Sensors and sensing for monitoring neuromuscular blockade

• US 8,506,502 B2
• Filed: 09/14/2007
• Issued: 08/13/2013
• Est. Priority Date: 09/16/2006
• Status: Active Grant

• Current Assignee: Terence Gilhuly
• Original Assignee: Terence Gilhuly
• Inventors: Gilhuly, Terence
• Primary Examiner(s): Szmal, Brian
• Assistant Examiner(s): LLOYD, EMILY M
• Application Number:
  US12/311,105
• Publication Number:
  US 20100081963A1
• Time in Patent Office: 2,160 Days
• Field of Search: 600/554, 604/31
• US Class Current: 600/554
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• 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 5/02055 Simultaneously evaluating both cardiovascular condition and temperature
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/1106 to assess neuromuscular blockade, e.g. to estimate depth of anaesthesia
• CPC Class Codes: A61B 5/4821 Determining level or depth of anaesthesia A61B5/1106 takes precedence
• CPC Class Codes: A61B 5/72 Signal processing specially adapted for physiological signals or for diagnostic purposes character recognition, recognising digital ink, document-oriented image-based pattern recognition G06V30/00; recognition or understanding of postal images G06V30/424
• 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 2005/14208 with a programmable infusion control system, characterised by the infusion program
• CPC Class Codes: G05B 17/02 electric
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: G16H 50/50 for simulation or modelling of medical disorders
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

Improved sensors and sensing methods for detection of Neuromuscular Blockade (NMB), for example to improve monitoring generally, as well as facilitate automated NMB drug administration. The methods, systems, devices, etc., herein can increase the quantity and quality of data available. The methods, etc., include translation between commonly available sensing types, use of partially saturated sensor measurements, use of a model of neurotransmitter storage and release and sophisticated use of more than one sensor simultaneously. These methods are aided by new sensors and methods of decreasing electrical noise. An implementation of the methods, systems, devices, etc., herein is automated drug delivery for NMB, whether through an advisor system or through with full computer control.

Claims

1. A system for quantifying a neuromuscular response, the system comprising:

(a) a stimulator configured to apply a first mode of stimulation to the patient, wherein the first mode of stimulation is Train Of Four (TOF);

(b) one or more sensors configured to measure the patient'"'"'s response to stimulation; and

(c) a computer configured to;

i. interpret the measured response to the first mode of stimulation as the measured response in terms of a second mode of stimulation when the measured response is not responsive to some or all of the stimulation from the first mode of stimulation, wherein the second mode of stimulation is one of Train of Three (TO3), Train of Two (TO2), and Single Twitch (ST); and

ii. translate the measured response in terms of the second mode of stimulation into an output representative with respect to the first mode of stimulation with an equation.

2. The system of claim 1, wherein the computer is further configured to interpret the measured response to the first mode of stimulation as the measured response in terms of a second mode of stimulation when the measured response is responsive to three of the stimulations from the first mode of stimulation, wherein the second mode of stimulation is Train of Three (TO3);

and the computer is further configured to translate the measured response in terms of the second mode of stimulation into an output representative with respect to the first mode of stimulation based on the equation;

TOF=0.97To3−

3.4%.

3. The system of claim 1, wherein the computer is further configured to interpret the measured response to the first mode of stimulation as the measured response in terms of a second mode of stimulation when the measured response is responsive to two of the stimulations from the first mode of stimulation, wherein the second mode of stimulation is Train of Two (TO2);

and the computer is further configured to translate the measured response in terms of the second mode of stimulation into an output representative with respect to the first mode of stimulation based on the equation;

TOF=1.07To2−

23%.

4. The system of claim 1, wherein the computer is further configured to store a baseline Single Twitch measurement (T0), the computer is further configured to interpret the measured response to the first mode of stimulation as the measured response in terms of a second mode of stimulation, wherein the second mode of stimulation is Single Twitch (ST), and wherein the measured response of ST is defined as the ratio of the first responsive twitch (T1) to T0;

and the computer is further configured to translate the measured response in terms of the second mode of stimulation into an output representative with respect to the first mode of stimulation based on the equation;

TOF=1.2*(T1/T0)−

31%.

5. The system of claim 1, wherein the computer is further configured to interpret the measured response to the first mode of stimulation as the measured response in terms of a second mode of stimulation, wherein the second mode of stimulation is Single Twitch (ST), wherein the measured response of ST is defined as the 25% when the measured response is responsive to three of the stimulations from the first mode of stimulation, wherein the measured response of ST is defined as 20% when the measured response is responsive to two of the stimulations from the first mode of stimulation, wherein the measured response of ST is defined as 10% when the measured response is responsive to one of the stimulations from the first mode of stimulation, wherein the measured response of ST is defined as 0% when there is no measured response to all of the stimulations from the first mode of stimulation, and wherein the measured response of ST is defined as the ratio (T1/T0);

and the computer is further configured to translate the measured response in terms of the second mode of stimulation into an output representative with respect to the first mode of stimulation based on the equation;

TOF=1.2*(T1/T0)−

31%.

6. The system of claim 1, wherein the computer is further configured to advise a user of the patient'"'"'s drug needs and/or the length of time until indicated response levels are reached.

7. The system of claim 1, wherein the computer is further configured to provide control for closed-loop drug administration.

8. A system for quantifying a neuromuscular response, the system comprising:

(a) a stimulator configured to apply first and second modes of stimulation to the patient, wherein the first mode of stimulation is Train Of Four (TOF) and the second mode of stimulation is Post Tetanic Count (PTC);

(b) one or more sensors configured to measure the patient'"'"'s response to stimulation; and

(c) a computer configured to;

i. direct the stimulator to apply the second mode of stimulation when the measured response is not responsive to all of the stimulation from the first mode of stimulation; and

ii. translate the measured response to the second mode of stimulation into an output representative with respect to the first mode of stimulation with an equation.

9. The system of claim 8, wherein the computer is further configured to advise a user of the patient'"'"'s drug needs and/or the length of time until indicated response levels are reached.

10. The system of claim 8, wherein the computer is further configured to provide control for closed-loop drug administration.

11. A system for quantifying a neuromuscular response, the system comprising:

(a) a stimulator configured to apply first and second modes of stimulation to the patient, wherein the first mode of stimulation is Train Of Four (TOF) and the second mode of stimulation is one of Double Burst Stimulation (DBS) or Single Twitch (ST);

(b) one or more sensors configured to measure the patient'"'"'s response to stimulation; and

(c) a computer configured to;

i. direct the stimulator to apply the first mode of stimulation;

ii. direct the stimulator to apply the second mode of stimulation; and

iii. translate the measured response to the second mode of stimulation into an output representative with respect to the first mode of stimulation with an equation.

12. The system of claim 11, wherein the computer is further configured to translate the measured response to the second mode of stimulation into an output representative with respect to the first mode of stimulation based on the equation:

TOF=(DBS+3.2%)/1.07

when the second mode of stimulation is DBS.

13. The system of claim 11, wherein the computer is further configured to store a baseline Single Twitch measurement (T0), the computer is further configured to interpret the measured response to the first mode of stimulation as the measured response in terms of a second mode of stimulation, wherein the second mode of stimulation is Single Twitch (ST), and wherein the measured response of ST is defined as the ratio of the first responsive twitch (T1) to T0;

and the computer is further configured to translate the measured response in terms of the second mode of stimulation into an output representative with respect to the first mode of stimulation based on the equation;

TOF=1.2*(T1/T0)−

31%.

14. The system of claim 11, wherein the computer is further configured to advise a user of the patient'"'"'s drug needs and/or the length of time until indicated response levels are reached.

15. The system of claim 11, wherein the computer is further configured to provide control for closed-loop drug administration.

16. A system for quantifying a neuromuscular response, the system comprising:

(a) a stimulator configured to apply first and second modes of stimulation to the patient, wherein the first mode of stimulation is Double Burst Stimulation (DBS) and the second mode of stimulation is Train Of Four (TOF);

(b) one or more sensors configured to measure the patient'"'"'s response to stimulation; and

(c) a computer configured to;

i. direct the stimulator to apply the first mode of stimulation;

ii. direct the stimulator to apply the second mode of stimulation; and

iii. translate the measured response to the second mode of stimulation into an output representative with respect to the first mode of stimulation with an equation.

17. The system of claim 16, wherein the computer is further configured to translate the measured response to the second mode of stimulation into an output representative with respect to the first mode of stimulation based on the equation:

DBS=1.07TOF−

3.2%.

18. The system of claim 16, wherein the computer is further configured to advise a user of the patient'"'"'s drug needs and/or the length of time until indicated response levels are reached.

19. The system of claim 16, wherein the computer is further configured to provide control for closed-loop drug administration.

20. A system for quantifying a neuromuscular response, the system comprising:

(a) a stimulator configured to apply first and second modes of stimulation to the patient, wherein the first mode of stimulation is Single Twitch (ST) and the second mode of stimulation is Train Of Four (TOF);

(b) one or more sensors configured to measure the patient'"'"'s response to stimulation; and

(c) a computer configured to;

i. direct the stimulator to apply the first mode of stimulation;

ii. direct the stimulator to apply the second mode of stimulation; and

iii. translate the measured response to the second mode of stimulation into an output representative with respect to the first mode of stimulation with an equation.

21. The system of claim 20, wherein the computer is further configured to store a baseline Single Twitch measurement (T0) and wherein the measured response of ST is defined as the ratio of the first responsive twitch (T1) to T0;

and the computer is further configured to translate the measured response in terms of the second mode of stimulation into an output representative with respect to the first mode of stimulation based on the equation;

(T1/T0)=TOF/1.2+31%.

22. The system of claim 20, wherein the computer is further configured to advise a user of the patient'"'"'s drug needs and/or the length of time until indicated response levels are reached.

23. The system of claim 20, wherein the computer is further configured to provide control for closed-loop drug administration.

24. A method for controlling the administration of a neuromuscular blockade based on a patient'"'"'s neuromuscular response, the method comprising:

(a) applying a first mode of stimulation to the patient, wherein the first mode of stimulation is Train Of Four (TOF);

(b) measuring the response produced by the first mode of stimulation;

(c) interpreting the measured response to the first mode of stimulation as the measured response in terms of a second mode of stimulation when the measured response is not responsive to some of the stimulation from the first mode of stimulation, wherein the second mode of stimulation is one of Train of Three (TO3), Train of Two (TO2), and Single Twitch (ST);

(d) translating the measured response in terms of the second mode of stimulation into an output representative with respect to the first mode of stimulation with an equation; and

(e) controlling the administration of the neuromuscular blockade via computer based on the measured response when the patient is responsive to all of the stimulation from the first mode of stimulation, and controlling the administration of the neuromuscular blockade based on the output representative with respect to the first mode of stimulation when the patient is not responsive to some or all of the stimulation from the first mode of stimulation.