Surgical needle abstract
A blunt tip surgical needle which significantly reduces the probability
of skin penetration of the gloved hand of an operator is disclosed.
The blunt tip needle includes a tip portion having at least one
flat surface. The flat surface(s) blends smoothly between each other
and with the outer surface of the tip portion such that the entire
tip portion has a continuously smooth outer surface lacking any
discontinuities or sharp edges.
Surgical needle claims
What is claimed is:
1. A surgical needle comprising:
a tip portion having a blunt tip at a distal end thereof and at
least one flat surface on the distal end of the tip portion, said
flat surface blending smoothly with an outer surface of said tip
portion such that the tip portion has a continuously smooth outer
surface lacking any discontinuities or sharp cutting edges, and
wherein said cross-sectional is circular and said blunt tip has
a flat circular shape.
2. The surgical needle according to claim 1 further including
a suture mounting portion having a hole to which a suture is to
be attached and a body portion which is disposed between and contiguous
with said suture mounting portion and said tip portion.
3. The surgical needle according to claim 2 wherein said needle
has an overall curved shaped with a constant radius of curvature.
4. The surgical needle according to claim 2 wherein said body
portion has a generally uniform cross-sectional area throughout
an entire length thereof.
5. The surgical needle according to claim 4 wherein said cross-sectional
area of said body portion has a shape selected from the shape consisting
of circular, square, modified square, rectangular and flat pressed
circular.
Surgical needle description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to surgical needles and, more
particularly, to a blunt surgical needle wherein the needle tip
portion has one or more flat surfaces which blend smoothly into
the needle and decrease potential skin penetration of the gloved
hand of an operator.
2. Description of the Prior Art
Everyone today is well aware of the severity of contracting Human
Immunodeficiency Virus (HIV) and Acquired Immune Deficiency Syndrome
(AIDS). The members of professions that must deal on a daily basis
with the risk of coming in contact with people that do or may have
HIV or AIDS are acutely aware of the severity. Members of the medical
profession, especially surgeons, are in an extremely high risk position
when performing operations. The knowledge that infectious diseases
such as the AIDS virus can spread by an accidentally inflicted needle
stick from a contaminated needle administered to the person having
AIDS is the cause for much concern for the profession. These professionals
are therefore taking every precaution to reduce the risks. For example,
the use of double gloving, blunt tipped needles and gloves thickened
at the fingers are known to reduce the rate of glove puncture. In
addition, the use of forceps designed to grip both the tissue and
needle more effectively and the use of staples for skin closure
are also known to reduce the incidence of glove puncture.
Accordingly, there has been an increasing amount of activity in
the area of surgical needle tip design. For example, U.S. Pat. No.
4828547 to Sahi et al. discloses a needle having a blunting member
which is moveable from a retracted position to an extended position.
In the retracted position, the blunting member does not interfere
with the puncture tip of the needle. In the extended position, the
blunting member extends beyond the puncture tip and therefor acts
as a guard against accidental needle sticks. Further examples of
shield or guard type assemblies for syringe needles are disclosed
in U.S. Pat. Nos. 4883469 to Glazier and 4883471 to Braginetz
et al.
The devices disclosed above are useful for hypodermic syringe needles
which are disposed of after a single stick. This design would not
be practical for use with surgical needles since such needles must
make repeated sticks into the body.
U.S. Pat. No. 5123910 to Mcintosh discloses a tapered needle
tip having a circular cross-section and terminating in a blunt head.
The blunt head has a part spherical or other curved shape with no
sharp edge surfaces. The problem with the prior art blunt head needles
is the force necessary to penetrate the tissue is too high so that
the momentum of the needle after it passes through the tissue is
also so high that the needle penetrates the gloved hand of the surgeon
thereby negating the safety factor of the blunt head. As a consequence,
this blunt tip needle does not significantly reduce the probability
of skin penetration of a gloved hand. Thus, there is a need to develop
an improved surgical needle for use in suturing non-cutaneous and
friable soft tissues of the body while at the same time significantly
reducing the probability of skin penetration of the gloved hand
of an operator.
SUMMARY OF THE INVENTION
The present invention is directed to a blunt tip surgical needle
which significantly reduces the probability of skin penetration
of the gloved hand of an operator thereby decreasing potential transmission
of all infectious agents. The blunt tip surgical needles of the
present invention include a tip portion which terminates in a blunt
tip. Moreover, the tip portion has one or more flat surfaces that
blend smoothly between each other and with the needle surface without
any sharp edges. The provision of the one or more flat surfaces
improves upon the prior art blunt tip needle in that the needles
of the present invention are less likely to penetrate the glove
and skin of the user. The needles of the present invention have
a blunt tip to provide protection against penetration of a surgical
glove and in addition includes the one or more flat surfaces on
the side of the tip that allows for less penetration force through
tissue. The force necessary to penetrate the tissue is, therefore,
not excessive and the momentum of the needle after the penetration
will not as in with prior art blunt tip needles overcome the bluntness
of the tip and not penetrate the glove of the operator.
In one embodiment of the present invention, the tip portion of
the needle has a flat pressed circular cross-section having two
flat surfaces substantially throughout its entire length. The flat
pressed circular tip portion terminates in a blunt head having a
flat pressed circular dome shape. The curved blunt head and the
two flat surfaces blend smoothly with the outer surface of the tapered
portion such that the entire tip portion has a continuously smooth
outer surface lacking any discontinuities or sharp edges. The blunt
tip needle with flat side surfaces of the present invention has
an increased resistance to penetration of a latex glove over a sharp
point needle while at the same time decreasing the penetration force
for non-cutaneous or friable tissue.
In another embodiment of the present invention, the tip portion
of the needle has a triangular cross-sectional shape having three
flat surfaces and rounded corners. The triangular cross-sectional
shape of the tip portion progressively decreases toward its distal
end and terminates in a blunt tip having a triangular dome shape.
The blunt tip and the three flat surfaces blend smoothly with the
outer surface of the tapered portion such that there are not sharp
edge surfaces or discontinuities. As with the flat pressed circular
embodiment above, the glove penetration resistance is increased
while the friable tissue penetration force is decreased.
In another embodiment of the needle of the present invention, the
tip portion has a circular cross-section which decreases progressively
towards the distal end which terminates in a flat blunt tip. The
flat blunt tip blends smoothly with the outer surface of the tapered
portion such that there are no discontinuities or sharp edges. By
having a flat surface on the needle tip, the resistance to penetration
is increased over prior art rounded blunt tip needles.
As a result of having at least one flat surface, the needles of
the present invention are a significant improvement in bluntness
over conventional sharp point needles and blunt tip needles having
no flat surfaces. The improved blunt tip surgical needle configurations
of the present invention permit relatively easy penetration of soft
non-cutaneous or friable body tissues while providing increased
protection against a unintended stick of the gloved hand of an operator.
The needle of the present invention is suitable for use in suturing
the liver, kidney, heart, muscle and fascia, adipose pericostal
tissue and other non-cutaneous or friable soft tissues, as well
as other types of tissue of the body, while simultaneously decreasing
the probability of skin penetration of the gloved hand of an operator
and operating personnel such as surgeons, surgeons' assistants,
scrub and circulating nurses.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the blunt tip surgical needle of
the present invention.
FIG. 2 is an enlarged fragmentary view of the tip portion of the
surgical needle of FIG. 1.
FIG. 3 is a cross-sectional view taken along lines 3--3 in FIG.
1.
FIG. 4 is an alternative embodiment of the cross-sectional view
taken along lines 3--3 in FIG. 1.
FIG. 5 is a cross-sectional view taken along lines 5--5 in FIG.
2.
FIG. 6 is an enlarged fragmentary view of the tip portion of another
embodiment of the present invention.
FIG. 7 is a cross-sectional view taken along lines 7--7 in FIG.
6.
FIG. 8 is an enlarged fragmentary view of the tip portion of a
further embodiment of the present invention.
FIG. 9 is a cross-section view taken along lines 9--9 in FIG. 8.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings in FIGS. 1-5 there is shown one embodiment
of the blunt tip surgical needle 10 of the present invention. The
needle 10 includes a suture mounting portion 12 a contiguous main
body portion 14 having a generally uniform cross-sectional area
throughout an entire length thereof and a contiguous tip portion
16.
The suture mounting portion 12 is straight and has a hole 20 extending
from a proximal end face of the suture needle along an axis thereof.
The length of the suture mounting portion 12 is generally equal
to or slightly greater than the length of the hole 20. A suture
22 is inserted at one end portion into hole 20 and then the suture
mounting portion 12 is deformed or compressed to hold the suture
22.
The cross-sectional shape of the main body portion 14 can have
a wide variety of conventional shapes including circular, square
and rectangular. However, in order to provide stability and control
of needle 10 during use, the main body portion 14 can have a flat
pressed circular cross section such as shown in FIG. 3 or, alternatively,
a modified square cross-sectional shape as shown in FIG. 4. In the
needle 10 the main body portion 14 and the tip portion 16 are curved
and can possess a constant radius of curvature. This configuration
is, however, not critical to the present invention and body portion
14 and tip portion 16 can therefore assume any straight and/or curved
configuration which is considered suitable for the particular purpose
that is intended.
The needle 10 is rigidly formed of a suitable material for suture
needle use inside the body such as surgical grade steel, martersite-type
stainless steel and precipitation hardened stainless steel.
Referring to FIGS. 2 and 5 there is shown one embodiment of a
tip portion of the surgical needle of the present invention. The
needle 10 undergoes a transition from its cross-sectional shape
at region 24 (e.g., modified square or flat pressed circular) to
a circular cross-section in tip portion 16. (Of course, if the body
portion 14 has a circular cross-section then there is no transition.)
The needle tip portion 16 has a circular cross-section which decreases
progressively from its proximal end 24 to the blunt distal end 18
of the needle. The needle tip portion 16 terminates in a flat circular
blunt head 18 which is configured to permit piercing of non-cutaneous
or friable soft tissues of the body while preventing skin penetration
of the gloved hand of an operator.
The head 18 has a flat circular shape that blends smoothly at its
circumference with the outer surface of the tapered portion by a
blend radius 26 such that there are no sharp edges at the needle
tip. Thus the entire tapered tip portion 16 including flat blunt
tip 18 has a continuously smooth outer surface lacking any discontinuities
or sharp cutting edges. By utilizing flat blunt head 18 the penetration
force of needle 10 needed to penetrate the gloved hand of an operator
is significantly increased as compared to conventional sharp point
needles and prior art blunt tip needles. Consequently, needle 10
significantly decreases the probability of skin penetration of the
gloved hand of an operator.
Turning now to FIGS. 6 and 7 there is shown a tip portion of another
embodiment of the present invention. In this embodiment, the needle
10 undergoes a transition from its cross-sectional shape at region
24 (e.g., circular, rectangular, square or modified square) to a
flat pressed circular cross-section in tip 16 having two flat surfaces
28. If body 14 also has a flat pressed circular cross-section, then
body 14 and tip portion 16 will have a uniform flat pressed circular
cross-section throughout its entire length. The two flat surfaces
28 extend substantially the entire length of tip portion 16.
The flat pressed circular tip portion 16 terminates at blunt head
30 having a flat pressed circular dome shape. The curved blunt head
30 blends smoothly at its perimeter with the outer surface of the
tip portion 16. In addition, the flat surfaces 28 blend smoothly
with each other and with the rest of the outer surface of tip portion
16 by means of blend radii 32. As a result, the entire tip portion
16 has a continuously smooth outer surface lacking any discontinuities
or sharp edges. The flat surfaces 28 in tip portion 16 along with
the curved blunt head 30 significantly increases the penetration
force needed to penetrate a gloved hand as compared to conventional
sharp point needles and prior art blunt tip needles.
A further embodiment of the tip portion of the present invention
is shown in FIGS. 8 and 9. The needle 10 undergoes, at region 24
a gradual transition from its cross-sectional shape in body portion
14 (e.g., circular, rectangular, square, modified square or flat
pressed circular) to a triangular cross-sectional shape in tip 16
having three flat surfaces 34. The three flat surfaces 34 extend
substantially the entire length of tip portion 16. The tip portion
has a triangular cross-section which progressively decreases from
proximal end 24 to blunt tip 36.
The blunt tip 36 has a triangular dome shape that blends smoothly
at its perimeter with the outer surface of tip portion 16. The flat
surfaces 34 blend smoothly between each other and with the outside
surface of tip portion 16 by means of blend radii 38. This results
in a substantially triangular cross-sectional tip portion 16 having
rounded corners to provide a smooth outer surface. Accordingly,
the entire tip portion 16 has a continuously smooth outer surface
lacking any discontinuities or sharp edges. The use of the flat
surfaces 34 along with blunt head 36 significantly increases the
penetration force needed to penetrate a gloved hand as compared
to conventional sharp point needles and prior art blunt tip needles.
The surprising results here were that the 51% needle required the
least amount of force to penetrate PORVAIR.RTM. as compared with
the other flat tip needles. Each of the flat tip needles of the
present invention required less force to penetrate the PORVAIR.RTM.
but is sufficiently blunt to provide a decreased risk of penetration
through the glove than a sharp point needle or prior art blunt tip
needles.
It is perceived that the blunt needle of the present invention
may, in addition to reducing the risk of infectious disease transmission
by reducing the risk of an accidental needle stick, also serve to
reduce the risk of needle contamination by reducing the amount of
bleeding caused by the needle. Decreased bleeding occurs because
the blunt needle is more likely to simply push blood vessels aside
rather than penetrate them as it is being advanced in the body.
While the invention has been particularly shown and described with
respect to illustrative and preferred embodiments thereof, it will
be understood by those skilled in the art that the foregoing and
other changes in form and details may be made therein without departing
from the spirit and scope of the invention which should be limited
only the scope of the appended claims. |