Apparatuses and methods for titrating drug delivery

• US 7,229,430 B2
• Filed: 07/31/2002
• Issued: 06/12/2007
• Est. Priority Date: 07/31/2001
• Status: Expired due to Term

• Current Assignee: Scott Laboratories, Inc.
• Original Assignee: Scott Laboratories, Inc.
• Inventors: Hickle, Randall S., Derouen, Jason
• Primary Examiner(s): DESANTO, MATTHEW F
• Application Number:
  US10/208,183
• Publication Number:
  US 20030051737A1
• Time in Patent Office: 1,777 Days
• Field of Search: 604/890.1, 604/892.1, 604 65- 67, 604 30- 34, 604/891.1, 604/500, 604/503, 604/504, 604/131, 604/151, 705/1, 705/2, 705/3, 128/898, 128/DIG.12, 128/DIG.13, 600/364, 600/365, 600/322, 600/301, 600/557
• US Class Current: 604/67
• 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 2202/048 Anaesthetics see also A61M19/00
• 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 20/17 delivered via infusion or injection
• CPC Class Codes: G16H 50/50 for simulation or modelling of medical disorders

Abstract

A method and apparatus for reducing the workload of titrating drug to effect while leaving clinician users in control of a related procedure is described. A drug delivery device is controlled to achieve a target drug concentration at a selected site in the patient or a predetermined infusion rate waveform. The time profile of the target drug concentration or a predetermined infusion rate waveform is controlled by a drug state model that uses clinical heuristics to implement safe, pre-defined changes in the target drug concentration or infusion rate and user-commanded changes in target drug concentration or infusion rate. The invention allows time to assess the response of the patient to changes in drug level by making small incremental and conservative changes in drug level over time.

Claims

1. A system for providing drug delivery to a patient, wherein said system comprises:

a user interface for accepting input from a user;

a drug delivery device that delivers an amount of drug to a patient;

two or more patient health monitors adapted so as to be coupled to a patient and generate a signal reflecting at least one health condition of the patient; and

a processor that integrates the user interface, drug delivery device, and patient health monitors according to a hierarchy of software algorithms defining different drug states that seamlessly allow for drug level adjustments by the user such that the amount of drug delivered to the patient by the delivery device is modulated based on an input from the user and based on a signal generated by the patient health monitors to achieve a target effect site concentration (ESC),

wherein said hierarchy of software algorithms include a drug state model and a flow control algorithm and an interface algorithm, said interface algorithm being one of a rate controlled infusion algorithm and a target controlled infusion algorithm that run in real time and said interface algorithm being capable of producing different time profiles of a target drug concentration at different effect sites, and

wherein automated actions initiated by said processor will not increase overall drug levels automatically without an explicit request for a higher drug level by said user.

2. The system for providing drug delivery of claim 1, wherein one of said two or more patient health monitors is an automated responsiveness test monitor.

3. The system for providing drug delivery of claim 2, wherein said drug state model includes the following states:

RAMP UP;

RAMP DOWN;

LEVEL; and

OFF.

4. The system for providing drug delivery of claim 3, wherein said drug state model further comprises the following states:

STAT UP;

STAT DOWN; and

REDUCTION.

5. The system for providing drug delivery of claim 3, wherein said RAMP UP state is the default state whenever said user enters a new target ESC which is greater than the current ESC.

6. The system for providing drug delivery of claim 3, wherein said RAMP DOWN state is the default state whenever said user enters a new target ESC which is less than the current ESC.

7. The system for providing drug delivery of claim 1, wherein said interface algorithm employs a pre-programmed infusion rate template.

8. The system for providing drug delivery of claim 1, wherein said drug is at least one of a sedative, amnestic and analgesic drug.

9. The system for providing drug delivery of claim 1, wherein monitoring sites for said patient health monitors include at least one of said patient'"'"'s blood plasma, brain, central nervous system, neuromuscular junction, alveolar space, kidney, liver, pancreas, hypothalamus, heart tissue and baroreceptors.

10. The system for providing drug delivery of claim 1, wherein said flow control algorithm manages said delivery controller so that the drug is accurately delivered at a requested infusion rate.

11. The system of claim 1, wherein at least one of said two or more patient health monitors is an electroencephalogram (EEG) used to assess the patient'"'"'s consciousness.

12. The system of claim 1, wherein said processor incorporates additional user input to override automated functions without switching operating modes.

13. A method for providing drug delivery to a patient, wherein said method comprises the steps of:

accepting input from a user via a user interface;

delivering an amount of drug to a patient via a drug delivery device;

generating a signal reflecting at least one health condition of the patient via two or more patient health monitors adapted so as to be coupled to a patient; and

integrating the user interface, drug delivery device, and patient health monitors according to a hierarchy of software algorithms defining different drug states that account for the event of additional input from the user using a clinician-knows-best logic such that the amount of drug delivered to the patient by the delivery device is modulated based on an input from the user and based on a signal generated by the patient health monitors to achieve a target ESC;

wherein said hierarchy of software algorithms include a drug state model and a flow control algorithm and an interface algorithm, said interface algorithm being one of a rate controlled infusion algorithm and a target controlled infusion algorithm that run in real time and are capable of producing different time profiles of a target drug concentration at different effect sites, and

wherein said hierarchy of algorithms will not result in an increase in overall drug levels to said patient without an explicit request for a higher drug level by said user.

14. The method for providing drug delivery of claim 13, wherein one of said two or more patient health monitors is an automated responsiveness test monitor.

15. The method for providing drug delivery of claim 14, wherein said drug state model is a finite state algorithm.

16. The method for providing drug delivery of claim 15, wherein said drug state model includes the following states:

RAMP UP;

RAMP DOWN;

LEVEL; and

OFF.

17. The method for providing drug delivery of claim 16, wherein said drug state model further comprises the following states:

STAT UP;

STAT DOWN; and

REDUCTION.

18. The method for providing drug delivery of claim 16, wherein said RAMP UP state is the default state whenever said user enters a new target ESC which is greater than the current ESC.

19. The method for providing drug delivery of claim 16, wherein said RAMP DOWN state is the default state whenever said user enters a new target ESC which is less than the current ESC.

20. The method for providing drug delivery of claim 13, wherein said interface algorithm employs a pre-programmed infusion rate template.

21. The system for providing drug delivery of claim 13, wherein said drug is at least one of a sedative, amnestic and analgesic drug.

22. The method for providing drug delivery of claim 13, wherein monitoring sites for said patient health monitors include at least one of said patient'"'"'s blood plasma, brain, central nervous system, neuromuscular junction, alveolar space, kidney, liver, pancreas, hypothalamus, heart tissue and baroreceptors.

23. The method for providing drug delivery of claim 13, wherein said flow control algorithm manages said delivery controller so that the drug is accurately delivered at a requested infusion rate.

24. The method of claim 13, wherein said signal reflecting at least one health condition of the patient is an EEG signal to assess the patient'"'"'s consciousness.

25. A system for providing computer-assisted drug delivery, wherein said system comprises:

a user interface for accepting input from a user;

a drug delivery device that delivers an amount of drug to a patient, wherein said drug is at least one of a sedative, amnestic and analgesic drug;

two or more patient health monitors adapted so as to be coupled to a patient and generate a signal reflecting at least one health condition of the patient, wherein one of said two or more patient health monitors is an automated responsiveness test; and

a processor that integrates the user interface, drug delivery device, and patient health monitors according to a hierarchy of software algorithms defining different drug states that account for the event of drug level adjustments by the user such that the amount of drug delivered to the patient by the delivery device is modulated based on an initial input from the user and based on a signal generated by the patient health monitors without further user input, if the automated action will maintain or decrease a drug level, and automatically altering said drug states to incorporate said drug level adjustments by the user;

wherein said system determines a drug level limit based on automated responsiveness test data received during a gradual drug increase initiated by the user, and wherein said drug level limit does not exceed the initial user input level, and wherein said automated responsiveness test query cycle frequency is set to FAST during said gradual drug increase.

26. The system of claim 25, wherein said two or more patient health monitors further comprise at least one of a pulse oximeter and non-invasive blood pressure monitor.

27. The system of claim 26, wherein said two or more patient health monitors further comprise at least one of a capnometer and ECG.

28. The system of claim 25, wherein a warning alarm indicates one or more failed response to said automated responsiveness test during a linear drug increase initiated by the user.

29. The system of claim 28, wherein said automated responsiveness test query cycle frequency is set to FAST during said linear drug increase.

30. The system of claim 25, wherein said system decreases a drug infusion rate upon receiving one or more failed responses to said automated responsiveness test.

31. The system of claim 30, wherein system maintains said drug infusion rate upon receiving one or more successful responses to said automated responsiveness test during said decrease of drug infusion rate.

32. The system of claim 25, wherein said system will prevent initiation of drug delivery if said signal reflecting at least one health condition of the patient is below acceptable values.

33. The system of claim 25, wherein at least one of said two or more patient health monitors is an electroencephalogram (EEG) used to assess the patient'"'"'s consciousness.