METHOD AND DEVICE TO MONITOR PATIENTS WITH KIDNEY DISEASE

• US 20170000936A1
• Filed: 09/13/2016
• Published: 01/05/2017
• Est. Priority Date: 04/29/2011
• Status: Active Grant

• Current Assignee: Mozarc Medical US LLC
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Soykan, Orhan, Manda, VenKatesh R., Gerber, Martin T., Hobot, Christopher M.
• Granted Patent: US 10,207,041 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2505/07 Home care
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61M 1/14 Dialysis systems; Artificial kidneys; Blood oxygenators semi-permeable membranes characterised by the material, manufacturing processes therefor B01D71/00 ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis
• CPC Class Codes: A61M 1/1601 Control or regulation
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 2205/3553 remote, e.g. between patient's home and doctor's office
• CPC Class Codes: A61M 2205/3584 using modem, internet or bluetooth
• CPC Class Codes: A61M 2205/52 with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: A61M 2230/005 Parameter used as control input for the apparatus
• CPC Class Codes: A61M 2230/06 Heartbeat rate only
• CPC Class Codes: A61M 2230/20 Blood composition characteristics
• CPC Class Codes: A61M 2230/208 pH-value
• CPC Class Codes: A61M 2230/30 Blood pressure A61M2230/04 takes precedence
• CPC Class Codes: A61M 2230/63 Motion, e.g. physical activity

Abstract

A medical monitoring device for monitoring electrical signals from the body of a subject is described. The medical monitoring device monitors electrical signals originating from a cardiac cycle of the subject and associates each cardiac cycle with a time index. The medical monitoring device applies a forward computational procedure to generate a risk score indicative of hyperkalemia, hypokalemia or arrhythmia of the subject. The medical monitoring device can adjust the forward computational procedure based upon clinical data obtained from the subject.

Claims

1. A method for determining hyperkalemia, hypokalemia or arrhythmia, comprising:

observing a cardiac cycles of a subject by means of a medical device;

calculating at least one risk score based upon a plurality of features of the cardiac cycle, the cycle associated with a time index and a risk score, wherein the risk score is calculated using a forward computational procedure; and

sending an alert when at least one risk score exceeds a threshold for a defined time period, for a number of time indices, or for a certain fraction or number of time indices within a defined time period.

2. The method of claim 1, wherein the threshold is determined based upon a baseline risk score value of the subject.

3. The method of claim 1, wherein one or more of a first risk score and a second risk score is calculated by one of the following:

the first risk score calculated by comparing one or more features selected from P-R interval, QRS width, Q-T interval, QT-dispersion, P-wave amplitude, P-wave peak, S-T segment depression, T-wave inversion, U-wave amplitude, T-wave peak amplitude, and heart rate variability to corresponding value criteria, and

the second risk score calculated by comparing one or more features selected from QRS width, Q-T interval, P-wave amplitude, P-wave peak and T-wave amplitude to corresponding value criteria.

4. The method of claim 3, wherein at least one of the first risk score and the second risk score is calculated based upon assigning values to one or more selected from feature scores P1, P2, P3, P4, P5, P6, P7, P8, P9 and P10, wherein the set values are assigned as follows:

P1 based upon a comparison with the feature P-R interval in time units,

P2 based upon a comparison with the feature QRS width in time units,

P3 based upon a comparison with the feature Q-T interval in time units,

P4 based upon a comparison with the feature P-wave amplitude in potential units per time unit,

P5 based upon a comparison with the feature P-wave peak in potential units,

P6 based upon a comparison with the feature of depression of the S-T segment,

P7 based upon a comparison with the feature of inversion of the T-wave,

P8 based upon a comparison with the feature of U-wave amplitude in potential units,

P9 based upon a comparison with the feature of T-wave amplitude in potential units, and

P10 based upon a comparison with the feature of heart rate variation in time units.

5. The method of claim 4, wherein the set values are assigned a non-zero value based on the following:

P1 assigned a non-zero value if P-R interval is greater than 200 msec,

P2 assigned a non-zero value if QRS width is greater than 130 msec,

P3 assigned a non-zero value if Q-T interval is greater than 200 msec,

P4 assigned a non-zero value if P-wave amplitude is less than 1 mV,

P5 assigned a non-zero value if P-wave peak is greater than 1 mV/msec,

P6 assigned a non-zero value if S-T segment is depressed,

P7 assigned a non-zero value if T-wave is inverted,

P8 assigned a non-zero value if U-wave amplitude is greater than 2 mV,

P9 assigned a non-zero value if T-wave amplitude is greater than 3 mV, and

P10 assigned a non-zero value if heart rate variation is less than 50 msec.

6. The method of claim 4, wherein the first risk score is determined by a non-weighted or weighted sum of P1, P6, P7, P8 and P10.

7. The method of claim 4, wherein the second risk score is determined by a non-weighted or weighted sum of P2, P3, P4, P5, P9 and P10.

8. The method of claim 5, wherein the first risk score is determined by a non-weighted or weighted sum of P1, P6, P7, P8 and P10.

9. The method of claim 5, wherein the second risk score is determined by a non-weighted or weighted sum of P2, P3, P4, P5 and P9.

10. The method of claim 1, further comprising incrementally increasing a risk counter for each consecutive time index that a risk score of the at least one risk score exceeds the threshold value.

11. The method of claim 1, further comprising incrementally increasing a risk counter for each time index within a defined time period that a risk score of the at least one risk score exceeds the threshold value.

12. The method of claim 10, wherein the threshold is determined based upon a baseline risk score value of the subject.

13. The method of claim 11, wherein the threshold is determined based upon a baseline risk score value of the subject.

14. The method of claim 1, wherein the medical device is implantable in the subject.

15. The method of claim 1, wherein the medical device is an external device comprising a plurality of electrodes for placement on the skin of the subject.

16. The method of claim 1, further comprising making a modification to a dialysis treatment received by the subject based upon the result of the forward computational procedure.

17. The method of claim 16, wherein the dialysis treatment is modified to occur at a more frequent basis compared to a prior dialysis treatment if blood serum potassium concentration of the patient is determined to be high by the forward computational procedure.

18. The method of claim 16, wherein the dialysis treatment is modified to use a dialysate with a non-constant concentration of a potassium over the course of the dialysis treatment if blood serum potassium concentration of the patient is determined to be high by the forward computational procedure.

19. The method of claim 16, wherein the dialysis treatment is modified to a longer period of time compared to a prior dialysis treatment if blood serum potassium concentration of the patient is determined to be high by the forward computational procedure.

20. The method of claim 16, wherein if blood serum potassium concentration of the patient is determined to be low by the forward computational procedure, the dialysis treatment is modified to use a dialysate having a higher concentration of a potassium salt compared to a prior dialysis treatment and/or the dialysis treatment is modified to a shorter period of time compared to a prior dialysis treatment.