CA1222365A

CA1222365A - Microwave sterilizer

Info

Publication number: CA1222365A
Application number: CA000446465A
Authority: CA
Inventors: Robert J. Bielawa; Gerald G. Bousquet; James F. Regan; Kenneth L. Carr
Original assignee: MA Com Inc
Current assignee: MA Com Inc
Priority date: 1983-02-16
Filing date: 1984-01-31
Publication date: 1987-06-02
Also published as: US4614514A; JPS6315855B2; EP0116921B1; DE3482570D1; MX155972A; JPS59156351A; EP0116921A3; ATE54052T1; EP0116921A2

Abstract

Abstract of the Disclosure A microwave sterilizer for sterilizing a connector or coupling that interconnects a first conduit from a source of liquid to be infused into a living body to a second conduit implanted in the body. The apparatus of the invention comprises a housing having first and second members forming a guided wave structure adapted to be removably closed around the coupling or connector and further including first and second clamping means. The clamping means are adapted to clamp respective conduits and are operable to isolate a charge of the liquid within the connector. A microwave source is used to generate energy which in turn is coupled to the guided wave structure to cause heating of the liquid charge to a temperature level to cause sterilization so as to destroy substantially all form of bacteria therein. After a predetermined heating sequence, the apparatus is released and the bag side clamping means is first released so as to pass the sterilized charge of liquid into the source or bag.

Description

3~;

MICROWAVE STERILIZEEI
.

~ackground of the Invention The present invention relates in general to a microwave sterilizer and pertains, more particularly, to a microwave sterilizer employing a balanced coaxial transmission line for providing intense heating for sterilization.
At present, patients who are require~ to connect to dialysis or the like equipment use a standard coupling connection. It has been found that bacteria, such as staphylococcus bacteria may exist at the coupling. Presently, patients have to be quite careful in making sure that the connection is made without making direct contact with the members that are intercoupled. Another problem, particularly for the elderly and those that lack manual dexterity is that they are required to provide a mating of the connector, either with or without assistance, that interconnects the source of liquid to the living body. Additionally, many patients are diabetic and may have limited vision which makes this interconnection difficult.
Accor~ingly, it is an object of the present invention to provide a microwave sterilizer for sterilizing the conduit cou~ling or connector that cou~les from a liquid source in which the 1iquid is infused into a living body. For example,, the systenl with which the microwave sterilizer mdy be used is with a technique callea ~continuGus ambulatory peritoneal dialysis~ or CAPD for short. CAPD means, quite literally, ambulatory dialy~is employing the peritoneum, the internal lininy of the abdominal cavity, as a filteriny membrane.
However, it is also understood that the concepts of this -3~5 invention also apply to other techniques for infusing a liquid into a living body from a source of the liquidO
For example, the concepts of the invention may also be applied in intravenous infusions.
Another ob~ect of the presen-t invention is to provide a microwave sterilizer apparatus which pro-vides for the mating of the connector or coupling with the mating preferably taking place concurrently with the clamping of the conduit on either side of the connector or coupling so as to isolate a charge ~small volume) of the liquid within the connector or couplingO
The mating and clamping is followed by the application of heat by means of a guided wave member adapted to enclose the coupling or connector.
Still another object of the present invention is to provide a microwave sterilizer in accordance with the preceding objects and which is relatively simple in construction, very safe in operation, extremely effective in providing the necessary sterilizing heat, and which is readily operable by the elderly, those with impaired vision, or those lacking manual dexterity.
Summary of the Invention To accomplish the foregoing and other objects of this invention, there is provided a system for in-fusing a liquid into a living body by means of a couplingor connector that intercouples a conduit from the source of the liquid to a conduit implanted in the body. In accordance with the invention, apparatus is provided for sterilizing the coupling or connector comprising a guid-ed wave member adapted to enclose the coupling and meansfor heating,by excitation, the guided wave member to heat an initial charge of the liquid to an eLevated temperature for a time long enough to destroy bacteria.
The apparatus preferably comprises a housing including first and second members forming the a~ore-mentioned guided wave member arranged to be removably closed around the connector or coupling. There is also provided first and second clamping means on opposite sides of the coupling or connector and means to operate the clamping means to isolate a charge of the liquid within the ~onnector. The clamping rneans is also operated to be subsequently released after the sterilization has been completed. In this connection, the clamps are released in sequence to ~irs~ discharge any liquid into the source rather than the ~ody. In the preferred construction one of the guided wave mem-10 bers is in a fixed position in the housing while the other member is pivoted relative to the one member to open and close the guided wave member. It is also preferred to employ as part of the apparatus, a car-ri.age in the housing for supporting one of the conduits and means for supporting the other conduit in a fixed position and also further including means for operating the carriage to cause the conduits to be joined by virtue of mating the coupling or connector.
In accordance with the method of this inven-tion, there is provided, for the infusing of a liquid into a living body, in a process which requires the initial step of coupling a conduit from a source of the liquid to a conduit implanted in the body. The method steps include the steps of, following the coupling, holding an initial charge of the liquid in the conduit bridging the coupled ends of the conduit, heating the initial charge to an elevated temperature for a time long enough to destroy bacteria and then releasing the liquid into the source.
The method preferably also includes the step of temporarily fixing the coupled ends in a microwave heating enclosure and heating the initial charge in the enclosure. By virtue of the connector or coupling being closed, this means that the liquid is put under elevated pressure while heating to intensify the heating a~d to bring the temperature up to a proper level to cause sterilization~

3~

In accordance with still a further aspect of the present invention there is provided an improved coupling or connector which comprises a hollow male ~ember connected ~o one of said conduits and a hollow fenlale mem~er connected to the other of said conduits. These conduits are the ones for infusing a li~uid into a living body including a condluit from the source of the liquid and a conduit implanted in the body. The male and female mernbers are adapted ~o engage and the male member is provided with a spike end entering the female member. The female member has an inner diameter along a section thereof greater than the diameter of the spike end so as to provide an annular space about the spike end to accommodate the liquid providing a reservoir charge of the liquid about the spike end capable of being heated for sterilization thereof.

Brief Description of the Drawings Numerous other objects, features and advantages of the invention should now become apparent upon a rea~ing of the following detailed descri~tion taken in conjunction with the accolnpan~ing drawing, in which:
FI~. 1 is a to~ plan view of the ap~aratus of ~his invention with the door open ana showing the coupling tubes in phantom;
FIG. 2 is a cross-sectional view taken along line ~-2 o~
~IG. 1 showing the apparatus in its cover-open position;
FIG. 3 is a cross-sectional view ~aken in the opposite direction along line 3-3 of FIG. l;
FIG. 4 is a second view of the invention in a view similar to the cross-sectional view of F~G. 3 but with the operating lever being moved to the coupling engaging position;
FIG. 5 is a oross-sectional view taken along line 5 5 of FIG. 4 showing further details of the heating blocks;
FIG. 6 is a cross-sectional view taken along line 6-6 of PIG. ~;

6~i FIG. 7 is a cross-sectional view taken along line 7-7 of FIG. 6 showing further details of the heating block;
~ IG. 8 is a view ~imilar to the cross-sec~ional views of FIGS. 3 and 4 showing a release sequence;
FIG. 9 is a graph of clinical sterilization time versus temperat~re in connection with the apparatus of this invention;
and FIG. 10 is a graph of pressure versus temperature in connection with the apparatus of this invention.

Detailed Des_r~etlon Referring now to the drawings, there is shown a complete apparatus for the microwave sterilizer of this invention. A
substantial part of this a~paratus is for carrying out mechanical functions such as the mating of the connector parts and the clamping of the conduits. As far as the sterilization is concerned, this is accomplished by means of the microwave sterilizer which broadly is eomprised of a solid state microwave source 10 coupled to a short coaxial cable 12 (see FIG. 2). With regard to the transmission line defined by ~he curved conductors 42 and 43, the loss~ or attenuation is determined by the microwave characteristics of the loading ~i.e. the liquid contained within the connector) forming a lossy structure. As indicated previously, a mechanism is provided for the mechanical mating of the two connector parts.
The mechanism to be described in further detail hereinafter also allows for the introduction and confinement of the liquid in the area of matiny or in other words, in the coupling or connector itself.
In accordance with the present invention and the apparatus and method described herein~ the sequence and duration of operation is significant. The general sequence of steps is the alignment and mating of ~he conduit or tubing, the clamping of the conduit or tubing, activation of the microwave source for a , . . .. . .. . . ... ....... ... .. . .......... . . .. . .

predetermined heating period and then release of the clamping in a predetermined manner to be described hereinafter. By way of example, in the application associated with CAPD patients, pushing of an actuating lever such as the lever 14 (FIGo 3 ) shown in the drawings combines the spike 16 of the male connector 18 with the female connector 20. This ac~ion also causes a piercing of the diaphragm 21 which has been placed between the separate par~s 22 and 23 oomprising the female member. The diaphragm 21 is used to seal the connection to the source of the liquid. Note the connection of the female member 20 to the conduit 24. Similarly, the male member 18 couples to the conduit 26~ It is also noted that the female member preferably has a sealing O-ring 27.
On the ret~rn motion of the lever 14, such as illustrated in FIG. 4, the clamps are opened with the clamp on the bag side opening first and just prior to reaching the full return stroke position, the clamp on the patient's side opens. This is to make sure that the liquid that has just been heated in the connector does not pass back into the body, but instead is discharged, should any discharge occur, back into the reservoir or bag that is used for the liq~id. This operation is relatively simple and it is safe for the patient to use.
In ~rief swQmary, the se~uence of operation is as follows:
1. The patient prepares the new bag containing the solution and positions the male and female connector members along with the silastic tubing into the fixture located in the apparatus. The silastic tubing is represented by the conduits 24 and 26~ previously mentioned.

2. The patient locates and positions the spike 16 along with its associated conduit or tubing 26 into a transfer nest 32.

3. The patient then closes the top cover 34. This motion engages the pivotal heater blQck 36 (see FIG. 7) so as to close both the heater block 36 and the stationary heater block 38 about the connector 40 which comprise~ the male member 18 and the female member 20.

2;~5

4. The patient tben ~ctuates the lever 1~ which clamps off bsth tubes 24 and 26 and transfer the spike 16 into the female connector 20. This pierces the diaphragm 21. A proper seal i~
provided to protect from liquid leaking by mean~ of the O-ring

5. The patient then activates a switch for exci ~ing the microwave source 1~ and the process runs until completion as either controlled by a timer or by ~ensing a temperature of 138C.

6. Upon completion of the heating cycle, a light and/or ~ound is preferably generated to indicate to the operator tha~
sterilization has been completed.

7. The patient then retracts the lever 14 and the tubing is unclam~ed in sequence with the tubing 24 being unclampe~
first, followed by unclamping of the tubing 26.

8. The top cover or door 34 is then o~ened. ~I~e heating blocks 36 and 38 have a spring 39 (see FIG. 7) associated therewith that normally pivots the pivotal heater ~lock to its open position so that when the door or cover is opened, then the heater blocks are also opened, or in other words, the guided wave member is opened so that the connector or coupling 40 may be removed therefrom.
As illustrated in PI~. ~, there is a two-wire transmission line configuration shown in ~IG. 2 in the open position of the cover 34~ Also refer to the detailed drawing of FIG. 7 which shows the curved conductors 42 and 43. Each of these may be made of stainless steel to minimize heat transfer from the liquid. A rotary hinge ~oint 45 is provided to permit the pivotal movement of the heater block 36. Each of the heater blocks preferably also includes respective housing members 46 an~ 47 and internal insulation 48 and 49. The outer mem~ers 46 and 47 may be of a plastic material and the insulation is adapted to maintain the heat concentrated within the connector 4~.
f r-- -2~

FIG. 2 also shows the balun 11 ~or converting frcm a unbalanced to an balanced conf igurationO A1SO shown are the end tuning variable capacitors for proper tuning of the guided wave structureO
With regar~ to the mechanism for carrying out the mating of the connector and the clamping functions, reference is made to FIG. 3 which shows a carriage 50 which suppor~s the transfer nest 32. The carriage 50 is adapted for lateral movement under control of the lever 14. When the lever is in the upper position of FIG. 3, then the carriage is to the left and when the lever 14 is moved to its downward position, then the carriage traverses to the right so as to provide the aforementioned mating. FIGo 3 shows the position of ~he lever in the unmated state. FIG. 4 shows the lever having been moved to cause the mating of the connector 40.
With regard to the clamping action, it is noted that the conduit 24 is clamped ~r crimped by means of pivot member 52 co-acting with fixed piece 53. PiVot member 52 is operated from the carriage 50 by means of the connector 54 (FIG. 8~.
There is also provided a ciamp member 56 also operated by means of lateral movement of the carriage 50. The clamping member 56 may be of the eccentric type that provides for a clamping of the conduit or tu~ing 26. As indicated previously, these clamps operate so that duriny the unclamping sequence after the water in the connector 40 has been heated, the clanlp member associated with the tubing 24 is released first. This is the conduit that couples back into the ba~ and it is d~sired to couple any heated liquid back intc the bag rather than into the patient, That is why the clam~ing member 5~ is finally released at a later time after release of the other clamping member associated with conduit 24.
The microwave structure that has been described, including the solid state s~urce, is quite compact, efficient, and safe to operate. With this arrangement, a small amount of liquid .~ ._ . , 6~;
g may be heated rapidly at a relatively low power level~ If, for example, one assumes a cylinder of water one centimeter-in diameter by five centimeters long, then:

Vol = _ d2h = 3.93 cu cm Mass, M = Vol x 1 gm/cm3 = 3.93 gms Energy, Q = Mc ~T

where c = specific heat Q = 3.93 gms x c = spec. heat in 1 cal/gmO cx 80C.

Q = 315 Calories Power, P = 4.18 Q
assume t = 5 min. or 300 sec.
p _ 4.18 (315), or 4.39 watts The connector 40 which includes the female member 20 and the male member 18 is uniquely constructed so that the inner diameter as represented by the dimension B is significantly greater than the diameter of the spike 16 as represented by the dimension A. See FIG. 6 for dimensions A and B. This thus provides a liquid accommodating space of annular construction surrounding the spike 16. This space ' " ~: , .
.

3~5;

within the female member 20 provides or a charge of liquid therein surrounding a substantial portion of the spike 16, which liquid is heated in accordance with the invention to provide sterilization. Because the liquid is trapped in the connector by the aforementioned clamping means~ and is thus held at a constant volume, there is a resu:Lting pressure increase which will allow the liquid temperature to rise well above the normal 100C~ boiling point sf water. In fact, as indicated in the graph of FIG. 9 which is a plot of clinical sterilization time vs. temperature, the temperature may reach in excess of 13B~C. Also note the grayh of FIG. 10 which is a gra~h of temperature vs. pressure.
The oonnector 40 and associated tubing 24 and 26 has low attenuation at the microwave freguency range employed. In this connection, the microwave source may be at a frequency of 915 MHz. However, the liquid contained within the microwave structure is highly absorptive. The balanced transmission line comprised of conductors 42 and 43 (FIG. 7) may be terminated in either a short circuit or open circuit. In this way the transmitter power not absorbed by the liquid initia]ly i5 reflected, or directed back~ into the lossy liquid. The loss of the structure is adequate to present a proper match to ~he microwave transmitter.
rrhe 915 MHz solid state source 10 preferably oper~tes from a typical voltage supply of 12 volts, allowing safe operation from either battery or low voltaye power supply. The output of the 915 M~z solid state source is a~proximately 15 watts. With this low power operation the device is thus compact, efficient and safe in operation.
Sterilization tests that have been performed verify that the sterilizer, or microwave autoclave, is capable of clinically steriliziny a connector in a reasonably short time using only a relatively low level of power. Cultures have been prepared (i.e.9 bacteria including spore form) in a sup~orting ~222~

media conducive to their growth. Bacteria included staph, aureus, pseudomonas, aeruginosa, candida~ albicans, and bacillus stenrotherm~philus. The culture media included 5%
sheep blood agar, chocolate agar with 5% sheep blood, trypticase soy ~roth, and Columbia broth. These samples were placed in the microwave sterilizer for 4.5 minutes at an incident, or transmitter, power level o~ l~W. During this period of time the temperature of the solution exceeded 138C.
The temperature of ~he solution within ~he plastic test section was determined through the use of heat sensitive indicators.
The various solutions were examined at the end of seven days and it was determined that the solutions were sterile (i.e., all forms of bacteria, including spores, were destroyed~
During sterilization it is possible that air may ~e trapped in the space about the spike between the spike and the mating female connector. With reference to PIG. 6 this may be in the area about the spike 16 at the left end of the female connector part 23. The trapped air with associated surface tension may prevent the flow of water into this air pocket in the gap or space about the male spike.
In connection with FIG. 6 one can also assume a radius Rl for the inner diameter of the female member and a radius ~2 for the radius of the spike. These are the radii that determine the aforementioned gap or space. For any given geometry (i.e.
for every ra~i~s ratio of Rl/X2) there exists some pressure differential wherein the pressure differential is the di~ference in pressure between the liquid ~eariny portion and the air ~earing portion of the volume, which will overcome the surface tension. It is preferred to use nominal values of pressure differential and one can assume a relatively small value of pressure differential to assure that small pressure fluxuatiGns produced as the water begins to boil are significan~ to overcome the surface tension associated with a ~.... . ... . . . ........ ...... .... . . ..... . ... .

~2~

trapped ~u~ble or volume of air. The pressure 1uxuation is in the order o U.5 psi for the formation of a steam bubble.
Therefore, one should choose the geometry such that the pressure differential is e~ual to 0.5 psi 50 that this value is sufficient to overcome the surface tension.
Determining the geometry involves a procedure that converges on the largest radiu~ ratio (Rl/R2) that is capable of supporting the surface tension when the pressure in the water is 0.5 psi higher than in the air bubble.
Assuming zero viscosity, this ratio is:
Rl/R2 = 1.00~
Any ratio above this number will not support the surface tension, and water will flow freely into the air pocket which is desired.
Herein~efore, there has been a brief description of the apparatus and of the seq~ences of operation. There now follows a more detailed description of the apparatus and operation.
Thus, in FIG. 1 there is shown a plan view with the door or cover 34 o~en showin~ the tu~es ~4 and 26 in ~hantom. In FIG.
1 in the cut away portion of the door 34, there is shown the start heater button 60 and the time-out light 62. FI~. 1 also shows the eccentric type ciamp 56. This is in the form of a pinch valve operating with an eccentric cam 63 (~I~. 5) and associated spring 64. The clamping member or valve is indexed by the extension spring 64 shown in phantom in FIG. 5. FIG. 5 also shows the preCsure roller 65 associated with the cam 63.
THe eccentric roller form of clamp is mounted in a fixed position while the pressure roller is mounted on the sliding door 34. The pressure roller pushes the tubing 1/32 of an inch into and toward the eccentric cam 63 in order that friction will rotate the oam counter clockwise when the carriage is moved to the right in FIG. 1. In FIG. 5 there is shown the position in which the clamping member 56 is in its pinched position. The surface of the cam 63 is constructed so that one inch of carriage travel pulls the tubing and rotates the cam . ~ , . . .. .... ... ... . . .. . .. . . . . .

~2~3~ ~

thus creating a 1/4 inch pinch of the tubing. This pinch valve arrangement once activated, stays pinched onto the tubing until the door is opened at the very end of the sequencel pulling the pressure roller back and releasing the binding action on the cam. This allows the extension spring 64 to index the cam 63 back clockwise to its narrowest point in relationship to the tubing in readiness for the next cycle. The cam also is made so that once one inch of travel has pinched the tube, any further rotation is a constant pressure. This is noted in FIG.
5 by the constant diameter of the cam 63 about the majority of its radius.
FIGo 2 is a cross-sectional view taken along line 2-2 of FIG. 1 showing the cradle arrangement for the female (bag end) en~ of the tubing. This cradle 67 is suspended from the fixed portion of the cover as represented by the top wall 68. In the view of FIG. 2 the heater blocks 36 and 38 are shown just behind the cradle 67. In FIG. 2 the block 36 is biased open under the bias of the extension spring 39 which is partially hidden in the view of FIG. 2 behind the balun 11 a~d associated variable capacitors. The variable capacitors are used for tuning as mentioned previously. It is noted that the block 36 carries at its upper left corner, a curved protrusion 70. This protrusion is adapted to be contacted by the block 71 mounted to the far left underside of the sliding door 34. This contact occurs as the door is slid closed or slid toward the right in FIG~ 2. Thus, as the cover is closed, this block 71 engages the protrusion 70 to close the guided wave member against the spring tension of spring 39. The safety latch 72 is part of the bearing mounting plate and comes forward behind the heater blocks after the sliding door is closed and is activated by the handle or lever 14 which slides the carriage. As is evident from the cross-sectional view of FIG~ 3, the safety latch 72 prevents the door from being opened by as little as l/16th of an inch travel of the carriage. FIG~ 2 also shows the power ~14-source 10 to the left having its output coupling by way of transmission line 12 to the ~uided wave member.
FIG. 3 is a front elevation view in cross~section ~aken along 3 3 of FIG~ 1. The pinch rollers, one of which is the aforementioned eccentric cam, is shown with one being in front of the other and wit~l the tubing 26 sandwiched therebetween.
Note in FIG~ 3 the pressure roller 65. The linkage between the bearing mounting plate and the right hand side pinch valve as represented by the linkage 52, is a lost motion linkage as represented by the connector 54 which is comprised of a spring biased arrangemen~ providing limited slip of 1/2 inch. This linkage includes a left hand member 74 which is a hollow tu~e with a slot milled in it. The right side o the linkage is a rod 7~ with a reduced neck with a pring 76 slid over the neck and a roll pin 77 inserted through a hole in the neck and through the slot. As the handle 14 is brought down, and the carriage moves from left to right, the linkage is pushing the pinch valve shut via the spring compression with a force of 4 lbs. spring pressure. The roll pin 77 does not bottom out on the push stroke. Instead, on the return stroke of the carriaget it does bottom out in the slot after 1/2 inch or less of movement and it then pulls the pinch valve on the bag side open. It is also noted that the limit lug on the pinch arm bracket which in FIG. 4 is shown in phantom prevents the arm from going over center in relation to the pinch block which is mounted on the sliding cover.
PIG. 4 shows the cover 34 closed with the safety latch and part of the rotating heater block partially cut away. The heater block is closed in this position and the safety latch 72 (FIG. 2) engages. It i s noted that the handle 14 is in its downward position thus causing both of the pinch valves or clamping members to operate. This also causes the spike (needle) 16 to pierce through the diaphragm 21 The sliding door is thus in a locked position~

;~2~
, -15-FIG. 5 shows the heater block partially ~roken away to show the details of the inserted spike 16~ FIG. 5 also shows the operation of the eccentric type clamping member and also ~hows in an oYerlying relationship the clamping at the bag side as represented by the interaction of the pivot Member 52 with the fixed piece 53. In phantom, in front of the rotating half of the heater block is the activating member 71 that closes the pivotal heater block 36. FIG. 5 al~o shows partially broken away and partially in phantom, the aforementioned safety latch which is part of the bearing plate assembly.
~ IG. 6 shows longitudinally the heater block partially broken away. FIG. 6 also shows the details of the l~inging including hinge pins 80 and 81 which facilitate pivoting of the pivotal heater block 36. FI~. 6 also shows the spring 39 and part of the cradle 67. Also shown are the tuning capacitors 82 and 83 and a portion of the input transmission line 12.
FIG. 7 is a cross sectional view taken along the cross-section line 7-7 of FIG. 6b In this view the cradle 67 is mostly broken away to show details of the hinge 45 and further details of the variable tuning ca~acitors or tuning elements. The biasing spring 39 is shown a~ the bottom of the heater block. It is also noted in FIG. 7 that there is shown the actuating block 71 that closes the movable heater block 36. FIG. 7 also shows the protrusion 70 that cooperates with the block 71. The end of the male spike 16 is seem inside of the female connector with the liquid thereabout in readiness for heating.
FIG. 8 shows the release sequence. The view of FIG. 8 is the same cross-sectional view as shown in FIGS~ 3 and 4. In this position, the lever or handle 14 has been raised again.
This action is taken after the heating sequence has terminated. This action moves the carri~ge 50 ~ack to the left leaving the male an~ female connector members together. It is noted that the pinch valve or clamp mem~er on the right side, ~2236~

namely the pivot member 52 has been released. However, the left clampirlg member 56 is still shut and remains shut until the door is opened.
In summary, the operation is as follows. The user opens the coYer 34 by sliding it forward. This opens the 7 inch wide cover to expose a gap of a~ut 3 1/2 inches thus exposing the cradle and transfer nest. The heater hlock is also open. THe user then places the male and female connectors in their respective cradles and slides the door closed. This closing of the door operates the heater block and pushes the pressure roller 36 against the tube on the patient tube side so that a frictional drag is created on the rotating cam pinch valve.
The user then starts to pull the handle 14 down. The first 1~16 inch travel of the carriage locks the door closed. The carriage continues on toward the heater block and a~ter one inch of travel, the patient side pinch valve, namely the one including the eccentric cam 63 closes off the tubi ng completely an~ evens out by virtue of the constant diameter so that no more pressure is exerted during the final half inch of travel of the carriage. The lost motion linkage 54 meanwhile is closing the bag side tubing under spring tension until it closes the tube completely with spring pressure. This occurs when the spike is approximately 1/8 inch away from piercing the diaphra~m. The carriage continues piercing the ~iaphragm and going well past so that the diaphragm will not interfere with flow. The spring pressure builds up to approximately 4 lbs. of pressure against the pinch valve even on the bag side. The handle rides over center of the linkage. The user then pushes the heater start button. This activates the RF source 10.
After the RF source times out or after a temperature is sensed, the light and/or buzzer goes off. The user then raises the handle 14 and the carriage starts returning empty. This means that the connector stays mated. After 1/2 inch of travel, the lost motion linka9e bottoms out and snaps the bag side pinch ~, " , .

~2~23i~ , , -17-valve open ~hus eausing liquid in the connector to be expelled into the bag side and not into the patien~. The car~iage continues back to the left releasing the filiding door. The user opens the door thus releasing the patient side pinch valYe and opening the heater block. This then frees the connector for removal from the apparatus.
Having described one embodiment of the present invention, it shculd now be apparent to those skilled in the art that numerous other embodiments are contemplated as falling within the scope of this invention as defined by the appended claimsO
What is claimed is-j~ ~

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:-

1. In a system for infusing a liquid into a living body by means of a coupling that intercouples a conduit from a source of said liquid to a conduit implanted in said body, apparatus for sterilizing said conduit coupling comprising, a guided wave member adapted to enclose said coupling, and RF source means for exciting said guided wave member to heat an initial charge of said liquid to an elevated temperature for a time long enough to destroy bacteria.

2. In a system as set forth in claim 1 wherein said guided wave member comprises first and second members arranged to be removably closed around at least portions of said coupling.

3. In a system as set forth in claim 2 including first and second clamping means on opposite sides of said coupling and means to operate said clamping means to isolate the charge of liquid within said coupling.

4. In a system as set forth in claim 3 wherein said means to operate includes means to release said clamping means.

5. In a system as set forth in claim 4 wherein the clamping means are released in sequence to first discharge any liquid into the source rather than body.

6. In a system as set forth in claim 5 including a housing for supporting the guided wave member and clamping means.

7. In a system as set forth in claim 6 wherein one of said first and second members is fixed in position in the housing while the other member is pivot-ed relative to the one member to open and close the guided wave member.

8. In a system as set forth in claim 7 including an operating handle to operate said clamping means.

9. In a system as set forth in claim 3 including a housing for supporting the guided wave member and clamping means.

10. In a system as set forth in claim 9 including a carriage in the housing for supporting one of the conduits and means for supporting the other conduit in a fixed position and means for operating the carriage to cause the conduits to be joined.

11. In a system as set forth in claim 10 wherein said coupling where the conduits are joined comprises an apertured member and cooperating hollow spike member adapted to engage with the apertured member.

12. In a system as set forth in claim 11 wherein said apertured member has an inner diameter along a section thereof greater than the diameter of the spike member so as to provide an annular space about the spike member to accommodate the liquid.

13. In a system as set forth in claim 10 wherein said means for operating said carriage concurrently also operates said clamping means.

14. Apparatus for infusing a liquid into a living body, in a process which requires the initial step of coupling a first conduit from a source of said liquid to a second conduit implanted in said body, comprising a housing having first and second members arranged to be removably closed around portions of said conduits includ-ing the confronting ends of said conduits, said housing including first and second clamp means having said con-fronting ends between them when said members are closed around said portions, said clamp means being operable to isolate a charge of said liquid within said portions, means to heat said charge to a sterilization temperature so as to destroy substantially all forms of bacteria therein, and means operable sequentially to release said clamp means so as to pass said sterilized charge of liquid from said coupling.

15. Apparatus for infusing a liquid into a living body as set forth in claim 14 wherein one of said first and second members is held stationary while the other is rotatable.

16. Apparatus for infusing a liquid into a living body as set forth in claim 14 wherein clamp means are adapted to pinch the conduits.

17. Method of infusing a liquid into a living body, in a process which requires the initial step of coupling a conduit from a source of said liquid to a conduit implanted in said body, comprising, following said coupling, the steps of holding an initial charge of said liquid in said conduits bridging the coupled ends of said conduit, heating said initial charge to an elevated temperature for a time long enough to destroy bacteria and then releasing said liquid.

18. Method according to claim 17 including the step of temporarily fixing said coupled ends in a microwave heating enclosure and heating said initial charge in said enclosure.

19. Method according to claim 17 including the step of putting said initial charge under elevated pressure while heating it.

20. In a system for infusing a liquid into a living body by means of a coupling that intercouples a conduit from a source of said liquid to a conduit implanted in said body, said coupling comprising, a hollow male member connected to one of said conduits and a hollow female member connected to the other of said conduits, said male and female members adapted to engage and said male member having a spike end enter-ing said female member, said female member having an inner diameter along a section thereof greater than the diameter of the spike end so as to provide an annular space about the spike end to accommodate the liquid providing a reservoir to store a charge of liquid about the spike end capable of being heated for sterilization thereof.

21. In a system as set forth in claim 20 in combination with microwave heating means including a guided wave member encasing said coupling for providing heating of the charge of liquid.

22. In a system for infusing a liquid into a liv-ing body by means of a coupling that intercouples a conduit from a source of said liquid to a conduit implanted in said body, apparatus for sterilizing said conduit coupling comprising, a guided wave member enclosing said coupling, means for clamping the conduits on opposite sides of said coupling to isolate a constant volume of a charge of liquid with-in said coupling and an electromagnetic energy source means for exciting said guided wave member to heat said charge of said liquid to an elevated temperature for a time long enough to destroy bacteria, the com-bination of said heating and clamping with a constant volume of liquid providing a pressure increase within the coupling that allows the liquid temperature to rise above the boiling point of the liquid.

23. In a system as set forth in claim 22 wherein said guided wave member comprises first and second members arranged to be removably closed around at least portions of said coupling.

24. In a system as set forth in claim 23 including first and second clamping means on opposite sides of said coupling and means to operate said clamping means to isolate the charge of liquid within said coupling.

25. In a system as set forth in claim 24 wherein said means to operate includes means to release said clamping means.

26. In a system as set forth in claim 25 wherein the clamping means are released in sequence to first discharge any liquid into the source rather than body.

27. In a system as set forth in claim 26 includ-ing a housing for supporting the guided wave member and clamping means.

28. In a system as set forth in claim 27 wherein one of said first and second members is fixed in posi-tion in the housing while the other member is pivoted relative to the one member to open and close the guided wave member.

29. In a system as set forth in claim 28 including an operating handle to operate said clamping means.

30. In a system as set forth in claim 24 including a housing for supporting the guided wave member and clamping means.

31. In a system as set forth in claim 30 including a carriage in the housing for supporting one of the con-duits and means for supporting the other conduit in a fixed position and means for operating the carriage to cause the conduits to be joined.

32. In a system as set forth in claim 31 wherein said coupling where the conduits are joined comprises an apertured member and cooperating hollow spike member adapted to engage with the apertured member.

33. In a system as set forth in claim 32 wherein said apertured member has an inner diameter along a section thereof greater than the diameter of the spike member so as to provide an annular space about the spike member to accommodate the liquid.

34. In a system as set forth in claim 31 wherein said means for operating said carriage concurrently also operates said clamping means.

35. Apparatus for infusing a liquid into a living body, in a process which requires the initial step of coupling a first conduit from a source of said liquid to a second conduit implanted in said body, comprising a housing having first and second members arranged to be removably closed around portions of said conduits including the confronting ends of said conduits, said housing including first and second clamp means having said confronting ends between them when said members are closed around said portions, said clamp means being operable to isolate a constant volume charge of said liquid within said portions, means to heat said charge to a sterilization temperature so as to destroy substantially all forms of bacteria therein, and means operable sequentially to release said clamp means so as to pass said sterilized charge of liquid from said coupling, the combination of said heating and clamping with a constant volume of liquid provid-ing a pressure increase within the coupling that allows the liquid temperature to rise above the boil-ing point of the liquid.

36. Apparatus for infusing a liquid into a living body as set forth in claim 35 wherein one of said first and second members is held stationary while the other is rotatable.

37. Apparatus for infusing a liquid into a living body as set forth in claim 35 wherein clamp means are adapted to pinch the conduits.

38. Method of infusing a liquid into a living body, in a process which requires the initial step of coupling a conduit from a source of said liquid to a conduit implanted in said body, comprising, following said coupling, the steps of holding an initial constant volume charge of said liquid in said conduits bridging the coupled ends of said conduit by clamping said conduit at points on either side of said coupled ends, heating said initial charge to an elevated temperature for a time long enough to destroy bacteria, the com-bination of said heating and clamping with a constant volume of liquid providing a pressure increase within the coupling that allows the liquid temperature to rise above the boiling point of the liquid and then releasing said liquid charge.

39. Method according to claim 38 including the step of temporarily fixing said coupled ends in a microwave heating enclosure and heating said initial charge in said enclosure.

40. Method according to claim 38 including the step of putting said initial charge under elevated pressure while heating it.

41. In a system for infusing a liquid into a living body by means of a coupling that intercouples a conduit from a source of said liquid to a conduit implanted in said body, said coupling comprising, a hollow male member connected to one of said conduits and a hollow female member connected to the other of said conduits, said male and female members adapted to engage and said male member having a spike end entering said female member, said female member having an inner diameter along a section thereof greater than the diameter of the spike end so as to provide an annular space about the spike end to accommodate the liquid providing a reservoir charge of liquid about the spike end capable of being heated for sterilization thereof, in combination with micro-wave heating means including a guided wave member encasing said coupling for providing heating of the charge of liquid, the combination of the heating and a clamping of the coupling to provide an isolated charge having a constant volume of liquid providing a pressure increase within the coupling that allows the liquid temperature to rise above the boiling point of the liquid.

42. In a system for infusing a liquid into a living body by means of a coupling that intercouples a conduit from a source of said liquid to a conduit implanted in said body, apparatus for sterilizing said conduit coupling comprising, a guided wave member enclosing said coupling, means for clamping the conduits on opposite sides of said coupling to isolate a constant volume of a charge of liquid with-in said coupling and an electromagnetic energy source means for exciting said guided wave member to heat said charge of said liquid to an elevated temperature for a time long enough to destroy bacteria, the com-bination of said heating and clamping with a con-stant volume of liquid providing a pressure increase within the coupling that allows the liquid tempera-ture to rise above the boiling point of the liquid, said guided wave member comprising first and second members arranged to be removably closed around at least portions of said coupling, first and second clamping means on opposite sides of said coupling and means to operate said clamping means to isolate the charge of liquid within said coupling, a housing for supporting the guided wave member and clamping means, a carriage in the housing for supporting one of the conduits, means for supporting the other conduit within a fixed position and means for operating the carriage to cause the conduits to be joined, said means for operating the carriage concurrently, also operating the clamping means.

43. In a system as set forth in claim 41 wherein said guided wave member comprises first and second members arranged to be removably closed around at least portions of said coupling.

44. In a system as set forth in claim 43 includ-ing first and second clamping means on opposite sides of said coupling and means to operate said clamping means to isolate the charge of liquid within said coupling.

45. In a system as set forth in claim 44 wherein said means to operate includes means to release said clamping means.

46. In a system as set forth in claim 45 wherein the clamping means are released in sequence to first discharge any liquid into the source rather than body.

47. In a system as set forth in claim 46 includ-ing a housing for supporting the guided wave member and clamping means.

48. In a system as set forth in claim 47 wherein one of said first and second members is fixed in posi-tion in the housing while the other member is pivoted relative to the one member to open and close the guided wave member.

49. In a system as set forth in claim 48 includ-ing an operating handle to operate said clamping means.

50. In a system as set forth in claim 44 includ-ing a housing for supporting the guided wave member and clamping means.

51. In a system as set forth in claim 50 includ-ing a carriage in the housing for supporting one of the conduits and means for supporting the other con-duit in a fixed position and means for operating the carriage to cause the conduits to be joined.

52. In a system as set forth in claim 51 wherein said coupling where the conduits are joined comprises an apertured member and cooperating hollow spike member adapted to engage with the apertured member.

53. In a system as set forth in claim 52 wherein said apertured member has an inner diameter along a section thereof greater than the diameter of the spike member so as to provide an annular space about the spike member to accommodate the liquid.