Computerized System for Blood Chemistry Monitoring

• US 20100217238A1
• Filed: 02/26/2010
• Published: 08/26/2010
• Est. Priority Date: 08/31/2007
• Status: Active Grant

• Current Assignee: Ideal Medical Technologies, Inc.
• Original Assignee: Ideal Medical Technologies, Inc.
• Inventors: DeJournett, Leon
• Granted Patent: US 8,956,321 B2
• Time in Patent Office: Days
• US Class Current: 604/890.100
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/14503 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors A61B5/1459, A61B5/1464, A61B5/1473, A61B5/1482, A61B5/14865 take precedence
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61M 2005/14208 with a programmable infusion control system, characterised by the infusion program
• CPC Class Codes: A61M 2005/1726 the body parameters being measured at, or proximate to, the infusion site
• CPC Class Codes: A61M 2205/52 with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: A61M 2230/201 Glucose concentration
• CPC Class Codes: A61M 5/16827 controlling delivery of multiple fluids, e.g. sequencing, mixing or via separate flow-paths infusion of multiple fluids without using a controller A61M5/1407
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00

Abstract

An apparatus and computerized method of intravenously monitoring a patient'"'"'s blood chemistry transmits real time measurements to an electronically controlled closed loop system that auto-regulates blood osmolality and glucose level with medications infused through a catheter designed for such purpose. The closed loop system utilizes a glucose algorithm and an osmolality algorithm implemented in hardware and software to control the flow of dextrose, insulin and hypertonic saline to a patient in an effort to achieve better patient outcomes in instances of trauma, surgery and medical illnesses.

Claims

1. A computerized glucose adjustment system for intravenously controlling a patient'"'"'s blood chemistry on a real time basis, said system comprising:

a glucose sensor measuring a patient'"'"'s glucose level;

a pump connected to a source of insulin and a source of dextrose for distributing insulin and dextrose'"'"'into a patient'"'"'s bloodstream;

a computer processor in electronic communication with said sensor and said pump, said processor receiving an electronic signal from said sensor for calculating the patient'"'"'s real time average glucose level over a specified time period;

a glucose control module stored in said processor for sending output signals to said pump for controlling the rate at which said pump distributes insulin and dextrose into the patient, wherein said glucose control module comprises pump controlling commands to (i) determine where the patient'"'"'s real time average blood glucose level lies along a continuum of glucose values;

(ii) track the rate at which the average blood glucose level is changing over time; and

(iii) iteratively adjust the dextrose flow rate and insulin flow rate into the patient'"'"'s body to adjust the average glucose level closer to a known normal glucose range.

2. A computerized glucose adjustment system according to claim 1, further comprising a catheter distributing insulin and dextrose into a patient'"'"'s bloodstream, wherein said glucose sensor is positioned on said catheter and in contact with the patient'"'"'s bloodstream.

3. A computerized glucose adjustment system according to claim 1, wherein said glucose sensor is positioned within the patient'"'"'s subcutaneous tissues.

4. A computerized glucose adjustment system according to claim 1, wherein said glucose sensor is in an extracorporeal position.

5. A computerized glucose adjustment system according to claim 1, wherein said dextrose flow rate is a function of the patient'"'"'s weight in kilograms.

6. A computerized glucose adjustment system according to claim 1, wherein said insulin flow rate is a function of the patient'"'"'s weight in kilograms.

7. A computerized glucose adjustment system according to claim 1, wherein said processor accepts as an input the initial concentration of said dextrose.

8. A computerized glucose adjustment system according to claim 1, wherein said processor accepts as an input the initial concentration of said insulin.

9. A computerized glucose adjustment system according to claim 7, wherein said initial concentration of said dextrose is selected from the group consisting of 5, 10, 12.5, 15, 20, and 25 in percent weight per volume.

10. A computerized glucose adjustment system according to claim 1, wherein said glucose control module operates continuously on a real time basis with updated glucose measurements.

11. A computerized glucose adjustment system according to claim 1, wherein a user sets a known normal glucose range between Xmin and Xmax, said system further comprising a “

Low Glucose”

alarm set point and a “

High Glucose”

alarm set point both of which are set by medical personnel.

12. A computerized glucose adjustment system according to claim 11, wherein said glucose control module calculates and stores an average blood glucose level Xa in units of milligrams per deciliter over a specified time period.

13. A computerized glucose adjustment system according to claim 12, wherein said glucose control module calculates and stores blood glucose value Xt in milligrams per deciliter every 30 seconds and calculates the average glucose level Xa in milligrams per deciliter over said specified time period equal to 10 minutes.

14. A computerized glucose adjustment system according to claim 13, wherein said pump controlling commands are divided into categories defined by glucose value ranges along a glucose value continuum.

15. A computerized glucose adjustment system, according to claim 14, wherein said pump controlling command category is selected from the group consisting of:

Category 1;

Xa−

Xmin<

−

10 mg/dl;

Category 2;

−

10<

Xa−

Xmin<

−

5 mg/dl

Category 3;

−

5<

Xa−

Xmin<

0 mg/dl

Category 4;

0≦

Xa−

Xmin<

(Xmax−

Xmin)/3

Category 5;

Xmax−

Xmin)/3≦

Xa−

Xmin<

2(Xmax−

Xmin)/3

Category 6;

2(Xmax—

Xmin)/3≦

Xa−

Xmin<

Xmax−

Xmin

Category 7;

0≦

Xa−

Xmax<

10

Category 8;

10≦

Xa−

Xmax<

30

Category 9;

Xa−

Xmax≧

30

16. A computerized glucose adjustment system according to claim 15, wherein said controller calculates the category for the current average glucose measurement Xa.

17. A computerized glucose adjustment system according to claim 16, wherein said controller compares a current glucose measurement Xa to a prior average glucose measurement Xb to determine the rate at which the average glucose level is changing.

18. A computerized glucose adjustment system according to claim 16, wherein said controller compares a current glucose measurement Xa to a prior glucose measurement Xc to determine the rate at which the average glucose level is changing over an extended time period.

19. A computerized glucose adjustment system according to claim 17, wherein said pump controlling commands adjust said pump output to control the flow rates of insulin (INSf) and dextrose (Dexf) according to the category in which the current glucose measurement fits and the rate at which the glucose level is changing.

20. A computerized glucose adjustment system according to claim 16 wherein for each category, the next insulin (INSfn) and next dextrose (Dexfn) flow rates are adjusted for condition Xa−

Xb (mg/dl), wherein said condition is selected from the group consisting of Xa−

Xb≦

−

15;

−

15<

Xa−

Xb≦

3; and

Xa−

Xb>

3.

21. A computerized glucose adjustment system according to claim 20, wherein the value for Xa−

Xb is selected from the group consisting of;

a) Xa−

Xb≦

−

15 mg/dL

b) Xa−

Xb>

−

15 mg/dL

c) Xa−

Xb≦

−

6 mg/dL

d) Xa−

Xb>

−

6 mg/dL

e) Xa−

Xb>

−

6 and ≦

0 mg/dL

f) Xa−

Xb≦

−

5 mg/dL

g) Xa−

Xb>

−

5 and ≦

0 mg/dL

h) Xa−

Xb≦

−

4 mg/dL

i) Xa−

Xb>

−

4 mg/dL and ≦

1 mg/dL

j) Xa−

Xb<

−

3 mg/dL

k) Xa−

Xb≦

−

3 mg/dL

l) Xa−

Xb≧

−

3 mg/dL

m) Xa−

Xb>

−

3 mg/dL

n) Xa−

Xb≧

″

3 mg/dL and ≦

1 mg/dL

o) Xa−

Xb>

−

3 mg/dL and ≦

0 mg/dL

p) Xa−

Xb>

−

3 mg/dL and ≦

3 mg/dL

q) Xa−

Xb<

−

2 mg/dL

r) Xa−

Xb≦

−

2 mg/dL

s) Xa−

Xb≧

−

2 mg/dL

t) Xa−

Xb>

−

2 mg/dL and ≦

3 mg/dL

u) Xa−

Xb<

−

1 mg/dL

v) Xa−

Xb≧

−

1 mg/dL

w) Xa−

Xb<

0 mg/dL

x) Xa−

Xb≦

0 mg/dL

y) Xa−

Xb≦

0 and >

−

4 mg/dL

z) Xa−

Xb≧

0 mg/dL

aa) Xa−

Xb>

0 mg/dL

bb) Xa−

Xb≦

1 mg/dL

cc) Xa−

Xb>

1 mg/dL

dd) Xa−

Xb≦

2 mg/dL

ee) Xa−

Xb>

2 mg/dL

ff) Xa−

Xb>

3 mg/dL

22. A computerized glucose adjustment system according to claim 20, wherein said pump controlling commands adjust said next insulin (INSfn) and next dextrose (Dexfn) flow rates as a function of the previous insulin (INSfp) and dextrose (Dexfp) flow rates within said specified time period.

23. A computerized glucose adjustment system according to claim 21, wherein said previous insulin flow rate (INSfp) is selected from the group consisting of:

(i) INSfp=0 units/hour;

(ii) INSfp>

0 units/hour;

(iii) 0<

INSfp≦

(0.01*Wt) units/hour

(iv) INSfp<

(0.05*Wt) units/hour

(v) 0<

INSfp≦

(0.02*Wt) units/hour;

(vi) 0<

INSfp≦

(0.05*Wt) units/hour

(vii) 0<

INSfp<

(0.05*Wt) units/hour

(viii) 0<

INSfp≦

(0.1*Wt) units/hour

(ix) INSfp>

(0.01*Wt) units/hour

(x) (0.01*Wt) units/hour<

INSfp≦

(0.1*Wt) units/hour;

(xi) INSfp>

(0.02*Wt) units/hour

(xii) (0.02*Wt) units/hour<

INSfp≦

(0.1*Wt) units/hour

(xiii) INSfp>

(0.05*Wt) units per hour;

(xiv) INSfp≧

(0.05*Wt) units per hour

(xv) INSfp>

(0.1*Wt) units/hour, wherein the value of Wt is the patient'"'"'s weight in kilograms.

24. A computerized glucose adjustment system according to claim 21, wherein the initial concentration of said dextrose solution is C, and said previous dextrose flow rate (DEXfp) is selected from the group consisting of:

(i) DEXfp=0;

(ii) DEXfp>

0 mL/hour;

(iii) 0 mL/hour<

DEXfp≦

(1/C*Wt) mL/hour;

(iv) 0 mL/hour<

DEXfp ((2/C)*Wt) mL/hour;

(v) DEXfp>

(1/C*Wt) mL/hour;

(vi) (1/C*Wt) mL/hour<

DEXfp≦

((6/C)*Wt) mL/hour;

(vii) ((2/C)*Wt) mL/hour<

DEXfp≦

((6/C)*Wt) mL/hour;

(viii) ((2/C)*Wt) mL/hour<

DEXfp

(ix) DEXfp>

((6/C)*Wt) mL/hour, wherein the value of Wt is the patient'"'"'s weight in kilograms.

25. A computerized glucose adjustment system according to claim 20, wherein said controller activates an alarm if the differential between Xa and Xb is greater than 25 or less than −

25 mg/dL.

26. A computerized glucose adjustment system according to claim 20 further comprising a secondary controller for adjusting the output of said glucose control module by multiplying the next insulin flow rate INSfn by a secondary adjustment factor.

27. A computerized method of adjusting a patient'"'"'s blood chemistry on a real time basis by adjusting the patient'"'"'s average glucose level toward a known normal range by multiplying a currently known insulin flow rate and a currently known dextrose flow rate by adjustment factors to control the amount of insulin and dextrose pumped into a patient'"'"'s bloodstream, the method comprising:

continuously measuring the patient'"'"'s real time glucose level;

storing each real time glucose level in a computer processor;

calculating via the computer processor an average glucose level, Xa, over a specified time period;

assigning the average glucose level to one of a series of glucose control ranges;

calculating the rate at which the average glucose level changes from one of said specified time periods to the next;

determining the insulin flow rate adjustment factor and the dextrose flow rate adjustment factor necessary for an average glucose level in an assigned glucose control range changing at a calculated rate.

28. A computerized method according to claim 27, wherein a maximum glucose value is Xmax, the current average glucose value is Xa, and the immediately prior average glucose value is Xb, further comprising the step of administering bolus doses of insulin for all glucose values greater than or equal to Xmax+20 mg/dL, when any of the following conditions are met:

(i) (Xa≧

(Xmax+20 mg/dL) and (Xa<

(Xmax+50 mg/dL) and (Xa−

Xb>

−

5 mg/dL);

(ii)(Xa≧

(Xmax+50) mg/dL) and (Xa<

(Xmax+90) mg/dL) and (Xa−

Xb>

−

15 mg/dL);

(iii) (Xa≧

(Xmax+90) mg/dL) and (Xa−

Xb>

−

20 mg/dL);

wherein the bolus doses may not be administered more often than every 30 minutes.

29. A computerized method according to claim 27, wherein the dextrose adjustment factor is selected from the group consisting of 0, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.2, 1.25, 1.3, 1.4, 1.5, 1.7.

30. A computerized method according to claim 27, wherein the insulin adjustment factor is selected from the group consisting of 0, 0.5, 0.75, 0.80, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7,

31. A computerized method according to claim 27, further comprising the step of setting the values of an initial insulin flow rate and an initial dextrose flow rate manually prior to the step of continuously measuring the patient'"'"'s real time glucose level.

32. A computerized osmolality adjustment system for intravenously controlling a patient'"'"'s blood osmolality on a real time basis, said system comprising:

a catheter placed within the patient'"'"'s venous system;

a conductivity sensor assembly attached to said catheter and in direct contact with the patient'"'"'s bloodstream;

a pump connected to a fluid source for infusing said fluid into a patient'"'"'s bloodstream through said catheter;

a computer processor in electronic communication with said conductivity sensor assembly to convert blood conductivity into an osmolality measurement, wherein the processor is also in electronic communication with said pump;

a fluid infusion control module stored in said processor for controlling the pumped fluid flow rate, wherein said fluid infusion control module comprises pump controlling commands to(i) determine where the patient'"'"'s real time average osmolality lies along a continuum of osmolality values;

(ii) track the rate at which the blood osmolality is changing over time; and

(iii) iteratively adjust the pump output so that the fluid flow rate into the patient'"'"'s body adjusts the average osmolality level closer to a known normal range.

33. A computerized osmolality adjustment system according to claim 32, wherein said fluid is hypertonic saline.

34. A computerized osmolality adjustment system according to claim 32, wherein said fluid infusion control module converts the conductivity measurement to an osmolality measurement using the formula

Serum Osmolality=18.95 (mOsm/mSiemen)×

measured conductivity (mSiemen).

35. A computerized osmolality adjustment system according to claim 34, wherein a user sets the known normal range for blood osmolality between OsmS1 and OsmSh.

36. A computerized osmolality adjustment system according to claim 35, wherein said fluid infusion control module calculates and stores an average blood osmolality level Ya over a specified time period.

37. A computerized osmolality adjustment system according to claim 34, wherein said fluid infusion control module calculates and stores blood osmolality value Yt every 30 seconds and calculates the average osmolality level Ya over said specified time period equal to 10 minutes.

38. A computerized osmolality adjustment system according to claim 34, wherein said pump controlling commands are divided into categories defined by osmolality value ranges along said osmolality value continuum.

39. A computerized osmolality adjustment system, according to claim 34, wherein said pump controlling command category is selected from the group consisting of the following where Ya is the most recently calculated average blood osmolality, OsmS1 is the lowest acceptable value for blood osmolality, and OsmSh is the highest acceptable value for blood osmolality:

Category 1;

Ya−

OsmS1<

−

5 mOsm/Kg

Category 2;

−

5<

Ya−

OsmS1<

0 mOsm/Kg

Category 3;

0 ≦

Ya−

OsmS1<

(OsmSh−

OsmS1)/3 mOsm/Kg

Category 4;

(OsmSh−

OsmS1)/3≦

Ya−

OsmS1<

2(OsmSh−

OsmS1)/3 mOsm/Kg

Category 5;

2(OsmSh—

OsmS1)/3≦

Ya−

OsmS1<

OsmSh−

OsmS1 mOsm/Kg

Category 6;

OsmSh−

OsmS1≦

Ya−

OsmS1<

(OsmSh−

OsmS1)+5 mOsm/Kg

Category 7;

OsmSh−

OsmS1)+5≦

Ya−

OsmS1 mOsm/Kg

40. A computerized osmolality adjustment system according to claim 39, wherein said controller calculates the category for the current average osmolality measurement Ya.

41. A computerized osmolality adjustment system according to claim 40, wherein said controller compares said current osmolality measurement Ya to a prior average osmolality measurement Yb to determine the rate at which the osmolality level is changing.

42. A computerized osmolality adjustment system according to claim 41, wherein said infused fluid is hypertonic saline and wherein said pump controlling commands adjust the flow rate of hypertonic saline by an adjustment factor defined by the category in which the current osmolality measurement fits and the rate at which the osmolality level is changing.

43. A computerized osmolality adjustment system according to claim 42, wherein for each category, the next saline flow rate is adjusted for condition Ya−

Yb, wherein said condition is selected from the group consisting of Ya−

Yb<

−

2;

2>

Ya−

Yb<

−

2; and

Ya−

Yb>

2.

44. A computerized osmolality adjustment system according to claim 43, wherein said pump controlling commands adjust said next saline flow rate as a function of the previous saline flow rate within said specified time period.

45. A computerized osmolality adjustment system according to claim 44, wherein said previous saline flow rate is selected from the group consisting of:

(i) HTSfp=0 mL/hour;

(ii) 0 mL/hour<

HTSfp≦

(0.2*Wt*3/Z) mL/hour;

(iii) (0.2*Wt*3/Z) mL/hour<

HTSfp≦

(0.6*Wt*3/Z) mL/hour

(iv) (0.6*Wt*3/Z) mL/hour<

HTSfp≦

(1.0*Wt*3/Z) mL/hour;

(v) HTSfp>

(1*Wt*3/Z) mL/hour;

wherein Z is the initial concentration of saline in percent weight/volume, and HTSfp is the past flow of saline into the patient and Wt is the patient'"'"'s weight in kilograms.

46. A computerized osmolality adjustment system according to 45, wherein said fluid infusion control module operates continuously on a real time basis with updated conductivity measurements from said conductivity sensor on said catheter.

47. A computerized method of adjusting a patient'"'"'s blood osmolality on a real time basis by adjusting the saline flow to the patient, the method comprising:

continuously measuring the patient'"'"'s real time blood osmolality;

storing each real time blood osmolality value in a computer processor;

calculating via the computer processor the average blood osmolality, Ya, over a specified time period;

electronically assigning the average osmolality level to one of a series of osmolality control ranges;

calculating the rate at which the average blood osmolality level changes from one of said specified time periods to the next;

determining the saline flow adjustment factor necessary for an average osmolality level in an assigned control range changing at a calculated rate.

48. A computerized method according to claim 47, further comprising the step of multiplying the current saline flow rate by respective adjustment factors.

49. A computerized method according to claim 48, wherein the saline adjustment factor is selected from the group consisting of 0, 0.5, 0.6, 0.7, 0.8, 0.85, 0.86, 0.87, 0.9, 0.92, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1.0, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.1, 1.15, 1.2, 1.24, 1.25, 1.3, 1.4

50. A computerized method according to claim 49, further comprising the step of adjusting the saline flow rate to a flow rate greater than zero.

51. A computerized method according to claim 49, further comprising the step of setting the values of the initial saline flow rate manually prior to the step of continuously measuring the patient'"'"'s real time osmolality level.