U.S. patent application number 11/339369 was filed with the patent office on 2006-07-27 for lock and release mechanism for a sternal clamp.
Invention is credited to Lorenz Gabele.
Application Number | 20060167458 11/339369 |
Document ID | / |
Family ID | 36697893 |
Filed Date | 2006-07-27 |
United States Patent
Application |
20060167458 |
Kind Code |
A1 |
Gabele; Lorenz |
July 27, 2006 |
Lock and release mechanism for a sternal clamp
Abstract
An engagement mechanism for a sternal clamp, the mechanism
allowing for an open status where the clamp may be lengthened or
shortened, a closing status where the clamp may only be shortened,
and a locked status where the clamp cannot be lengthened or
shortened.
Inventors: |
Gabele; Lorenz; (Sauldorf,
DE) |
Correspondence
Address: |
ROGERS TOWERS, P.A.
1301 RIVERPLACE BOULEVARD, SUITE 1500
JACKSONVILLE
FL
32207
US
|
Family ID: |
36697893 |
Appl. No.: |
11/339369 |
Filed: |
January 25, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60646732 |
Jan 25, 2005 |
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Current U.S.
Class: |
606/916 ;
606/151; 606/324 |
Current CPC
Class: |
A61B 17/8076 20130101;
A61B 17/8004 20130101; A61B 17/823 20130101 |
Class at
Publication: |
606/072 |
International
Class: |
A61B 17/58 20060101
A61B017/58 |
Claims
1. A sternal clamp device comprising: a first clamp member and a
second clamp member slidingly engaged such that the overall length
of said sternal clamp device may be shortened or lengthened by
relative movement of said first and second clamp members, each said
clamp member comprising at least one leg members to abut the sides
of a sternum; engagement means controlling relative movement of
said first and second clamp members; and status control means to
select one of three operating statuses for said sternal clamp
device, said operating statuses consisting of an open status, a
closing status and a locked status; whereby in said open status
said sternal clamp device may be lengthened or shortened, in said
closing status said sternal clamp device may be shortened but not
lengthened, and in said locked status said sternal clamp may be
neither lengthened nor shortened.
2. The device of claim 1, wherein said engagement means comprises a
biased engagement arm having a plurality of teeth, said engagement
arm disposed on said first clamp member, and a ratchet bar having a
plurality of teeth, said ratchet bar disposed on said first clamp
member, whereby said engagement arm teeth and said ratchet bar
teeth are able to engage with each other.
3. The device of claim 2, wherein said status control means
comprises a cam opening disposed in said engagement arm and a
rotatable cam follower positioned within said cam opening, whereby
selection of said operating status and freedom of movement of said
engagement arm is determined by the position of said cam
follower.
4. The device of claim 3, wherein said engagement arm is pivotally
mounted, such that in said locked status said engagement arm is
precluded from pivoting away from said ratchet bar, in said closing
status said engagement arm can pivot sufficient distance from said
ratchet bar to allow said engagement arm teeth and said ratchet bar
teeth to slide over each other, and in said open status said
engagement arm is held in a fixed position away from said ratchet
bar such that said engagement arm teeth and said ratchet bar teeth
are not in contact.
5. The device of claim 3, wherein said status control means further
comprises a post member retaining said cam follower, a head member
disposed on said post member and a slot disposed in said head
member, said post member being rotatably mounted in said second
clamp member.
6. The device of claim 2, wherein said engagement arm teeth each
have an inclined side and an abutment side, said abutment sides
being more perpendicularly oriented than said inclined sides, and
wherein said ratchet bar teeth each have an inclined side and an
abutment side, said abutment sides being more perpendicularly
oriented than said inclined sides, whereby the inclined sides of
said engagement arm teeth and said ratchet bar teeth face each
other and the abutment sides of said engagement arm teeth and said
ratchet bar teeth face each other.
7. A sternal clamp device comprising: a first clamp member and a
second clamp member to engage the sides of a sternum; sliding means
joining said first and second clamp members together whereby said
sternal clamp can be lengthened or shortened; engagement means to
restrict relative motion of said first and second clamp members;
status control means to control said engagement means, said status
control means being operable in a locked status, a closing status
and an open status; whereby said status control means disposed in
said locked status precludes relative movement of said first and
said second clamp members, disposed in said closing status allows
relative movement of said first and said second clamp members
together so as to shorten said sternal clamp but precludes relative
movement of said first and second clamp members apart so as to
lengthen said sternal clamp, and disposed in said open status
allows relative movement of said first and said second clamp
members both together and apart.
8. The device of claim 7, wherein said engagement means comprises a
biased engagement arm having a plurality of teeth, said engagement
arm disposed on said first clamp member, and a ratchet bar having a
plurality of teeth, said ratchet bar disposed on said second clamp
member, whereby said engagement arm teeth and said ratchet bar
teeth are able to engage with each other.
9. The device of claim 8, wherein said status control means
comprises a cam opening disposed in said engagement arm and a
rotatable cam follower positioned within said cam opening, whereby
selection of said operating status and freedom of movement of said
engagement arm is determined by the position of said cam
follower.
10. The device of claim 9, wherein said engagement arm is pivotally
mounted, such that in said locked status said engagement arm is
precluded from pivoting away from said ratchet bar, in said closing
status said engagement arm can pivot sufficient distance from said
ratchet bar to allow said engagement arm teeth and said ratchet bar
teeth to slide over each other, and in said open status said
engagement arm is held in a fixed position away from said ratchet
bar such that said engagement arm teeth and said ratchet bar teeth
are not in contact.
11. The device of claim 9, wherein said status control means
further comprises a post member retaining said cam follower, a head
member disposed on said post member and a slot disposed in said
head member, said post member being rotatably mounted in said
second clamp member.
12. The device of claim 8, wherein said engagement arm teeth each
have an inclined side and an abutment side, said abutment sides
being more perpendicularly oriented than said inclined sides, and
wherein said ratchet bar teeth each have an inclined side and an
abutment side, said abutment sides being more perpendicularly
oriented than said inclined sides, whereby the inclined sides of
said engagement arm teeth and said ratchet bar teeth face each
other and the abutment sides of said engagement arm teeth and said
ratchet bar teeth face each other.
13. A sternal clamp device for securing two severed halves of a
sternum in abutting relation, said device comprising: a first clamp
member comprising a main body and at least one leg member; a second
clamp member comprising a main body and at least one leg member,
said second clamp member joined to said first clamp member in a
sliding manner whereby said sternal clamp device may be lengthened
by relative movement of said first and second clamp members away
from each other and whereby said sternal clamp device may be
shortened by relative movement of said first and second clamp
members toward each other, such that said sternal clamp device is
lengthened and positioned on said sternal halves such that said
sternal halves are between said leg members of said first and
second clamp members, and said sternal clamp device is shortened to
force said sternal halves together; engagement means to control
relative movement of said first and said second clamp members;
status control means to control said engagement means, whereby said
engagement means is set in one of three operating statuses, a
locked status wherein relative movement of said first and said
second clamp members is precluded, a closing status wherein
relative movement of said first and said second clamp members
toward each other is allowed but relative movement away from each
other is precluded, and an open status wherein relative movement of
said first and said second clamp members in either direction is
allowed.
14. The device of claim 13, wherein said engagement means comprises
a biased engagement arm having a plurality of teeth, said
engagement arm disposed on said first clamp member, and a ratchet
bar having a plurality of teeth, said ratchet bar disposed on said
second clamp member, whereby said engagement arm teeth and said
ratchet bar teeth are able to engage with each other.
15. The device of claim 14, wherein said status control means
comprises a cam opening disposed in said engagement arm and a
rotatable cam follower positioned within said cam opening, whereby
selection of said operating status and freedom of movement of said
engagement arm is determined by the position of said cam
follower.
16. The device of claim 15, wherein said engagement arm is
pivotally mounted, such that in said locked status said engagement
arm is precluded from pivoting away from said ratchet bar, in said
closing status said engagement arm can pivot sufficient distance
from said ratchet bar to allow said engagement arm teeth and said
ratchet bar teeth to slide over each other, and in said open status
said engagement arm is held in a fixed position away from said
ratchet bar such that said engagement arm teeth and said ratchet
bar teeth are not in contact.
17. The device of claim 15, wherein said status control means
further comprises a post member retaining said cam follower, a head
member disposed on said post member and a slot disposed in said
head member, said post member being rotatably mounted in said
second clamp member.
18. The device of claim 14, wherein said engagement arm teeth each
have an inclined side and an abutment side, said abutment sides
being more perpendicularly oriented than said inclined sides, and
wherein said ratchet bar teeth each have an inclined side and an
abutment side, said abutment sides being more perpendicularly
oriented than said inclined sides, whereby the inclined sides of
said engagement arm teeth and said ratchet bar teeth face each
other and the abutment sides of said engagement arm teeth and said
ratchet bar teeth face each other.
Description
[0001] This application claims the benefit of U.S. Provisional
Patent Application Ser. No. 60/646,732, filed Jan. 25, 2005.
BACKGROUND OF THE INVENTION
[0002] The invention relates generally to the field of lock and
release mechanisms for telescoping or sliding paired members, more
particularly relates to such mechanisms that allow the paired
members to have three operational settings--a locked status
precluding relative movement of the member pair, a closing status
allowing relative movement of the paired members only in the
direction toward each other to shorten the overall length of the
combination of members, and a free travel status whereby the paired
members can be moved in either direction relative to each. More
particularly, the invention relates to such devices that utilize
engaging opposing teeth of a ratchet bar type of construction. In
particular, the invention is applicable for use with a sternal
clamp device, and such an application shall be utilized to describe
the invention herein.
[0003] A sternal clamp is a device that is used to secure two
lateral halves of a sternum that has been longitudinally severed
and divided in surgery, such as is often required to provide access
to the interior of the chest cavity. The sternal clamp comprises a
pair of sliding or telescoping clamp members, with each paired
clamp member having means to grasp or abut the exterior edge of the
sternum, such as a single or multiple leg or hook members extending
to the rear of the clamp member. The sternal clamp device is
positioned across the sternum with the hook members positioned
between adjacent ribs. The two clamp members are then compressed,
i.e., moved toward each other in sliding fashion, to shorten the
device and thereby pull the sternal halves together. The clamp
members are then locked or secured in this contracted position by
various mechanical means. Examples of sternal clamps can be seen in
U.S. Pat. No. 4,201,215 to Crossett et al., U.S. Pat. No. 4,279,248
to Gabbay, U.S. Pat. No. 4,802,477 to Gabbay, U.S. Pat. No.
5,928,231 to Klein et al., U.S. Pat. No. 6,007,538 to Levin, U.S.
Pat. No. 6,051,007 to Hogendijk et al., U.S. Pat. No. 6,217,580 to
Levin, and U.S. Pat. No. 6,540,769 to Miller, III.
[0004] A problem with the known devices is that the locking
mechanisms utilized to maintain the sternal clamp in the compressed
or contracted position are typically cumbersome, difficult to
adjust and difficult to remove. Some mechanisms are not releasable
at all once the clamp has been compressed. Some mechanisms do not
allow the clamp members to be extended once the device has been
compressed. Some mechanisms require the use of screws or similar
fasteners that can be dropped or lost by the surgeon during the
clamping step. All of these problems are exacerbated in emergency
situations where immediate removal of the sternal clamp is
required, such that in many cases destruction of the clamp by
sawing or the like is the only suitable method for rapid
access.
[0005] It is an object of this invention to provide a lock and
release mechanism that enables the sternal clamp to have three
functional statuses or settings--a first status where the device is
locked to preclude relative movement of the clamp members in either
direction, a second status where the device can be compressed or
shortened by sliding the clamp members toward each other, but where
release or extension of the device is precluded, and a third status
where movement of the clamp members in either direction is allowed,
to the point where the clamp may even be disassembled. It is a
further object to provide such a device where the status of the
sternal clamp may be easily and quickly changed from one status to
either of the remaining statuses, and where any status may be
chosen at any time. It is a further object to provide such a device
where removal of the device from the patient can be quickly and
easily accomplished at any time.
SUMMARY OF THE INVENTION
[0006] The invention is a locking and release mechanism and sternal
clamp comprising this lock and release mechanism, where the sternal
clamp comprises a pair of opposing clamp members, the clamp members
cooperating with each other in a sliding or telescoping manner such
that the sternal clamp can be shortened, contracted or compressed
by relative sliding movement of the clamp members toward each
other, and where the sternal clamp can be extended or disassembled
by relative sliding movement of the clamp members away from each
other. In this manner the sternal clamp may have a locked, closing
or open status. One or more hook or leg members are connected to
each of the clamp members such that opposite sides of a sternum can
be abutted with the hook members in order to secure the
longitudinally divided sternal halves in abutting relationship.
[0007] The lock and release mechanism comprises an engagement means
and a status control means. The engagement means comprises a spring
biased engagement arm pivotally mounted to one of the clamp
members. The engagement arm is provided with engagement teeth that
cooperate with engagement teeth of a ratchet bar disposed on the
other of the clamp members. The status control means controls the
position and freedom of movement of the engagement arm, such that
the status control means can be adjusted to determine whether the
device is in the locked, closing or open status. The status control
means comprises a rotating member having a cam follower disposed
within a cam opening provided in the engagement arm. The cam
opening is of a non-symmetrical shape, such that with the cam
following oriented in a first position, designated as the open
status, the engagement arm is pivoted and held free of the clamp
engagement teeth such that relative movement of the two clamp
members is not precluded or controlled in either direction. With
the cam follower oriented in a second position, designated as the
closing status, the teeth of the engagement arm mate with the clamp
engagement teeth, but the engagement arm is allowed limited travel
away from the clamp engagement teeth such that the clamp members
can be slid together. With the cam follower oriented in a third
position, designated as the locked status, the teeth of the
engagement arm mate with the clamp engagement teeth, but the
engagement arm is prevented from traveling away from the clamp
engagement teeth, thereby preventing relative movement of the clamp
members in either direction. The status of the device can be
changed from one to the other at any time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective view of the invention shown in the
locked status.
[0009] FIG. 2 is a partial front view of the invention shown in the
open status, where the head of the status control means is shown in
outline to expose the cam opening and the cam follower.
[0010] FIG. 3 is a view of the invention similar to FIG. 2, where
the invention is shown in the closing status.
[0011] FIG. 4 is a view of the invention similar to FIG. 2 or 3,
where the invention is shown in the locked status and a portion of
the ratchet bar has been removed to expose the ratchet bar
teeth.
[0012] FIG. 5 is a view of certain elements of the engagement means
and the status control means, illustrating the relative positions
of the engagement arm and spring body for the open, closing and
locked positions of the cam follower, designated as O, C and L.
[0013] FIG. 6 is a perspective view of the status control
means.
[0014] FIG. 7 is a side view of the invention with a portion of the
second clamp members removed to expose the status control
means.
DETAILED DESCRIPTION OF THE INVENTION
[0015] With reference to the drawings, the invention will now be
described in detail with regard for the best mode and the preferred
embodiment. In general, the invention is a locking and release
mechanism and a sternal clamp comprising this mechanism, the
sternal clamp comprising a pair of opposing clamp members that
engage in a sliding or telescoping manner, whereby the sternal
clamp can be placed into an open, closing or locked status. In the
open status, the sternal clamp can be lengthened or shortened by
bringing together or pulling apart the paired clamp members, as
well as disassembled by fully separating the clamp members from
each other. In the closing status, the clamp members can only be
pushed together such that the sternal clamp can be shortened, but
the clamp members cannot be pulled apart to lengthen the sternal
clamp. In the locked status, the clamp can be neither lengthened
nor shortened as relative movement of the clamp members is
precluded.
[0016] The sternal clamp 100 comprises a first clamp member 10 and
a second clamp member 20 that mate or engage in a sliding or
telescoping manner such that the length or overall longitudinal
dimension of the sternal clamp 100 can be adjusted as required, and
preferably such that the clamp members 10 and 20 are fully
separable from each other. The first or superior clamp member 10
comprises a main body 11, generally flat and thin. Sternum engaging
means, such as one or more leg or hook members 12, are connected to
the exposed free or outer end of the clamp body 11 and extend in a
generally perpendicular manner to the rear of the main body 11. The
second or inferior clamp member 20 likewise comprises a main body
21, generally flat and thin, with sternum engaging means, such as
one or more rearward extending leg or hook members 22, connected to
the free outer end of the clamp body 21. Pivot means, such as a
relatively short pivot post 25, is mounted on the main body 21 of
the second clamp member 20 to receive the engagement means 40. The
two main bodies 11 and 21 are constructed to have sufficient
separation, such as through the presence of a gap or slot, such
that the pivot post 25 and the engagement means 40 reside between
the two main bodies 11 and 21 when the sternal clamp 100 is greatly
contracted. An aperture 24 is provided in main body 21 to receive
the post 51 of the status control means 50.
[0017] Sliding or telescoping means 30 are provided such that
relative linear movement between the clamp members 10 and 20 is
permitted in the longitudinal direction. As shown, the sliding
means 30 may comprise a tongue member 31 disposed on each of the
opposing edges of the first clamp member main body 11, the tongue
members 31 mating with groove members 32 formed by shoulder members
33 disposed on each of the opposing edges of the second clamp
member main body 21. Equivalent structures for the sliding means 30
are possible.
[0018] One part of the lock and release mechanism comprises
engagement means 40, which comprises a biased pivoting engagement
arm 41 provided with a pivot aperture 43 corresponding in size to
the pivot post 25 of the second clamp member 20, such that the
engagement arm 41 is retained on and may pivot in a plane parallel
to the upper surface of the second clamp main body 21. One or more
engagement teeth 42, preferably a plural number in linear
alignment, are disposed on the outer edge of the engagement arm 41.
A cam opening 46 of non-symmetrical shape is positioned in the base
of the engagement arm 41 on the opposite side of the pivot aperture
43 from the engagement teeth 42. Extending from the engagement arm
41 and generally adjacent the cam opening 46 is curved spring
segment 45, a thin biasing member that joins the engagement arm 41
to the spring body 44. Spring body 44 comprises a member that is
restrained in a controlled position relative to the second clamp
main body 21 by suitable means, such as by abutment with a stop
member 23 disposed on the upper surface of second clamp main body
12. The combination of the spring body and the spring segment 45
creates a biasing force against the engagement arm 41 such that the
engagement arm 41 is pushed outwardly toward the ratchet bar 13 of
the first clamp member 10.
[0019] The other part of the lock and release mechanism comprises
status control means 50, which comprises a means to select or
initiate one of the three status positions available. As shown,
status control means 50 comprises a post member 51 that is inserted
through aperture 24 in the second clamp main body 21. A head 53 is
joined to the post 51 and a slot 54 is disposed on the head 53 such
that the head 53 and post 51 can be rotated by use of a tool with a
linear element, such as for example a flat head screwdriver. A cam
follower 52 is mounted on post 51, such that cam follower 52
resides within cam opening 46 on the engagement arm 41 when the
post member 51 is properly disposed in the second clamp member body
21.
[0020] The main body 11 of the first clamp member 10 is provided
with an extended ratchet bar member 13 having a row of engagement
teeth 14, which comprise another component of the engagement means
40. The clamp engagement teeth 14 are configured so as to interact
or mate with the engagement teeth 42 of the engagement arm 41. Both
the clamp engagement teeth 14 and the arm engagement teeth 42 each
have an inclined side 61 and a generally more perpendicular, i.e.,
less angled, abutment side 62, with the inclined sides 61a of the
engagement arm 41 facing the inclined sides 61b of the ratchet bar
13, and the abutment sides 62a of the engagement arm 41 facing the
abutment sides 62b of the ratchet bar 13. The inclined sides 61 are
disposed such that they come into direct contact with each other,
yet may pass slidingly over each other when the sternal clamp 100
is set in the closing status and contraction or shortening of the
sternal clamp 100 is attempted. The abutment sides 62 are disposed
such that they contact each other and prevent lengthening of the
sternal clamp 100 when in the locked status or closing status. In
the open status, neither the inclined surfaces 61 nor the abutment
sides 62 contact each other when the clamp members 10 and 20 are
compressed or lengthened.
[0021] The status control means 50 is rotatable over approximately
180 degrees such that the cam follower 52 likewise rotates
approximately 180 degrees within the cam opening 46. In a first
position, designated as the open status and shown in FIG. 2 and at
position "O" of FIG. 5, the cam follower 52 abuts the cam opening
46 such that the engagement arm 41 is pivoted toward the spring
body 44 and maintained in a position separated from the ratchet bar
13 of the first clamp member 10, such that the arm engagement teeth
42 and the clamp engagement teeth 14 are not in contact and the
clamp members 10 and 20 can be freely moved in either
direction.
[0022] In a second position, designated as the closing status and
shown in FIG. 3 and at position "C" of FIG. 5, the cam follower 52
is positioned within the cam opening 46 such that a small amount of
pivoting movement of the engagement arm 41 is permitted away from
the ratchet bar member 13 of the first clamp member 10, as
illustrated by the dashed lines of FIG. 2. In this status, the
clamp members 10 and 20 can be moved so as to shorten the sternal
clamp, the sliding contact of the inclined sides 61 of the
engagement teeth 42 and 14 causing the engagement arm 41 to be
forced a small distance backward against the biasing force of the
spring 45 as the clamp members 10 and 20 are contracted, the
inclined sides 61 allowing the teeth 14 and 42 to fully slide over
each other. Movement of the clamp members 10 and 20 in an attempt
to lengthen the sternal clamp 100, however, is precluded by contact
between the more perpendicular abutment sides 62 of engagement
teeth 42 and 14, since these sides are negatively inclined and no
ramping effect is created to slide across each other.
[0023] In the third position, designated as the locked status and
shown in FIG. 4 and as position "L" in FIG. 5, the cam follower 52
is positioned across the cam opening 46 such that the engagement
arm 41 is maintained in a fixed position and prevented from
pivoting in either direction. In this status, the sternal clamp 100
can be neither lengthened nor shortened, as the engagement teeth 42
and 14 cannot be separated sufficient distance to allow relative
movement of the clamp members 10 and 20, even in the direction of
the inclined sides 61.
[0024] In this manner, the lock and release mechanism provides for
a sternal clamp 100 that can be easily assembled, positioned across
the gapped sternum, contracted to secure the separated sternal
halves, and locked in the compressed or shortened configuration to
maintain the sternal halves in an abutting relation. In the event
that the sternal clamp 100 must be rapidly removed, the status
control means 50 is easily rotated to the open status position,
thereby retracting the engagement arm 41 from contact with the
ratchet bar 13 and allowing the two clamp members 10 and 20 to
elongated and completely separated for removal.
[0025] It is understood and contemplated that equivalents or
substitutions for descriptive elements set forth above may be
obvious to those skilled in the art, and therefore the true scope
and definition of the invention is to be as set forth in the
following claims.
* * * * *