ELECTROPHYSIOLOGICAL ANALYSIS SYSTEM

• US 20100274113A1
• Filed: 02/22/2008
• Published: 10/28/2010
• Est. Priority Date: 02/23/2007
• Status: Active Grant

• Current Assignee: Impeto Medical Incorporated
• Original Assignee: Impeto Medical Incorporated
• Inventors: Brunswick, Philippe, Bocquet, Nicolas
• Granted Patent: US 8,655,443 B2
• Time in Patent Office: Days
• US Class Current: 600/372
• 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 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1477 non-invasive
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/6825 Hand
• CPC Class Codes: A61B 5/6829 Foot or ankle
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61B 5/743 Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots

Abstract

The invention provides an electrophysiological analysis system, in particular for detecting pathological states. This system comprises: electrodes intended to be placed in different regions of the body that are well away from each other; an adjustable DC voltage source for generating successive DC voltage pulses varying in magnitude from one pulse to another, the duration of the pulses being equal to or greater than about 0.2 seconds; a switching circuit for selectively connecting a pair of active electrodes to the voltage source and for connecting at least one other high-impedance electrode; and a measurement circuit for recording data representative of the current in the active electrodes and potentials on at least certain high-impedance connected electrodes in response to the application of said pulses. The range of voltages covered causes, from one pulse to another, the appearance or disappearance of electrochemical phenomena in the vicinity of the active electrodes.

Claims

1. Electrophysiological analysis system which is intended, in particular for the detection of pathological conditions, characterised in that it includes:

a series of electrodes (E1-E6) intended to be placed at various regions of the human body distant from one another,

an adjustable DC voltage source (21) which is controlled in order to produce successive waves of a DC voltage which varies from one wave to the other, the duration of the waves being greater than or equal to approximately 0.2 second,

a switching circuit (30) designed to selectively connect a pair of so-called active electrodes to the voltage source, and to connect at least one other high-impedance electrode, and

a measuring circuit (22, 40) designed to collect data representative of the current in the active electrodes and of the potentials on at least some electrodes connected in high impedance, in response to the application of said waves,

and in that, from one wave to the other, the range of voltages covered by the waves is capable of causing the appearance or disappearance of electrochemical phenomena in the vicinity of the active electrodes.

2. System of claim 1, characterised in that it further includes a processing device (10) designed to analyse the reciprocal evolution of said current and said potentials based on the wave voltage, and to compare such evolution with at least one reference evolution.

3. System as claimed in claim 1 or 2d, characterised in that the switching circuit (30) is designed to successively connect various pairs of active electrodes to said voltage source (21).

4. System of claim 3, characterised in that, when a pair of electrodes is connected to the voltage source (21), the switching circuit (30) is designed to connect all of the other high-impedance electrodes.

5. System as claimed in one of claims 1 to 4, characterised in that the measuring circuit (22, 40) includes a resistor (Rmes) designed to be connected between one of the electrodes of an active pair and a reference voltage.

6. System of claim 5, characterised in that it likewise includes calibration circuit (40, 10) which, for a given pair of active electrodes, is designed to adjust the value of the measurement resistor so that it is of the same order of magnitude as the resistance present between the two active electrodes in the presence of a DC voltage.

7. System of claim 6, characterised in that the calibration circuit (40, 10) is designed to adjust the value of the measurement resistor (Rmes) so that it is close to the resistance of the human body.

8. System as claimed in one of claims 5 to 7, characterised in that the data representative of the current in the active electrodes is produced from the potential difference measured at the terminals of the measurement resistor (Rmes).

9. System of claim 8, characterised in that the measuring circuit (22, 40) is designed to measure the potentials on all of the electrodes.

10. System of claim 9, characterised in that it includes an offset voltage-compensating circuit (10), which is designed to correct the measured voltages by means of correction voltages obtained by individually connecting each electrode to the voltage source, delivering a constant DC voltage, whereas the other electrodes are connected in high impedance, and by measuring the potentials on said other electrodes.

11. System as claimed in one of claims 1 to 10, characterised in that the voltage waves have a voltage value of between approximately 1 and 4 volts, and a duration of between approximately 0.2 and 5 seconds.

12. System of claim 11, characterised in that it is designed to vary the voltage of the successive waves in one direction and then in the other.

13. System of claim 12, characterised in that it is designed to vary the voltage of the successive waves by a first step and then by a second step, which is smaller than the first.

14. System as claimed in one of claims 11 to 13, characterised in that the voltage of the successive waves varies by steps of between approximately 0.05 and 1 volt.

15. System as claimed in one of claims 11 to 14, characterised in that the successive waves are spaced apart by a duration of between approximately 0.5 and 5 seconds.

16. System as claimed in one of claims 1 to 15, characterised in that the switching circuit (30) is designed to connect a single pair of electrodes to the voltage source in two reversed polarities.

17. System as claimed in one of claims 1 to 16, characterised in that it includes two electrodes for left and right frontal lobes, two electrodes for left and right hands and two electrodes for left and right feet.

18. System as claimed in claims 16 and 17 taken in combination with one another, characterised in that the switching circuit (30) is designed to connect, to the voltage source (21), electrode pairs consisting of the left forehead electrode and the right forehead electrode, the right forehead electrode and the left forehead electrode, the left hand electrode and the right hand electrode, the right hand electrode and the left hand electrode, the left foot electrode and the right foot electrode and the right foot electrode and the left foot electrode.

19. System of claim 18, characterised in that, after having connected a certain pair of electrodes to the voltage source with a certain polarity, the switching circuit (30) is designed to connect this same pair of electrodes to the voltage source (21) with a reversed polarity, only after another distant pair of electrodes on the body has been connected to the voltage source.

24. Method of claim 23, wherein said measurements are supplied by a system as claimed in one of claims 1 to 19.

25. Method of claim 24, which is implemented in computer equipment remote from the system and connected thereto via a data communication channel.

20. Method for diagnosing a patient, with a view to detecting a disease, a pathological predisposition or another disorder, characterised in that it includes the following steps:

receiving a set of data comprising measurements revealing electrochemical phenomena in the vicinity of the electrodes applied to the skin of the patient at predetermined locations on the body,

accessing at least one set of stored reference data comprising measurements revealing electrochemical phenomena, which were obtained under the same conditions, on patients identified as suffering or not suffering from this disease, and

reconciling said set of data received with the sets of reference data, and, based on proximity criteria between the set of data received and the sets of reference data, identifying the patient as ill or not ill.

21. Method of claim 20, wherein the data sets further include data of a physiological and/or behavioural and or environmental nature.

22. Method of claim 20, wherein the data sets comprise measurements taken on a patient after a predetermined exertion by the patient.

23. Method as claimed in one of claims 20 to 22, wherein the measured data is obtained from current values in the active electrodes and from potential values on high-impedance electrodes, in response to the application of voltage waves between active electrodes, the level of which varies from one wave to the other, in order to cause the appearance or disappearance of electrochemical phenomena in the vicinity of the active electrodes.