System and method for guidance of anesthesia, analgesia and amnesia

• US 20060241562A1
• Filed: 06/20/2006
• Published: 10/26/2006
• Est. Priority Date: 10/23/2002
• Status: Active Grant

• Current Assignee: New York University
• Original Assignee: New York University
• Inventors: John, Erwin R., Prichep, Leslie S.
• Granted Patent: US 7,711,417 B2
• Time in Patent Office: Days
• US Class Current: 604/503
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/02028 Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction
• 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 5/08 Detecting, measuring or recording devices for evaluating the respiratory organs A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/374 Detecting the frequency distribution of signals, e.g. detecting delta, theta, alpha, beta or gamma waves
• CPC Class Codes: A61B 5/38 Acoustic or auditory stimuli
• 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: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61B 5/7405 using sound
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 5/7455 characterised by tactile indication, e.g. vibration or electrical stimulation
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: A61M 16/01 specially adapted for anaesthetising A61M16/104, A61M16/18 take precedence
• CPC Class Codes: A61M 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 16/0683 Holding devices therefor
• CPC Class Codes: A61M 16/12 by mixing different gases
• CPC Class Codes: A61M 16/18 : Vaporising devices for anaesthetic preparations
• CPC Class Codes: A61M 16/201 : Controlled valves
• CPC Class Codes: A61M 2016/0661 : with customised shape
• CPC Class Codes: A61M 2202/048 : Anaesthetics see also A61M19/00
• CPC Class Codes: A61M 2210/0618 : Nose
• CPC Class Codes: A61M 2230/10 : Electroencephalographic signals
• CPC Class Codes: A61M 5/00 : Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests vaccination appliances for veterinary use A61D1/025 ; tube connectors, tube couplings, valves or branch units specially adapted for medical use A61M39/00; containers specially adapted for medical or pharmaceutical purposes A61J1/00; combinations of vial and syringe for mixing or transferring their contents A61J1/20; holders for containers for collecting, storing or administering blood or medical fluids A61J1/16
• 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 5/1723 : using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00

Abstract

Described is a system and method which includes the following steps. A plurality of interventional agents are administered to a patient until the patient attains a predetermined plane of anesthesia. Brain waves of the patient are amplified and digitized before and after the administering step to generate a first set of digital data. The brain waves of the patient are amplified and digitized during a medical procedure to generate a second set of digital data. Separate trajectories for at least two different indices of an anesthetic state of the patient are computed during the medical procedure as a function of a comparison of the first and second sets of digital data. The indices include a Depth Index (DI), a Memory Index (MI) and a Pain Index (PI). The DI corresponds to a depth of anesthesia of the patient, the PI corresponds to a sensitivity of the patient to pain and the MI corresponds to an ability of the patient to form and store memories.

Claims

1. A method, comprising the steps of:

administering a plurality of interventional agents to a patient until the patient attains a predetermined plane of anesthesia;

amplifying and digitizing brain waves of the patient before and after the administering step to generate a first set of digital data;

amplifying and digitizing brain waves of the patient during a medical procedure to generate a second set of digital data; and

computing separate trajectories for at least two different indices of an anesthetic state of the patient during the medical procedure as a function of a comparison of the first and second sets of digital data, the indices including a Depth Index (DI), a Memory Index (MI) and a Pain Index (PI), wherein the DI corresponds to a depth of anesthesia of the patient, the PI corresponds to a sensitivity of the patient to pain and the MI corresponds to an ability of the patient to form and store memories.

2. The method as in claim 1, further comprising the step of:

controlling delivery of an amount of at least one of the interventional agents as a function of the trajectories, wherein the interventional agents include at least one of anesthetic, analgesic and amnesic agents.

3. The method as in claim 1, further comprising the step of:

providing a control signal when any of the trajectories indicates that the patient is deviating from the selected plane of anesthesia.

4. The method as in claim 3, further comprising the step of:

automatically, in response to the control signal, adjusting the amount of the at least one of the interventional agents administered to the patient, wherein the interventional agents include at least one of anesthetic, analgesic and amnesic agents.

5. The method as in claim 2, wherein each of the interventional agents is directed toward regulating a corresponding one of the DI, the MI and the PI.

6. The method as in claim 5, further comprising the step of:

computing an adaptive transfer function for each of the indices, wherein each transfer function reflects an effect on each selected trajectory of at least one of an addition and a reduction of the delivery of the interventional agent directed primarily toward regulating the index corresponding to the selected trajectory.

7. The method as in claim 1, further comprising the step of:

displaying each of the trajectories.

8. The method as in claim 1, further comprising the step of:

analyzing the first and second sets of digital data in at least one of a time domain and a frequency domain.

9. The method as in claim 8, wherein the frequency domain is analyzed using at least one of a Fast Fourier Transform (FFT), an Inverse Fast Fourier Transform (IFF) and a time-frequency wavelet transform.

10. The method as in claim 1, further comprising the step of:

stimulating the patient to obtain evoked responses both before and during the medical procedure, the stimulations including at least one of an auditory stimulus and a somatosensory stimulus.

11. The method as in claim 1, wherein the first set is a sample of at least 2.5 seconds of artifact free data.

12. The method as in claim 1, further comprising the step of:

comparing the second set to data derived from a control group of patients who have undergone one of the same and a substantially similar medical procedure and used the same interventional agents.

13. The method as in claim 5, wherein the amnesic agent relating to the MI is midazolam, the analgesic agent relating to the PI is remifentanyl and the anesthetic agent relating to the DI is propofol.

14. A system, comprising:

a delivery arrangement administering a plurality of interventional agents to a patient; and

a microprocessor analyzing digital brain wave data corresponding to brain waves of the patient, the microprocessor computing separate trajectories for at least two different indices of an anesthetic state of the patient as a function of the analysis of the digital brain wave data, the indices including a Depth Index (DI), a Memory Index (MI) and a Pain Index (PI), the DI corresponding to a depth of anesthesia of the patient, the PI corresponding to a sensitivity of the patient to pain and the MI corresponding to an ability of the patient to form and store memories,

wherein the microprocessor controls an amount of at least one of the interventional agents as a function of the trajectories.

15. The system as in claim 14, further comprising:

a plurality of electroencephalogram (EEG) electrodes coupled to a scalp of the patient and producing electrical signals corresponding to brain waves of the patient.

16. The system as in claim 15, further comprising:

amplifiers amplifying the electrical signals.

17. The system as in claim 16, further comprising:

an analog-to-digital multiplexer converting the amplified electrical signals into digital signals.

18. The system as in claim 17, further comprising:

a digital signal processor executing a signal processing algorithm on the digital signals to generate the digital brain wave data.

19. A device, comprising:

a communication arrangement coupled to a delivery arrangement administering a plurality of interventional agents to a patient; and

a microprocessor analyzing digital brain wave data corresponding to brain waves of the patient, the microprocessor computing separate trajectories for at least two different indices of an anesthetic state of the patient during the medical procedure as a function of the analysis of the digital brain wave data, the indices including a Depth Index (DI), a Memory Index (MI) and a Pain Index (PI), the DI corresponding to a depth of anesthesia of the patient, the PI corresponding to a sensitivity of the patient to pain and the MI corresponding to an ability of the patient to form and store memories,

wherein the microprocessor generates a control signal as a function of the trajectories, the control signal being transmitted to the delivery arrangement via the communication arrangement to control an amount of at least one of the interventional agents delivered to the patient.

20. A method, comprising the steps of:

amplifying and digitizing brain waves of a patient to generate a first set of digital data, the patient receiving a plurality of interventional agents; and

computing separate trajectories for at least two different indices of an anesthetic state of the patient as a function of a comparison of the first set of digital data to a second set of digital data, the second set of digital data including predetermined reference values for each of the at least two different indices, the indices including a Depth Index (DI), a Memory Index (MI) and a Pain Index (PI), wherein the DI corresponds to a depth of anesthesia of the patient, the PI corresponds to a sensitivity of the patient to pain and the MI corresponds to an ability of the patient to form and store memories.

21. The method as in claim 20, further comprising the step of:

providing a control signal when any of the trajectories indicates that the patient is deviating from the predetermined reference values.

22. The method as in claim 21, further comprising the step of:

transmitting the control signal to a computing device monitoring the trajectories.

23. The method as in claim 20, wherein the interventional agents correcting digression from the predetermined reference value for a corresponding one of the indices, the administration of each of the interventional agents being controlled based on the trajectory corresponding to the index.

24. The method as in claim 23, wherein the trajectories are computed for each of the DI, the MI and the PI.

25. The method as in claim 24, further comprising the step of:

computing an adaptive transfer function for each of the indices, each transfer function reflecting effects on each selected trajectory of at least one of addition and reduction of the delivery of the corresponding interventional agent.

26. The method as in claim 20, further comprising the step of:

displaying each of the trajectories.

27. The method as in claim 20, further comprising the step of:

analyzing the first set of digital data in at least one of a time domain and a frequency domain.

28. The method as in claim 27, wherein the frequency domain is analyzed using at least one of a Fast Fourier Transform (FFT), an Inverse Fast Fourier Transform (IFFT) and a time-frequency wavelet transform.

29. The method as in claim 27, further comprising the step of:

stimulating the patient to obtain evoked responses, the stimulations including at least one of an auditory stimulus and a somatosensory stimulus.

30. The method as in claim 20, further comprising the step of:

computing the indices as a function of the first set and second sets of digital data, the predetermined reference values being at least one of (i) data representing a self-norm of the patient and (ii) data representing a population norm for patients who have utilized the same interventional agents.