Suture needle abstract
A method of forming a suture needle holder for a suture needle.
A suture needle is placed in a trough cut into the surface of a
die. This trough intersects a cavity within the die. A sheet is
placed onto the surface of the die after the needle is placed in
the trough. The sheet is then thermoformed into the cavity to form
a pedestal around the needle. During thermoforming the needle is
captured by the sheet and a slot is formed about the suture needle.
Suture needle claims
I claim:
1. A method of forming a suture needle holder for a suture needle
comprising:
a) placing a suture needle into a trough cut into the surface of
a die, wherein a cavity is cut into the surface of the die such
that the trough intersects the cavity;
b) placing a sheet of planar plastic onto the surface of the die
after placing the needle in the trough; and
c) thermoforming the sheet of planar plastic into the cavity of
the die to form a pedestal around the needle thereby capturing the
needle and forming a slot that retains the suture needle.
2. A method according to claim 1 wherein thermoforming is accomplished
by applying a vacuum to the at least one cavity of the die.
Suture needle description
FIELD OF THE INVENTION
This invention relates to the field of suture needle holders useful
for packaging armed sutures.
BACKGROUND OF THE INVENTION
Suture packages containing armed sutures typically incorporate
a means for securing the needle to the package so that the needle
does not move while being grasped with suture forceps. The needle
holder must also secure the needle from movement during shipping
of the package, a requirement that prevents the needle point from
possibly causing damage to the suture as well as preventing damage
to the needle itself.
Needle holders for suture packages have taken many forms. Frequently,
the point of the needle is inserted through a piece of plastic foam
to hold it secure. The use of flaps cut from the packaging material
is also common, the flap compressively holding the needle against
the surface of the adjacent packaging material. Some flaps incorporate
a slit through which a needle is placed, as taught by U.S. Pat.
No. 4884681. Another alternative is described by U.S. Pat. No.
4961498 which involves a flexible rail and an adjacent post wherein
a needle is held captive between the rail and post.
U.S. Pat. No. 4424898 teaches the construction of a needle holder
incorporating adjacent pedestals having straight slots between the
adjacent pedestals, wherein curved needles are fitted into the straight
slots. The resulting interference due to the curvature of the needle
retains the needle within the straight slot.
U.S. Pat. No. 4699271 describes a needle holder using two parallel
ridges having pairs of shaped slots extending in predetermined curves
across a U-shaped notch, wherein the curves are chosen to match
the curvature of the needle intended to be fitted into a pair of
slots.
SUMMARY OF THE INVENTION
The present invention relates to a suture needle holder for a suture
package intended to contain an armed suture, comprising a sheet
of planar plastic having at least one raised pedestal formed therein,
the at least one raised pedestal having at least one slot therein
oriented orthogonal to the sheet of planar plastic, the at least
one slot having an open portion and a needle-holding portion releasably
holding a portion of the length of a suture needle therein with
the length of the suture needle lying in a plane parallel to the
sheet of planar plastic, wherein the open portion of the slot is
of a width narrower than the diameter of the length portion of the
suture needle held within the needle-holding portion of the slot.
The needle holder is made by forming a sheet of planar plastic
with a die having a flat surface, the die having at least one cavity
cut into the flat surface for forming at least one pedestal into
the sheet of planar plastic, the die further having at least one
trough cut into the flat surface for holding a suture needle during
forming of the sheet of planar plastic, the at least one trough
intersecting the at least one cavity, the at least one trough having
a depth less than the depth of the at least one cavity, wherein
thermoforming techniques are used to apply heat and a pressure differential
to the sheet of planar plastic to cause the sheet of planar plastic
to form a pedestal into the cavity and to form a slot into the pedestal
around the length portion of the suture needle lying in the intersection
of the trough and the cavity. The pressure differential is preferably
accomplished by vacuum forming wherein a vacuum is applied within
the cavity or cavities of the die to form at least one slotted needle-holding
pedestal into the planar plastic. The portion of the planar plastic
intended to be formed into the pedestal should be heated to aid
in the forming process. An additional portion of the planar plastic
sheet material may be formed to package and retain the suture, such
as by forming serpentine passageways into the planar plastic sheet.
It is anticipated that the inventive needle-holder will be made
as a part of a complete suture package capable of withstanding ordinary
sterilization methods. Such a package would typically be enclosed
in a protective bacteria impermeable envelope. The envelope may
be partially or entirely made from a gas or steam permeable material
for gas or steam sterilization. Because the sheet of planar plastic
can function as an effective bacterial barrier in its own right,
a practical package can be made by simply sealing a sheet of a protective
bacteria impermeable material to the perimeter of the sheet of planar
plastic. At least a portion of this sheet may also be made from
a steam or gas permeable material if steam or gas sterilization
is desired. Tyvek.RTM., available from du Pont de Nemours, Inc.
(Wilmington, Del.), is one such steam and gas permeable, bacteria
impermeable sheet material.
The inventive needle holder capable of holding a range of needle
sizes may be formed from a single die; further, the needle holder
forming step is simultaneous with the packaging of the needle because
the pedestal and slot are formed around the needle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 describes a perspective view of a suture package made of
a sheet of planar plastic and incorporating a suture needle holder
of the present invention.
FIGS. 1A and 1B describe end and side sectional views respectively
of the suture needle holder of the present invention.
FIG. 1C describes a side sectional view of an alternative embodiment
designed to hold two needles.
FIG. 2 describes a perspective view of a die useful for forming
the suture needle holder of the present invention.
FIGS. 2A and 2B describe sectional views of the die of FIG. 2 containing
a suture needle as intended for use during forming of the suture
needle holder.
FIG. 2C describes a perspective view of an alternative die.
FIGS. 3A and 3B describe side and end sectional views of an alternative
embodiment of the suture needle holder incorporating supporting
projections extending outwardly from the pedestal sides.
FIGS. 4 and 4A describe perspective and end sectional views of
an alternative embodiment of the present invention incorporating
a two-pedestal suture needle holder.
FIGS. 5A and 5B describe end and side sectional views of an alternative
embodiment of the suture needle holder described in FIGS. 4 and
4A.
FIG. 6 describes a suture package incorporating the inventive needle
holder, sealed within a protective bacteria impermeable envelope.
FIG. 7 describes a sterilizable suture package formed by sealing
a sheet of protective bacteria impermeable material to the perimeter
of the sheet of planar plastic from which the needle holder was
formed.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 describes a perspective view of a suture package made of
a sheet of planar plastic and incorporating a suture needle holder
of the present invention. It is apparent that the needle holder
may be an integral part of a complete suture package.
The needle holder 10 is formed from a portion of a sheet 12 of
planar plastic from which the entire package may be formed. The
needle holder 10 comprises a raised pedestal 14 having at least
one slot 16 formed therein to releasably retain a suture needle
18. The pedestal 14 and slot 16 are formed around the needle 18
during the packaging process so that a single forming die may be
used to form needle holders for a wide variety of needle sizes.
An additional portion of the sheet of planar plastic 12 may be
used to package and retain a length of suture 19 attached to the
needle 18such as by the use of a formed serpentine passageway 17.
FIGS. 1A and 1B describe end and side sectional views respectively
of the inventive needle holder. FIG. 1A shows that the pedestal
14 and slot 16 can be formed to hold the needle 18 in a way that
provides a clearance 20 between the needle and the surface of the
sheet 12 of planar plastic. The provision of clearance 20 allows
improved ease of grasping of the needle 18 by conventional suture
forceps. FIG. 1B shows that the width 22 of the slot 16 is made
to be significantly narrower than the diameter of the needle portion
24 retained within the slot 16. The width 22 of the slot 16 should
be about 5 to 95 percent of the diameter of the needle portion 24
intended to be retained by the slot 16. A more preferred range is
for the slot width to be about 50 to 95 percent of the diameter
of the retained needle portion. This relationship provides for adequately
secure retention of the needle while allowing the needle to be easily
removed with a minimum of force. The relationship between slot width
and needle diameter is the result of the amount of heat and the
quantity of pressure differential applied to the sheet of planar
plastic during the forming process. The depth of the cavity extending
beyond the depth of the trough can also affect this relationship.
It is believed that a useful needle holder of the present invention
may be made using a thin sheet 12 of planar plastic wherein the
two opposing sides of the slot 16 retaining the needle are actually
in contact with each other but not thermally fused together, that
is, the slot width is effectively 0 percent of the diameter of the
retained needle portion 24.
The needle is typically removed from the needle holder by grasping
an exposed portion of the needle with suture forceps and lifting
it upwardly out of the slot in a direction generally orthogonal
to the planar surface of the needle holder and suture package.
FIG. 1C describes a side sectional view of an alternative pedestal
14 providing two slots 16 for retaining two needles 18. It is apparent
that as many needle retaining slots can be provided within a single
pedestal 14 as desired as long as a practical amount of separation
is provided between adjacent needles in order to allow for their
individual removal.
FIG. 2 describes a perspective view of a die for forming the needle
holder of the present invention. The die 30 has a flat surface 32
on which the sheet of planar plastic intended to be formed is laid.
The flat surface 32 is interrupted by a cavity 34 and a trough 36
which intersects the cavity 34. Cavity 34 is used to form the pedestal
14 of the needle holder 10 while the trough 36 holds the suture
needle 18 during the forming process. As shown, the depth of cavity
34 must be greater than the depth of the trough 36. Cavity 34 preferably
provides a means for producing a pressure differential across the
two opposing surfaces of the sheet of planar plastic during the
forming process such as vacuum ports 38. Alternatively, a positive
pressure may be applied to the opposite side of the sheet of planar
plastic during forming. Likewise, a positive pressure may be used
simultaneously with a vacuum. Trough 36 should be of depth greater
than the diameter of the needle portion 24 intended to be held by
the slot 16 within the pedestal. The difference between the diameter
of the needle portion 24 and the depth of the trough 36 will be
the clearance 20 between the needle 18 and the surface of the sheet
12 of planar plastic in the finished needle holder 10. The floor
39 of the needle trough 36 may optionally be made of a magnetic
material to aid in holding the needle 18 in place within the trough
36 during the forming process.
As shown by the end sectional view of FIG. 2A, the needle holder
10 is formed by placing a needle 18 into the trough 36 prior to
placing a sheet 12 of planar plastic onto the flat surface 32 of
the die 30. A pressure differential is created across the two opposing
sides of the sheet 12 of planar plastic above the cavity 34 of the
die 30 with the higher relative pressure applied to the portion
37 of the side of the sheet 12 of planar plastic opposing the cavity
34. This is preferably accomplished by pulling a vacuum within the
cavity through optional vacuum ports 38 in the floor of the cavity.
The portion 37 of the side of the sheet 12 of planar plastic intended
to be deformed into the cavity 34 to form the pedestal 14 should
be heated to aid in the forming process. The heat may be applied,
for example, by hot air or by momentarily contacting the portion
37 of the side of the sheet 12 of planar plastic opposite the die
cavity 34 with a heated metal shoe. The amount of heat and the time
of its application are the most critical parameters in the needle
holder forming process. As shown by the side sectional view of FIG.
2B, the presence of a suture needle 18 within the trough 36 and
spanning the cavity 34 results in the formation of the pedestal
14 around the needle 18. simultaneously capturing the needle 18
and forming the slot 16 within the pedestal 14. The amount of pressure
differential, heat and time of application, in conjunction with
the thickness of the sheet 12 of planar plastic and the type of
plastic used, will control the width 22 of the slot 16.
FIG. 2C describes an alternative die 31. In the embodiment shown,
the die 31 incorporates two pairs of grooves 42 to allow it to produce
a needle holder for retaining two needles. For clarity, only one
needle 18 is shown held by one pair of grooves 42. It is apparent
that a die may be configured with as many troughs 36 or pairs of
grooves 42 as required to hold the desired number of needles 18.
In the embodiment of FIG. 2C a rim 44 surrounds cavity 34. The depth
of grooves 42 corresponds to the depth of trough 36 described previously.
The flat surface 46 of the die surrounding rim 44 is recessed below
the rim 44 only for convenience of placing the needle. The recession
of the flat surface 46 is not intended to cause significant deformation
of the planar plastic into this area and consequently there is no
differential pressure or heat applied to the sheet of planar plastic
immediately above flat surface 46 during the forming process. Magnets
48 are provided to hold the needles securely during the forming
process; the surface of the magnets 48 should lie in the same plane
as the floor 49 of the grooves 42.
The advantage of the die described by FIG. 2C is that it is able
to accommodate a wider variety of needle shapes, from straight needles
to highly curved needles. A die of the type shown by FIGS. 2 2A
and 2B incorporating a trough will only accommodate needles fitting
the shape of the trough.
FIGS. 3A and 3B show end and side sectional views respectively
of a variation of the needle holder wherein a supporting projection
52 extends outwardly away from the sides of the pedestal 14 and
lies between a portion of the needle adjacent to the pedestal and
the plane of the sheet 12 of planar plastic prior to forming. Supporting
projection 52 results from deformation of the sheet 12 of planar
plastic into the corresponding die space during forming. The supporting
projection 52 is useful to further support the needle 18 and increase
the stability of the needle within the needle holder.
FIGS. 4 and 4A show perspective and end sectional views of an alternative
embodiment of the needle holder wherein each needle 18 is held by
two pedestals 14 with each pedestal having a slot for holding different
length portions of the same needle 18. A needle holder incorporating
two pedestals may be desirable when it is intended to make the center
portion of the needle length available for grasping with suture
forceps.
FIGS. 5A and 5B show end and side perspective views of a variation
of the embodiment of FIGS. 4 and 4A wherein a supporting projection
54 extends between the pedestals into the space between the needle
and the plane of the sheet of planar plastic prior to forming.
FIG. 6 shows the needle holder as a part of an armed suture package
enclosed by a protective envelope 61 intended to allow the suture
and package to be sterilized and maintained sterile until the envelope
is opened. The envelope 61 can be made at least partially from a
steam and gas permeable, bacteria impermeable material if steam
or gas sterilization is desired. FIG. 7 shows an alternative sterilizable
suture package wherein a cover sheet 71 of protective bacteria impermeable
material is sealed around the perimeter of the sheet 12 of planar
plastic from which the needle holder was formed. The cover sheet
71 may be made at least partially from a steam and gas permeable
material if steam or gas sterilization is desired. The sealed sterilizable
packages represented by FIGS. 6 and 7 may additionally be sealed
in outer protective envelopes (not shown) for mechanical and sterility
protection until ready for use.
The suture needle holder and suture package may be formed from
various types of thermoplastic sheet materials including polypropylene,
polyethylene terephthalate, polycarbonate, polyethylene, polyvinyl
chloride and polystyrene. It is also anticipated that formable metal
foils may also be useful for the needle holder of the present invention
using ordinary metal foil forming technology. |