The present invention concerns medical surgery, and in particular, dental surgery that are impeccably sterile.

More particularly, the invention concerns dental sur- gery with equipment designed to guarantee the same ste- rility levels present in an operating room in normal daily conditions ; practically speaking, this provides the means necessary to reduce transferred infection that can be provoked through dental care.

Ensuring sterility is the main characteristic of the present invention ; however, no less important is the possibility of providing a surgery that medical practi- tioners with different specialties can use simultane- ously ; this contributes not only towards offering much better service but also provides enormous cost savings for the evolution of modern medicine.

In particular, when these sterile conditions are com- bined with the behaviour protocol for the whole staff as well as the sterilisation protocol, this can reduce to a great extent, and even practically eliminate, transferred infection that results from dental care.

For example, worldwide literature and the statistics provided by the Higher Institute of Health (Istituto Superior della Sanity) SEIEVA, as well as the conclu- sions in the manual ("Le raccomandazioni per la preven- zione delle infezioni in odontoiatria""Recommendations for the prevention of infection in dentistry"published by the Higher Institute of Health and the Marche Re- gional Authority, as well as information published af- ter the Congress of the College of University profes- sors held in Rome in March 2001,"Infective risks in sprays generated by medical equipment for dental care", provide a terrifying picture of the origin of hepati- tis, and the figures in these statistics are no doubt lower than the actual situation given the difficulty in tracing the source of infection ; it is sufficient to remember that the incubation period for hepatitis var- ies between 50 and 150 days.

The almost exclusively technical branch of dentistry has become predominantly surgical today (gum surgery, implant surgery, bone grafting, opening and modifia- tion of the maxillary sinus, etc).

With regard to this aspect, in this medical branch, even the slightest dental intervention, including fear of treatment and standard control check-ups present a certain danger risk since check-ups and/or interven- tions involve probing in the pockets (the zone where

the gum is attached to the tooth) and the instrument that is used for this exploration always creates tiny cuts and is soiled with blood.

This blood can be infected, so it is necessary to clean and sterilize the instrument immediately in order to prevent any transmission of infection from one patient to another with the use of the same instrument.

The problems involving complete sterilisation in medi- cal surgeries and in particular, in dental surgeries is even more complex if one considers the fact that if the surgeon's hands or the surface where the instruments are placed are not completely decontaminated from in- fectious germs, even though the instruments have been previously sterilised, they can become infected again and can transfer infection.

This situation is even more serious since it has been ascertained that the transmission of many illnesses, from the most banal to the more serious are the result of a dental intervention and that the transmission of these infections does not depend entirely on the in- struments used for tooth care (drills, syringes, electric scalpels, ablation drills, etc.) and/or the hands of the surgeon and the assistants, but also on the equipment and containers (dental instrument complex units) for these instruments.

Under this aspect it is assumed that modern dental sur-

geries envisage the installation of equipment for con- taining (instrument complex units) and distribution, each one of which is directly and individually con- nected through one or more of the transmission systems, be it electricity, air and/or water, to a single in- strument for specific intervention. Therefore it can easily be deduced that a serious problem exists with these distribution systems because of the difficulty in sterilising the container structure, as stated previ- ously, since the use and placing or not of rotating in- struments on the complex is the real source of contai- nation between one patient and another.

Moreover, at the present time, known dental complex units are not equipped with sterilisation systems, ei- ther on the external cover, or for the various holders arranged for placing dental instruments.

Lastly, the complex is cumbersome, full of slits and areas that are difficult to access for cleaning and disinfection ; moreover, it hinders the circulation of the other equipment that is absolutely necessary in a dental surgery also making access difficult for the dental assistants.

Therefore, the aim of the present invention is to cre- ate a medical, and in particular, a dental surgery that will eliminate the drawbacks described above, and more specifically, to create a medical surgery where the

doctor can work with completely sterile equipment that will remain in sterile condition patient after patient, in order to prevent infection transfer.

Another aim of the present invention is to create a medical surgery, and in particular a dental surgery where every part is easily disinfected.

A further aim of this invention is to create a medical surgery, and in particular a dental surgery with high technology, but that is relaxing and comfortable at the same time to make the patient feel at ease and certain that the dental care will be safe and painless.

The last but not least aim of the present invention is to create a medical surgery, and in particular a dental surgery, with completely sterile conditions in a simple and economical manner for use with existing equipment, and without the need for adopting complex and particu- larly expensive technology.

The aims of the present invention are to create abso- lutely sterile conditions in medical surgeries, and in particular in dental surgeries according to claim 1, to be referred to for brevity.

Advantageously, the present invention aims at transforming dental surgeries and their equipment com- pletely to obtain the total sterilisation of the whole environment.

For this purpose all the instruments the dentist may

need are assembled in units that are extremely compact in size and that can be moved easily to provide ergo- nomic working conditions.

In particular, the air and water syringes, turbines, micro-motors, and dynamic instruments (that replace the "old"single flexible cords) that connect them to the unit containing the energy sources (electricity, air, water) are connected with individual sterile tubes through rapid connection systems, that can be easily and rapidly replaced for each patient. These air and water tubes are disposable.

Exhaustive researches have also demonstrated unques- tionably that the water supplied to the dental complex is highly contaminated ; moreover, it is clear that a link exists between the contamination and the struc- tural morphology of the complex itself, both internally and externally. It is a fact that the aspect that is mainly responsible for contamination is determined by the water that is sprayed into the patient's mouth through the nozzles, since the micro-organisms that find an ideal terrain inside the complex tubes come from patients and the water supply.

In particular, the stagnant water inside the tubes is an ideal terrain for micro-organisms that remain strongly attached to the inside walls of the tubes themselves ; these bacteria colonies become even more

organised with time gradually creating a terrain that is increasingly more favourable for their development, and this is the reason why dental instrument complex units are being considered increasingly more responsi- ble for contamination in dental surgeries as time goes on.

In fact, the tubes inside the complex result as being increasingly more contaminated, and consequently, the water that passes through the tubes becomes more and more dangerous, both for patients and for the dentist.

The substances that accumulate inside the supply tubes, the seals, the valves and in all the connection parts called"Biofilm", form a fertile terrain for entire bacteria colonies.

However, the present invention also permits the steril- ising of water and air at their source before they reach the spray nozzles.

More generally speaking, the invention not only takes into consideration the various units containing the in- struments, but also the whole medical surgery in its totality in order to eliminate the danger of trans- ferred infection completely.

With this aspect in mind, the invention envisages the pre-cabling of the water supply system, the electronic processors, the air conditioning system, the walls, the ceilings, furniture, trolleys, lighting and electrical

boards in the surgery so that they do not touch the floor or walls.

In addition, the chair/bed in the surgery will have no connection to any equipment cables or piping from the flooring so it can be moved at any time and according to the operators'needs.

This mobility is possible because steel spherical wheels are mounted under the base of the chair making movement very easy ; naturally, when the spherical wheels are retracted the chair/bed remains fixed in the required position.

All this creates a considerable saving in time and money because the possibility of moving the chair/bed to different positions in the surgery makes it easier to adapt the room for various specialties.

The first problem that arises in a medical or dental surgery today is that of reducing running costs and im- proving service quality.

The only possibility is to group several doctors in the same surgery so that it can provide long consulting hours with different doctors on each shift ; this con- tributes towards reducing fixed costs by almost half.

Naturally if a dentist works in this group of medics, the context becomes even easier.

Sterilising air and water that pass through the instru- ment spray nozzles is obtained by avoiding pollution in

the hosing and tubes, as previously described, with the use of rapid connections and water flow adjustment sys- tems that can be sterilised, so that spray nozzles, electrovalves and instruments can be removed and placed in autoclaves.

In this way, it is possible to change all tubing com- pletely, replacing it with new tubes or others that can be treated in autoclaves ; this is to be performed at regular intervals while the whole circuit of the inter- nal tubing will be disinfected automatically with liq- uid disinfectant and ozonized water that act within a few minutes and must be sent through the circuit after intervention on each separate patient.

Moreover, care must be taken so that the liquid disin- fectant cannot act in the presence of porous tubes or incrusted (scaling) portions of metal or plastic tub- ing.

The possibility of being able to remove and replace each component inside the equipment proposed in this invention, and to possess replacement duplicates of each single piece means that all parts can be inserted in special containers and sent for gamma ray sterilis- ing at least once a year.

This occurs"at regular intervals", but the special as- pect of this invention is the changing of about one me- ter of all the tubes that carry water, air and elec-

tricity to the rotating instruments and the spray sy- ringes for each patient.

Lastly, the present invention provides a completely new environmental definition for dental surgeries, begin- ning with the form of the instrument complex and the dentist's chair, that must have no sharp corners or edges, and must not be equipped with accordion pleated tubing (as envisaged in the known art) or other parts that are not easily accessible for cleaning and disin- fection.

Secondly, all the air in the environment is filtered, washed and sterilised, so that work in the surgery is always conducted in the best possible conditions for all types of specialty.

Lastly another intervention is envisaged at the psy- chological level of the patient, by creating an envi- ronment that is highly technological, but relaxing and comfortable at the same time, to create in the patient a feeling of serenity and confidence in safe and pain- less treatment : for this reason, the reduction in the amount of equipment visible helps to eliminate unpleas- ant associations for the patient.

The fundamental equipment needed for a medical surgery as described above, is as follows : a medical consulting bed/dentist's chair (figure 1, reference 11), a unit for the instruments used by the medic (doctor's column,

figure 1 reference 12), a cabinet unit 13 next to the medic (figure 2) which, like the wash-basin 21, also contains an absolute filter for air sterilisation, con- tained in the lower part of zone 22, or in proximity to the unit on the wall, a set of pressure gauges (figure 3, reference 31) and adjustment regulators (reference 32) for air and water, the turbine, all sprays and sy- ringes, a container for the sterile water bottles at 4 AT pressure, the disinfectant bottles in position 23 in figure 2, and a service tray (reference 24) that can be placed in a wide variety of positions. Another cabinet O O unit 16, is positioned near the assistant (figure 4) and contains the suction unit equipped with decontami- nation tanks for destroying bacteria, and the compres- sor equipped with its absolute filter and dryer. In po- sition 45 on shelf 41 is the assistant's wash-basin 42, the ultrasound container for instrument washing, 43, and the sealer 44.

To complete the concept of simplifying the creation of the surgery, and to make cleaning and disinfection eas- ier, a service beam has also been created (figure 5).

This beam results as being absolutely necessary in cases where the chair head is near a window, or where the ceiling cannot support the light and the screen.

Where these conditions do not exist, the beam is not necessary as it can be replaced by a vertical pole

fixed between the flooring and the ceiling or to the wall (figure 5, reference 51) the negative viewing screen can be fixed to the pole.

The vertical pole supports the X-ray system 52, the computer 53, the suction unit 54 with the water foun- tain, the tumbler holder, and the keyboard for the as- sistant with all the identical commands that are pres- ent on the doctor's column, the flowmeter oxygen /protoxide 55, and the telephone-interphone 56.

In the first solution, where the vertical pole is at- tached to a mobile trolley 57, the beam is supported by a metal arch placed on the floor on the two sides 58 ; a shadowless lamp 18 and the TV monitor 19, are attached to the centre of the arch, while in the version com- posed of a vertical pole only, the lamp, 18 and the TV monitor 19, are attached to the ceiling. The beam is also equipped with all the environmental lighting.

In this manner, the cabling of the whole surgery is al- most complete.

Further aims and advantages of the present invention will be made clear from the following descriptions and enclosed drawings that are supplied simply as an expla- nation and are not to be considered limiting in any way, in which : - Figure 1 represents a schematically plan view of a typical medical/dental surgery as described in this in-

vention ; - figure 2 is a front view of the cabinet unit posi- tioned on the doctor's side ; - figure 3 shows a range of service pressure gauges ; - figure 4 is the front view of the furniture unit po- sitioned on the assistant's side ; - figure 5 shows an installation example of a support beam inside the medical surgery ; - figure 6A is a block diagram of the air/water supply system to the doctor's column ; - figure 6B is a block diagram of the disinfection sys- tem inserted inside the supply system to the doctor's column ; - figure 7 is a side view diagram of the doctor's col- umn as described in this invention - figure 8 is a front view of the same column shown in figure 7 ; - figure 9A is the rear view of the same column as that shown in figure 7 ; - figure 9B is plan view of the column shown in figure 7 ; - figure 10A is the view of a rear portion of the con- sole on the doctor's column ; -figure lOB is a top plan view of the console on the doctor's column ; - figure 10C represents the profile of the upper part

of the console as seen from the side ; - figure 11 shows schematically the commands on the keyboard ; - figure 12 is a simplified block diagram of the elec- tromagnetic valve board that controls the functions on the column shown in figure 7 ; - figure 13A is a partial side view of the instrument holder included on the doctor's column - figure 13B is a view of a vertical portion of the in- strument holder shown in figure 13A ; figure 13C is a top plan view of the instrument holder shown in figure 13A (this instrument holder can be removed and placed in an autoclave thus ensuring the complete sterilisation of the support where the instru- ments are placed) ; - figure 14A shows the view in perspective of a sterile water bottle container (this is composed of two cast blocks) for use in the surgery, object of this inven- tion (the bottles are disposable, like the drip bags and act as an autoclave at 4 bar pressure that can be regulated to higher or lower pressure) ; - figure 14B is a side view of a rapid connection for sterile water removal from the inside of the bottles in the container ; - figure 15 is a block diagram showing the sterile wa- ter in its containers, that provides the supply to the

spray systems on the various instruments (at the end of each treatment, an automatic self-disinfection process is carried out on all components on the doctor's col- umn : meaning the tubes that are not replaced, and in- cluding electrovalves, rapid connections, pressure gauges, etc) ; - figure 16A is a side view of a rapid insert connec- tion for connecting the air and water supply tubes ; - figure 16B is a top plan view of the connection shown in figure 16A ; - figure 16C is a bottom plan view of the connection shown in figure 16A (in any case, a non-return valve is inserted between this connection and the final insert, composed of the air/water syringe or the rotating in- strument) ; - figure 16D is a schematic diagram of the gripper for tube expulsion ; - figures 16E and 16F show other portions of the grip- per shown in figure 16 D ; - figure 17A shows a schematic exploded view of a con- nection used for attachment to the turbine with the air and water tubes present in the dental surgery as de- scribed in this invention ; - figure 17B is a bottom plan view of the connection shown in figure 17A ; - figure 18A is a top plan view of the generator shown

in figure 18B ; figure 18B is a side view of a spray generator for the electric micro-motor in a dental surgery as de- scribed in the invention ; - figure 18C is a bottom plan view of the generator shown in figure 18A ; - figure 19A is a schematic exploded diagram of a sy- ringe for use in a dental surgery as described in this invention ; - figure 19B is a bottom plan view of the syringe shown in figure 19A ; - figure 19C is a top plan view of the spray generator of the syringe shown in figure 19A ; - figure 20A is a plan showing the pedal system in the dental surgery ; - figure 20B is a side view of the pedal system shown in figure 20A ; - figure 21 shows another block diagram of the simple disinfection system to be used on the doctor's column after each individual patient's treatment, once the disposable tubes have been removed ; - figure 22A shows the water supply/suction unit at- tached to the vertical service pole in the surgery ; - figure 22B shows the automatic washing and disinfec- tion system of the filter, electrovalves, and all non- disposable tubes on the suction unit ;

- figure 23A is a top view of the assistant's keyboard that is identical to that on the doctor's column (Fig- ure 11) ; - figure 23B is a schematic view showing the portable computer attached to the vertical service by a bracket arm ; - figure 24A is a top plan view of a chair/bed used in a dental surgery as described in this invention ; - figure 24B is a top plan view of an alternative em- bodiment of the chair/bed shown in figure 24A ; - figure 24C is a view in perspective of an adjustable height cushion for use in the chair/bed shown in fig- ure 24A ; figure 24D is a front view of the base of the chair/bed shown in figure 24A ; - figure 25 is a side view of the chair/bed shown in figure 24A ; - figures 26A-26G are a set of schematic diagrams show- ing the various positions of the chair/bed shown in figure 24A.

In special reference to figure 6A, concerning the air/water supply system to the doctor's column, the compressor is identified by N° 61, and 62 is the refer- ence for the sterile water bottle container at 4AT and 63 identifies the disinfectant container, while 64 and 65 identify the channels that transfer the air and wa-

ter, respectively.

66 refers to the sterile water bottle electrovalves, and 67 refers to the disinfectant electrovalve, while the doctor's column is identified by 68. Numbers 69 and 610 refer respectively to the air and water electro- valves.

611 indicates the air tube that carries the water from the 4 AT bottles, and 612 indicates the work instrument inserted using the rapid connection marked 613, while 614 refers to the suction pump and 615 refers to the pump electrovalve. 616 identifies the internal circuit disinfection tube, and 617 refers to the rapid connec- tion for the disinfection system, while 618 refers to the disposable water and air supply tubes that are at- tached to the top rapid connections.

Layout 6B shows when the electrovalve 66 is closed and the electrovalve 67 is open, and when the rapid connec- tion 617 is attached to connection 613, how the disin- fectant in tank 63 is sucked in by pump 614. In this manner it is possible to perform disinfection on all the tubes, electrovalves, connections, and in particu- lar, in the existing internal tubes positioned before the disposable tubes.

Once the disinfectant has taken action, an automatic system closes the circuit to return to the previous situation described in figure 6A, but with tube 616

still attached to the rapid connections 617 and 613.

In this manner a washing action is performed to elimi- nate the disinfectant so that when the disposable tubes 618 are inserted for the new patient, the spray can be used without disinfectant. Naturally this wash- ing action is also automatic and is performed by a timer with an optical and acoustic signal to inform that the cycle is completed.

Figures 7, 8, 9A and 9B show the control panel 72 with the micro-motor keyboard plus the main control board and the base 715 with the spherical wheels 710 used to place the doctor's column in the most convenient and ergonomic work position.

On the left and right hand sides of the column are the instrument gripper forks designed to hold the turbine, micro-motor and syringe.

These forks can be removed and sterilised for each pa- tient, and under each fork are four tube lugs 79 from which the small air/water tubes exit for the sprays, syringes, and the micro-motor electric cord.

These tubes have attachments 74 for easy insertion and removal to and from the disposable water/air tubes 77.

78 refers to the disinfection tube described in figures 6A and 6B, while an umbilical cord 75 exits from the rear to connect all the water/air supply tubes and key- board cables to the doctor's column.

Inside the column is a the micro-motor electronic panel and the terminal board 713, while the lower compart- ment 714 contains all the electrovalves.

On the doctor's column console illustrated in figures lOA-lOC, there are two more keyboards covered with an adhesive sterile sheet that is changed for each pa- rient ; the sterile sheet ensures equipment sterilisa- tion continuity, and consequently, it does not contai- nate the operator's gloves.

In particular, figure 10A is a view of the rear portion of the console on the doctor's column, with the exit hole of the umbilical cord and a hole designed for aeration inside the column.

Moreover, figure 10C represents the profile of the up- per part seen from the side, and figure 11 shows a schematic diagram of the commands on the keyboard ; starting from the left hand side, are the consent for the turbine (T) with the commands for the spray water (AQ) and air (AR).

Continuing towards the right, is the consent for the micro-motor (ME) with the commands for the spray water (AQ) and air (AR) ; further to the right is the consent for the syringe water (AQ) and air (AR) ; this can also be controlled by the foot pedal, or the syringe spray can be automatically inserted with another spray (the turbine or the micro-motor sprays) to increase cooling

action during special treatment. Continuing further towards the right the shadowless light can be switched on or off (Light on/off) with the possibility of in- creasing or reducing the intensity (+/-).

On the far right hand side is the possibility of acti- vating the saliva suction system (SA) of the surgical tube (CH) or the funnel (IM) ; below to the left are three pre-selected positions in which the number 2 in- dicates a standard position for the dentist, and the number 1 indicates the completely horizontal position (operating bed or examination bed). The sign indi- cates the most convenient position for the patient for moving him to the required position.

Below in the centre are 8 press-buttons, that indicate the rise of the podalic position up to the completely horizontal position (PA position) and the lowering of the same zone until it reaches 90° (PB position).

TA indicates the raising of the"Trendelemburg", while TB indicates the lowering of the same system ; in the same way BA indicates the total raising of the base, while BB indicates its lowering and SA indicates the raising of the chair back until it reaches almost 90°, while SB indicates its lowering to horizontal position.

In particular reference to figure 12, the first three electrovalves control the turbine spray water (refer- ence 121) the micro-motor spray water (122) and the sy-

ringe water (123).

The four lower electrovalves control the air to the turbine (reference 124) the turbine spray air (refer- ence 125) the micro-motor spray air (126) and the last controls the syringe air (127) ; the water is supplied from the sterile water bottles 128 and is transmitted to the doctor's column instruments 129, and the air is supplied by the compressor 1210 with an absolute filter for sterility, and is also transmitted to the doctor's column instruments. A special deviation, shown in fig- ure 6A, transfers the air to the sterile water bottles to produce pressure of 4 AT.

Figures 13A-13C show a gripper fork that has two ridges 131 on the rear (figure 13B) that are designed for in- sertion into two grooves channeled in small Teflon cylinders 132 (figure 13A) that maintain them in posi- tion and at the same time, permit them to be removed easily when necessary.

Attached to each end of the fork (figure 13C) are two bushes 133 that grip the instruments, maintaining them in vertical position.

Figures 14A and 14B show the plastic bottle 141 inside a cast block 142 made from two pieces, a lower and an upper part 143, that prevent explosion when the air is introduced to raise the pressure to 4 AT. After the bottle is inserted into the lower cast block, the upper

part is inserted and then the cap 144 is screwed onto the plastic bottle neck.

The metal cap 144 has two rapid connections, one (145) for air introduction, and another (146) to release the water ; the bottle is hermetic once the cap is main- tained in pressed down position by a closing device 147 and blocked using a block bolt 148.

Figure 15 shows the illustrations in figures 6A and 6B in more detail.

There are two bottles of sterile water in separate con- tainers, 151, 152, with an air stabiliser/regulator in- serted in bottle 154.

The air exits from the compressor 155 equipped with a service cock ; this unit is equipped with an air breather electrovalve 156, and two more electrovalves, one for air inlet to the first bottle (159) and one for the second bottle (1510).

The air exit pipe is identified by 1511, while the wa- ter exit from the first bottle is identified by 1512, and from the second bottle with 1513.

There is also a disinfectant container 1514 for the three water tubes on the doctor's column, while elec- trovalve 1515 controls the disinfectant pipe.

The doors on the unit that contains the water bottles are pneumatically blocked to guarantee safety condi- tions and are not opened until no pressure remains in-

side the bottles.

In the drawing showing the side view of figure 16A, is a central Teflon sleeve on the rapid connection 161 to which the two rapid connections 162 of both parts are screwed.

As clearly illustrated in figures 16B and 16C, there is a slot 163 in the centre of the teflon sleeve for the gripper (figure 16D) to make removal of the spray and syringe air and water plastic tubes easier. On the top of the rapid connections is an elastic ring that per- mits the release of the plastic tube.

Figure 16E shows a schematic diagram of the part of the gripper in figure 16D that is positioned on the two elastic rings 164 that expel the tubes when they are compressed.

Figure 16F shows the part of the gripper that is an- chored to the slot 163 to apply pressure on element 164. Figures 17A and 17B show a connection used to at- tach the disposable air and water tubes to commercial turbines ; in particular this is equipped with a screw- on sleeve 171 for connection to the standard turbine screw, and at the base of the attachment are four rapid connections 172, that, when seen from underneath, are positioned in a square arrangement.

The first connection 173 is for the turbine air, the second 174, for the air release, the third 175 for

spray water, and the fourth 176 for spray air.

A very important feature of the invention concerns the water and air adjustment control for each single in- strument, syringe included ; this adjustment is very precise and sophisticated, as shown in figure 3, pro- viding the possibility of reading the pressure rates on each single gauge in order to obtain perfect spray con- trol for every function.

The spray generator dedicated to the micro-motor and illustrated in figures 18A, 18B, 18C, is composed of a main body 181, with two rapid connections 182 screwed to the base, one for water and the other for air.

A small coaxial tube 182 exits from the upper portion, to form the spray generator to which the small plastic tube is fastened to direct the spray itself on the drill mounted on the micro-motor.

Another important feature of the invention comprises the fact that when the small disposable plastic wa- ter/air tubes are detached from the rapid connections 192, the syringe in figures 19A-19C can be completely sterilised ; in fact, it is an extremely important fac- tor in dentistry that all objects that come into con- tact with the operator's hands can be sterilised (in this specific case the syringe can be completely ster- ilised and the tubes are disposable).

A plastic tube can be added to the coaxial tube 191,

spray generator, to extend it so it can reach any point in the oral cavity directly ; in addition there is a groove 192 in the syringe case for vertical positioning on the support. Once consent has been given on the as- sistant's water/suction unit (this is necessary so that the instrument holder fork is free of press- buttons), the foot pedal is pressed to activate the ro- tating instruments and the syringe ; the main foot pedal control is identified by 201.

For safety reasons, the turbine or the micro-motor will not start up if they have not been removed from the fork ; a photocell blocks all action as long as they are positioned in the fork.

202 is the reference for the foot pedal rotation axis ; in the foot pedal there are certain commands that are also on the keyboard for the doctor's convenience while working on the patient.

In fact it is possible to exclude the spray water by pressing key 203, and to exclude the air by pressing key 204 ; another key 205 is also provided to include or exclude any filming that may be made using a telecam- era.

Normally the syringe is controlled by pressing the main foot pedal buttons ; this is to prevent equipping the syringe with buttons and to make sterilisation easier.

If the diode LED 207 is switched off, the syringe will

function using the foot pedal, otherwise it acts as a supplementary spray together with the turbine or the micro-motor.

The foot pedal can also be moved by foot by lifting it with the bar 208.

Figure 21 is a schematic diagram showing the disinfec- tion circuit of the doctor's column 211, where 212 in- dicates the sterile water container and 213, the disin- fectant container.

The suction pump 214 discharges its contents into a container 215 that collects the liquid after it has completed the disinfection cycle.

During work function, electrovalves 218 and 216 are closed, while 217 is open.

To pass over to the disinfection stage, the disposable tubes that are attached to the rotating instruments are removed, and tube 2110 is connected using rapid connec- tions 2111 that exit from the lugs 2112 ; naturally this is only for the three tubes that transfer the water.

Electrovalve 217 is then closed and electrovalves 216 and 218 are opened to start up the suction pump 214 that discharges into the container 215.

In short, the disinfectant liquid contained in 213 is sucked up by the pump and discharged into container 215 ; during the passage it disinfects all the internal tubes, the seals, the electrovalves, the rapid connec-

tions, etc.

After disinfection,. electrovalve 218 is closed and the pump sucks up the sterile water from the bottles 212 ; this washes all the tubes and other components that have been disinfected.

These cycles are automatic and controlled by timers ; when the rapid connection 2111 is removed from tube 2110 the disposable tubes can be inserted and the sys- tem can return to standard work function with the bot- tles 212 at 4 AT.

Figures 22A and 22B represent the washing and disinfec- tion diagram for the filter, the electrovalves and all the non-disposable tubes on the suction unit that is attached by a mobile bracket arm to the vertical serv- ice pole. (figure 5).

In particular, figure 22A represents the water/suction unit in the form where it is attached to the vertical service pole with a mobile arm 221.

On the upper part there is a keyboard identical to that on the doctor's column, the rinsing fountain 223, and the basin where the tumbler is placed 224 ; the basin can be removed for washing and disinfection between each patient. Opposite is a fork 225, that is identical to that on the doctor's column ; this fork is used to hold the saliva drain tube, as well as for moving the water/suction unit to the most convenient position.

On the left and right hand sides 2217 there are a sec- ond and a third fork for holding the surgical tube and the funnel.

Figure 22B shows a schematic diagram of the disinfec- tion system, that is also automatised, but in a differ- ent manner from that on the doctor's column.

In this case the suction pressure of the general suc- tion system of the single operating unit 2212 is used to eliminate the disinfectant from the container 2214.

This liquid follows the path shown by the arrows and when tube 229 is attached to 2211 by the rapid connec- tion 2210, the liquid passes through the electrovalves 2216 and the filter 2215 as far as the central electro- valve 2212 and is then discharged into the sewerage system by the central suction system of the single op- erating unit.

Figure 23A is a top view of the assistant's keyboard, that is identical to that on the doctor's column (fig- ure 11) and with the keyboard used in parallel mode so that commands can be controlled by both the doctor and the assistant.

Figure 23B is a schematic diagram showing the portable computer support 233 that is attached by a bracket to the vertical service pole on the opposite side to the water/suction unit (identified with n° 53 in figure 5).

Figure 23B also shows a schematic diagram of the port-

able computer 231 on the support ; the figure shows the work position with the keyboard 231 positioned on a slant, while the screen 232 is in vertical position.

This computer can be used either by the doctor or by the assistant simply by moving the bracket arm 234 ; last of all, when the simple plastic adhesive strip is placed on the keyboard 231, work on the keyboard is also sterile.

In figure 24, the details show that the upper part of the chair/bed is composed of five parts. For example, the central seat 243 can be raised and lowered by con- trols on two columns (that will be described further on), and one of the two columns controls the "Trendelemburg"movement ; the raising and lowering of the seat and the"Trendelemburg"are followed by the chair back and the podalic part.

The chair back 242 is controlled by a motor placed un- der the seat and has a very wide position range, from completely horizontal (Figure 26B) to almost vertical (figure 26F) ; the chair back is also hinged to the seat 243 by a large hinge 245.

The head-rest is composed of a semi-circle 247 in alu- minium that slides along a guide inserted in the chair back 242 : therefore it is possible to adapt the posi- tion of the head-rest according to the height of the patient by sliding the semi-circle along the guide to

move it away from the seat back.

The position can be blocked by a knob 258 located on the rear of the chair back, and this movement can be performed by a small motor inserted in the bulk of the chair back. To make the cervical position more comfort- able for the patient, a small cushion can be placed in various positions and heights (figure 24C) ; in fact it is possible to add various layers that adhere to each other through magnets 24C1. Inside the cushion are two small loudspeakers so that the patient can listen to music or messages without the discomfort of the ear- phones normally used for this purpose.

The podalic part 244 is also controlled by a motor un- der the seat, and this too has a wide variety of posi- tions ; in fact it can be moved from horizontal posi- tion, turned downwards by 90° until it is positioned vertically (figure 26G). The podalic part 244 is hinged to the seat with a large hinge 246.

The foot-rest 248 is identical to the head-rest, both in form and movement, so it is possible to adapt the position according to the height of the patient by mov- ing it along the guide.

The foot-rest must be removed in order to place the po- dalic part at 90°, to prevent creating a base that is too high ; this position is essential for elderly pa- tients who find it difficult to lie down or when a gy-

necological couch is required.

As stated previously, this chair/bed can be used in multiple ways ; the very elongated shape of the basic model design is to make the movements of the personnel easier inside the operating rooms, since most surgeries are not very big.

The three cushions that cover the base, the chair back and the podalic part 251 can be very easily removed for washing and disinfection ; they can be just as easily replaced in order to change the chair/bed form.

For example in figure 24B the form of the cushions has been changed completely to provide an authentic operat- ing bed.

Two column motors 24D1 are attached to the base of the chair and large screws 24D2 are fixed to the four sides of the chair base so that when they are turned in a clockwise direction the spherical wheels under the chair will exit so that chair can be moved very easily.

When they are turned in an anticlockwise direction, the spherical wheels are retracted under the chair base so that the base is in contact with the floor blocked in the required position.

The chair/bed is moveable so that the operator can find the most convenient work position, but above all this means it can be moved for careful floor cleaning ; the problem with current dental chairs being the fact that

lots of dirt accumulates in the area of the tube con- nections that exit from the flooring under the chair base and this is certainly not suited to an environment that must be kept sterile.

Figure 25 shows the side view of the chair with the central part 251, the chair back 252, and the podalic part 253.

Numbers 254 and 255 indicate the large hinges for the chair back and the podalic part, while hinge 259 pro- vides the"Trendelemburg"position with the raising of the podalic column only.

Numbers 256 and 257 refer to the head-rest and foot- rest, while 2510 indicates the three parallelepipeds that slide on top of one another to follow the rise and descent movement of the chair/bed on the columns.

These columns are fixed to the base 2511 (figure 25).

At the four corners of the base are four large screws 24D2 and 2512 that push the spherical wheels on the floor when the chair/bed needs to be moved.

The motors for the chair back and podalic part move- ment, located lower down than the centre part are cov- ered by two small aprons 2514 that are to be equipped with sensors in the lower part to block any movement when the sensor encounters an obstacle.

A similar pair of aprons are positioned on the sides of the chair back and the podalic part for the sake of ap-

pearance and to help guarantee the total safety of the chair 2515.

Figures 26A-26G demonstrate how the chair/bed can be transformed into a wide variety of positions. For exam- ple, the position illustrated in figure 26B shows a completely horizontal operating table, figure 26C shows a very accentuated"Trendelemburg"movement obtained by moving only the podalic part.

Figure 26D shows the classical dental position that can be modified with each component in another position, be it seat, back-rest, or podalic part.

Figure 26E shows a neutral position used to permit the patient to climb in and out of the chair easily, or to rinse the mouth.

Figure 26F shows the position of the chair with the pa- tient seated ; this position is suitable for elderly people who are uncomfortable when lying down, and natu- rally all the variations of the three components are possible (seat, back-rest, podalic part, for height level).

Figure 26G shows the gynecological couch position. A medical surgery combined at the same time with a dental surgery as described in this invention is shown in a general view in figure 1.

The concept of the dental surgery as it currently ex- ists has been changed completely because of the abso-

lute necessity to eliminate all sources of infection of very serious illnesses such as hepatitis, AIDS, and an infinity of other pathologies that have been widely demonstrated as being a result of dental surgeries.

This invention eliminates the dentist's complex involv- ing the whole room and providing new and essential units to ensure sterile conditions, the first of which being the use of sterile water instead of the public water supply as used by current instrument complex units ; another important characteristic is the complete filtering of the air using absolute filters. The air used for the sprays and for the surgery environment is continually passed through absolute filters to purify it, exactly like the system used in operating rooms.

In dental surgeries, this necessity is a guarantee for the patient, the doctor, and the assistants since it has been demonstrated that the sprays directed into the mouth create an infected aerosol that contaminates eve- rything and everybody.

As we have seen, the tubes that supply the rotating in- struments and the relative sprays used, are all dispos- able in order to eliminate the causes of contamination.

Moreover, as well as amalgam collection filter, the single suction system for each work unit provides for a decantation tank containing disinfectant to kill bacte- ria before it is sent into the sewer system.

Today it has become a standard rule that the environ- ment must be protected, so as we have already explained for the doctor's column and for the water/suction unit, all tubing is disposable.

This equipment (like the sterile water at 4AT, the suc- tion system with the decantation tank to kill bacteria, the absolute filters for air purification, the contain- ers for the disinfectant to be sent through the tube circuits on the doctor's column and in the wa- ter/suction unit) are a completely new concept for a dental surgery, and according to this invention, they have been positioned in two furnishing units, one alongside the doctor, and one alongside the assistant.

The other components in the surgery include a scialitic lamp, a TV monitor (attached to the ceiling or to a horizontal beam fixed between two walls, an X-ray sys- tem, a computer, a water/suction unit, and a tele- phone/interphone controlled from a vertical pole at the head end of the chair/bed.

The chair/bed is also a part of this invention, and has very special characteristics ; in particular the elec- tric cable that supplies the chair bed comes from the assistant's unit, as does that for the water/suction unit, and the foot pedal for rotating instrument con- trol and all the commands on doctor's and assistant's keyboards.

The chair/bed is not attached to the floor, because it is equipped with wheels that makes it ergonomic, and at the same time respects the need for cleaning and disin- fecting the flooring, because it is impossible to clean and disinfect flooring where there is a chair with holes underneath to pass electrical cables and air and water hosing.

The chair/bed base, complete with the motors for its movement, as described previously, permit the movements necessary for an authentic operating table, and do not include any of the typical characteristics of a typical dentist's chair that is infected and that can cause in- fection.

The present invention proposes the various components as a single unit that respects the concept of sterile conditions essential in a dental surgery, concepts that have been repeated by a very large number of sci- entific surveys all over the world, and that till now has never been totally resolved.

The whole operating unit with the various components that are synergically connected with each other pro- vides all the equipment a dentist requires, and the op- erating unit conceived in this manner is also extremely suitable for use by medics with other specialties.

The total concept is part of the present invention since these components globally replace as an ensemble

the previous dental complex unit. As far as the elec- tricity supply for all the equipment present in the medical surgery is concerned, in this invention, the whole surgery is wired with cables that start from the general electrical board, continue around the perimeter of the ceiling, and then descend to the two corners of the head of the chair/bed in a suitable channel easily inspectable.

The electrical wiring to the X-ray, telephone, com- puter, film negative viewer, shadowless lamp, TV and the environmental lighting pass from the two corners of the chair head for insertion inside the vertical and horizontal poles/beams. The water and air piping to the wash basins is passed up and down at the same two cor- ners, as do the wash and suction unit basin drainage pipes, controlled by lift pumps.

The large exhaust suction tube for septic aerosol re- moval from the operating area to reduce pollution to a minimum, also descends on the assistant's side ; this is particularly important when working with a laser or an electric bistoury.

This contributes enormously towards installation and maintenance because no pipes or wires pass inside the flooring or the walls.

The shadowless lamp 18, descends from the ceiling, and is positioned so that the light can be moved to the

cervical or podalic position when the chair/bed 11 is converted to bed form.

The upright that supports the lamp 18 can be fitted with a second bracket to hold a liquid crystal TV 19, that can be moved to various positions for use as a monitor for a telecamera. The monitor is connected to a computer 53, and possibly also to a video tape player.

The monitor is attached to an articulated bracket fixed to the pole that supports the shadowless lamp on the left hand side of the surgery, easily accessible for both the doctor and the assistant (figure 5).

With this system, the patient can watch a series of digital images such as photos or X-rays ; and lastly, a neck-rest equipped with two small loud speakers con- nected to a hi-fi system can be used as a psychological influence to relax the patient.

Every aspect has been studied especially to make the installation of the equipment in a dental surgery ex- tremely easy, but easy maintenance has also been taken into consideration.

For example, the keyboards on the column (figure 7) can be removed from the support structure, in the same way as the water/suction unit on the assistant's side can be removed (figures 22A, 23A), so that the terminal board can easily be disconnected for any repairs and/or replacement. The rear side of the doctor's column (fig-

ure 9A) is designed with the upper part in fixed posi- tion 712 where the umbilical cord 75 enters to trans- port the water, air and electricity. Half way down, a hatch 713 is provided for access to the micro-motor electronic card and the terminal board, to make mainte- nance as easy as possible.

Another hatch 714 lower down provides access to the electrovalves, for the same easy maintenance operations while in the water/suction unit, the upper panel (figures 22A, 23A) is hinged on the right hand side for easy access to the filter (for cleaning) and to the electrovalves (for maintenance).

The objectives of the present invention are all di- rected at obtaining maximum sterility in the dental surgery environment in order to eliminate as much transferred infection possible.

As stated previously the air and water hoses terminate with rapid insert connections 74 for connecting the plastic air and water supply tubes.

The use of rapid connections 74, combined with an ex- tension that permits disinfection circulation in all the internal circuits 78 (figures 21, 22), means that replacements can be made easily between one patient and another.

Moreover, the fact of using external disposable tubes as well as the internal tube disinfection cycle helps

to optimise the whole system.

After the passage of the disinfectant through all the tubing inside the doctor's column (figure 7), the dis- infection circuit closes automatically, and the sterile water circuit opens for a washing cycle that continues until all disinfectant has been eliminated from the tubing.

Once the cycle is completed the circuit closes again with an optical and acoustic signal to inform that the new disposable tubes can be inserted for a new patient.

In this manner, the dental surgery as described in this invention is able to guarantee the same sterility lev- els as all equipment in a standard daily operating room, so that it constitutes an essential method for reducing, if not eliminating, infection transferred by dental treatment.

The particular characteristics of the equipment that comprises the dental surgery, object of the present in- vention are the following : easy removal and replacement of the tubes that supply the instruments ; as well as the aspect of simply being able to change the tubes, it must also be taken into consideration that the cost is acceptable even for public health dentists in order to guarantee sterile conditions ; Possibility of replacing instrument holders (2 for the doctor's unit and 3 for the assistant's unit) and

the possibility of sterilising them in an autoclave ; Possibility of using exchangeable sterile tubes in the doctor's column and in the water/suction unit ; Possibility of disinfecting all internal circuits using an extremely easy method on both the doctor's and assistant's columns between patients ; -Presence of high speed exhaust unit to remove fumes and septic aerosol spray ; Extremely precise spray regulating on all instru- ments (turbines, micro-motors, syringes) both for air and water ; Possibility of activating instrument and suction system consent using a perfectly sterile keyboard ; -Presence of a display unit on the console or con- trol panel (figure 7) and commands for the electric mi- cro-motor, so that the speed and torque can be adjusted for micro-motor use in endodontics, implants and in delicate conservation and denture work (figure 10B).

As well as the commands located on the keyboard (figure 11) on the doctor's unit (figure 7) and the assistant's unit (figure 23A) there are another five function com- mands that can be controlled by the foot pedal (fig- ures 20A, 20B) : 1) For activating the selected instrument (main com- mand with reference numeral 201 in the figures) ; 2) For excluding the water spray from the turbine or

electric micro-motor (command reference : 203) ; 3) For excluding the air spray from the turbine or electric micro-motor (command reference : 204) ; 4) For the switch-on and switch-off of the video tape recorder connected to the telecamera for filming images visible on the monitor attached to upright 19 from the ceiling (command reference : 205 in the figures) ; 5) Syringe command 206 using the foot pedal (with the LED 207 switched off) while, with the LED switched on, the syringe will distribute the spray in combination with the turbine or micro-motor spray.

The foot pedal shown in figures 20A, 20B includes a ro- tation axis 202 and a bar 208 for moving the pedal with the foot. It has been shown how the doctor's column (figure 7) is actually composed of five units that can be replaced very easily using rapid connections and terminal boards ; this system is useful for temporary replacement of various parts during column maintenance and for complete or periodic gamma ray sterilisation of all detachable portions to maintain the column or den- tal complex (figure 7) in the best and most sterile condition possible.

In particular, the units that are separately detachable include the following : 1) The electronic box of the electric micro-motor in- cluded inside the portion 713 of the rear side of the

complex (figure 9A) ; 2) The keyboard (figure 11) ; 3) The set of pressure gauges positioned in the cabi- net on the doctor's side (figure 2) ; 4) The set of electrovalves arranged on portion 714 on the rear side of the complex (figure 9A) ; 5) The connection terminal board divided so that each individual unit can be easily separated from the others for maintenance ; the terminal board is positioned in portion 713 on the rear side of the doctor's column (figure 9A).

In the same manner, the assistant's water/suction unit (figure 22) is identical to that on the doctor's column (figure 7), and on the lower part, the water and vacuum tubes and the electric cables are linked to it through the umbilical supply cord.

From the main board, these tubes and cables pass through small channels to the corners of the head on the work zone, until they reach the keyboard (figure 23A) of the assistant's water/suction unit, that is identical to that on the doctor's column (figure 7) and that is also easy to remove for repairs and/or replace- ment.

Figure 21 represents the very simple layout of the dis- infection circuit for all tubing, filters, electro- valves, connections, etc. that are included inside the

doctor's column.

Figures 22A and 22B represent the circuit and/or hy- draulic layouts, also very simple, for the disinfection of all the tubing 229, the filter 2215, the electro- valves and the connections in the assistant's wa- ter/suction unit.

From the base of the unit shown in figures 22A and 22B exit the tubes that after a distance of about 10 cm terminate with the rapid connections 2211 attached to hose 228 ; the rapid connections 2211 are attached to the rapid connections 2210. The rapid connections 2211 are the same as those used to attach the disposable tubes that are fixed to the suction canula. When the rapid connections 2210 and 2211 are attached to each other and the central suction system is activated, the disinfectant liquid contained in tank 2214 passes through all the internal tubes, the filter 2215 and the electrovalves 2216.

In this manner once treatment is finished the assistant removes the disposable tubes from the rapid connections 2211, and with the simple maneuver described above, activates the disinfection process.

The disinfection action time permits the assistant to prepare the water/suction unit for the next patient.

For the suction system, tube washing is not necessary, however it is essential for the doctor's column.

The whole operation is extremely simple, requires only a few minutes, and resolves a very serious problem such as having a highly infectious zone only a few centime- tres from the patient's mouth, during work on gums, bone, and sometimes open maxillary sinus.

Figure 22B represents the filter 2215 disinfecting and washing circuit layout for the electrovalves 2216, and all the internal tubing ; this method provides the double advantage of fluidifying the liquids that have been sucked into the system (saliva and blood) and of disinfecting what passes into the central suction unit.

As has been previously underlined, the present inven- tion is aimed at redefining the dental surgery environ- ment completely ; as well as the possibility of filter- ing, purifying and sterilising all the environmental air in the surgery, the interventions can also be con- sidered from the psychological point of view of the pa- tient with the creation of an environment that is both highly technical, but at the same time relaxing and comfortable (for example : with the reduction of the amount of equipment that is visible to the patient) in order to eliminate unpleasant associations, and to pro- vide a sensation of serenity and confidence in safe painless treatment.

Also in relation to this aspect, the chair/bed 11 in the surgery presents certain interesting ergonomic

characteristics, the first being the fact that there are no sharp corners, areas where dust can accumulate, accordion pleated tubes, large hinges (as envisaged in well-know prior art) or other parts are not easily ac- cessible for cleaning and disinfection.

A support bracket can be added to the side of the chair 11 to hold an instrument tray, and other components can be added like thigh supports, an arm-rest for drip ap- plication, and/or a drip bag support ; when these char- acteristics are combined with those of the chair 11 and the doctor's column (figure 7) the dentist's surgery can also be used for other specialties in general medi- cine, plastic surgery, gynecology, etc.

A further characteristic of this dental surgery is the possibility of transforming the chair 11 into an oper- ating bed, medical examination bed, gynecological bed, psychotherapist's couch or massage bed.

The chair/bed described in the present invention is ex- tremely ergonomic with a large number of possible posi- tions (figures 26A-26G) plus the possibility of a ver- tical range up to 40 cm (figure 25).

The rectangular metal base 2511, is positioned on the floor (figure 25), has a very compact size (figure 24D) and is designed for the insertion of four spherical steel wheels for easy moving for hygiene and practical- ity.

Figure 24D shows the knobs that raise the spherical wheels and maintain the chair/bed in contact with the floor.

Another characteristic of the chair/bed is its compact size, and in addition, since it has no plastic parts it can be manufactured in a smaller size than traditional chair/beds, making it easily accessible for complete cleaning and sterilisation.

Therefore the chair 11 as a whole constitutes a recep- tacle for dust and germs that is far less than dental chairs in prior art.

More specifically (as can be seen in figures 24A-24D, 25, 26A-26G), the chair 11 comprises a frame divided in three parts (seat 243, back 242 and podalic part 244), with the addition of two accessory parts (head rest 247 and foot rest 248), that slide in a guide, to be extended as necessary and to be maintained in the re- quired position by screwing the knob identified with numbers 258 and 2516.

The parts 242, 243, 244 are covered with padding 252, while parts 256, 257 are manufactured in aluminium without padding.

Large hinges 254, 255 are envisaged for positioning be- tween seat 251 and the back rest 252 and the podalic part 253 to permit a 90° movement for the podalic part in a downward direction, and in an upward direction for

the back rest (figure 26G).

The seat 251 has another hinge 259 that permits the ("Trendelemburg") 263 movement with the fulcrum in 259.

A set of parallelepipeds 2510 that slide over each other during the raising and lowering movements permit the chair/bed to be moved until it is transformed into an operating bed.

The base (figure 24D) that is positioned on the floor- ing, is equipped with four spherical wheels 24D2 and 2512, that permit the chair/bed 11 to be shifted ; when the four large screws 2512 are rotated half a turn to raise the chair/bed these spherical wheels exit from under the base so it can be moved easily.

The retraction of the spheres in the base immobilises the chair/bed.

The mobility of the chair/bed is necessary to obtain suitable ergonomic positions according to the work to be performed on the patient, but above all, to maintain flooring hygiene.

The electrical supply is furnished by a cable from a channel that descends from the corner of the work sur- gery on the assistant's side.

Two motors set in the base control the rise and descent movement (reference 2510) and in turn, these motors are controlled by activating the keys on the keyboard (figures 11, 23A).

The motors are covered by three parallelepipeds 2510 and each one follows the rise and descent of the hori- zontal plane of the chair by sliding on top of each other.

To put it briefly, two motors control the rise and de- scent of the complete base (seat, back rest and podalic part).

The motor of the podalic part governs the "Trendelemburg"263 with the fulcrum on hinge 259. There are two motors for the centre part of the seat 2514, one on the right and the other on the left.

One of these motors governs the rise and descent of the back rest (figures 26A-26G) and the other governs the rise and descent of the podalic part that can reach 90° after removal of the foot rest 248 (figures 26F, 26G).

The rounded configuration of all chair parts (figure 24) provides a decided advantage in terms of general cleaning and the complete sterilisation of the dental surgery.

Lastly, in certain frame configurations (figure 25) and the corresponding padding 251, 252, 253, the division of the chair/bed into the various positions permits multiple chair positions, thanks to the movements of the chair back, podalic part and parallelepipeds con- trolled by electric motors as shown in the schematic diagrams in figures 26A-26G.

To be more specific, it is possible to obtain positions that are totally horizontal, or when the back rest is folded back to various degrees, as well as a downward 90° position of the podalic part. The last part 257 is simply removed to obtain this position.

Some of these positions have been clearly illustrated in figures 26A-26G and in particular, the position for creating an operating bed (figure 26B), the "Trendelemburg"positionifigure 26C), a relaxation po- sition (figure 26D), the gynecological position with the removal of part 257 (figure 26G), and a position for bioenergetic treatment (with the removal of part 257 and the insertion of a support for the soles of the feet in its place).

The easy removal of the cushions 251, 252, 253 (figure 25) for cleaning and disinfection also helps to trans- form the upper part of the bed for surgical interven- tion, but also for the sake of appearance of the den- tal chair according to the needs and requirements of each operator (for an extreme example refer to figure 24B).

There are three pre-selection positions on the keyboard (figures 11, 23A). The position (zero setting) shown in figure 26E makes it easy for the patient to sit down, lie down, or descend from the chair/bed.

The pre-selected position N°1 is the standard dental

chair position that can be modified by moving the back rest to obtain the most comfortable position for the patient and the most ergonomic for the operator.

The preselected position 2 is completely horizontal at maximum height to form a medical/surgical bed.

One aspect that has not yet been described, is the safety concept of the chair/bed in question.

The large scale movements must be sufficiently pro- tected to ensure maximum safety for the hands of the patient and the legs of the operator and the assis- tants.

The metal aprons 2514 that cover the motors positioned on the sides of the seat have another metal part inside that protrudes for a distance of about 1 centimetre and that slides upwards in the case of the slightest con- tact.

When this occurs it triggers an electric contact that blocks all movement.

The same safety is guaranteed on the sides of the back rest and the podalic part 2515.

The zone that is near the hinges 254 and 255 include safety protection spaces for the hands.

The characteristics of this invention and all the ad- vantages to be gained are clearly provided in the de- scriptions.

First of all the present invention provides an operat-

ing unit that is completely sterile because of the dis- posable parts, and the parts for each patient that can be sterilised in the autoclave.

Moreover, the internal parts of the doctor's column and of the water/suction unit can be disinfected after each patient and are easy to access for replacement or for non-recurring sterilisation to provide instruments that are always new and therefore do not contaminate.

Lastly, unlike traditional dental surgeries, all in- struments are contained inside a small column that can be closed away under a shelf, while the dental chair can be transformed into a medical examination bed, mak- ing the surgery suitable for all types of medical spe- cialties.

Therefore, all equipment and installations used in the dental surgery as described in this invention guarantee perfectly sterile conditions, in order to reduce trans- ferred infection drastically.

In particular, the water used for the sprays is con- tained in disposable bottles under 4AT pressure, while the safety protection fitted on the pressurised bot- tles, the rapid insertion caps, and the electronic board that controls the disinfection and washing cycles comprise further characteristics that are installed only in the dental surgery as described here. It has also been emphasised that all the water and air supply

tubes to the instruments are disposable to completely eliminate the danger of infection between one patient and another.

These tubes are then grouped together with completely original and varied forms according to the type of in- strument to which they are attached ; the fact that the connections between the energy source and each instru- ment are realized by rapid attachments, which are eas- ily removable for the exchange and/or sterility of the instrument contributes to the complete sterility of the equipment and the installation in the dental surgery.

The insertion and removal of the tubes using the rapid connections is just as easy and rapid, especially with the use of the special grippers.

Moreover another factor that must be considered is the fact that this perfect sterilisation does not involve costs that are so expensive that they impede the ap- plication of the whole protocol ; for example, under this aspect, the replacement of the disposable tubes and the activation of the disinfection cycles on all the internal circuits have cost estimates that can be considered compatible with public health levels.

In fact, in modern medicine it is considered extremely important to obtain the best possible performance at the cheapest price in order to offer high professional quality to all social categories.

To reach these objectives, efforts must be made con- cerning the following aspects : 1) the cost of creating medical surgeries ; 2) management costs ; 3) extending working hours as long as possible with various shifts and teams of different doctors.

Under this aspect the project design of the dental sur- gery as described in the present invention is created to provide modern surgeries in answer to today's needs that can be constructed immediately without the need for specialised qualified labour.

For this reason, all equipment is pre-cabled so that walls do not need to be broken for pipe and wiring in- stallation, and the surgery can be installed very rap- idly. As well as this advantage, the present invention offers an extremely simple repair system because all equipment is composed of a few parts that can be re- placed within a few minutes with identical spare parts and each faulty part can be repaired in centralised workshops organised for this purpose.

The instrument holders that support the hand instru- ments, turbine, syringe and spray when they are not in use, can be easily removed for sterilisation and re- placement between patients.

Moreover, the consent for the start-up of one instru- ment or another is not provided by sensors that may not

be very sterile, but by special keys on a keyboard cov- ered with an effectively sterile transparent adhesive sheet.

The same method is applied to the suction circuit key- board located in the assistant's column ; in traditional suction equipment, the start buttons are inserted in the instrument holders, and for this reason they are no doubt infected, while the plastic sheath that should protect the buttons provides absolutely no guarantee.

Lastly, in conventional instrument complex units the suction tubes that are located only a few centimetres from the cannula placed in the patient's mouth are highly infectious. On the contrary, in the case of the dental surgery described in the present invention, the suction tubes are disposable and therefore easily and rapidly replaced because of the rapid connections, that totally eliminate the source of the infection described above.

Another completely sterile component is the water/air syringe. The supply tubes are completely replaceable for each patient and the syringe itself can be com- pletely sterilised to protect it from infection trans- ferred by the dentist.

All internal tubes are subject to complete and auto- matic disinfection after each patient has been treated, on both the doctor's column and the assistant's unit,

for the suction unit.

The time for tidying the equipment is sufficient for the automatic disinfection.

It has been shown how simple systems can reduce trans- ferred infection drastically ; naturally the sterilisa- tion protocol is applied to the instruments and to all medical staff, keeping in mind that each detail in the dental surgery in the present invention has been stud- ied to provide maximum sterility, of the type found in a standard operating rooms.

A further objective of the dental surgery described is to extend working hours as long as possible with vari- ous shifts and teams of different doctors. Unlike the current existing equipment installations in traditional dental surgeries, all instruments are contained inside a small column that can be fitted away under a shelf ; moreover, the dental chair can be transformed into a medical bed, making the surgery suitable for use by any type of specialist ; internists, dermatologists, psy- chologists, naturopaths and gynecologists can work eas- ily in the same surgery as that used by the dentist.

The sophisticated structures such as the autoclaves, ultrasound machines for instrument washing, envelope- stuffing machines, surgical suction systems, high speed air suction exhaust systems, systems for air recycling and sterilisation, electric bistouries, lasers, and

electrocardiographs, protoxide distribution machines, cardiac monitors, defibrillators, to list only a few, can be made available for several doctors, in order to create professional associations of doctors with dif- ferent specialties. This will contribute towards enor- mous cost savings, a great advantage for the doctors, but above all for the patients who will have access to high quality treatment at reasonable prices.

The dental surgery as described in the present inven- tion resolves the problem of sterility and the elimina- tion of transferred infection perfectly ; lastly, said surgery can be used by doctors with different special- ties in other sectors, making it possible to make best use of the high technology and the organisation of these structures.

Last of all, it is clear that numerous other variants can be applied to the medical surgery in question, how- ever without departure from the innovative principles of the present invention, and it is just as clear that with the practical embodiment of this invention, the materials, forms, sizes of the details illustrated can be altered according to necessity, and can be replaced by others that are technically equivalent.