BACKGROUND ART Dialysis treatment is normally performed using extremely complex, bulky machines, and therefore at hospitals under skilled paramedic supervision.

This means regular hospital attendance by patients, who are thus committed to a life totally subordinated to treatment.

Dialysis machines for home use, to eliminate the inconvenience of regular hospital attendance by the patient, exist, but are extremely bulky, still require paramedic supervision, and are difficult to transport.

DISCLOSURE OF INVENTION It is an object of the present invention to provide a portable extracorporeal dialysis machine designed to provide a straightforward, low-cost solution to the problems of the known state of the art.

According to the present invention, there is

provided a portable extracorporeal dialysis machine comprising a dialysis filter; a circuit for the dialysis solution flowing through said dialysis filter; first connecting means for connecting said circuit to a water source ; second connecting means for connecting said circuit to concentrated saline solutions for producing a dialysis solution; third connecting means for connecting the dialysis filter to a patient's blood circuit ; and a central control unit to which the machine components are connected; said portable machine being characterized by comprising fourth connecting means located between said first connecting means and the second connecting means, to connect said circuit to a demineralizing assembly ; and a control assembly comprising a pump for controlling the ultrafiltration process, and a weighing device for determining the actual weight loss of the patient.

BRIEF DESCRIPTION OF THE DRAWINGS A non-limiting embodiment of the invention will be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows, schematically, a preferred embodiment of the portable extracorporeal dialysis machine ; Figure 2 shows a view in perspective of a possible embodiment of the Figure 1 machine.

BEST MODE FOR CARRYING OUT THE INVENTION Number 1 in Figure 1 indicates schematically and as a whole the portable machine according to the present

invention. Machine 1 comprises a dialysis solution circuit 2; a water connecting member 3 for connecting circuit 2 to a water mains not shown; and a connecting system 4 for connecting a demineralizing assembly 5 comprising cartridges of anionic resin and cationic resin. Downstream from connecting system 4, circuit 2 comprises a 5 Am sieve 4a ; a pressure reducer 6; a water inlet solenoid valve 7; a flow meter 9 for regulating the operating speed of a pump 8 to maintain a constant water flow of 500 ml/min ; a degasser 10; and, parallel to degasser 10, a heater 11 and a temperature sensor 12.

Downstream from degasser 10 and temperature sensor 12, machine 1 comprises two connecting members 13 for connecting circuit 2 by means of two peristaltic pumps 15 to two concentrated solutions 14-one basic and one acid - for producing the dialysis solution. Downstream from each connecting member, circuit 2 comprises a respective conductimetric sensor 16. Continuing in the dialysis solution flow direction, circuit 2 comprises a pH-meter 17; a peristaltic water inlet pump 8; a pressure sensor 18; a safety solenoid valve 19; a temperature sensor 20; and a three-way solenoid valve 21 controlling flow of the dialysis solution into a dialysis filter 22. Solenoid valve 21 also controls flow of the dialysis solution into a bypass circuit 23 parallel to dialysis filter 22, and along which, as is known, the dialysis solution is fed when its parameters are not yet all optimum. Machine 1 also comprises two connecting members 24 for connecting

filter 22 to a patient's blood circuit not'shown.

Downstream from filter 22, circuit 2 comprises a blood loss sensor 25 followed by a second three-way solenoid valve 26 to which bypass circuit 23 is also connected.

Downstream from second solenoid valve 26, circuit 2 comprises a"T"connecting member 27 for directing the dialysis solution from filter 22 along two branches. A first part of the dialysis solution from the filter is pumped along circuit 2, and eventually drained, by a peristaltic pump 28 set to also permit liquid withdrawal and therefore weight reduction of the patient; and a second part of the solution is fed to a control assembly 29 comprising a pressure sensor 30, a peristaltic pump 31, a flow meter 32, and a load cell 33 in which graduated bags containing the ultrafiltrate are weighed to give the patient an immediate indication of the actual weight loss.

Machine 1 also comprises a connecting member 34 located along circuit 2, downstream from connecting system 4 and upstream from pressure reducer 6, to connect circuit 2 to a disinfectant solution 35.

Finally, machine 1 comprises a central control unit 36 for controlling all the components referred to above, for setting operating values, and for controlling the signals from sensors such as the pH-meter, flow meters, and conductimetric sensors; a monitor 37 for displaying operation of the various components and the information recorded by central control unit 36; and a known

operating current generator or connector not shown or described for the sake of simplicity.

Machine 1 weighs less than 15 kg, and may be in the form of a compact case 38 (Figure 2), the bottom portion 38a of which houses and conceals circuit 2 as described above, and the top portion 38b of which houses central control unit 36 and monitor 37.

Central control unit 36 and monitor 37 may be formed in one unit, which may removed from its seat and remains connected to the seat by a lead for easy manual use.

As will be obvious from the foregoing description, the machine according to the present invention has the big advantage of being portable, and of not requiring devices external to the machine for constantly weighing the patient, or other external devices for performing the dialysis treatment. The machine in fact comprises everything required for diffusive dialysis with no paramedic supervision, is compact and lightweight enough to be carried easily, and so provides for a more normal life of the patient despite the necessity for constant treatment.

For which purpose, the machine comprises various safety components, such as the weighing system, and a demineralizing assembly can be connected for use with any available drinking water source.