PRIORITY STATEMENT

The present application hereby claims priority under 35 U.S.C. § 119 to European patent application number EP18172315.6 filed May 15, 2018, the entire contents of which are hereby incorporated herein by reference.

FIELD

Embodiments of the invention generally relate to a fault detection device; and/or to a method for the detection of signal path defects in a voltage measuring system, preferably a differential voltage measuring system, having a signal measuring circuit for measuring bioelectric signals with a number of useful signal paths. Embodiments of the invention also generally relate, moreover, to a voltage measuring system having a fault detection device of this kind.

BACKGROUND

Voltage measuring systems, in particular differential voltage measuring systems, for measuring bioelectric signals are used for example in medicine for measuring electrocardiograms (ECG), electroencephalograms (EEG) or electromyograms (EMG). With such applications, preferably a high input impedance of at least several MOhm should be observed on any measuring channel in order to reduce, or at least not to amplify, the effect of interference. The high, sought input impedance should also be maintained in the cables of the above-mentioned devices for measuring bioelectric signals. Conventionally, the measuring leads of cables are surrounded by a shield. To obtain better handleability the cables are also flexible, narrow and light. These features lead, however, to a conflict between the life and the handleability of the cables and increase the risk of a cable defect.

The causes of defective cables are for example broken leads or often kinks. Kinks can occur after a torsion or bending of the long cables if the measuring leads bulge and do not return to their original form. The bulging measuring leads can then break through the lead insulation and contact the shield, and this can lead to a reduced input impedance in the cables and therewith to an intensification of interference. The problem here is that, without a special test environment such interference may not always be clearly attributed to a reduced input impedance in the cables. In addition kinks and other input impedance-reducing cable defects often occur as loose connections, and this similarly makes fault detection difficult. There is therefore the risk that a defective cable will unintentionally be worked with until the signal quality is no longer sufficient to be able to carry out bioelectric measurements and examinations.

A common solution for avoiding or detecting interference by way of a reduced input impedance in the cables is to replace the cables at regular intervals or at least have them examined by service personnel. On checking of the cables by service personnel, a reference signal generated by a simulator is emitted to the cable to be examined. The cable is then moved and an output signal is measured. This output signal is compared with the reference signal and checked as to whether there are differences between the two signals and therefore interference. The interference with which a cable break is assumed is based on expert opinion, however. This checking is relatively laborious, moreover.

In U.S. Pat. No. 5,766,133 voltage measurements are made on cables of an ECG measuring system in order to detect a cable break.

SUMMARY

Embodiments of the present invention provide a device and/or a method to detect signal path defects, in particular cable defects, in a voltage measuring system.

Embodiments of the present invention are directed to a fault detection device, a voltage measuring system and by a method.

An embodiment of the present invention is directed to a fault detection device for the detection of signal path defects in a voltage measuring system including a signal measuring circuit for measuring bioelectric signals with a number of useful signal paths, the fault detection device comprising:at least one electricity generating unit, to impress a signal on a first useful signal path;at least one first comparison unit, to determine if the signal of the first useful signal path lies within a measuring range;at least one first interference signal path, designed as a current measurement path, for current-detecting measurement of a first interference signal; anda signal path defect analysis unit, to detect a signal path defect in a useful signal path of the voltage measuring system upon the impressed signal not being measured on the at least one first interference signal path and upon the checked signal of the comparison unit being determined to lie within the measuring range.

An embodiment of the present invention is directed to a voltage measuring system, comprising:at least one signal measuring circuit, including a number of useful signal paths for measuring bioelectric signals; andthe fault detection device of an embodiment.

An embodiment of the present invention is directed to a method for the detection of signal path defects in a voltage measuring system for measuring bioelectric signals, the bioelectric signals being measured via a signal measuring circuit including a number of useful signal paths, the method comprising:impressing at least one first signal on at least one first useful signal path, of the number of useful signal paths, via at least one first electricity generating unit;determining, via at least one first comparison unit, whether the signal of the at least one first useful signal path lies within a measuring range;current-detecting measurement of at least one first interference signal on at least one first interference signal path designed as a current measuring path; andperforming an analysis, via a signal path defect analysis unit, to detect a signal path defect in a useful signal path of the number of useful signal paths of the voltage measuring system, upon the impressed signal not being measured on the at least one first interference signal path and upon the signal being determined, via the comparison unit, to lie within the measuring range.

A large proportion of the above-mentioned components of the voltage measuring device, in particular the signal path defect analysis unit, can be wholly or partially implemented in the form of software modules in a processor of a corresponding voltage measuring system. An implementation largely in terms of software has the advantage that even previously used voltage measuring systems can be easily retrofitted by way of a software update in order to operate inventively. In this regard the object is also achieved by a corresponding computer program product having a computer program, which can be loaded directly into a storage device of a voltage measuring system, having program segments in order to carry out all steps of at least one embodiment of the inventive method when the program is run in the voltage measuring system.

In addition to the computer program, at least one embodiment is directed to a computer program product of this kind can optionally comprise additional components, such as, for example documentation and/or additional components also hardware components, such as, for example hardware keys (dongles, etc.) in order to utilize the software.

A computer-readable medium, for example a memory stick, a hard disk or another portable or permanently fitted data carrier, on which the program segments of the computer program, which can be read-in and executed by an arithmetic unit of the voltage measuring system are stored, can be used in at least one embodiment for transportation to the voltage measuring system and/or for storage on or in the voltage measuring system. The arithmetic unit can have one or more cooperating microprocessor(s) or the like for this purpose.

