APPARATUS FOR EXTRACORPOREAL BLOOD TREATMENT AND METHOD FOR ADMINISTERING NUTRITIONAL PRODUCTS IN AN APPARATUS FOR EXTRACORPOREAL BLOOD TREATMENT

Abstract

An apparatus for extracorporeal blood treatment for chronic therapy comprises a nutritional bag (33) containing a nutritional solution, a weighing device (36) configured to determine a weight (W) of the nutritional bag (33), a nutritional line (34) for infusing the nutritional solution into either a blood return line (7) or into the patient vascular system. An ultrafiltration device (30) is configured to achieve a fluid removal from the patient through a semi- permeable membrane (5) of a filtration unit (2) and a sensor (31, 32) is configured to determine an ultrafiltration rate (UFR). A control unit (100) connected to the ultrafiltration device (30), to the weighing device (33) and to the sensor (31, 32) is programmed for receiving a patient prescription and for controlling the ultrafiltration device (30) to achieve the patient prescription based on the weight (W) and on ultrafiltration rate (UFR).

Claims

1-33. (canceled)

34. An apparatus for extracorporeal blood treatment for chronic therapy, the apparatus comprising: a filtration unit having a primary chamber and a secondary chamber separated by a semi-permeable membrane; a blood circuit coupled to the filtration unit and comprising a blood withdrawal line connected to an inlet of the primary chamber, a blood return line connected to an outlet of the primary chamber, said blood withdrawal line and blood return line being configured for connection to a patient cardiovascular system; a blood pump configured to be coupled to a pump section of the blood circuit; a dialysis circuit comprising a dialysis supply line for a fresh dialysis fluid connected to an inlet of the secondary chamber and a dialysis effluent line for a spent dialysis fluid connected to an outlet of the secondary chamber; a preparation device for preparing the fresh dialysis fluid, wherein the preparation device is connected to the dialysis supply line and comprises a regulating device for regulating the composition of the fresh dialysis fluid; a nutritional bag containing a nutritional solution; a nutritional line having a first end in fluid communication with the nutritional bag and a second end for infusing the nutritional solution into either the blood return line or directly into the patient vascular system; at least one sensing element configured to provide a first signal related to an actual flow rate in the nutritional line; an ultrafiltration device configured to achieve a fluid removal from the patient through the semi-permeable membrane; at least one sensor configured to provide a second signal related to an ultrafiltration rate; and a control unit connected to the ultrafiltration device, to the sensing element, and to the at least one sensor, the control unit programmed for: receiving a patient prescription including at least one of: a total patient weight loss to be achieved at the end of the blood treatment and a total treatment time, and a desired net ultrafiltration rate, collecting from the sensing element the first signal and determining a first parameter related to the actual flow rate in the nutritional line, collecting from the at least one sensor the second signal and determining a second parameter related to the ultrafiltration rate, and controlling the ultrafiltration device to achieve the patient prescription based on the first parameter and on the second parameter.

35. The apparatus of claim 34, wherein the at least one sensing element is a weighing device configured to provide a weight of the nutritional bag, wherein the control unit is configured to receive a weight signal from the weighing device and to determine the first parameter based on the weight variation over time of the nutritional bag, the first parameter being the actual flow rate in the nutritional line.

36. The apparatus of claim 34, wherein the control unit is programmed for calculating and/or storing data related to the nutritional solution administered during the extracorporeal blood treatment, said data comprising at least one of: the weight of the nutritional bag, a feeding rate of the nutritional solution through the nutritional line, an amount of nutritional solution administered at an instant of time, a total amount of the nutritional solution to be administered, or a composition of the nutritional solution.

37. The apparatus of claim 34, comprising the nutritional solution contained in said nutritional bag, said nutritional solution comprising a mixture of protein, carbohydrate, and fat.

38. The apparatus of claim 34, wherein a feeding rate of the nutritional solution during blood treatment is between 50 ml/h and 500 ml/h.

39. The apparatus of claim 34, comprising an infusion pump coupled to the nutritional line to deliver a feeding rate of the nutritional solution through the nutritional line, wherein the control unit is connected to the infusion pump and is programmed for controlling the infusion pump and for changing the feeding rate of the nutritional solution.

40. The apparatus of claim 34, wherein the first parameter includes the weight of the nutritional bag at an instant of time, and wherein the second parameter includes the ultrafiltration rate.

41. The apparatus of the preceding claim 40, wherein a net ultrafiltration rate is calculated by calculating a feeding rate of the nutritional solution from the weight of the nutritional bag and by subtracting the feeding rate from the ultrafiltration rate, and wherein the ultrafiltration device is controlled so that the net ultrafiltration rate matches the desired net ultrafiltration rate.

42. The apparatus of the preceding claim 40, wherein a patient weight loss at an instant of time is calculated by integrating the ultrafiltration rate at that instant of time and by subtracting the weight of the nutritional bag at that instant of time from the integrated flow rate, and wherein the ultrafiltration device is controlled so that the patient weight loss at the end of the blood treatment matches the total patient weight loss.

43. The apparatus of claim 34, wherein the at least one sensor comprises a flowmeter placed on at least one of the dialysis supply line and the dialysis effluent line, and wherein the second signal is a signal from said flowmeter.

44. The apparatus of claim 34, wherein the nutritional line comprises a pump segment, a feeding tube segment connected to an inlet of the pump segment, a delivery tube segment connected to an outlet of the pump segment and one rigid portion comprising two pump connectors for receiving opposite ends of the pump segment, a delivery tube segment connector for receiving one end of the delivery tube segment, and a feeding tube segment connector for receiving one end of the feeding tube segment, wherein the feeding tube segment and/or the delivery tube segment includes a respective removable connector, the removable connector of the delivery tube segment configured to be connected to a corresponding counter connector on the blood return line.

45. The apparatus of claim 36, comprising a display screen connected to the control unit, wherein the control unit is programmed for displaying on said display screen the data related to the nutritional solution.

46. The apparatus of claim 39, comprising a main body, wherein the control unit is contained in or supported by the main body, wherein the infusion pump and the blood pump are supported by the main body, wherein the blood circuit and the filtration unit are disposable and are coupled in removable manner to the main body and to the blood pump, wherein the nutritional line is disposable and is coupled in removable manner to the main body and to the infusion pump, and wherein the dialysis circuit is non-disposable and is integrated in the main body.

47. The apparatus of claim 46, wherein the infusion pump and the blood pump are peristaltic pumps.

48. The apparatus of claim 46, wherein the ultrafiltration device comprises at least one dialysis pump coupled to the dialysis supply line and/or to the dialysis effluent line, and wherein said at least one dialysis pump is mounted on the main body.

49. The apparatus of claim 34, wherein the patient prescription includes at least one of: (i) a total patient weight loss to be achieved at the end of the blood treatment and a total treatment time, (ii) an ultrafiltration rate and a total treatment time, (iii) a total patient weight loss to be achieved at the end of the blood treatment and an ultrafiltration rate, and (iv) a desired net ultrafiltration rate and a nutritional flow rate, or a nutritional total weight to be infused during the treatment, together with a total treatment time or together with a total patient weight loss.

50. The apparatus of claim 34, wherein the sensor for providing the second signal related to an ultrafiltration rate senses one or more of: a difference between an amount or a flow rate of fresh dialysis fluid prepared by the preparation device and entering into the filtration unit and a spent dialysis fluid exiting the filtration unit; a difference between an amount or a flow rate of fresh dialysis fluid prepared by the preparation device and infused into the blood circuit and a spent dialysis fluid exiting the filtration unit; and a difference between an amount or a flow rate of fresh dialysis fluid prepared by the preparation device and entering both into the filtration unit and into the blood circuit and a spent dialysis fluid exiting the filtration unit.

51. The apparatus of claim 34, wherein the sensor for providing the second signal related to an ultrafiltration rate takes into account a net amount/flow rate of the fresh dialysis fluid prepared by the preparation device, irrespective of the fresh dialysis fluid being fed to the filtration unit, removed from the filtration unit and infused into the blood circuit.

52. The apparatus of claim 34, wherein the apparatus comprises an infusion line branching from the dialysis supply line to infuse fresh dialysis fluid into the blood circuit, the sensor configured to provide a second signal related to an ultrafiltration rate being operative at least upstream a branch of the infusion line to take into account for the fresh dialysis fluid fed either or both to the filtration unit through the dialysis supply line or/and the blood circuit through the infusion line.

53. The apparatus of claim 34, wherein the at least one sensor comprises either: a flowmeter placed on the dialysis supply line and another flowmeter placed on the dialysis effluent line, the control unit configured to receive the signals from the two flowmeters to determine a differential flow between dialysis fluid supplied to the supply line and removed with the dialysis effluent line; or a differential flowmeter placed on the dialysis supply line and the dialysis effluent line to sense a differential flow between the dialysis supply line and the dialysis effluent line.

54. The apparatus of claim 34, further comprising: balance chambers operatively coupled to the dialysis circuit to precisely balance fresh dialysis fluid prepared by the preparation device with spent dialysis fluid exiting the filtration unit; and an ultrafiltration line and pump to remove spent dialysis fluid from upstream of the balance chamber in the dialysis effluent line, the at least one sensor sensing the amount of spent dialysis fluid removed by the ultrafiltration pump, wherein the second parameter is a flow rate in the ultrafiltration line or a liquid volume removed through the ultrafiltration line.

55. The apparatus of claim 54, wherein the ultrafiltration device comprises a first dialysis pump coupled to the dialysis supply line and a second dialysis pump coupled to the dialysis effluent line.

56. The apparatus of claim 54, wherein a first balance chamber operates on the dialysis supply line and a second balance chamber operates on the dialysis effluent line.

57. The apparatus of claim 34, wherein the control unit is programmed for: receiving, as prescription input: a desired blood flow rate, a desired nutritional feeding rate target or a total amount of the nutritional solution administered at the end of the treatment time, and the total patient weight loss and the total treatment time or the desired net ultrafiltration rate, commanding the blood pump to pump blood according to the desired blood flow rate or to reach the total amount of the nutritional solution administered at the end of the total treatment time, commanding the infusion pump to deliver the nutritional solution according to the nutritional feeding rate target, and commanding the ultrafiltration device to achieve the total patient weight loss or the desired net ultrafiltration rate.

58. The apparatus of claim 34, wherein the control unit is programmed to receive, as a prescription input, a total amount of the nutritional solution to be administered within the end of the total treatment time, to determine a nutritional feeding rate target to deliver the total amount of the nutritional solution at the latest at an end of the total treatment time and to command the infusion pump to deliver the nutritional solution according to the nutritional feeding rate target.

59. The apparatus of claim 34, wherein the extracorporeal blood treatment apparatus includes a main body, and wherein the infusion pump is attached to the main body and is placed on a front panel of the main body.

60. An apparatus for extracorporeal blood treatment for chronic therapy comprising: a main body; a filtration unit having a primary chamber and a secondary chamber separated by a semi-permeable membrane; a blood circuit coupled to the filtration unit and comprising a blood withdrawal line connected to an inlet of the primary chamber, a blood return line connected to an outlet of the primary chamber, said blood withdrawal line and blood return line being configured for connection to a patient cardiovascular system; a blood pump configured to be coupled to a pump section of the blood circuit; a dialysis circuit comprising a dialysis supply line, for a fresh dialysis fluid, connected to an inlet of the secondary chamber and a dialysis effluent line, for a spent dialysis fluid, connected to an outlet of the secondary chamber; a preparation device for preparing the fresh dialysis fluid comprising a preparation line connected to a liquid source and a container of concentrate, wherein the container is located on a respective injection line predisposed to supply substances to the preparation line, wherein the preparation device is connected to the dialysis supply line and comprises a regulating device for regulating the composition of the fresh dialysis fluid; a nutritional solution comprising a mixture of protein, carbohydrate and fat; a nutritional bag containing the nutritional solution; a nutritional line having a first end in fluid communication with the nutritional bag and a second end for infusing the nutritional solution into either the blood return line or directly into the patient vascular system; an infusion pump attached to the main body and coupled to the nutritional line to deliver a feeding rate of the nutritional solution through the nutritional line; at least one sensing element, including a weighing device configured to provide a weight of the at least one nutritional bag, configured to provide a first signal related to an actual flow rate in the nutritional line; an ultrafiltration device configured to achieve a fluid removal from the patient through the semi-permeable membrane; at least one sensor configured to provide a second signal related to an ultrafiltration rate and sensing one of: a difference between an amount or a flow rate of fresh dialysis fluid prepared by the preparation device and entering into the filtration unit and a spent dialysis fluid exiting the filtration unit, a difference between an amount or a flow rate of fresh dialysis fluid prepared by the preparation device and infused into the blood circuit and a spent dialysis fluid exiting the filtration unit, and a difference between an amount or a flow rate of fresh dialysis fluid prepared by the preparation device and entering both into the filtration unit and into the blood circuit and a spent dialysis fluid exiting the filtration unit; and a control unit connected to the ultrafiltration device, to the infusion pump, to the sensing element and to the at least one sensor, the control unit programmed for: receiving a patient prescription including two parameters out of: a total patient weight loss to be achieved at the end of the blood treatment, a total treatment time, and the ultrafiltration rate, receiving a weight signal from the weighing device and determining the first parameter being the actual flow rate in the nutritional line, collecting from the at least one sensor the second signal and determining a second parameter being the ultrafiltration rate, controlling the infusion pump, and controlling the ultrafiltration device to achieve the patient prescription based on the first parameter and on the second parameter so that the patient weight loss at the end of the blood treatment matches the total patient weight loss to be achieved at the end of the blood treatment.

61. The apparatus of claim 60, comprising an infusion line branching from the dialysis supply line to infuse fresh dialysis fluid into the blood circuit, the sensor configured to provide a second signal related to an ultrafiltration rate being operative upstream of a branch of the infusion line to take into account for the fresh dialysis fluid fed either or both to the filtration unit through the dialysis supply line or/and the blood circuit through the infusion line.

62. The apparatus of claim 60, wherein the at least one sensor comprises a differential flowmeter placed on the dialysis supply line and the dialysis effluent line to sense a differential flow between the dialysis supply line and the dialysis effluent line, and wherein the second parameter is a signal from said differential flowmeter.

63. The apparatus of claim 60, wherein the at least one sensor comprises a flowmeter placed on the dialysis supply line and another flowmeter placed on the dialysis effluent line, the control unit configured to receive the signals from the flowmeter and the another flowmeter to determine a differential flow between dialysis fluid supplied to the supply line and removed with the dialysis effluent line.

64. The apparatus of claim 63, wherein the flowmeter on the dialysis supply line is operative upstream of a branch of the infusion line to take into account for the fresh dialysis fluid fed either or both to the filtration unit through the dialysis supply line or/and the blood circuit through the infusion line.

65. The apparatus of claim 60, comprising: balance chambers operatively coupled to the dialysis circuit to precisely balance fresh dialysis fluid prepared by the preparation device with spent dialysis fluid exiting the filtration unit; and an ultrafiltration line and pump to remove spent dialysis fluid from upstream the balance chamber in the dialysis effluent line, the at least one sensor sensing the amount of spent dialysis fluid removed by the ultrafiltration pump, wherein the second parameter is a flow rate in the ultrafiltration line or a liquid volume removed through the ultrafiltration line.

66. The apparatus of claim 65, wherein a first balance chamber of the balance chambers operates on the dialysis supply line and a second balance chamber of the balance chambers operates on the dialysis effluent line, the first balance chamber located upstream of a branch of the infusion line to take into account for the fresh dialysis fluid fed either or both to the filtration unit through the dialysis supply line or/and the blood circuit through the infusion line.

67. An apparatus for extracorporeal blood treatment for chronic therapy comprising: a main body; a filtration unit having a primary chamber and a secondary chamber separated by a semi-permeable membrane; a blood circuit coupled to the filtration unit and comprising a blood withdrawal line connected to an inlet of the primary chamber, a blood return line connected to an outlet of the primary chamber, said blood withdrawal line and blood return line configured for connection to a patient cardiovascular system; a blood pump configured to be coupled to a pump section of the blood circuit; a dialysis circuit comprising a dialysis supply line, for a fresh dialysis fluid, connected to an inlet of the secondary chamber and a dialysis effluent line, for a spent dialysis fluid, connected to an outlet of the secondary chamber; a preparation device for preparing the fresh dialysis fluid comprising a preparation line connected to a liquid source and a container of concentrate, wherein the container is located on a respective injection line predisposed to supply substances to the preparation line, and wherein the preparation device is connected to the dialysis supply line and comprises a regulating device for regulating the composition of the fresh dialysis fluid; a nutritional solution comprising a mixture of protein, carbohydrate and fat; a nutritional bag containing the nutritional solution; a nutritional line having a first end in fluid communication with the nutritional bag and a second end for infusing the nutritional solution into either the blood return line or directly into the patient vascular system; an infusion pump coupled to the nutritional line to deliver a feeding rate of the nutritional solution through the nutritional line, wherein the infusion pump is attached to the main body; at least one sensing element configured to provide a first signal related to an actual flow rate in the nutritional line; an ultrafiltration device configured to achieve a fluid removal from the patient through the semi-permeable membrane; at least one sensor configured to provide a second signal related to an ultrafiltration rate, the at least one sensor comprising at least one flowmeter operable with at least one of the dialysis supply line or the dialysis effluent line; and a control unit connected to the ultrafiltration device, to the infusion pump, to the sensing element and to the at least one sensor, the control unit and programmed for: receiving a patient prescription including at least one of: a total patient weight loss to be achieved at the end of the blood treatment and a total treatment time, and a desired net ultrafiltration rate, collecting from the sensing element the first signal and determining a first parameter related to the actual flow rate in the nutritional line, wherein the at least one sensing element is a weighing device configured to provide a weight of the nutritional bag, and wherein the control unit is configured to receive a weight signal from the weighing device and to determine the first parameter based on the weight variation over time of the nutritional bag, the first parameter being the actual flow rate in the nutritional line, collecting from the at least one sensor the second signal and determining a second parameter related to the ultrafiltration rate, wherein the second parameter is the ultrafiltration rate, controlling the infusion pump, and controlling the ultrafiltration device to achieve the patient prescription based on the first parameter and on the second parameter.

Description

DESCRIPTION OF THE DRAWINGS

[0144] The description will now follow, with reference to the appended Figures, provided by way of non-limiting example, in which:

[0145] FIG. 1 shows a front view of an extracorporeal blood treatment apparatus according to the invention;

[0146] FIG. 1a shows a disposable nutritional line;

[0147] FIG. 2 schematically shows the extracorporeal blood treatment apparatus of FIG. 1;

[0148] FIG. 3 shows an enlarged portion of the extracorporeal blood treatment apparatus of FIG. 2;

[0149] FIG. 4 shows a portion according to a variant embodiment of the apparatus of FIGS. 2 and 3;

[0150] FIG. 5 is a flow diagram of a method for administering nutritional products according to the invention.

DETAILED DESCRIPTION

[0151] An apparatus 1 for extracorporeal blood treatment for chronic (long term) therapy is represented in FIGS. 1 and 2. The apparatus 1 comprises a filtration unit 2 having a primary chamber 3 and a secondary chamber 4 separated by a semi-permeable membrane 5. Depending upon the treatment, the semi-permeable membrane 5 of the filtration unit 2 may be selected to have different properties and performances.

[0152] A blood circuit is coupled to the primary chamber 3 of the filtration unit 2. The blood circuit comprises a blood withdrawal line 6 connected to an inlet 3a of the primary chamber 3, a blood return line 7 connected to an outlet 3b of the primary chamber 3. The withdrawal line 6 and blood return line 7 are configured for connection to a cardiovascular system of a patient “P”.

[0153] In use, the blood withdrawal line 6 and the blood return line 7 are connected to a needle or to a catheter or other access device which is then placed in fluid communication with the patient “P” vascular system, such that blood may be withdrawn through the blood withdrawal line 6, flown through the primary chamber 3 and then returned to the patient’s vascular system through the blood return line 7. An air separator, such as a deaeration chamber 8, may be present on the blood return line 7. Moreover, a monitor valve 9 may be present on the blood return line 7, downstream the deaeration chamber 8.

[0154] The blood flow through the blood circuit is controlled by a blood pump 10, for instance a peristaltic blood pump, acting either on the blood withdrawal line 6 or on the blood return line 7. The embodiment of FIG. 2 shows the blood pump 10 coupled to a pump section of the withdrawal line 6. A control unit 100 is connected and controls the blood pump 10 to regulate a blood flow rate.

[0155] A dialysis circuit is connected to the secondary chamber 4 of the filtration unit 2 and comprises a dialysis supply line 11 connected to an inlet 4a of the secondary chamber 4 and a dialysis effluent line 12 connected to an outlet 4b of the secondary chamber 4 and to a drain, not shown.

[0156] The dialysis supply line 11 is connected to a preparation device 13 for preparing a fresh dialysis fluid. The preparation device 13 comprises a regulating device 14 for regulating the composition of the fresh dialysis fluid. The dialysis effluent line discharges a spent dialysis fluid into the drain.

[0157] In the example of FIG. 2, the preparation device 13 comprises three containers of concentrate 15, 16, 17 located on respective injection lines 18, 19, 20 which are predisposed to supply substances such as electrolytes, buffer agents or others towards a preparation line 21 of the fresh dialysis fluid. The concentrate containers 15, 16, 17 may comprise concentrates in the liquid state or solid state, for example powder.

[0158] The regulating device 14 comprises injection pumps 22, 23, 24 placed on the injection lines 18, 19, 20 to move the fluid along the respective injection line 18, 19, 20 towards the preparation line 21 which collects the liquid, for example water, from a source 25. The preparation line 21 is located upstream the dialysis supply line 11 and has one end connected to the source 25, e.g. a deionized/purified water source or a reverse osmosis water plant, and an opposite end connected to the dialysis supply line 11. The source 25 may comprise the water source, as shown, or a source of ultra-pure liquid.

[0159] Concentration or conductivity sensors 26, 27, 28 are located on the preparation line 21 and are able to provide the control unit 100 with a signal related to conductivity or concentration of a predetermined substance (for example sodium) of the fluid crossing the preparation line 21 such that the control unit 100 is able to control the injection pumps 22, 23, 24 in order to regulate the conductivity Cd or concentration, for example of sodium [Na], of the liquid crossing the dialysis supply line 11. A fluid check organ 29 may be used to selectively enable or inhibit a passage of fluid across the dialysis line 21 and into the filtration unit 2 in case the liquid does not meet the required parameters.

[0160] An infusion line 11′ departs from the dialysis supply line 11 and is connected to the blood return line 7 to infuse part of the fresh dialysis fluid into the blood circuit.

[0161] An auxiliary infusion pump 45 may be coupled to the infusion line 11′ to deliver said part of the fresh dialysis fluid into the blood circuit.

[0162] Of course the infusion line 11′ may alternatively or in addition being connected to the blood withdrawal line 6 (in particular downstream the blood pump 10) for pre-infusing a substitution fluid.

[0163] An ultrafiltration device is configured to achieve a fluid removal from the patient through the semi-permeable membrane 5 of the filtration unit 2. The ultrafiltration device comprises a dialysis pump 30 located on the dialysis effluent line 12. In a variant embodiment, a first dialysis pump is coupled to the dialysis supply line 11 and a second dialysis pump coupled to the dialysis effluent line 12. A first flow-meter 31 is active on the dialysis supply line 11 and is placed between the fluid check organ 29 and the inlet 4a of the secondary chamber 4. A second flow-meter 32 is active on the dialysis effluent line 12 and is placed between the outlet 4a of the secondary chamber 4 and the dialysis pump 30.

[0164] The infusion line 11′ is connected to the dialysis supply line 11 between the first flow-meter 31 and the inlet 4a of the secondary chamber 4. The first flow-meter 31 and the second flow-meter 32 are connected to the control unit 100 and are configured to determine an ultrafiltration rate UFR.

[0165] The ultrafiltration rate UFR is a difference between the spent dialysis fluid exiting the outlet 4b of the secondary chamber 4 and the prepared fresh dialysis fluid routed to the inlet 4a of the secondary chamber 4 and infused into the blood circuit through the infusion line 11′ (FIG. 3).

[0166] As shown in FIG. 3, Q.sub.b1 is the blood flow rate entering the primary chamber 3 through the inlet 3a, Q.sub.b2 is the blood flow rate leaving the primary chamber 3 through the outlet 3b, Q.sub.in is the flow rate entering the secondary chamber 4 through the inlet 4a, Q.sub.inf is the flow rate crossing the infusion line 11′, wherein:

[00002]${\text{Q}}_{\text{dial}}={\text{Q}}_{\text{in}}+{\text{Q}}_{\text{inf}}$

[0167] The first flow-meter 31 and the second flow-meter 32 provide the control unit 100 with an instant value of the respective flows and thus enable the control unit 100 to calculate an instant ultrafiltration rate UFR. Alternatively, a differential sensor may be provided, active on the dialysis supply line 11 and on the dialysis effluent line 12 and therefore able directly to provide a signal relating to the ultrafiltration rate UFR. Instead of flowmeters, balance chambers may operatively be coupled to the dialysis circuit is provided. The balance chambers principle operates so that the amount of fluid entering into the first chamber on the dialysis supply line 11 is equal to the amount of fluid exiting from the dialysis effluent line 12. To achieve the ultrafiltration, an ultrafiltration line (not represented) is added to the effluent line upstream the balancing chamber. An ultrafiltration pump removes the desired amount of ultrafiltered liquid before that the spent dialysis liquid reaches the second balance chamber thereby achieving an ultrafiltered volume. In this alternative embodiment, the second parameter is related to the amount of liquid volume that is removed through the ultrafiltration line and in particular is the ultrafiltration rate through the ultrafiltration line. Of course absolute volume variation through ultrafiltration line may be measured too.

[0168] The apparatus 1 further comprises one nutritional bag 33 containing a nutritional solution and a nutritional line 34 having a first end in fluid communication with the nutritional bag 33 and a second end connected to the blood return line 7 for infusing the nutritional solution into the patient vascular system through said blood return line 7. In an alternative embodiment, the nutritional solution may be infused directly into the patient vascular system. An infusion pump 35 is coupled to the nutritional line 34 to deliver the nutritional solution through the nutritional line 34. A sensing element in the form of a weighing device 36 is configured to weigh the nutritional bag 33 while the nutritional solution is infused and to provide a first signal allowing calculation of a first parameter W related to a weight of the nutritional bag 33 and, therefore, to the weight or volume of nutritional solution contained in the nutritional bag 33. In general, the weighing device 36 provides the time variation of the bag weight which is directly linked to the actual flow rate of the nutritional solution through the nutritional line. Indeed, the control unit knows the nutritional line cross section and may therefore easily and very accurately calculate the actual flow rate of the nutritional solution through the nutritional line starting from measurements of weight/weight variation over time of the corresponding bag. Optionally the first parameter is the weight of the nutritional bag 33 measured over time. As an alternative, a flow meter on the nutritional line may be used as a sensing element.

[0169] Finally, though less precise, the pump speed may be used to determine flow rate through the nutritional line, the speed being monitored through a suitable sensor, such as a Hall sensor or a sensor sensitive to pump electric parameters such as resistance or power consumption.

[0170] As shown in FIG. 1, the apparatus 1 comprises a main body 37 provided with a base resting on the ground and hosting all the components of said apparatus 1, i.e.: the filtration unit 2, the blood circuit, the blood pump 10, the dialysis circuit, the preparation device 13, the weighing device 36, the nutritional line 34, the infusion pump 35, the control unit 100. The weighing device 36 is a weight scale and is configured to hang the nutritional bag 33.

[0171] The control unit 100 is housed in the main body 37. The infusion pump 35 and the blood pump 10 are peristaltic pumps supported by the main body 37. Each peristaltic pump comprises an actuator or motor, not shown, connected to a rotor. The rotor of the infusion pump 35 and the rotor of the blood pump 10 are placed on a front face of the main body 37.

[0172] The blood circuit and the filtration unit 2 are disposable (i.e. they are disposed after each blood treatment) and are coupled in removable manner to the main body 37. The pump section of the withdrawal line 6 is coupled in removable manner to the rotor of the blood pump 10. The nutritional line 34 is disposable and is coupled in removable manner to the main body 37. A pump section of the nutritional line 34 is coupled in removable manner to the infusion pump 35.

[0173] FIG. 1A shows an example of disposable nutritional line 34. The nutritional line 34 comprises a pump segment 39, a feeding tube segment 40 connected to an inlet of the pump segment 39, and a delivery tube segment 41 connected to an outlet of the pump segment 39. In particular, the pump segment 39 may have a passage section for the nutritional solution larger than a passage section of the delivery tube segment 41 and/or than a passage section of the feeding tube segment 40. In general, the passage section of the delivery tube segment is equal to the passage section of the feeding tube segment. On a first end for connection to the nutritional bag (or to a tubing connected to the nutritional bag), the feeding tube segment 40 includes a respective removable connector 42, in particular a Luer connector. The other end is joined to a rigid connector 44b associated to a rigid portion 44 of the nutritional line 34 supporting the pump segment 39. Correspondingly, the delivery tube segment 41 includes a respective removable connector 43, in particular a Luer connector, connectable to a corresponding counter connector on the blood return line 7, for example at the deareation chamber 8. As mentioned, the nutritional line further comprises one rigid portion 44 (the portion being more rigid than the flexible feeding and delivery tube segments 40, 41) comprising two pump connectors 44a for receiving opposite ends of the pump segment, the delivery tube segment connector 44c for receiving one end of the delivery tube segment 41 and the feeding tube segment connector 44b for receiving one end of the feeding tube segment 40.

[0174] The extracorporeal blood treatment apparatus main body 37 includes a coupling device; the rigid body 44 is configured to couple with the apparatus coupling device to position the nutritional line on the main body in specific arrangement with respect to the infusion pump so that the pump segment may be precisely received around the infusion pump rotor. In particular the coupling device is placed on the front panel of the main body 37.

[0175] The dialysis circuit is not-disposable and is configured to be sterilized after each blood treatment. Tubes, pumps, sensors of the dialysate circuit are not configured to be replaced after each treatment but only for maintenance purposes or in case of faults. Therefore, the dialysis circuit is integrated in the main body 36 and mounted fixed in or on the main body 37. The dialysis pump 30 is a volumetric pump crossed by the effluent fluid and is mounted in the main body 37.

[0176] The control unit 100 is contained in or supported by the main body 37. The control unit 100 is connected to the blood pump 10, the weighing device 36, the infusion pump 35, the injection pumps 22, 23, 24 of the regulating device 14, the concentration or conductivity sensors 26, 27, 28, the first flow-meter 31, the second flow-meter 32, the fluid check organ 29 and to the dialysis pump 30 of the ultrafiltration device. The control unit 100 controls the weighing device to measure the weight at instants of time, e.g. with an acquisition frequency 1 Hertz. The control unit 100 is also connected to a display screen 38 (FIG. 1) mounted on the main body 37.

[0177] The control unit 100 may comprise a digital processor (CPU) with memory (or memories), an analogical type circuit, or a combination of one or more digital processing units with one or more analogical processing circuits. In the present description and in the claims it is indicated that the control unit 100 is “configured” or “programmed” to execute steps: this may be achieved in practice by any means which allow configuring or programming the control unit 100. For instance, in case of a control unit 100 comprising one or more CPUs, one or more programs are stored in an appropriate memory: the program or programs containing instructions which, when executed by the control unit 100, cause the control unit 100 to execute the steps described and/or claimed in connection with the control unit 100. Alternatively, if the control unit 100 is of an analogical type, then the circuitry of the control unit 100 is designed to include circuitry configured, in use, to process electric signals such as to execute the control unit 100 steps herein disclosed.

[0178] The control unit 100 is configured to or programmed for receiving signals from the sensors and from other inputs and for commanding pumps and valves according to said signals, in order to perform the blood treatment and to administer nutritional products to the patient during blood treatment. The control unit 100 is also configured to or programmed for displaying data on the display screen 38.

[0179] The nutritional solution contained in the nutritional bag 33 comprises a mixture of amino-acids, glucose or dextrose and lipids. For instance, the solution consists of 300 ml of amino-acids at a concentration of 15%, 150 ml of dextrose at a concentration of 50% and 150 ml of lipids at a concentration of 20%. The amount of nutritional solution contained in the nutritional bag 33 may be the total amount administered to the patient at the end of the blood treatment and may correspond to 800 kcal per treatment or 200 kcal/h.

[0180] In an alternative embodiment, shown in FIG. 4, a plurality of nutritional bags 33′, 33″, 33‴ are provided and each nutritional bag containing a component of the nutritional solution. A first bag 33′ contains a solution of amino-acids, a second bag 33″ contains a solution of glucose or dextrose, a third bag 33‴ contains a solution of lipids. The three nutritional bags 33′, 33″, 33‴ are each hanging on a respective weight scale 36′, 36″, 36‴ and connected to a common nutritional line 34 provided with the infusion pump 35. In an alternative embodiment, not shown, each of the three nutritional bags 33′, 33″, 33‴ may be coupled to a respective infusion pump.

[0181] According also to the method of the invention, the control unit 100 is programmed for receiving a patient prescription for the blood treatment, i.e. target values for the blood treatment and target values for the administration of the nutritional products to the patient. These target values may be entered manually, e.g. through the display touch screen 38 or a keyboard placed on the main body 37 of the apparatus 1. The prescription may alternatively be read from a patient card or from another kind of storage media device or received by the machine by means of a data transmission channel (wired or wireless).

TABLE-US-00001 Example (FIG. 5) The control unit 100 is programmed for receiving as input the following target values: Q.sub.b .sub.target Desired blood flow rate through the pump section of the blood withdrawal line T Total treatment time WL.sub.target Target weight loss at the end of the blood treatment Q.sub.nutr .sub.target Desired nutritional feeding rate target Q.sub.dial Flow rate of the fresh dialysis fluid

The control unit 100 is programmed for receiving:

TABLE-US-00002 W(t) from the weighing device, the weight of the nutritional bag at an instant of time (first parameter)

TABLE-US-00003 UFR from the first flow-meter 31 and the second flow-meter 32, the ultrafiltration flow rate (second parameter)

The control unit 100 is programmed for calculating:

TABLE-US-00004 Q.sub.nutr the nutritional feeding rate from W(t), as dW(t)/dt nUFR the net ultrafiltration rate corresponding to the weight loss rate WLR of the patient as nUFR = UFR - Q.sub.nutr nUFR.sub.target a desired net ultrafiltration rate during the blood treatment such that the patient weight loss at the end of the blood treatment matches the total patient weight loss [00003]${\text{WL}}_{\text{target}}={\text{nUFR}}_{\text{target}}\text{*}\text{T}$ UFR.sub.target a target ultrafiltration rate during the blood treatment such that the patient weight loss at the end of the blood treatment matches the total patient weight loss WLR*T = nUFR*T = WL(T) = WL.sub.target [00004]${\text{WL}}_{\text{target}}={\text{nUFR}}_{\text{target}}\text{*}\text{T}={\text{UFR}}_{\text{target}}\text{*}\text{T}\text{-}{\text{Q}}_{\text{nutr}\text{target}}\text{*}\text{T}$ [00005]${\text{UFR}}_{\text{target}}=\left(\left({\text{WL}}_{\text{target}}\right)/\text{T}\right)+{\text{Q}}_{\text{nutr}\text{target}}$

The control unit 100 is programmed for controlling: [0182] the blood pump 10 such that Q.sub.b = Q.sub.btarget [0183] the infusion pump 35 such that Q.sub.nutr = Q.sub.nutrtarget [0184] the ultrafiltration device (dialysis pump 30) such that UFR = UFR.sub.target or nUFR = nUFR.sub.target

[0185] In particular, the control unit 100 is programmed for controlling the ultrafiltration device (dialysis pump 30) such that the flow rate of the spent dialysis fluid Q.sub.eff is equal to Q.sub.eff .sub.target wherein

[00006]${\text{Q}}_{\text{eff}\text{target}}={\text{UFR}}_{\text{target}}+{\text{Q}}_{\text{dial}}=\left(\left({\text{WL}}_{\text{target}}\right)/\text{T}\right)+{\text{Q}}_{\text{nutr}\text{target}}+{\text{Q}}_{\text{dial}}$

TABLE-US-00005 Numerical example T 4 hours WL.sub.target 3.5 kg = 3500 ml (blood density is very close to water density) Q.sub.nutr .sub.target 150 ml/hour = 2.5 ml/min Q.sub.dial 500 ml/min

[00007]${\text{Q}}_{\text{eff}\text{target}}=\left(\left({\text{WL}}_{\text{target}}\right)/\text{T}\right)+{\text{Q}}_{\text{nutr}\text{target}}+{\text{Q}}_{\text{dial}}=517\text{ml}/\text{min}$

[0186] According to other embodiments, the target value entered directly into the control unit 100 may be, instead of the target weight loss rate WLR.sub.target, the desired net ultrafiltration rate nUFR.sub.target (corresponding to the target weight loss rate WLR.sub.target).

[0187] According to other embodiments, instead of the desired nutritional feeding rate target Q.sub.nutr .sub.target, the control unit 100 is programmed for receiving as input a total amount of the nutritional solution W.sub.nutr target administered to the patient P at the end of the treatment time T. The control unit 100 is programmed for calculating the desired nutritional feeding rate target Q.sub.nutr .sub.target as W.sub.nutr .sub.target/T or to calculate a desired nutritional feeding rate target Q.sub.nutr .sub.target(t) which changes over time during treatment and such that the integration of Q.sub.nutr .sub.target(t) over time T is equal to W.sub.nutr .sub.target.

[0188] According to other embodiments, the control unit is programmed for integrating the ultrafiltration flow rate UFR (second parameter) received from the first flow-meter 31 and the second flow-meter 32, and by subtracting the weight W(t) of the nutritional bag (first parameter) from the integrated ultrafiltration rate UFR to calculate the patient weight loss (WL(t)) at time t. Then to compare the calculated patient weight loss (WL(t)) at time t with the target total weight loss at the end of the blood treatment WL.sub.target and to stop the treatment when the patient weight loss is equal to WL.sub.target.

[0189] According to some embodiments, the nutritional feeding rate Q.sub.nutr, the ultrafiltration flow rate UFR(t), the net ultrafiltration rate nUFR(t) and other related values are constant over time during blood treatment.

[0190] According to some embodiments, the feeding rate Q.sub.nutr of the nutritional solution, the ultrafiltration flow rate UFR(t), the net ultrafiltration rate nUFR(t) and other related values may be controlled to change over time during blood treatment. For instance, the net ultrafiltration rate nUFR(t) (or the weight loss rate WLR) may be greater at the start of the blood treatment, when the patient P may release more of liquid, than at the end. For instance, the nutritional feeding rate target Q.sub.nutr may be greater at the end of the blood treatment, where it is more likely that the nutritional solution is not eliminated through the blood treatment, than at the start.

[0191] The control unit 100 may be programmed for changing the feeding rate Q.sub.nutr of the nutritional solution by controlling the infusion pump 35 and/or for changing the ultrafiltration flow rate UFR(t) by controlling the dialysis pump 30.

[0192] The control unit 100 may also be programmed for storing data related to the nutritional solution administered during the extracorporeal blood treatment and to display on the display screen said data together with other values related to the blood treatment. For instance, said data may comprise at least one of: the weight of the at least one nutritional bag, a feeding rate Q.sub.nutr, an amount of nutritional solution administered at an instant of time, the total amount of the nutritional solution to be administered, a composition of the nutritional solution.

[0193] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.