape even after
`the item is permanently plastically deformed. The return to
`the original shape is brought about by heating the item to a
`temperature well below the heat-treating temperature. Thus,
`the device 10 shown in FIG. 1 would be initially formed at
`room ‘temperature. The sheathed devices 20 and 30 would
`have the core 22 and wires 32-35, formed initially in the con
`?guration shown. All of the preformed parts would then be
`placed in a constraining device for mechanically holding the
`shape, heated to around 900° F., held at that temperature for a
`few minutes, and then cooled by quenching in water. When
`the parts are sufficiently cooled, the sheaths 25 and 40 may be
`molded onto core 22 and wires 32-35, respectively. All of the
`devices 10, 20 and 30 may now be plastically deformed to
`whatever con?guration desired. For example, device 10 could
`be deformed to an elongated straight strand. Similarly, the
`device 50 of FIG. 3 could be deformed to a straight strand.
`The device 20 of FIG. 2 could be deformed into an elongated
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`Edwards Exhibit 1007, p. 3
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`3,620,212
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`10
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`they would coil along with wires 33 and 34. When the device
`30 was to be removed, wires 32 and 35 could be subjected to a
`low voltage to heat the wires to their transition temperature at
`which point the device would straighten and could then be
`easily removed. The resistance by wires 33 and 34 to
`straightening could be easily overcome by making the wires 32
`and 35 larger in diameter.
`It is emphasized here that when the intrauterine devices are
`reformed to their initial shap_e_they have the same physical
`properties as when they were initial y formed. ln other words,
`the nickel-titanium alloys reform at their transition tempera
`ture from a pliable, reduced yield strength stage to a stiff and
`high yield strength stage.
`While we have particularly shown and described particular
`embodiments of this invention, it is to be distinctly understood
`that the invention is not limited thereto, but that modi?cations
`may be made within the scope of the invention, and such
`variations as are covered by the scope of the appended claims.
`We claim:
`1. An intrauterine contraceptive device, comprising an
`elongated strand, shaped in a con?guration lying substantially
`in one plane to ?t within a uterine cavity; said strand being
`composed at least partially through the length thereof of an
`alloy comprising 53.5-56.5 weight percent nickel, the
`remainder being essentially titanium; and said strand being
`heat-treated while the con?guration thereof is mechanically
`constrained.
`'
`2. The contraceptive device as set forth in claim 1 including
`a sheath surrounding the strand and composed of a material
`which will slough away upon insertion of the strand into a
`uterine cavity.
`3. The contraceptive device as set forth in claim 1 wherein
`said strand is composed of a continuous core of said alloy
`throughout the length thereof and a continuous sheath of
`molded plastic material surrounding said core.
`4. The contraceptive device as set forth in claim 1 wherein
`the alloy is characterized by being restored to its initial shape,
`after plastic deformation thereof, above human body tempera
`ture.
`5. The contraceptive device as set forth in claim 1 wherein
`said strand is shaped and then heat-treated to about 900° F.
`while the shape thereof is mechanically constrained.
`6. The contraceptive device as set forth in claim 1 wherein
`said strand is composed of a plurality of wires of said alloy ex
`tending throughout the length thereof and a continuous sheath
`of molded plastic material surrounding the wires.
`7. An intrauterine contraceptive device comprising an elon
`gated strand shaped in a compact con?guration to ?t in a cer
`vical canal for insertion into a uterine cavity; said strand being
`composed at least partially through the length thereof of an
`alloy comprising 53.5-56.5 weight percent nickel, the
`remainder being essentially titanium; said strand being ?rst
`formed with a free shape in substantially one plane to fit
`within a uterine cavity, and then heat-treated while the free
`shape is mechanically constrained, and ?nally plastically
`deformed into said compact con?guration; and said alloy
`being characterized as being restored to said free shape when
`said strand in the compact con?guration is heated to a tem
`perature above body temperature.
`8. The contraceptive device as set forth in claim 7 including
`a sheath of material surrounding said strand when in said com
`pact con?guration, and composed of a material which will
`slough away upon insertion of the strand into a uterine cavity.
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`3
`compact fold con?guration. The device 60 of FIG. 7 is shown
`in FIG. 8 in a deformed compact fold con?guration. Any of
`the devices in their deformed con?gurations may be inserted
`into cannulas for insertion through cervical canals into uterine
`cavities. In the case of device 60, a gelatinous wax sheath 70 is
`molded around the deformed compact con?guration. The wax
`sheath will serve to retard the reforming of the device 60 to its
`free shape when the device is inserted into the uterus. The wax
`sheath will slough away due to the heat in the uterus, after
`which the device 60 itself will begin heating and gradually will
`reform to its original shape. The device 60 is illustrated as
`being formed entirely of the nickel-titanium alloy, as is device
`50 of FIG. 3, but both may be made with a solid or wire core
`surrounded by plastic sheaths. Similarly, devices 20 and 30
`could be formed entirely from the nickel-titanium alloy.
`The particular composition of nickel-titanium alloy selected
`to use in forming the intrauterine devices will result in a
`reforming of initial free shape of the devices at around 98° F.
`with this temperature being called the transition temperature.
`That is, the devices will reform when they reach a temperature
`around body temperature. Also, the alloy will begin reforming
`at around 70° F. Thus, it would be important to keep the
`device always below 70° F. before insertion into a uterus, or
`alternatively to keep the device in a container which will hold
`the deformed shape. It would be particularly desirable to place
`the deformed devices in metal shipping containers to hold the
`deformed shape during transport through temperature en
`vironments above 70° F. Otherwise, inadvertent shape
`recovery would result.
`In addition to exhibiting the mechanical memory charac
`teristic, the nickel-titanium alloy is stronger, stiffer, and less
`creep prone than the plastics commonly used in forming in
`trauterine devices. The details of the nickel-titanium alloys,
`including their physical properties are set forth in U.S. Pat.
`Nos. 3,174,851 and 3,351,463. The particular range of alloys
`used in this invention are described in the latter mentioned
`patent. Because of the favorable physical properties, namely
`stiffness and strength, of the nickel-titanium alloy, the intrau
`terine devices will not exhibit the high-ejection rate inherent
`with plastic devices. Also, the low creep rate of the alloys will
`minimize, if not totally eliminate, uterine perforation. The
`alloy is also corrosion resistant and therefore useable in the
`highly corrosive uterine cavity without any special chemical
`treatments. Finally, the alloy is not subject to the high in
`cidence of stress relaxation and stress cracking found in the
`plastics commonly used with intrauterine devices, and, ac
`cordingly, will result in having devices which will retain their
`true shape for long periods of time. Thus, removal and
`replacement of devices for reasons of malformation or
`breakage will be greatly reduced.
`In the device 30 of H6. 6, the wires 33 and 34 in the inside
`portion would have the same nickel-titanium alloy composi
`tion with a transition temperature at approximately body tem
`perature. The wires 32 and 35 in the outside portion of the
`device would have the same nickel-titanium alloy composition
`with a transition temperature much higher than that of wires
`33 and 34. Wires 33 and 34 would be given a memory for the
`coiled portion of the device while wires 32 and 35 would be
`given a memory for the straight portion of the device. The
`coiled portion would be straightened by plastic deformation
`prior to insertion of the device into a uterus. Upon insertion,
`wires 33 and 34 would heat up to body temperature and would
`coil. Since wires 32 and 35 would be below their transition
`temperature the yield strength would be low enough so that
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`Edwards Exhibit 1007, p. 4
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