Method of monitoring a dialysis unit

• US 5,401,238 A
• Filed: 05/06/1993
• Issued: 03/28/1995
• Est. Priority Date: 07/16/1991
• Status: Expired due to Term

• Current Assignee: Gambro Hospal Schweiz AG
• Original Assignee: Hospal Ltd.
• Inventors: Pirazzoli, Paolo
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): Nasser, Robert L.
• Application Number:
  US07/982,747
• Time in Patent Office: 691 Days
• Field of Search: 128/630, 604/4-6, 604/65, 604/66, 604/27-31, 210/646, 210/647, 210/321.71
• US Class Current: 604/6.11
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 2205/17 with redundant control systems
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/52 with memories providing a history of measured variating parameters of apparatus or patient

Abstract

The monitoring method comprises the stages of acquiring and storing the values (Q_inf, Q_b and Q_UF) of a plurality of parameters set by the operator for the individual dialysis treatment to be carried out and for determining the doctor'"'"'s clinical prescription [[HCO₃^- ]_b ] on the basis of the stored values of the parameters prior to the commencement of treatment. During the dialysis treatment, the current values (Q_inf1, Q_b1 and Q_UF1) of the parameters set are continuously acquired (block 29) and if these current values differ significantly from the stored values or in such a way as to entail a change to the predetermined prescription, an alarm signal (36) is generated and a new value (Q_infs) for some parameters calculated in advance (block 31) is suggested so as to maintain the previous prescription unchanged.

Claims

1. A dialysis treatment method comprising the steps of:

conducting blood through a blood side of a dialysis unit during a treatment session;

withdrawing a used fluid from a used fluid side of the dialysis unit during the treatment session;

storing in a first memory location desired values for a plurality of treatment parameters relating to a treatment to be carried out by the dialysis unit, at least one of the plurality of parameters being a controlled parameter having an initial value, the plurality of treatment parameters corresponding to a desired clinical prescription;

detecting, during the treatment session, current values of said plurality of treatment parameters;

comparing the current values with the stored desired values;

calculating a suggested value of the controlled parameter to maintain the clinical prescription when at least one of the current parameter values differs from a corresponding desired value;

comparing the suggested value of the controlled parameter with the initial value of the controlled parameter to determine a difference;

determining whether the suggested value of the controlled parameter falls within a threshold range when an absolute value of the difference is greater than a predetermined value; and

generating a warning signal indicating that the current values are not in accordance with the desired clinical prescription when the suggested value of the controlled parameter falls outside of the threshold range.

2. A method according to claim 1, further comprising the step of replacing in the first memory location the desired values of the treatment parameters with the current values when said difference is lower than a predetermined threshold.

3. A method according to claim 1, further comprising the step of generating an alarm signal and displaying the suggested value of the controlled parameter when the suggested value of the controlled parameter falls within the threshold range.

4. A method according to claim 3, further comprising the steps of obtaining a current value of the controlled parameter, comparing the current value with the suggested value, storing the current value in memory and disabling the alarm signal if the current value is identical to the suggested value.

5. A method according to claim 3, further comprising the steps of obtaining new current values of the treatment parameters, comparing the new values with the desired values stored in the first memory location, and disabling the alarm signal when the new current values are substantially the same as the stored values.

6. A method according to claim 5, further comprising the steps of detecting a confirmation signal of the current values, calculating a new value for the desired clinical prescription based on the new parameter values, storing the current parameter values and the new desired clinical prescription in memory, and disabling the alarm.

7. A method according to claim 1, wherein the desired values of the parameters are related to the desired clinical prescription by a mathematical model, the desired values of the parameters being input variables of the mathematical model and the desired clinical prescription being an output value of the mathematical model, the method further comprising the step of storing the output value in a second memory location.

8. A method according to claim 7 wherein the treatment parameters include both control parameters and controlled parameters, and wherein the step of calculating a suggested value for at least the controlled parameter includes calculating a suggested value based on a current value of at least one control parameter and a value of the desired clinical prescription stored in said second memory location.

9. A method according to claim 8 wherein the control parameters include blood flow and ultrafiltration rate, the controlled parameters includes infusion rate and the clinical prescription include bicarbonataemia.

10. A dialysis treatment method comprising the steps of:

storing in a first memory location desired values for a plurality of treatment parameters relating to a treatment to be carried out, at least one of the plurality of parameters being a controlled parameter having an initial value, the plurality of treatment parameters corresponding to a desired clinical prescription;

detecting, during a treatment session, current values of said plurality of treatment parameters;

comparing the current values with the stored desired values;

calculating a suggested value of the controlled parameter to maintain the clinical prescription when at least one of the current parameter values differs from a corresponding desired value;

comparing the suggested value of the controlled parameter with the initial value of the controlled parameter to determine a difference;

determining whether the suggested value of the controlled parameter falls within a threshold range when an absolute value of the difference is greater than a predetermined value;

generating a warning signal indicating that the current values are not in accordance with the desired clinical prescription when the suggested value of the controlled parameter falls outside of the threshold range; and

adjusting the controlled parameter to substantially maintain the desired clinical prescription by replacing the initial value of the controlled parameter with the suggested value of the controlled parameter when the suggested value of the controlled parameter falls within the threshold range.

11. A dialysis treatment method comprising the steps of:

conducting blood through a blood side of a dialysis unit during a treatment session;

withdrawing a used fluid from a used fluid side of the dialysis unit during the treatment session;

storing in a first memory location desired values for a plurality of dialysis treatment parameters relating to a treatment to be carried out by the dialysis unit during the treatment session, at least one of the plurality of parameters being a controlled parameter having an initial value, the plurality of dialysis treatment parameters corresponding to a desired clinical prescription;

detecting, during the treatment session using the dialysis unit, current values of said plurality of dialysis treatment parameters;

comparing the current values with the stored desired values;

calculating a suggested value of the controlled parameter to maintain the clinical prescription when at least one of the current parameter values differs from a corresponding desired value;

comparing the suggested value of the controlled parameter with the initial value of the controlled parameter to determine a difference;

determining whether the suggested value of the controlled parameter falls within a threshold range when an absolute value of the difference is greater than a predetermined value;

generating a warning signal indicating that the current values are not in accordance with the desired clinical prescription when the suggested value of the controlled parameter falls outside of the threshold range; and

adjusting the controlled parameter to substantially maintain the desired clinical prescription by replacing the initial value of the controlled parameter with the suggested value of the controlled parameter when the suggested value of the controlled parameter falls within the threshold range.