Note: Descriptions are shown in the official language in which they were submitted.
CA 02127903 2004-11-10
29937-1
BACKGROUND OF THE INVENTION
The present invention is directed to a cassette
for the acceptance of medical instruments, such as dental
instruments so that they may be hygienically treated. To
subject the instruments in the cassette to the treatment,
the cassette is placed into a pressure-tight closable
chamber of an apparatus.
U.S. Patent No. 5,271,893 discloses a cassette
which receives instruments and is inserted into a chamber of
an apparatus which injects treatment fluid into the cassette
for treating instruments disposed therein. The cassette of
the patent is constructed of two parts when the instruments
are deposited on a grating in the lower cassette half. The
cassette is then closed with the upper half and placed in a
sterilizer.
The instruments can only be subjected to a
sterilization with the known cassette, whereby it is mainly
only the exterior surface of the instruments that are
sterilized by the hot steam. With this cassette, a
treatment of instruments, particularly of their internal
parts or cavities, does not occur beyond the contact of hot
steam on the outer surfaces of the instrument.
SUMMARY OF THE INVENTION
The object of the present invention is to provide
an improved cassette for use in a treatment apparatus for
treating medical instruments, such as dental instruments.
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To accomplish these goals, the invention is
directed to an improvement in a cassette for the acceptance
of medical instruments, particularly dental instruments for
the purpose of a hygienic treatment, said cassette being
placeable in a pressure-tight closable chamber of an
apparatus so that the instruments are subjected to a
treatment process, the improvement comprising the cassette
having at least one adaptor for holding at least one
instrument.
The invention of the present cassette is the
advantage that the instrument is placed onto the adaptor and
can be wetted substantially better by the cleaning fluids.
Further, they can be stored on the adaptor until the next
use.
When, as proposed in the advantageous development
of the invention, the adapter will comprise line channels
for the delivery of cleaning agents into the internal part
and these are connectable to delivery channels and then the
instrument can be optimally treated, i.e., cleaned,
disinfected and being cleaned with a lubricating oil or the
like and then can be sterilized. After the patient
treatment, the instruments are placed into the cassette and
can remain therein until the complete hygienic treatment.
The instruments need not be picked up by the operator in the
meantime and need not be placed in the special care means
for care, as previously was the case in the prior art. In
addition, the instruments need not be taken from this care
means and placed into a separate sterilizing means.
A broad aspect of the invention provides in a
cassette having an interior for receiving medical
instruments including dental instruments for purposes of
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CA 02127903 2006-03-16
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hygienic treatment, said cassette being placeable in a
pressure-tight closable chamber of a treatment apparatus and
having at least one opening so that the interior of the
cassette may be subjected to a treatment process, the
improvements comprising the cassette having at least one
adapter for holding at least one instrument, said adapter
comprising line channels for delivering a treatment agent to
the interior of the instrument.
Other advantages and features of the invention
will be readily apparent from the following description of
the preferred embodiments, the drawings and claims.
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Fig. 1 is a schematic partially exploded perspective view of an embodiment
of the apparatus of the present invention;
Fig. 2 is an exploded perspective view of an instrument cassette in
accordance with the present invention;
Fig. 3 is a partial perspective view taken from the rear of the cassette with
a closure flap in the closed position;
Fig. 4 is a partial perspective view similar to Fig. 3 with the closure flap
in
the opened position;
Fig. 5 is a longitudinal cross sectional view through an adapter illustrated
in
Fig. 2 and a portion of an instrument mating with the adapter;
Fig. 6 is a longitudinal cross sectional view of the cassette of the present
invention disposed in the apparatus with portions in elevation for purposes of
illustration;
Fig. 7 is a diagram illustrating the hydraulic and pneumatic connections of
the present invention;
Fig. 8 is a diagram illustrating the sequence of pulses with respect to time
during operation of the device of the present invention; and
Fig. 9 is a modification of the apparatus and cassette illustrated in Fig. 6.
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The principles of the present invention are particularly useful when
incorporated in a cassette 12 illustrated in Figs. 2 and 6, which is used with
an apparatus,
generally indicated at 1 in Fig. 1.
The apparatus 1 is used for the purpose of a hygienic preparat(on of various
dental instruments. The apparatus contains a housing which forms a chamber 2
on the
front side for the acceptance of a cassette 12 (see Fig. 2). The chamber 2 has
a plurality ,
of nozzle arms 3 (nine are illustrated) which project into the chamber 2. The
instruments
are capable of being sprayed on the outside with the assistance of these
nozzle arms 3.
The chamber 2 has guide beads 4 for the guidance of the cassette arranged on
both
sides. The chamber 2 can be closed pressure-tight on its front side with a
cover or door
5, which operates in a known way.
The housing for the apparatus 1 has a container far demineralized or
distilled water which is located adjacent an upper surtace of the housing and
has a filling
opening 6. On the right-hand side near the.rear of the apparatus, the
apparatus 1 has
a diaphragm closure provided in a known way, which closure is punctured by a
connection shank 7a when the container 7 is placed on the connection shank so
that
removal of the lubricant can occur. A door or lid 7b can close the pitch that
receives the
container 7 once the container has been inserted.
The apparatus also has an electrical lead 8, a line 9 for receiving water
indicated by the arrow W and an air line 10 which receives compressed air
indicated by
the arrow L. To assure that a largely germ-free gas or air Is avallabie for
the method
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steps set forth in greater detail below, the air line 10 passes through a
filter chamber
which receives a removable and, thus, replaceable sterile filter 11.
The cassette 12, as illustrated in Fig. 2 in an exploded view, is introducibie
into the chamber 2 and will receive a plurality of instruments, such as a
handpiece 13 and
a manual instrument 14. The instrument 13 is shown as either a handpiece or an
angle
y piece whose inside comprises various drive parts and bearings as well as
media
channels. The instrument 14, by contrast, is a hand instrument that comprises
no moving
parts and, therefore, has no media channels. The cassette 12 is composed of a
base
part or a lower part 12a and an upper cassette part 12b which is removable
therefrom.
The lower cassette part 12a is constructed trough-like and contains four
different adapters
for the acceptance of differently-shaped instruments on a raised backwall 15.
In the
exemplary embodiment, the adapter 16 is matched to receive the instrument 13
which is
accepted thereon. The four adapters are provided for instruments that comprise
moving
internal parts and media channels, such as, for example, handpieces, angle
pieces,
turbine handpieces, handpieces for removing dental tartar or spring
handpieces. The
instruments that contain no moving internal parts and also contain no media
channels,
such as, for example, hand instruments 14 in the Figure, are placed on the
floor or base
of the lower cassette part with a suitable holder for the purpose of
preparation.
The backwail 15 of the lower cassette part 12a also contains bores 17 (nine
of which are illustrated), through which the nine nozzle arms or nozzle tubes
3 of the
chamber 2 can pass through when the cassette 12 is introduced into the
chamber. The
arrangement of the nozzle arms and of the bores 17 which correspond thereto
is,
respectively, a triangular arrangement around the centrally-placed adapters,
as illustrated
in the Figure.
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The upper part 12b can be placed on the lower cassette part 12a and can
be latched thereto. The upper part 12b contains lateral guide channels 18 that
interact
with the above-mentioned guide beads 4 of the chamber and assure the exact
centering
and guidance of the cassette 12 when it is inserted into the chamber 2.
At a suitable location, preferably at the floor and (n the immediate proximity
of the backwall 15, the cassette is provided with one or more outlet openings
19 for the
discharge of the supplied cleaning fluids, as well as any condensed water.
This outlet
opening or outlet openings are advantageously provided with a part that
automatically
closes when the cassette is removed from the chamber 2. These automatic
closures can
be spring-loaded slides or covers.
The upper cassette part 12b is advantageously provided with a cover on a
back end, and this cover will cover, respectively, both the closing
connections leading to
the adapter 16 as well as the outlet openings 19 when the cassette is removed
from the
apparatus. As illustrated in Figs. 3 and 4, the cover 20 is hinged around a
bearing or axle
21. The movement of the cover occurs automatically when the cassette 12 is
inserted
into the chamber 2 of the apparatus. To accomplish this, the cover plate 20
comprises
a projection 20a that strikes against the upper edge 22 (Fig. 1 ) of the
chamber 2 upon
insertion of the cassette 12 into the chamber. As a result of this, the flap
will be tilted
upward to the position illustrated in Fig. 4. Thus, the openings 17 located
behind the
cover plate, as well as the connections, which are not shown in Fig. 4, for
the adapters
will be uncovered or exposed. Upon removal of the cassette, the cover plate,
in tum,
automatically pivots or hinges down and, thus, covers the openings so that the
hygienically prepared instruments located in the cassette are protected
against the
penetration of germs, at least for a certain time period.
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Alternatively to the automatically opening and closing flap set forth above,
a roller shutter ,element can also be provided. This will effect an automatic
covering or,
respectively, clearing of the openings or, respectively, connections provided
In the
backwali 15 with the assistance of a correspondingly provided setting means.
The structure and function of the adapters, as well as the interaction with
the instruments that can be plugged thereon, is illustrated in Fig. 5 with
reference to an
example of the adapter 16.
The adapter 16 is provided for connecting a hand and angle piece 13 in Fig.
2. The hand or angle piece 13, as illustrated in Fig. 5, has an axial bore 13a
which
receives bearing 26 that mount a drive shaft 25 for rotation. In addition, the
handpiece
has media channels 27, 28 for delivering cooling air and cooling water to a
preparation
location, and these channels proceed on the interior of the handpiece. The
bore 13a
adjacent an open end is provided with bail catches 29, which will be received
in an
annular channel, similar to 30, of a motor housing when the handpiece is
inserted thereon
to form a connection therewith.
The adapter 16 contains a connecting shank 24 that is structurally matched
to the design of the bore 13a of the instrument. The adapter 16 is fashioned
so that the
end facing away from the instrument can be secured to the backwall 15 of the
lower
cassette part 12a in an easily detachable way. To accomplish this, it contains
a catch
nose 31 that interacts with an annular channel 37 of a flange or nipple 38
(Fig. 6) that is
mounted on the backwail 15 of the lower cassette part 12.
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2i2'790~
The adapter 16 has a bore containing a control plunger or spool valve
member 32 that is displaceable parallel to the axis of the adapter, and this
plunger 32 acts
against a spring force so that when the Instrument 13 is plugged onto the
shank 24, the
control plunger 32 is depressed so that the input channel 33 is connected to a
centrally-
placed channel 34 and an input channel 35 is connected to an aligned channel
36 which
has peripheral openings that are aligned with openings for the media channels
27 and 28
of the instrument. Thus, drive air or lubricating oil can be introduced via
the channel 33
to the drive shaft 25 and the bearings 26 and air and water are guided in
common in the
lines 27 and 28 via the channels 35 and 36.
When an instrument, such as 13, is removed from the adapter 16, the
plunger valve will assume the position illustrated in Fig. 5 and interrupt the
connection
between the inlet channel 33 and channel 34 and also betweeri the channel 35
and
channel 36. This will prevent any supplied media or oil from being emitted
from an
adapter which is not occupied with an instrument.
As already mentioned, the connection dimensions with respect to the
instruments are different for all four adapters mounted in the cassette in
order to, thus,
be able to hold different instruments. The connecting dimensions with respect
to the
connector 38 on the backwall 15 of the cassette, however, are the same for all
adapters
so that they can be easily interchanged with one another or, respectively, can
be replaced
by adapters having different connecting contours for different instruments.
The allocation of the individual washing and cleaning nozzles or channels
is ill,~strated in Fig. 6 with reference to an example of the instrument 13
and adapter 16.
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In a highly simplified illustration, Fig. 8 shows the arrangement of the
cassette 12 in the chamber 2 in the condition wherein the cassette 12 is
nearly completely
introduced. Corresponding to the plurality of existing adapters, connecting
flanges 38 are
located on a backwall 15 of the cassette 12 and the adapter is, as already
mentioned,
capable of being put in place on these connecting flanges 38 in an easily
detachable way.
The connecting flange 38 has a coupling sleeve 40 that will form a connection
with a lead
41 and a sleeve 39 forms a connection with a lead 42. The lead 42 corresponds
to the
lead 35 for pressurized water, compressed gas or air and steam indicated I~r
arrow
W/L/D, while the: lead 42 corresponds to the channel 33 for lubricant and air
indicated
by arrow D.. Each of the nozzle arms 3 are arranged star-like or,
respectively, tri~gularly
around the instrument 13 and are firmly arranged in the housing wall 43 that
deanes the
back side of the chamber 2. These tubes or arms 3 are connected to the line 47
to
receive pressurized water, compressed gas and steam, as.indicated by arrow W/t-
/D.
The tubes or arms 3 are fashioned as hollow tubes and comprise a plurality of
exit
openings 44 that are arranged aligned at a specific angle to a surface of the
instrument.
The nozzle bores are advantageously arranged along the nozzle arm or tube not
only in
one plane but in a plurality of planes offset relative to one another by a
defined angle.
The offset can be advantageously arranged zig-zag or wave-like in the
longitudinal
direction along the reference plane.
As illustrated in Fig. 1, as well as from the following hydraulic and
pneumatic
connection diagram set forth in greater detail in Fig. 7, nine nozzle arms are
advantageously provided for preparing a maximum of four instruments. The
arrangement
is therefore undertaken so that the nozzle arms are arranged in two rows and
offset so
that three arms are arranged around an instrument at a respective angle of
120° relative
to one another.
9
' 212'790
before the method of the invention is set forth in greater detail with
reference
to the drawings already described and. with reference to the hydraulic and
pneumatic
block circuit diagram of Fig. 7, it should be pointed out that the steam
generator 45
connected to the pressurized line 9, as well as the preheating means 46 for
water, are
accommodated in the apparatus housing in addition to the above-mentioned oil
reservoir
or container 7. Thus, it should be pointed out that the nozzle arms 3 length
from the
backwail is limited so that the lid 20 is able to tip from the closed position
to the opened
position as the projection 20a engages the edge 22 without striking the ends
of the tubes
3.
In the hydraulic/pneumatic connection block diagram of Fig. 7, a
compressed air supply source 48 and a pressurized water source 49 are
connected
through the lines 10 and 9, respectively. For purposes of illustration, the
filters, oil
separators for the compressed air as well as the over-pressure valves that are
standard
on the input side are not illustrated for the sake of simplicity.
All solenoid valves MVi through MV16, as well as the water heater 16 and
the steam generator 45, are controlled by a microprocessor 50. Reflex or check
valves
RV are connected in all of the lines.
The injection of a lubricant (maintenance oil mixed with air) from the
reservoir 7 occurs pneumatically here via two solenoid valves MV1 and MV12 as
well as
by a restriction point or throttle point 51. Alternatively, the lubricating
oil could also be
supplied with a suitable oii pump. The microprocessor 50 controls the valves
MVi
through MV9 and MV11 through MV16 so that the agents of water, air and also
lubricating oil can be supplied to the adapter 16 and to the nozzle arms 3
separately for
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each instrument during a method step of pre-cleaning, after-cleaning and,
potentially,
during the care, procedure so that the instruments are cleaned and potentially
maintained
in chronological succession.
The chronological offset may be seen from the pulse/time diagram of Fig.
8 that shows the chronological course of the valve connections for the various
agents of
. air and water for the four instruments referenced 11-14. A high cleaning
efficiency given
a low water consumptiori is achieved with this chronologically successive cut-
in of the
agents.
The method utilizing the cassette is as follows:
The cassette 12 is charged with instruments and the instruments that have
movable internal parts, such as the angle pieces, turbines, sprays or the
like, are plugged
onto corresponding adapters 16 of which a maximum of four are allowed in the
cassette.
The otherinstruments are placed at a holder device above the floor of the
container. The
cassettes are then closed by putting the upper cassette part 12b on the lower
part 12a
and the cassette is introduced into the chamber 2 of the apparatus. During
this insertion,
the rear cover 20 is lifted and, as a result thereof, .the nine nozzle arms 3
extend through
the bores 1T of the backwall 15 of the cassette. After the cassette has been
inserted into
the chamber to such an extent that the connection of lines 41 and 42 with the
connectors
39 and 40 (see Fig. 8) has been produced, the cover 5 of the apparatus is
closed and
the apparatus is turned on.
After a self-test, which lasts approximately half a minute, a cold cleaning of
the instruments occurs utilizing cold water which is supplied to the adapter
16 and to the
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nozzle arms 3 via leads 9 and the lines 41 and 47. The cold water is
preferably supplied
in a pulsating fashion whereby compressed air at high pressure, which Is also
pulsating,
is mixed with the water into the pulse pauses Illustrated in Fig. 8. A high-
energy water jet
is thus produced and this surprisingly causes a very thorough cleaning of the
surfaces
and of the inside channels as well. At the same time, the gearing channel is
charged with
air via a line 42 with the oil delivery valve MVi 1 remaining closed so that
the penetration
of dirt and contaminated wash water is therefore prevented. The pulse
frequency with
which the compressed air is supplied to the water amounts to approximately 3
Hz.
The cold cleaning is ended after about two minutes. The warm cleaning of
the exterior surfaces of the instrument and of the inside channels follows
thereafter,
likewise with a pulsating water jet upon addition of pulsed compressed air.
This
procedure follows the sequence in the above-mentioned way. After about two
minutes
of warm cleaning, an intense after-cleaning and a vapor disinfection occurs by
blowing
the exterior surface of the instruments and of the media and gearing channels
in the
interior of the instrument off and out with the hot water or water vapor at a
temperature
in a range of 60°C through 100°C. To this end, the water is
heated by the heater 46
which acts as a flow-through heater. This procedure lasts for about 30-45
seconds.
Care of the moving inside parts follows this intensive after-cleaning by
injecting a metered quantity of lubricant from the lubricant reservoir 7. The
metering can
occur dependent on the adapted instrument and amounts to about 1 gram per
instrument
in the injection cycle on average. This maintenance step lasts approximately
half a
minute.
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A sterilization of the Instrument then subsequently occurs, namely both from
the outside as,well as from the inside with saturated water steam at a
temperature of
approximately 134°C given a pressure of approximately 2-2.5 bar. The
sterilization
procedure amounts to between 5 and fi minutes. The sterilization procedure is
followed
by a drying and cooling of the instrument with cold air. The cooling procedure
lasts
approximately 3-5 minutes. Given an overall time of approximately 15-20
minutes for
preparing the instruments, the cassette 12 with the prepared instruments can
be
subsequently removed and can be kept ready for use in its closed condition.
The method of execution which automatically sequences in and of itself in
the described way can be varied by intervention. For example, on the basis of
an
appropriate program, pre-selection can be called in at a control and display
panel 52 (Fig.
1) on the front side of the apparatus 1, for example, in that an intermediate
drying, for
example with air, is implemented following the intensive after-cleaning and
disinfection of
the external surfaces. An interruption can likewise occur after the
maintenance in order
to be able to remove articles which are not to be sterilized from the
cassette.
For removing existing dry air, particularly from cavities, and particularly
from
cavities of the instruments; the chamber can be evacuated before the
sterilization of the
instruments in an advantageous modification. In order to achieve an optimum
removal
of the dry air; the vacuum should lie in the range of between 40 mbar and 500
mbar
absolute. The vacuum can be produced according to a known fractional, mufti-
step
method or according to a pre-vacuum method.
E-xtremely short times for an optimum, hygienic preparation of the instrument
occur with the described method. Due to the pulsating water Jet to which high-
energy
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compressed air is supplied in surges, an especially intense cleaning of the
parts is
obtained. A reliable transport to the. treatment location is established in
that the
instruments can remain in the cassette after the preparation. In addition, the
cassette
may be used to receive used instruments and store these used or contaminated
instruments until they are to be sent for preparation. The instruments
contaminated with
germs after being used remain in the cassette until they are taken again
therefrom and,
therefore, a risk of injury to the operating personnel, among other things, is
precluded as
a result of this procedure. Processing, storing and transport will occur in
the cassette.
Since the cassette is largely closed, a sterile storing of the instrument is
assured over at
least an adequately long time, as measured in hours. In that the internal
parts and the
agent channels are flooded with hot water and steam, a relatively rapid
heating time for
the overall instrument occurs. A certain lime-dissolving effect is also
achieved in the lines
due to the fact that the lines are blown out with the water and/or steam and
the exteriors
aye blown off with the water and/or steam. A critical advantage is that no
cleaning and
drive agent whatsoever need be employed.
A modification or embodiment of the cassette is illustrated in Fig. 9 by a
cassette generally indicated as 112. This modification is with regard to the
nozzle arms
3. For example, the nozzle arms can be component parts of the cassette, as
shown in
the exemplary embodiment of Fig. 9, and are mounted in the backwall 15. In
addition,
even though this would be relatively involved, the nozzle arms can be pivoted
around their
longitudinal axis and can also be potentially arranged movable in an axial
direction. The
cover shown in Figs. 3-5 can alternatively also be a component part of the
lower cassette
or can be allocated to both cassette halves.
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Although various minor modifications may be suggested by those versed
in the art, it should be understood that we wish to embody within the scope of
the patent
granted hereon all such modifications as reasonably and properly come within
the scope
of our contribution to the art.
