APPARATUS FOR LOCAL ONCOLOGICAL TREATMENT

TECHNICAL FIELD The present invention relates to an apparatus for local oncological treatment. BACKGROUND ART

As is known, local oncological treatment is substantially of two types. In a first, blood circulation in a predetermined body region of the patient is isolated/ the blood is then circulated outside the body; and, finally, a liquid chemotherapy drug is fed into the blood in the circuit outside the body. In the second type, performed after surgical removal of the tumour, the operated region is washed with a physiological solution, in which the liquid chemotherapy drug is diluted, by circulating the solution to and from the patient. Whichever the case - whether circulating a blood and liquid chemotherapy drug solution, or a physiological solution in which the liquid chemotherapy drug is diluted - the solution, before being administered to the patient, must be heated to a maximum temperature of 42-45 ⁰ C : in the first case, to enhance the effectiveness of the

liquid chemotherapy drug, and, in the second, to reduce the risk of relapse caused by the presence of active tumour cells. An apparatus is therefore required which, among other things, provides for determining an extremely precise temperature of the solution.

In addition to means for conducting the various fluids involved, and means for determining the temperature along the various conduits, currently marketed apparatuses also comprise a hot-plate heat exchanger, at which heat is yielded to the solution.

Apparatuses of the above type have numerous serious drawbacks .

Foremost of these is the long time - roughly forty minutes in known apparatuses - taken to bring the solution to be administered to the patient to a predetermined temperature, and which is mainly due to the high degree of thermal inertia typical of the hot plate of the heat exchanger. Obviously, the faster the predetermined temperature is reached, the sooner the treatment described above can be commenced, with obvious benefits to the patient. Another drawback of known apparatuses is that they fail to provide for rapidly varying heat exchange and, therefore, the temperature of the solution. The required solution temperature is obviously established by the operator according to the type of treatment, the type of liquid chemotherapy drug used, the patient's personal characteristics, and the type of surgery performed on the patient, and cannot be

varied rapidly on account of the high degree of thermal inertia of the hot plate. Another important point to note is that the heat exchanger is installed in a frame containing most of the devices forming part of the apparatus, so that conduits are provided to conduct the solution from the exchanger to the patient and vice versa. Along the conduits, heat is obviously lost in direct proportion to the length of the conduits, so that the temperature of the solution administered to the patient is lower than that of the solution leaving the heat exchanger, whereas, as stated, fast intervention and extremely precise temperature of the solution administered to the patient are essential for ensuring the effectiveness of the treatment. DISCLOSURE OF INVENTION

It is an object of the present invention to provide an apparatus for local oncological treatment, designed to eliminate the aforementioned drawbacks, and which, in particular, provides for rapidly heating the solution to be administered to the patient to a predetermined temperature, comprises an easy-to-handle heat exchanger that can be moved closer to the patient to greatly reduce heat dispersion, has an extensive heat-exchange surface, and provides for rapidly varying the desired solution temperature .

According to the present invention, there is provided an apparatus for local oncological treatment, comprising :

a first conduit for conducting a first liquid to and from a body region of a patient; a heat exchanger installed along said first conduit; a source of a second liquid defined by a chemotherapy drug; a second conduit originating from said source and connected to said first conduit upstream from said heat exchanger; a member for feeding a third liquid, at a given temperature, to said heat exchanger to produce, inside the heat exchanger, heat transfer to said first liquid; characterized in that said heat exchanger is a shell-and-tube exchanger.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the present invention will be described with reference to the accompanying drawings, in which:

Figure 1 shows a block diagram of an apparatus for local oncological treatment, for use in a first type of treatment;

Figure 2 shows a block diagram of an apparatus for local oncological treatment, for use in a second type of treatment;

Figure 3 shows a larger-scale section of a member of the Figure 1 and 2 apparatuses .

BEST MODE FOR CARRYING OUT THE INVENTION

Number 1 in Figure 1 indicates as a whole an apparatus for local oncological treatment. Once the blood

circulation in a predetermined body region of the patient 2 is isolated, apparatus 1 provides for circulating the blood outside the body, and for feeding a liquid chemotherapy drug into the blood circulating outside the body.

Apparatus 1 comprises: a conduit 3 for conducting the patient's blood to and from said body region; a first pump 4 installed along conduit 3; a blood filter 5 installed along conduit 3, downstream from pump 4; a heat exchanger 6 installed along conduit 3, downstream from blood filter 5; a source 7 of a liquid chemotherapy drug, which is fed by a conduit 7a into conduit 3, upstream from pump 4; a bag 8 of physiological solution for supplementing the blood downstream from blood filter 5; a conduit 9 originating from bag 8 and connected to conduit 3, between blood filter 5 and heat exchanger 6; means 11 for determining the weight of the supplementing physiological solution inside bag 8; a second pump 12 installed along conduit 9; a conduit 13 originating from blood filter 5 and which conducts the ultrafiltrate from blood filter 5 to a container 14 (shown schematically in Figure 1) ; means 15 for determining the weight of the ultrafiltrate in container 14; a member 16 for heating a liquid, e.g. water, to a

predetermined temperature; and an electronic central control unit 17 for controlling apparatus 1.

A display 18, for displaying the quantities involved, and a data entry block 21 are connected to electronic central control unit 17. Apparatus 1 also comprises a conduit 22, which originates from conduit 9, feeds a predetermined amount of supplementing physiological solution into conduit 3, between pump 4 and blood filter 5, and is fitted with a pump 23.

With reference to Figure 3, heat exchanger 6 is a shell-and-tube type. More specifically, heat exchanger 6 comprises a hollow cylindrical central body 31 closed at its axial ends by respective walls 32 and 33, and in which are installed a number of preferably equally spaced tubes 34 with longitudinal axes parallel to one another and to the longitudinal axis X of body 31. In walls 32, 33 are formed respective numbers of through holes 32a, 33a, in which the corresponding axial ends of tubes 34 are fixed, e.g. glued, to form a hydraulic seal between the inside of tubes 34 and the inside of body 31. At the axial ends of body 31, heat exchanger 6 has a hollow cylindrical body 35, of which wall 32 forms the bottom wall; and a hollow cylindrical body 36, of which wall 33 forms the top wall. The lateral wall 36a of body 36 has an inlet 37, to which is connected the free end of the portion of conduit 3 extending between blood filter 5 and heat exchanger 6. The lateral wall 35a of body 35 has an

outlet 38, to which is connected the free end of the portion of conduit 3 extending between heat exchanger 6 and the body region of patient 2. Close to body 35, body 31 has an inlet 41, to which is connected the free end of a conduit 42 for conducting the heated liquid from member 16. Close to body 36, body 31 has an outlet 43, to which is connected the free end of a conduit 44 for feeding the liquid back to member 16. Walls 32 and 33 may be made of rigid plastic material, or of semirigid or flexible plastic material, such as polyurethane, in which to embed the axial ends of tubes 34.

A number of sensors are installed along the conduits described above, to determine the temperature and pressure along the conduits, and to supply this information to electronic central control unit 17. More specifically, apparatus 1 comprises: a pressure sensor 51 installed along conduit 3, upstream from pump 4; a pressure sensor 52 installed along conduit 3, immediately downstream from pump 4; a pressure sensor 53 installed along conduit 3, between blood filter 5 and heat exchanger 6 and downstream from the connection to conduit 9; two temperature sensors 54 and 55 installed in series along conduit 3, immediately downstream from heat exchanger 6; a temperature sensor 56 installed along conduit 42; and

a temperature sensor 57 installed along conduit 44. Apparatus 1 also comprises: a bypass conduit 58 installed along conduit 3, in parallel with blood filter 5; a clamp 61 installed along bypass conduit 58 to open or close circulation along conduit 58; a clamp 62 installed along conduit 3, immediately upstream from blood filter 5 and downstream from where bypass conduit 58 branches off from conduit 3, to open or close circulation to blood filter 5; a clamp 63 installed along conduit 3, immediately downstream from blood filter 5 and upstream from connection of bypass conduit 58 to conduit 3, to open or close circulation from blood filter 5; a drip 64 installed along conduit 3, immediately downstream from sensor 53; a clamp 65 installed along conduit 3, immediately downstream from drip 64; a blood loss detector 66 installed along conduit 13; and an ultrafiltrate flow regulator 67 installed along conduit 13, downstream from detector 66.

Clamps 61, 62, 63, 65 and regulator 67 may be operated manually or controlled by central control unit 17.

In actual use, the operating data of apparatus 1 - substantially, the temperature to which the blood is to be heated in heat exchanger 6, and the amount of

ultrafiltrate to be removed from, the blood in blood filter 5 - is set on the basis of the patient's personal characteristics, the type of surgery performed on the patient, and the body region in which blood circulation has been isolated. Once the above data is set, the liquid is heated by member 16 and temperature-controlled by sensors 56 and 57. Once the liquid from member 16 reaches a predetermined temperature, the blood is circulated along conduit 3, and the temperature of the blood from heat exchanger 6 is controlled by sensors 54 and 55. The double temperature control by sensors 54 and 55 enhances the safety of apparatus 1. At this point, electronic central control unit 17 compares the temperature readings of sensors 54 and 55 with the temperature setting of block 21, and accordingly commands member 16 to regulate the temperature of the liquid from member 16 and therefore heat exchange with the blood inside heat exchanger 6. To improve performance of heat exchanger 6, a temperature sensor may be installed along conduit 3, at the outlet from the body region.

With reference to Figure 2, number Ia indicates an apparatus for washing the operated body region with a water and liquid chemotherapy drug solution, by circulating the solution to and from patient 2. Apparatus Ia comprises: a conduit 71 for conducting to and from patient 2 a quantity of physiological infusion solution, in which a quantity of liquid chemotherapy drug is diluted;

a first pump 72 installed along conduit 71; a container 73 (shown schematically) installed along conduit 71; means 74 for determining the weight of the liquid in container 73; said source 7 of a liquid chemotherapy drug which is fed by conduit 7a into conduit 71, upstream from pump 72; a bag 79 of physiological solution; a conduit 75 originating from bag 79 and connected to conduit 71, downstream from container 73; means 80 for determining the weight of bag 79; a pump 76 installed along conduit 75; a pump 77 installed along conduit 71, downstream from the connection to conduit 75; said heat exchanger 6 installed along conduit 71, downstream from pump 77; said member 16 for heating a liquid, e.g. water, to a predetermined temperature; said electronic central control unit 17 for controlling apparatus Ia; said display 18; said data entry block 21; and said conduits 42 and 44.

Apparatus Ia also has a number of sensors installed along the conduits described above, to determine the temperature and pressure along the conduits, and to supply this information to electronic central control unit 17.

More specifically, apparatus Ia comprises: a temperature sensor 80 installed along conduit 71, immediately downstream from the outlet of the body region; a pressure sensor 81 installed along conduit 71, upstream from pump 72; a pressure sensor 82 installed along conduit 71, immediately downstream from pump 72; a pressure sensor 83 installed along conduit 71, immediately downstream from pump 77; a temperature sensor 84 installed along conduit 71, immediately downstream from heat exchanger 6; said sensor 56 installed along conduit 42; and said sensor 57 installed along conduit 44. Finally, apparatus Ia comprises a clamp 85 installed along conduit 71, between container 73 and the connection to conduit 75; and a clamp 86 installed along conduit 75.

In actual use, a space in the body region from which the tumour has been removed is fed by conduit 71 with a quantity of physiological solution, in which a liquid chemotherapy drug is diluted, and which of course is first heated to a predetermined temperature by heat exchanger 6. The flow rates, temperatures, and pressures involved are controlled by central control unit 17 in the same way as for apparatus 1 in Figure 1. At the start of treatment, container 73 is filled with a predetermined quantity of solution from bag 79, and, after closing conduit 75 by means of clamp 86, the solution, in which

the liquid drug is diluted, is circulated along conduit 71.

The numerous advantages of the present invention will be clear from the foregoing description. In particular, an apparatus is provided which, with only minor alterations, can be used for two different types of treatment. Moreover, using a shell-and-tube heat exchanger provides for fast, effective heat exchange. In laboratory tests conducted by the Applicant, circulation of the liquid (blood diluted with a liquid chemotherapy drug, or solution in which a liquid chemotherapy drug is diluted) into the patient was found to take only a few minutes . The speed with which the predetermined temperature is reached is mainly due to the extensive exchange surface of the heat exchanger. All of which provides for fast, effective treatment immediately following surgery. Another important point to note is that the heat exchanger used is an easy-to-handle item, can be located outside the frame housing the various component parts of the apparatus, and, in particular, can be located close to the patient to reduce the length of the conduit portion between the exchanger and the patient, and therefore greatly reduce heat dispersion. In fact, the temperature of the liquid infused into the patient differs hardly at all (by a barely detectable amount) from the temperature of the liquid issuing from the heat exchanger. Another point to note is that, with the exception of the pumps, central control unit 17, and

member 16, all the other components are disposable, thus ensuring a high degree of user safety. Finally, the apparatus comprises sensors and detectors for continuously monitoring the quantities involved, and so enabling adjustment of certain quantities and termination of treatment in the event of anomalies.

Clearly, changes may be made to the apparatus as described and illustrated herein without, however, departing from the scope of the present invention. In particular, in heat exchanger 6, the heating liquid may obviously circulate along tubes 34, and the liquid for infusion into the patient may circulate inside body 31.