Method and apparatus for non-invasively measuring blood flow and for acquiring and processing an ECG signal

• US 7,467,005 B2
• Filed: 11/10/2003
• Issued: 12/16/2008
• Est. Priority Date: 11/11/2002
• Status: Expired due to Fees

• Current Assignee: Schiller AG
• Original Assignee: Schiller AG
• Inventors: Schmid, Johann-Jakob, Felblinger, Jacques, Abächerli, Roger
• Primary Examiner(s): Manuel; George
• Application Number:
  US10/703,524
• Publication Number:
  US 20040097818A1
• Time in Patent Office: 1,863 Days
• Field of Search: 600509-527, 600/41, 600/504, 600/407, 600/419, 600/505, 600/420, 359/566
• US Class Current: 600/419
• CPC Class Codes: A61B 5/0265 using electromagnetic means, e.g. electromagnetic flowmeter

Abstract

The flow of blood in a vessel (G) in a living being (P) which is exposed to a magnetic field (B) is determined by measuring the potential difference (ΔV) between at least two points (P1, P2) next to the vessel (G). The potential difference (ΔV) is produced on the basis of the Hall effect by the moving charge carriers (Q) in the blood in the presence of the magnetic field (B). When recording an ECG, the cardiac output can be determined in this manner under the influence of a magnetic field (B). At the same time, the ECG signal can be corrected in the knowledge of the component (T) of the ECG signal (E) which can be attributed to the Hall effect.

Claims

1. A non-invasive method for acquiring and processing an electro-physiological ECG signal from a patient who is exposed to an extraneous magnetic field which produces interference in said ECG signal, said method comprising steps of:

recording a signal by measuring potential differences between at least two points on a person'"'"'s body surface near a blood vessel, the signal being an ECG signal overlaid with a magnetic interference component,

determining a portion of said ECG signal curve in which the signal is overlaid with a signal component produced on the basis of the Hall effect on charge carriers in the blood flowing in the vessel, and subsequently

processing the signal curve and eliminating the component of the signal which is brought about by the Hall effect in said portion of the signal curve.

2. A method according to claim 1, comprising a further step of determining the cardiac output on the basis of the determined signal curve profile in said portion of the signal curve.

3. An apparatus for acquiring and processing an electro-physiological signal, said apparatus comprising

an ECG arrangement having at least two electrodes for measuring a potential difference between at least two points on a surface of the body near a blood vessel and for producing a potential signal, the signal being an electro-physiological ECG signal overlaid with interference signals due to the magnetic field, and

means for ascertaining a component of the potential signal curve which is produced on the basis of the Hall effect by the movement of charge carriers in the vessel.

4. An apparatus according to claim 3, further comprising means for automatically determining the flow of blood on the basis of the determined component of the potential signal curve.

5. An apparatus according to claim 3, further comprising means for suppressing the component of the potential signal curve.

6. A non-invasive method for operating an electro-physiological instrument and for evaluating an electro-physiological signal acquired from a body exposed to a magnetic field by measuring potential differences between at least two points on a body surface near a blood vessel, the potential being overlaid with interference signals due to the magnetic field, said method comprising steps of

determining a component of the signal curve which is caused by the Hall effect on charge carriers in blood flowing in the blood vessel and subsequently

deriving from the component of the signal curve which is caused by the Hall effect a value which is characteristic of the flow of blood in a vessel.