Drug infusion system and method for controlling blood pressure

• US 9,867,936 B2
• Filed: 09/15/2011
• Issued: 01/16/2018
• Est. Priority Date: 09/15/2010
• Status: Active Grant

• Current Assignee: Singapore Health Services Pte Limited (MOH Holdings Pte Limited)
• Original Assignee: Singapore Health Services Pte Limited (MOH Holdings Pte Limited)
• Inventors: Sia, Tiong-Heng Alex
• Primary Examiner(s): Osinski, Bradley
• Application Number:
  US13/822,599
• Publication Number:
  US 20130226138A1
• Time in Patent Office: 2,315 Days
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/4821 Determining level or depth of anaesthesia A61B5/1106 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 5/1407 Infusion of two or more substances
• CPC Class Codes: A61M 5/142 Pressure infusion, e.g. using pumps
• CPC Class Codes: A61M 5/16804 Flow controllers
• 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 5/16877 Adjusting flow; Devices for setting a flow rate
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• CPC Class Codes: G16H 10/40 for data related to laboratory analysis, e.g. patient specimen analysis
• CPC Class Codes: G16H 20/17 delivered via infusion or injection
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass

Abstract

Various embodiments relating to a method of controlling the blood pressure of a subject is provided, the method includes generating blood pressure data indicating the blood pressure of the subject, controlling a plurality of pumps to infuse, in dependence on the blood pressure data, drugs into the subject, wherein each of the plurality of pumps is adapted to infuse one out of a plurality of different drugs into the subject, and wherein each of the plurality of different drugs has a particular influence on the blood pressure of the subject, wherein the plurality of pumps is controlled such that, in dependence on the blood pressure data, a mix of drugs is infused into the subject which stabilizes the blood pressure of the subject.

Claims

1. A method of controlling a blood pressure of a subject, comprising:

(a) calibrating a blood pressure baseline for the subject;

(b) selecting a blood pressure threshold corresponding to said blood pressure baseline;

(c) calibrating a heart rate baseline for the subject;

(d) selecting a heart rate threshold corresponding to said heart rate baseline;

(e) calculating a final mean blood pressure indicating the blood pressure of the subject during a pre-determined period, wherein the blood pressure is generated by a non-invasive blood pressure data generating unit such that calculating the final mean blood pressure includes the step of applying a greater weight to blood pressure measured in a later part of the pre-determined period than during an earlier part, wherein the earlier part of the pre-determined period is longer than the later part of the pre-determined period and wherein the step of applying a greater weight to blood pressure measured in the later part of the pre-determined period comprises the steps of;

(i) calculating an earlier part mean blood pressure from blood pressure readings for each second up to the end of the earlier part of the pre-determined period to obtain the earlier part mean blood pressure;

(ii) calculating a later part mean blood pressure from blood pressure readings for each second during the later part of the pre-determined period to obtain the later part mean blood pressure; and

then

(iii) calculating the final mean blood pressure as an average of the earlier part mean blood pressure and the later part mean blood pressure;

(f) generating heart rate data indicating a heart rate of the subject;

(g) controlling a plurality of pumps to infuse drugs into the subject, wherein each of the plurality of pumps is adapted to infuse one out of a plurality of different drugs into the subject, and wherein each of the plurality of different drugs has a particular influence on the blood pressure of the subject;

wherein the plurality of pumps is controlled such that, in dependence on the final mean blood pressure relative to the blood pressure threshold and the heart rate data relative to the heart rate threshold, a mix of drugs is infused into the subject which stabilizes the blood pressure of the subject, wherein the plurality of pumps is controlled to infuse drugs into the subject if the blood pressure of the subject falls below the blood pressure threshold, wherein the injection of drugs into the subject is continued in regular time intervals ranging between 15 and 30 seconds until the blood pressure exceeds the blood pressure threshold.

2. The method according to claim 1, wherein the blood pressure threshold is below 90% of a baseline blood pressure.

3. The method according to claim 1, wherein a first pump of the plurality of pumps is controlled to infuse a first drug into the subject if the heart rate of the subject exceeds the heart rate threshold.

4. The method according to claim 3, wherein the first drug is Phenylephrine.

5. The method according to claim 4, wherein Phenylephrine is injected with a dose of between about 0.01 mg to 0.2 mg or 0.025 mg at regular time intervals .

6. The method according to claim 1, wherein a second pump of the plurality of pumps is controlled to infuse a second drug into the subject if the heart rate of the subject falls below the heart rate threshold.

7. The method according to claim 6, wherein the second drug is Ephedrine.

8. The method according to claim 7, wherein Ephedrine is injected with a dose of between about 0.5 mg to 4 mg or 2 mg at regular time intervals.

9. The method according to claim 1, wherein the heart rate threshold is below 60 beats per minute.

10. The method according to claim 1, wherein the blood pressure data and/or heart rate data is collected in real time.

11. The method according to claim 1, wherein the calibrating step includes the steps of taking 3 blood pressure readings from the subject and calculating an average of said readings.

12. The method according to claim 1, wherein the pre-determined period is 15 seconds with the earlier part of the period being up to 10 seconds and the later part being from 10 to 15 seconds, and the step of applying a greater weight including the steps of:

calculating a 1 to 10 second mean blood pressure from blood pressure readings for each second up to 10 seconds and;

calculating a 10 to 15 second mean blood pressure from blood pressure readings for each second from 10 to 15 seconds, then;

calculating the final mean blood pressure from the average of the 1 to 10 second mean and the 10 to 15 second mean.

13. A system of controlling a blood pressure of a subject, comprising:

(a) a blood pressure data generating unit adapted to generate blood pressure data indicating the blood pressure of the subject, and further adapted to calibrate a blood pressure baseline for the subject and select a blood pressure threshold corresponding to said blood pressure baseline, wherein the blood pressure data generating unit is non-invasive and wherein

said blood pressure data generating unit is adapted to calculate a final mean blood pressure pressure indicating the blood pressure of the subject during a pre-determined period such that the final mean blood pressure includes a greater weight to blood pressure measured in a later part of the pre-determined period than during an earlier part of the pre-determined period, wherein calculating the final mean blood pressure includes the step of applying a greater weight to blood pressure measured in a later part of the pre-determined period than during an earlier part of the pre-determined period, wherein the earlier part of the pre-determined period is longer than the later art of the pre-determined period and wherein the step of applying a greaer weight to blood pressure measured in the later part of the pre-determined period comprises the steps of;

(i) calculting an earlier part mean blood pressure from blood pressure readings for each second up to the end of the earlier part of the pre-determined period to obtain the earlier part mean blood pressure;

(ii) calculating a later part mean blood pressure from blood pressure readings for each second during the later part of the pre-determined period to obtain the later part mean blood pressure; and

then

(iii) calculating the final mean blood pressure as an average of the earlier part mean blood pressure and the later part mean blood pressure;

(b) a heart rate data generating unit adapted to generate heart rate data indicating a heart rate of the subject, and further adapted to calibrate a heart rate baseline for the subject and select a heart rate threshold corresponding to said heart rate baseline;

(c) a plurality of pumps, wherein each of the plurality of pumps is adapted to infuse one out of a plurality of different drugs into the subject, each of the plurality of different drugs having a particular influence on the blood pressure of the subject;

(d) a controlling unit adapted to control the plurality of pumps to infuse, in dependence on the final mean blood pressure relative to the blood pressure threshold and the heart rate data relative to the heart rate threshold, a mix of drugs into the subject which stabilizes the blood pressure of the subject, wherein the plurality of pumps are controlled such that drugs are infused into the subject if the blood pressure of the subject falls below the blood pressure threshold, wherein the controlling unit is adapted to cause the injection of drugs into the subject in regular time intervals ranging between 15 and 30 seconds until the blood pressure exceeds the blood pressure threshold.

14. The system according to claim 13, wherein the blood pressure threshold falls below 90% of a baseline blood pressure.

15. The system according to claim 13, wherein the controlling unit is adapted to control a first pump of the plurality of pumps to infuse a first drug into the subject if the heart rate of the subject exceeds the heart rate threshold.

16. The system according to claim 15, wherein the first drug is Phenylephrine.

17. The system according to claim 16, wherein the controlling unit is adapted to cause injection of Phenylephrine with a dose of between about 0.01 mg to 0.2 mg or 0.025 mg at regular time intervals.

18. The system according to claim 13, wherein the controlling unit is adapted to control a second pump of the plurality of pumps to infuse a second drug into the subject if the heart rate of the subject falls below the heart rate threshold.

19. The system according to claim 18, wherein the second drug is Ephedrine.

20. The system according to claim 19, wherein the controlling unit is adapted to cause injection of Ephedrine with a dose of between about 0.5 mg to 4 mg or 2 mg at regular time intervals.

21. The system according to claim 13, wherein the heart rate threshold falls below 60 beats per minute.