Medical devices may be packaged in order to protect the medical device from physical damage during shipment and/or storage. Medical devices may also be packaged in order to protect the sterility of the medical device. Packaging of medical devices is common because medical devices may be subjected to shock, temperature cycles, contaminated environments and other conditions detrimental to the medical device's physical condition and/or sterility during storage and transport prior to use.
Methods and systems are described for packaging medical devices. Packages are described for constraining expansion of medical devices along at least one axis. Removal devices for removing the medical devices from the packages are described. Medical devices stored in and removed from packages can include shape memory materials (e.g., polymers, alloys) which can cause the medical device to expand due to activation of the shape memory material. Medical devices can also expand due to other reasons, such as elastic recoil and/or thermal expansion. The methods and systems described herein may be used to limit the expansion of a medical device along at least one axis while inside a package. The methods and systems described herein may be used to relieve some of the stored strain in the medical device upon the opening of the package. Methods and systems are also described for opening a package which is subject to expansive forces from the medical device.
In one aspect the disclosure describes a package for a medical device containing a shape memory polymer. The package includes at least one intermediate member which has an interior surface capable of mating with a portion of the medical device, a constraining member disposed around the at least one intermediate member, and a compressing member disposed between the at least one intermediate member and the constraining member.
In another aspect, the disclosure describes a method of packaging a shape memory medical device. The method includes packaging a shape memory medical device in a chamber created by interior surfaces of a plurality of sabots, and encompassing a circumference of the plurality of sabots with a constraining member. The method also includes initiating an expansion of the medical device, and limiting the expansion of the medical device via limiting movement of the sabots.
In another aspect, the disclosure describes a removal device for removing a medical device from a package. The removal device includes a housing for containing the package in an unopened state, wherein the housing comprises a handle body and a hinged lid body attached to the handle body. The removal device also includes a chamber defined by an interior surface of the handle body and the hinged lid body, the chamber adapted to contain the package in the unopened state. The removal device also includes a cylinder adapted to engage a constraining member of the package, wherein turning about the axis of the cylinder winds a removed portion of the constraining member of around the cylinder. The removal device also includes an opening shaped to allow the medical device to pass out of the chamber.
In another aspect, the disclosure describes a package for a medical device containing a shape memory polymer. The package includes at least one intermediate member which has an interior surface capable of mating with a portion of the medical device. The package also includes a means for constraining the at least one intermediate member, the means for constraining disposed around the at least one intermediate member. The package may also include a means for compressing the medical device disposed between the at least one intermediate member and the means for constraining the medical device.
The following description of various embodiments is merely exemplary in nature and is in no way intended to limit the disclosure. While various embodiments have been described for purposes of this specification, various changes and modifications may be made which will readily suggest themselves to those skilled in the art, and which are encompassed in the disclosure.
Medical devices may expand for a number of reasons, including activation of shape memory elements within the medical device. Because medical devices often require restrictive tolerances to be met in order to be used with a patient (e.g., inside a patient), the expansion of medical devices may be controlled. Expansion of medical devices can include thermal expansion, expansion due to shape change of a shape memory element in a medical device, expansion due to absorption (e.g., absorption of water vapor from the air), or expansion for other reasons. The description herein includes packages and methods of packaging which constrain a medical device from expansion along at least one axis.
Exemplary embodiments of a sabot material include metals (e.g., stainless steel), polymer, and/or a composite material. The sabots 102 may be constructed in any manner which can withstand the expansive forces of a medical device. The sabots may be constructed as a solid element, as an element with porosity (e.g., honey comb, corrugated), or as other structures. Materials of sabots may be chosen for bio-compatibility as the medical devices which are contacted by the sabots may be used in surgery. The material may be formed into a sabot using any available method, including molding, extrusion, cutting, lathing, and/or etching.
Exemplary embodiments of a constraining member material include metals (e.g., stainless steel), polymer, and/or a composite material. The constraining member 104 can be formed into a band, web, tube or other structure capable of withstanding the expansive forces of the medical device.
In the embodiment shown, a system of sabots 102 contain the medical device 106 inside the package 100. The sabots 102 define an interior surface which mates with the medical device 106. The interior surfaces of the sabots provide constraint against expansion of the medical device by restraining any movement of the medical device. In addition, the medical device may conform to the interior surface(s) of the sabots.
The exterior surface of the medical device or the medical device itself may be shaped by expanding the medical device against the interior surface(s) of the sabots. Interior surfaces of the sabots can be used for in-package shaping and/or forming of the exterior surface and/or shape of the medical device. For example, the shape of the medical device can be created by expanding the medical device against the interior surface(s) of the sabots. Alternatively or additionally, surface textures may be imparted on the medical device by expanding the medical device against the interior surface(s) of the sabots. Thus, forming of the medical device (“in-package” forming) may be accomplished through expanding the medical device against interior surface(s) of the sabot(s).
The expansive forces of the medical device can be related to recovery of a shape memory material in the medical device (e.g., shape memory polymer, shape memory alloy) and/or to elastic recoil of any material in the medical device due to deformation of that material while contained inside the package. In one embodiment, the medical device is reduced along one dimension in order to fit the medical device within the package. The medical device may then be allowed to partially expand, or may be activated to expand. Partial expansion may relieve a part of the stored strain in the medical device while it is in the package. The medical device may continue to have some stored strain which causes an expansive force to develop. The expansive force could be generated by recovery of a shape memory material which does not result in shape change (e.g., stored strain which can be recovered, but is not recovered due to the constraint). Any expansive force, no matter what its genesis, can be used for the in-package forming operations which are described further above.
Recovery of a shape memory material can be induced actively or passively. For example, active inducing of recovery may include intentional activation (e.g., heating, radiation) of the material. The recovery may be induced passively, through storage in an environment which induces recovery and/or subjecting the shape memory material to an environment which activates the material. For example, the storage and/or transportation of shape memory materials (e.g., included in medical devices) may passively induce recovery of the shape memory material through subjecting the shape memory material to temperatures which activate the shape memory material. As described herein, the activation of a shape memory material with an stored strain induces recovery of that material. Recovery of the material may include shape change, the development of force against a constraint, or both.
With the sabots in an assembled configuration, the cavity may define the negative of the shape (e.g., impression) of the entire medical device, or only a part of the medical device. For example, as described further herein, portions of the medical device may not be expected to expand and/or intended to be constrained by the package.
As shown, there are internal flat surfaces 110 of the sabot which are meant to mate with other sabots of the package. In addition, in the embodiment shown, there are mating elements 112 designed to engage other mating elements on the other sabots of the package. In one embodiment, the interior surfaces 108 of the sabots of a package define an entire complete contiguous interior surface of a medical device. In another embodiment, the interior surfaces 108 of the sabots of a package define a partial surface of a medical device. For example, sabots of a package may define interior surfaces which engage surfaces of a medical device which are expected to expand and/or which are desired to be constrained.
In one embodiment, sabots may be linked, hinged, bonded or otherwise attached to each other to form a single intermediate member. For example, the single intermediate member may be able to be opened, unrolled or otherwise configured in a different configuration from the configuration which fits within the constraining member. In another embodiment, a plurality of intermediate members may each be a separate sabot. There are multiple embodiments using combinations of intermediate members, such as using separated sabots, attached sabots, partially attached sabots, and/or sabots with attachments which are destroyed when opening the sabots from an assembled configuration (e.g., with a constraining member) into another configuration.
For example, a medical device may be designed to expand along one axis in one direction or through the movement of a particular surface of a medical device. In such a medical device, the expansion of the medical device along that axis may be advantageously controlled through coupling of that surface of the medical device with an interior surface 108 of a sabot, and other sabots, coupling with other surfaces of the medical device, may not be necessary or required in order to limit expansion of the medical device.
The sabots of a package may define an exterior surface 114 which may be contiguous, such as the exterior surface of the constraining member as shown in
An exterior surface 114 defined by the sabots may be tailored to control the exterior surface area of the sabots which contacts the constraining member. For example, an exterior surface with a star-shaped and/or ribbed cross-section will contact a constraining member with a circular cross-section only at certain points of the circumference of the constraining member. By reducing the surface area of contact between the exterior surfaces 114 of the sabots and the constraining member, the frictional forces therebetween can be controlled. The frictional forces may be controlled depending on the expansive forces transmitted from the medical device through the intermediate members (e.g., sabots) to the constraining member in order to facilitate removal of the constraining member from the sabots.
The key elements may be disposed outside of the constraining member and may not necessarily be subjected to the expansive forces of the medical device. Therefore, there may be fewer design constraints on the design of the key elements. For example, the key elements may be hinged together, and the hinge bodies need not be contained by the constraining member. As another example, the key elements may be made larger, with respective larger mating surface areas, than the main body of the sabot. Furthermore, the size and shape of the medical device and the cavity created by the sabots do not affect the mating surfaces of the key elements, though they may affect the mating surface of the sabots. As another example, the key elements may be made from a material different from the material of the sabot.
In some embodiments, as shown by
The opening may be at an angle to the axis of any expected expansion (e.g., relief of stored compressive strain) so as to minimize the possibility that the opening will allow the medical device to expand and/or deform into the opening. For example, the angle may be about 45 degrees or greater.
In an embodiment where the compressing member 306 is removed as part of the opening process, such as the embodiment shown in
For example, the contact surface area of the constraining member and the compressing member may be less than the contact surface area of constraining member and the intermediate member(s). In other words, the constraining member and compressing member contact surface area may be up to about 100% of the constraining member and intermediate member(s) contact surface area in total. In other embodiments, the compressing member may contact up to about 40% of the surface area contacted in total by the intermediate member(s). In some embodiments, the compressing member may contact at a minimum about 10% of the surface area contacted in total by the intermediate member(s).
Other techniques, such as material selection, may be used to adjust the frictional force between the constraining member and the compressing member and/or to adjust the frictional force between the constraining member and the intermediate member(s).
The removal of the compressing member 306 can reduce the surface area of contact between the sabots and the constraining member 304, allowing the frictional forces between the sabots and the compressing member to be varied. In some embodiments, removal of the compressing member 306 can allow the sabots to move relative to the constraining member 304 and relieve stored strain in the medical device and/or in the sabot(s). The space 308 left by the removal of the compressing member 306 may allow the sabot(s) to move relative to the constraining member 304.
The space 308 left by the removal of the compressing member 306 may allow the sabot(s) to move relative to other sabot(s). Such movement may allow for stored strain in the medical device and/or in one or more of the sabots to be relieved.
Relieving of stored strain (e.g., through recovery of a shape memory material in the medical device, through elastic recoil of part(s) of the medical device and/or sabot(s)) may reduce forces between one or more of the sabots and the constraining member. Reducing these forces may ease the removal of the constraining member 304 from around the sabots.
The sabots are contacted by a rotational compressing member 406. Unlike the compressing member shown in
In the configuration shown, the sabots 402 are in a heightened compression configuration due to the rotational position of the sabots relative to the grove in the rotational compressing member 406. The peak of the sabots, configured as shown, is not aligned with the grove 408 in the compressing member. Instead, the peak of the sabots is aligned with another part of the compressing member. The interface between the peak of the sabots and the rotational compressing member provides for a heightened compression configuration of the package.
In other embodiments, a compressing member does not need to have a grove which mates with a peak in the sabots to establish a lessened compression configuration. In one embodiment, for example, a rotational compressing member may have a ridge or peak and the sabots, as assembled, may have a grove into which the ridge or peak mates, thereby establishing a lessened compression configuration. In another embodiment, a rotational compressing member may have a ridge or peak and the sabots, as assembled, may be shaped so as to provide a gradually increasing radius, thereby establishing a gradually increasing/decreasing compression in a plurality of configurations with different rotational relationships between the sabots and the compressing member.
The rotation of the rotational compressing member, the constraining member and/or the sabots, relative to one another, may be accomplished as described herein through the use of handles, knobs or other rotational devices. In addition, other elements may be used to apply rotational leverage to one or more of the rotational compressing member, the constraining member and/or the sabot(s).
Alternatively, the compressing member 602 can be removed, as described further above. Removing the compressing member can further ease removal of the constraining member, also as described further above.
Rotating the elliptical compressing member 602 (e.g., such that a portion of the elliptical cross-section between the longer and shorter axes is perpendicular to the constraining member) can vary the compression/decompression of the sabots and compressing member within the constraining member. The description above of a greater compression state and a lower compression state is meant only to illustrate two states of the compressing member, and many more states are available at intermediate states thereof.
In addition, the compressing member may have a more complex cross-sectional shape than the ellipse shown. For example, the compressing member may have ridges, slopes, and/or discontinuities which can cause a gradual change in force when utilizing one region of the compressing member and a discontinuous change in force when utilizing another region of the compressing member. The compressing member may have a more complex shape along the axis of rotation (“rotational axis”) of the compressing member. For example, the compressing member need not have the same cross-section along the entirety of the rotational axis of the compressing member. As described further above, the exterior surface of the sabot(s) may also be shaped to interface with the compressing member in order to cause varying degrees of compression as the sabot(s) and/or the compressing member are rotated relative to each other. Complex shapes of the compressing member and/or the exterior surface of the sabot(s) may be created and/or varied to meet design considerations such as compression, expansion, in-package forming, and release of the medical device from the package.
The handle shown in
As shown in
The removal device 800 has a base handle 812 which allows an operator (e.g., surgeon, nurse, technician) to hold the removal device while, for example, placing the package 808 containing the medical device into the removal device, and/or operating the handle 806 to open the packaging.
In the embodiment shown, the handle 806 is attached to a cylinder 814 with a slot for engaging a part of the constraining member of the package. As indicated by the dashed line 811, a portion of the package (specifically a portion of the constraining member of the package) fits into the cylinder 814 in order to engage the package 808 and the handle 806 and to allow the rotation of the cylinder to open the package. By rotating the cylinder 814, a portion of the constraining member is torn and/or peeled away from the rest of the constraining member. By tearing and/or peeling a part of the constraining member from the rest of the constraining member, the constraining member is partially destroyed and may lose its ability to constrain expansive forces of the medical device transmitted through the intermediate members of the package (e.g., the sabots). This type of opening through tearing/peeling a portion of the constraining member is described further below with respect to
In another embodiment, the handle may be attached to a knife-type element (not shown) which can cut, score and/or destroy the constraining member while the package is in the chamber. For example, the handle may be attached to a blade which engages the constraining member (e.g., externally contacting the constraining member, fitting between the constraining member and a sabot, pressing into the constraining member in multiple places) and the handle may be slid along a track to open the package. The blade may score the constraining member so that the expansive forces of the medical device rupture the constraining member. The blade may sever a portion of the constraining member allowing the expansive forces to rupture the constraining member. The blade may sever all of the constraining portions of the constraining member, allowing the expansive forces to release unimpeded by the constraining member. The functions of a blade in opening a constraining member are described further below with respect to
In one embodiment, the handle 806 may be rotated (e.g., in the direction designated by the arrow 807) once the housing 802 is closed in order to destroy a constraining member of the package and allow the medical device to be removed from the package. As described above, the handle 806 may be rotated (in the direction shown by the arrow) in order to tear and/or peel part of the constraining member from the rest of the constraining member.
Also shown is a slot 816 in which the handle rotates and/or slides. In one embodiment, the handle travels along the slot 816 as the handle is rotated. The handle 806 may travel due to the rotation of the cylinder along the length of the package. The handle 806 may travel due to a gear attached to the handle (not shown) which engages with the slot 816. The gear may be provided to ensure a consistent translation of the handle while it is rotated along the length of the package.
In another embodiment, the package travels within the chamber while the handle is rotated. For example, the handle may be rotated and as the portion of the constraining member is torn/peeled from the rest of the constraining member, the package may translate. The package may be translated by the rotation of the cylinder, which may be engaged with a gearing mechanism to ensure that the package translates while the handle is rotated.
In another embodiment, the handle may be slid along the slot 816 in order to open the package. As described above, in some embodiments, the handle 806 may be slid in order to actuate a knife-type element with respect to the package. For example, as described above, the handle 806 may be attached to a blade or other knife-type element. The knife-type element may be actuated against the constraining member by sliding the handle 806 along the slot 816.
After the package has been opened inside the housing, the medical device may be removed from the housing without opening the housing. In the embodiment shown, a plunger 810 is shown in a position to push the medical device out of the housing 802 after the package 808 has been opened. For example, the plunger 810 can be slid along the chamber 804 to clear the medical device out of the chamber and out of the housing 802.
The plunger 810 may be configured as a rod, as shown. In other embodiments, the plunger 810 may be configured in a different manner, such as with a scooped end for cradling the medical device as it is pushed out. In some embodiments, the plunger may have elements which clear away parts of the package (e.g., sabots, portions of the constraining member) which may surround the medical device after the package is opened.
A starting portion 906 may be separated from the constraining member 900. Alternatively, a starting portion 906 may be attached to the constraining member 900, specifically the portion 902 of the constraining member which is to be torn. A rotating opening device 908 may engage the starting portion 906 in a similar fashion to a starting tab of a food can (e.g., a can of sardines) is held and twisted by a rotating opening device. The rotating opening device 908 may be used to tear/peel a portion 902 of constraining member 900 and roll the portion around the opening device.
The knife-type element may impart forces on a boundary, such as described above, which concentrates forces applied on and near the boundary to facilitate separating of the constraining member along the boundary. The knife-type element may cut the constraining member. The knife-type element may score, weaken, and/or remove material from the constraining member and allow expansive forces of the medical device and/or sabot(s) to separate the constraining member.
In the embodiment shown, the knife-type element 1000 has a concave blade 1002. Surrounding the concave blade 1002 are guide points 1004 which may span the constraining member when the concave blade is engaged with the constraining member. For example, one of the guide points 1004 may be placed between a sabot and the constraining member while another of the guide points 1004 may be placed outside of the constraining member.