Medical Engineering Corporation

Jeffrey E Bark

Donald V Hillegass

Eric J Woodruff

Vaughan B Weeks

Jeffrey R Gengler

William Hubbard

Keith A Young

John E Falk

A mammary prosthesis for augmentation mammoplasty is comprised of a shell containing an insoluble, fibrous material which when the shell is inflated with inflating fluid adjusts the feel and appearance of the inflated shell to approximate natural mammary tissue. The shell is sealed except for a valve which can be used to inflate the shell.

Mammary prosthesis

The tissue expander includes a shell with a base layer and an expansion layer that define an expansion chamber therebetween. A conduit or fill tube extends from the shell and is the sole source of communication with the expansion chamber. The base and expansion layers are thermoplastically joined together by a major seam and a minor seam. The major seam is substantially concealed within the expansion chamber whereas the minor seam defines a border portion of the expansion chamber and is not concealed. The tissue expander can be of any selected size and shape. The base layer can be made expandable along with the expansion layer or nonexpandable as desired.

Tissue expander

The self-sealing tissue expander includes inner and outer layers of relatively nonflowable material and a median layer of flowable material. The median layer of flowable material which can include one or more sublayers of flowable material is under a predetermined compression imposed by the inner and outer layers due to a prestressing of the tissue expander shell during formation of the tissue expander. The self-sealing shell seals an opening in the shell wall following removal of an infusion needle. In all embodiments of the invention a needle stop member is provided to prevent the needle that accesses the fluid chamber from passing outwardly of the tissue expander. The need for a septum, a fluid conduit or a special fluid entry opening in the tissue expander shell is thus optional. The shell can also be made relatively more stretchable in some areas than in other areas.

Method for expanding a self-sealing tissue prosthesis

The tissue expander includes a closed shell structure having a shell wall formed of a needle-penetrable material with self-sealing characteristics. The shell defines a fluid expandable chamber. In some embodiments of the invention, a self-sealing layer of elastomeric material is joined or otherwise bonded to an inner surface of a non-flowable layer of elastomeric material. In other embodiments of the invention, the self-sealing layer is joined to the outer surface of a layer of non-flowable elastomeric material. The self-sealing layer may also be sandwiched between two layers of non-flowable elastomeric material. In a further embodiment the self-sealing layer constitutes the entire shell of the tissue expander. In all embodiments of the invention, a needle stop member is provided to prevent a needle that accesses the fluid chamber from passing outwardly of the tissue expander in the same direction in which it has accessed the fluid chamber. Fluid for expanding the chamber is infused directly therein through a needle that penetrates the shell wall. The self-sealing material seals any opening in the shell wall produced by removal of the infusion needle. Self-sealing is accomplished by a flowing together of wall material at the needle opening when the needle is withdrawn from the wall.

Tissue expander and method

The self-sealing tissue expander includes inner and outer layers of relatively nonflowable material and a median layer of flowable material, The median layer of flowable material which can include one or more sublayers of flowable material is under a predetermined compression imposed by the inner and outer layers due to a prestressing of the tissue expander shell during formation of the tissue expander. The self-sealing shell seals an opening in the shell wall following removal of an infusion needle. In all embodiments of the invention a needle stop member is provided to prevent the needle that accesses the fluid chamber from passing outwardly of the tissue expander. The need for a septum, a fluid conduit or a special fluid entry opening in the tissue expander shell is thus optional. The shell can also be made relatively more stretchable in some areas than in other areas.

Self-sealing tissue expander and method

The flexible needle stop includes a normally unfolded needle impenetrable needle barrier formed of a flexible foldable material. The flexible foldable material can be a single layer sheet material, a wire mesh material and/or one or more layers of scale-like components arranged side by side. The scale-like components are physically unconnected and of a size that permits flexion of the needle stop that incorporates the scale-like components. The flexible needle stop member can include a bead-like periphery which affords the needle stop member with a resilient memory and helps restore the needle stop member to its normally unfolded condition after a folding restraint is removed. The needle stop can be freely disposed within a fill chamber of a tissue expander, attached to an inner surface of the fill chamber or incorporated in the shell wall of a tissue expander.

Flexible needle stop

The septum includes a fill chamber having a port that is reinforced or otherwise protected by a needle stop structure. The needle stop structure prevents a needle that has accessed the fill chamber from penetrating the fluid flow structure that extends from the fill chamber. In one embodiment of the invention, the needle stop structure overhangs the port thereby preventing a needle from entering the port. In a further embodiment of the invention the needle stop structure includes a nozzle-like annular collar which extends from the port into the fill chamber. In another embodiment of the invention, the needle stop structure includes a nozzle-like annular collar that extends from the port into the fluid flow structure. In yet another embodiment of the invention, the needle stop structure includes a cup-shaped structure that extends from the port into the fluid flow structure and has an opening in the fluid flow structure. In still another embodiment of the invention, the needle stop structure includes a conduit that extends from the port across the fill chamber. In all embodiments of the invention the needle stop structure is impermeable to penetrations by a needle and thus protects the fluid transfer structure from penetrations by a needle.

Septum with a needle stop at the fluid transfer port

The septum includes a unit with two fill chamber sections, each having a corresponding needle penetrable seal member for sealing the respective fill chamber sections. The seal members are oppositely disposed and thereby permit access to a corresponding fill chamber section at two different orientations of the septum. Thus, when the septum has flipped over from its original position, one of the fill chamber sections continues to remain accessible for fluid infusion and/or fluid withdrawal. A needle stop portion in the unit which forms a partition between the fill chamber sections prevents a needle that has entered one of the fill chamber sections from passing out of the other fill chamber section. In several embodiments of the invention, the partitioning needle stop section is moveable and in other embodiments of the invention, the partitioning needle stop section is immoveable. Thus there is provision for expanding and contracting the fill chamber sections in some of the embodiments of the invention. In all embodiments of the invention the fill chamber sections are communicable.

Septum

The self-sealing subcutaneous infusion and withdrawal device or septum includes a cup-shaped needle stop member that defines a fluid chamber having a fluid transfer opening. A jacket envelops the needle stop member and includes an integrally formed delivery tube that aligns with the fluid transfer opening in the needle stop member. The fluid chamber of the needle stop member is sealed by a needle penetrable sealing member that is forced against a wall of the needle stop member by a clamping member to provide a mechanical leak-tight seal. The seal member has opposite convex surfaces which cooperate with the clamping member to impose a compression force upon a needle that penetrates the seal member during the fluid infusion and fluid withdrawal processes.

Self sealing subcutaneous infusion and withdrawal device

A skin mounted retention disc for maintaining a catheter indwelling comprises an elastomeric disc having a centrally disposed bore therethrough dimensioned to receive the catheter. About the periphery of the elastomeric disc is a plurality of very small holes to enable the disc to be sutered to the skin. Integrated to and extending upwardly from the elastomeric disc is a projection having a helically disposed channel therein for engaging the catheter as the catheter tube is wrapped about the disc after exiting the skin. A connecting tube having low release force connectors at either end is secured to the disc and links the catheter to a drainage bag. Because the force required to break the connection between the connecting tube and either the drainage bag or the catheter is less than the force required to dislodge the skin mounted retention disc, the connecting tube serves as a safety release to prevent the disc from becoming dislodged should the patient stray from the drainage bag.

Growing community of inventors

Racine, WI, United States of America

Jeffrey E Bark