This application is divided out of the Indian Patent Application Number
2883/KOLNP/2006 Filed on 06 October 2006 which, in turn, is the national phase entry
of International PCTApplication No. PCT/NZ2005/000069 having an International
Filing Date of 05 April 2005
BACKGROUD TO THE INVENTION
Field of the Invention
This invention relates to a lens warming and cleaning device and particularly but
not solely to the warming and cleaning of the distal portion of an optical instrument such as
a laparoscope prior to insertion into a body cavity to prevent lens fogging.
Summary of the Prior Art
A number of products are known in the art for warming and cleaning the distal
portion of a laparoscope prior to insertion into a body cavity, thereby preventing the lens
incorporated at the distal portion of the laparoscope from fogging when the laparoscope is
first inserted into a patient thus obstructing the surgeon's view of the patient's internal
organs. This fogging is caused as a result of moisture condensing on the laparoscope lens.
The lens temperature is below the dew point temperature of the insufflation gas that is
pumped into the patient in order to increase the surgeon's work space within the body
cavity. The gas temperature is approximately 37°C as the human body will humidify the
gas to approximately 100% relative humidity and raise the gas temperature to body
temperature causing micro-droplets of water to condense on the colder laparoscope lens.
WO01/60239 of the University of Massachussets discloses a lens wanning and
cleaning device to warm and clean the lens at the distal portion of an optical instrument
such as a laparoscope. The lens warming and cleaning device includes a heat conducting
tube sized and shaped to receive the lens portion of the laparoscope, a heating element
thermally coupled to the exterior of the heat conducting tube and a cleaning member
disposed within the conducting tube. The preferred heating element is a heating pad that
includes a flexible, air-permeable outer bag that encases a chemical mixture. The chemical
mixture when activated generates an exothermic reaction thereby generating sufficient heat
to warm the laparoscopic lens to between 45° and 60°C. The cleaning member disclosed is
a sponge inserted into the distal end of the heat conducting tube which is moistened with a
saline solution plus an additive such as an anti-fogging additive or surfactant. The
warming and cleaning device is self-contained and does not require power to operate. The
exothermic heating pad can provide sufficient heat for up to six hours or more and needs to
be replaced after one operating procedure whilst the remainder of the equipment is
sterilized for re-use.
US patent 6,234,635 issued to Michael R. Seitzlinger and David Platts discloses an
apparatus for maintaining a region of the proximal lens of a laparoscope at a temperature
greater than ambient to prevent lens fogging during use. The heating device is a pre-
sterilized chemical heat pack which when activated, is attached in the region of the
proximal lens end of the laparoscope for the duration of the operating procedure thereby
ensuring the lens temperature is maintained to above ambient. The heating device is
disposable. However with the device attached to the region of the laparoscope proximal
lens the extra weight in this region would modify the balance of the equipment in use.
In US patent 5,549,543 issued to I1 G. Kim a defogging apparatus for heating and
maintaining the lens and end portion of a laparoscope to above ambient temperature is
disclosed. The apparatus includes an internal water filled receptacle for receiving the lens
and laparoscope end portion surrounded by a second water filled container mounted onto a
heating plate. The heating plate includes a temperature control mechanism which ensures
the water in the inner receptacle and outer container is maintained at a constant
temperature. Whilst providing an effective and controlled heating device the equipment
requires a power source to operate thereby reducing portability and the receptacles must
undergo sterilization procedures prior to use.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a lens warming and cleaning
system for wanning the lens temperature above ambient which goes some way to
overcoming the abovementioned disadvantages in the prior art or will at least provide the
industry with a useful choice.
It is a further object of the invention to provide a lens warming device which is
disposable and portable within an operating environment.
Accordingly, in a first aspect the present invention consists in a warming device
capable of warming the distal portion of an optical instrument including a lens portion
comprising:
a double walled cylindrical tube having an internal wall, external wall, upper
surface and open distal portion with central cavity there between,
a protrusion extending from said upper surface, sized and shaped to receive the lens
portion of said optical instrument,
a circular cap sized to attach to said distal portion of said double walled cylindrical
tube,
an insulation layer between said internal wall and said external wall of said double
walled cylindrical tube, and
a heating element enclosed within said central cavity and thermally coupled to said
insulation layer.
In a second aspect the present invention consists in a warming device capable of
warming the distal portion of an optical instrument such as a laparoscope comprising:
a double walled cylindrical tube having an internal wall, external wall, upper
surface and open distal portion with central cavity there between,
a protrusion extending from said upper surface, sized and shaped to receive the lens
portion of said optical instrument,
a circular cap sized to attach to said distal portion of said double walled cylindrical
tube,
an insulation layer between said internal wall and said external wall of said double
walled cylindrical tube, and
a material coating said central circular protrusion.
In a third aspect the present invention consists in a warming device capable of
warming the distal portion of an optical instrument such as a laparoscope comprising:
a double walled cylindrical tube having an internal wall, external wall, upper
surface and open distal portion with central cavity there between,
a protrusion extending from said upper surface sized and shaped to receive the lens
portion of said optical instrument,
a circular cap sized to attach to said distal portion of said double walled cylindrical
tube,
an insulation layer between said internal wall and said external wall of said double
walled cylindrical tube,
a material coating said protrusion, and
an input and an output gas tubing connector attached to said double walled
cylindrical tube such that in use at least heated insufflation gas is passed through said
device thereby warming said central cavity.
In a fourth aspect the present invention consists in an apparatus for calibrating an
optical instrument whilst warming the distal portion of an optical instrument such as a
laparoscope comprising:
a double walled cylindrical tube having an internal wall, external wall, upper
surface and open distal portion with central cavity there between,
a protrusion extending from said upper surface sized and shaped to receive the lens
portion of said optical instrument,
a circular cap sized to attach to said distal portion of said double walled cylindrical
tube,
an insulation layer between said internal wall and said external wall of said double
walled cylindrical tube,
a whitening block inserted into the distal portion of said protrusion, and
a heating element enclosed within said central cavity and thermally coupled to said
insulation layer.
This invention consists in the foregoing and also envisages constructions of which
the following gives examples.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred forms of the present invention will now be described with reference to the
accompanying drawings.
Figure 1 is a cross-section of the insulated medical lens warming device of the
present invention.
Figure 2 is a perspective view of the handle clip attached to the insulated lens
warming device of Figure 1.
Figure 3 is an exploded view of the insulated lens warming device of Figure 1.
Figure 4 is a cross-section of a second form of the insulated lens warming device
of the present invention.
Figure 5 is a cross-section of a third form of the insulated lens warming device of
the present invention.
Figure 6 is a perspective view of the insulated lens warming device of Figure 5.
Figure 7 is a cross-section of a fourth form of the insulated lens warming device of
the present invention.
Figure 8 is a perspective view of the insulated lens warmer of Figure 7.
Figure 9 is a cross-section showing the use of a flexible grommet attached to the
insulated lens warming device upper surface of another embodiment of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides a warming device capable of warming the lens
portion of an optical instrument, such as a laparoscope, to a temperature above ambient to
prevent lens fogging and a means of cleaning the lens during a surgical procedure to
remove any biological matter that may adhere to the lens. The lens warming device is self-
contained and does not require the attachment of any power source thereby making the
device portable for use anywhere within the surgical operating environment.
In particular a lens warming device is described which provides a means for
warming the lens portion of an optical instrument to a temperature above ambient
temperature for a prolonged period. At any stage during the operating procedure where the
surgeon has to withdraw the laparoscope from the body cavity the lens portion is re-
inserted into the lens warmer to maintain the lens portion temperature above ambient and
where a cleaning member is disposed at the distal end of the lens warming device, the lens
will be cleaned on contact with the cleaning member. At the end of the operating
procedure the lens warming device may be disposed of thereby potentially eliminating the
requirement for the equipment to undergo autoclave or other sterilization procedures.
It will be appreciated that the lens warming device as described in the preferred
embodiment of the present invention can be used for many forms of surgical optical
instruments generally but will now be described below with reference to the surgical
optical instrument being a laparoscope.
With reference to Figures 1 and 3, a laparoscope distal portion 1 having a lens 2 at
the distal end is shown inserted into the insulated lens wanning device 30 of the present
invention. The insulated lens warming device 30 is preferably constructed of a
thermoplastic or thermoset plastics material such as ABS, polyethylene or other
appropriate material. The insulated lens warming device 30 is a double walled cylindrical
tube 3 a and 3b with central cavity 4, having an open distal portion 7 to which a circular cap
5 is attached by ultrasonic welding, friction fit, snap fit or other appropriate fastening
known in the art. Between the inner 3b and outer walls 3a of the double walled cylindrical
tube 3 is an insulation layer 6 comprising air. The proximal end 8 of the double walled
cylindrical tube 3 is closed and has a protrusion 9 extending into the central cavity 4
towards the distal end 7 of the double walled cylindrical tube 3, sized and shaped to
receive the lens portion 2 of the optical instrument 1. The protrusion 9 is preferably a
cylindrical protrusion located about the central portion of the proximal end 8 of the double
walled cylindrical tube 3. The central cavity 4 is filled with a conductive heating element
15 such as water, saline solution, wheat, oat or barley grass grains, rice, or other
appropriate heat conducting material, prior to permanently fitting the circular cap 5 to the
distal end 7 of the double walled cylindrical tube 3.
A non-woven cleaning member 12 made from acrylic, polypropylene or other
appropriate filter type material may be disposed at the distal end 14 of the cylindrical
protrusion 9 such that when the lens portion 2 of the laparoscope 1 is inserted into the
cylindrical protrusion 9, the lens portion 2 contacts the cleaning member 12. A similar
cleaning member may be provided in any one of the embodiments of the lens warming
device as described herein.
As shown in Figure 9, the lens warming device 39 may have a flexible grommet 40
made from a plastics based material such as silicon attached at the proximal end 41 of the
cylindrical protrusion 42. The flexible grommet 40 enables optical instruments 1 of
differing sizes to be inserted into the cylindrical protrusion 42 whilst providing a degree of
support for the optical instrument 1. Alternatively or in combination with the flexible
grommet 40, the cross-section of the cylindrical protrusion 42 may comprise a plurality of
decrementing steps extending from the proximal 41 to the distal portion. This will provide
increased support for the optical instrument 1 when it is inserted into the insulated lens
warming device 39. The lens warming device 39 is of a similar double cylindrical
construction as described above with reference to Figure 1.
With reference to Figure 2 the insulated lens warming device 30 may have a handle
11 of preferably L-shaped configuration, attached to the upper surface 8 of the insulated
lens warming device 30. The handle 11 is preferably an integral part of the insulated lens
warming device 30 formed during the plastics moulding process however other attachment
techniques may be employed such as ultrasonic welding, gluing or other appropriate
attachment mechanism. The handle 11 provides a means for transporting the insulated lens
warming device 30 around the operating environment as well as providing a means for
removably attaching the insulated lens warming device 30 to surgical drapes or table.
Alternatively, the handle 11 may comprise a handle clip type mechanism which opens and
closes such that the insulated lens warming device 30 can securely grip onto the surgical
drapes or table.
Note should be made that any of the embodiments described herein may be
provided with a handle as described above in relation to Figure 2.
Prior to use, the insulated lens wanning device 30 is placed in a microwave or other
conventional oven type surgical warming device in order to raise the temperature of the
heating element 15 to a temperature above ambient body temperature. The cleaning
member 12 may then be inserted toward the distal portion 14 of the cylindrical protrusion
9. The lens portion 2 of the laparoscope 2 is then inserted into the cylindrical protrusion 9
such that the lens portion 2 may contact the cleaning member 12. The thermal energy
produced by the heating element 15 warms the lens portion 2 to a temperature above
ambient such that the lens portion 2 becomes warm enough to prevent lens condensation
on insertion of the lens portion 2 into a body cavity while the cleaning member 12 may
clean the lens portion 2 in preparation for surgical use.
The insulation layer 6 is in thermal contact with the heating element 15 such that
the heating element temperature is maintained for at least the duration of the surgical
procedure. Therefore, when the lens portion 2 is removed from the body cavity, it can be
re-inserted into the insulated lens warming device 30 to maintain the temperature of the
lens portion 2 to at least above ambient. Also, when the cleaning member 12 is inserted
into the cylindrical protrusion 9 the lens potion 2 may also be cleaned in preparation for re-
insertion into the body cavity.
A second embodiment of the insulated lens warming device 43 of the present
invention is shown in Figure 4. Here the lens portion 2 of an optical instrument 1 is
inserted into the insulated lens warming device cylindrical protrusion 44. The walls 20 of
the cylindrical protrusion 44 may be impregnated during the plastics moulding and forming
process with a black coloured material such as dye. The insulated lens warming device 43
is not pre-heated prior to use as the light source emanating from the lens portion 2 of the
optical instrument 1 strikes the distal portion 14 of the cylindrical protrusion 44 and being
coated black, absorbs the light energy and converts it to thermal energy due to conduction.
The thermal energy therefore warms the lens portion 2 of the optical instrument 1 up to
above the dew point of the insufflation gas used within the body cavity thus preventing
lens fogging.
Alternatively, instead of impregnating the cylindrical protrusion walls with black
dye during the plastics moulding and forming process, a removable black plastic moulded
insert 21 of preferably cylindrical cross-section, having a closed distal end 22 may be
inserted into the cylindrical protrusion 44. The black insert 21 provides an alternative
means of converting light energy into thermal energy due to conduction using the light
source emanating from the lens portion 2 of the optical instrument 1.
An insulated lens warming device of the third embodiment of the present invention
is shown in Figures 5 and 6. The lens warming device 31 here has two gas tubing
connectors 23, 24 in fluid connection with the double walled cylindrical tube 32. The
input gas tubing connector 23 is located towards the proximal portion 33 and the output
gas tubing connector 24 is located towards the distal portion disposed at substantially 180°
to each other, penetrate the body of the double walled cylindrical tube 32. Prior to
inserting the lens portion 2 of an optical instrument 1 into the body cavity, a gas tube
supplying heated and preferably humidified gas from the same source used to insufflate the
body cavity, is diverted and attached to the input gas tubing connector 23 thus inserting at
least heated gas into the central cavity 34. The resultant thermal energy generated within
the central cavity 34 raises the temperature up to above the dew point temperature of the
gas. The thermal energy generated will increase the temperature within the cylindrical
protrusion 35 such that when the lens portion 2 of the optical instrument 1 is inserted into
the cylindrical protrusion 35 the lens portion 2 absorbs the thermal energy heating the
instrument prior to insertion into the body cavity thus preventing lens fogging.
The gas can exit from the central cavity 34 via the output gas tubing connector 24
located towards the distal portion 36 of the insulated lens warming device 31. There is no
requirement to attach a gas tube to the second gas tubing connector 24 as the gas is allowed
to exit to free air space.
In a fourth embodiment, shown in Figure 7, the lens warming device 37 preferably
has a whitening insert 26 disposed at the distal end 38 of the cylindrical protrusion 45. The
whitening insert 26 may be inserted into the cylindrical protrusion 45 prior to the insertion
of the lens portion 2 of the optical instrument 1. At the beginning of surgery the optical
instrument 1 is switched on such that light emanates from the distal portion of the optical
instrument 1. The lens portion 2 is then inserted into the insulated lens warming device 37.
As well as being pre-warmed the light emanating from around the distal portion of the
optical instrument 1 strikes the whitening insert 26 and is reflected back into the lens
portion 2 enabling the equipment to be calibrated to ensure bodily tissue appears the
correct colour on insertion of the distal portion of the optical instrument 1 into the body
cavity. Note, the general construction of the lens warming device 37 is similar to that of
that of Figure 1 in that the lens warming device 37 has a double walled cylindrical tube
construction 46.
Alternatively, as shown in Figure 8 a cavity 27 may be formed during the plastics
moulding process to provide an opening extending from the double walled cylindrical tube
outer surface and inner surface, across the distal portion of the cylindrical protrusion (not
shown, but similar to 45 in Figure 7) towards the opposite inner surface wall. Hence, a
removable whitening block 28 may be inserted into the double walled cylindrical tube
cavity 27 opening such that when the lens portion 2 of a optical instrument 1 is inserted
into the insulated lens warming device 47 the scope can be calibrated and warmed prior to
insertion into a body cavity. This is achieved by switching on the optical instrument light
source such that the lens portion 2 of the optical instrument 1 receives light reflections off
the whitening block 1. Again, the general construction of the lens warming device 47 is
similar to that of that of Figure 1 in that the lens warming device 47 has a double walled
cylindrical tube construction 48.
CLAIMS:
1. A warming device capable of warming the distal portion of an optical instrument
including a lens portion comprising:
a double walled cylindrical tube having an internal wall, external wall, upper
surface, open distal portion and central cavity formed inwards in relation to the internal
wall,
a protrusion extending from said upper surface within the central cavity, sized and
shaped to receive the lens portion of said optical instrument,
a circular cap sized to attach to said distal portion of said double walled cylindrical
tube,
an insulation layer between said internal wall and said external wall of said double
walled cylindrical tube, and
a heating element enclosed between said central cavity and said protrusion.
2. A warming device according to claim 1 wherein said protrusion comprises a
plurality of steps of decreasing circumference toward the distal portion of said protrusion.
3. A warming device according to claim 1 or 2 wherein said heating element
comprises a conductive material.
4. A warming device according to any one of claims 1 to 3 wherein said heating
element is heated prior to use by micro-waving said warming device.
5. A warming device according to any one of claims 1 to 3 wherein said heating
element is heated prior to use by inserting said warming device into a conventional oven
type surgical warmer.
6. A wanning device according to any one of claims 1 to 5 wherein said insulation
layer comprises air.
7. A warming device according to any one of claims 1 to 6 wherein said warming
device is disposable.
8. A warming device according to any one of claims 1 to 7 wherein said double
walled cylindrical tube has an attachment mechanism attached to said upper surface
configured to removably attach said warming device to a surgical drape or table in use.
9. A warming device according to any one of claims 1 to 8 wherein a flexible
grommet surrounds the proximal end of said protrusion.
10. A wanning device according to any one of claims 1 to 9 wherein said protrusion
has a cleaning member disposed at the distal portion.
11. A warming device according to any one of claims 1 to 10 further comprising a
whitening block inserted into the distal portion of said protrusion.
12. A warming device capable of warming the distal portion of an optical instrument
comprising:
a double walled cylindrical tube having an internal wall, external wall, upper
surface, open distal portion and central cavity formed inwards in relation to the internal
wall,
a protrusion extending from said upper surface within the central cavity, sized and
shaped to receive the lens portion of said optical instrument,
a circular cap sized to attach to said distal portion of said double walled cylindrical
tube,
an insulation layer between said internal wall and said external wall of said double
walled cylindrical tube, and
a material coating said protrusion such that when an optical instrument is inserted
into said protrusion the light energy emanating from the optical instrument is absorbed by
said material coating and converted to thermal energy and said material coating is black
dye impregnated into a plastics type material making up the internal wall during the
manufacture of the warming device.
13. A warming device according to claim 12 wherein said protrusion comprises a
plurality of steps of decreasing circumference toward the distal portion of said protrusion.
14. A warming device according to any one of claims 13 and 13 wherein said double
walled cylindrical tube has an attachment mechanism attached to said upper surface
configured to removably attach said warming device to a surgical drape or table in use.
15. A warming device according to any one of claims 12 to 14 wherein a flexible
grommet surrounds the proximal end of said protrusion.
16. A warming device according to any one of claims 12 to 15 wherein an input and an
output gas tubing connector is attached to said double walled cylindrical tube such that in
use at least heated insufflation gas is passed through said warming device thereby warming
said central cavity.
17. A warming device according to any one of claims 12 to 16 further comprising a
whitening block inserted into the distal portion of said protrusion.
18. An apparatus to calibrate an optical instrument according to claim 17 wherein said
double walled cylindrical tube has a horizontal cavity extending from said external wall
through said distal portion of said protrusion, sized and shaped to fit said whitening block.

ABSTRACT

A wanning device (30) is disclosed that is capable of warming the lens portion (2) of
an optical instrument (1), such as a laparoscope, to a temperature above ambient to
prevent lens fogging and a means of cleaning the lens during a surgical procedure to
remove any biological matter that may adhere to the lens. The lens warming device
(30) is self-contained and does not require the attachment of any power source thereby
making the device portable for use anywhere withm the surgical operating
environment.