Method for detecting leads off in multi-electrode medical diagnostic system
First Claim
1. A method for detecting leads off in a multi-electrode medical diagnostic system, said multi-electrode medical diagnostic system comprising a carrier circuit unit connected to a plurality of active electrodes and a reference electrode connected to a patient to be detected;
- a pre-stage protecting circuit coupled to said carrier circuit unit; and
a leads-off detection unit coupled to said carrier circuit unit;
said method comprising the following steps;
(1) generating a plurality of carrier signals of lead impedances with opposite phases and impedance pneumography by said carrier circuit unit;
(2) generating a plurality of input impedance signals by said pre-stage protecting circuit to prevent the apparatus from being damaged by defibrillation;
(3) demodulating said plurality of input impedance signals into lead impedance related voltages by said leads-off detection unit;
(4) setting a threshold voltage of said medical diagnostic system;
(5) capturing physiological signals of the patient to be detected;
(6) if a current time reaches a predetermined period for checking whether a leads-off occurs, the following steps will be executed;
(6.1) determining whether the plurality of the lead impedance related voltages are higher than the maximal lead impedance related voltage multiplied by a threshold value;
(6.2) a corresponding bit of a status register is set to logic 1 if any of the plurality of lead impedance related voltages is higher than the maximal lead impedance related voltage multiplied by a threshold value.
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Abstract
The present invention relates to an apparatus and a method for detecting leads off in a multi-electrode medical diagnostic system. The multi-electrode medical diagnostic system comprises: a carrier circuit unit connected to a plurality of active electrodes and a reference electrode connected to a patient to be detected for generating a plurality of carrier signals of lead impedances and impedance pneumography; a pre-stage protecting circuit coupled to the carrier circuit unit and generating a plurality of input impedance signals to prevent the apparatus from being damaged by defibrillation; and a leads-off detection unit coupled to the carrier circuit unit for demodulating the plurality of input impedance signals into lead impedance related voltages. This present invention further comprises a central processing unit and an analog-to-digital converter for receiving the output of the leads-off detection unit, and calculating the amount and the position of the leads-off, depending on an algorithm embedded in the central processing unit.
43 Citations
3 Claims
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1. A method for detecting leads off in a multi-electrode medical diagnostic system, said multi-electrode medical diagnostic system comprising a carrier circuit unit connected to a plurality of active electrodes and a reference electrode connected to a patient to be detected;
- a pre-stage protecting circuit coupled to said carrier circuit unit; and
a leads-off detection unit coupled to said carrier circuit unit;
said method comprising the following steps;(1) generating a plurality of carrier signals of lead impedances with opposite phases and impedance pneumography by said carrier circuit unit;
(2) generating a plurality of input impedance signals by said pre-stage protecting circuit to prevent the apparatus from being damaged by defibrillation;
(3) demodulating said plurality of input impedance signals into lead impedance related voltages by said leads-off detection unit;
(4) setting a threshold voltage of said medical diagnostic system;
(5) capturing physiological signals of the patient to be detected;
(6) if a current time reaches a predetermined period for checking whether a leads-off occurs, the following steps will be executed;
(6.1) determining whether the plurality of the lead impedance related voltages are higher than the maximal lead impedance related voltage multiplied by a threshold value;
(6.2) a corresponding bit of a status register is set to logic 1 if any of the plurality of lead impedance related voltages is higher than the maximal lead impedance related voltage multiplied by a threshold value. - View Dependent Claims (2, 3)
if (time_out) { FLAG2←
FLAGFLAG←
0if (VRA>
K·
(maximum of VRA))FLAG[0]←
1if (VLL>
K·
(maximum of VLL))FLAG[L]←
1if (VLA>
K·
(maximum of VLA))FLAG[2]←
1if (VV>
K·
(maximum of VV))FLAG[3]←
1if (VRL>
K·
(maximum of VRL))FLAG[4]←
1disconnect=FLAG[0]+FLAG[1]+FLAG[2]+FLAG[3]+FLAG[4] } else exit.
- a pre-stage protecting circuit coupled to said carrier circuit unit; and
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3. The method of claim 1, further comprising a second algorithm showing the number and position of the leads-off, said second algorithm executing the following steps:
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if (FLAG{0}==1) print “
lead RA off”if (FLAG{1}==1) print “
lead LL off”if (FLAG{2}==1) print “
lead LA off”if (FLAG{3}==1) print “
lead V off”if (FLAG{4}==1) print “
lead RL off”switch (disconnect) { case ‘
0’
;
print “
the connection between leads and patient is fine”
break;
case ‘
1’
;
print “
one lead off”break;
case ‘
2’
;
print “
totally two leads off”break;
case ‘
3’
;
print “
totally three leads off”break;
default;
print “
totally more than four leads off, please check soon”
}.
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Specification
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- Resources
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Current AssigneeIndustrial Technology Research Institute
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Original AssigneeIndustrial Technology Research Institute
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InventorsYu, Ching-Liang, Cheng, Yao-Ming, Tao, Teh-Ho, Kao, Shin-Dean
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Primary Examiner(s)Schaetzle, Kennedy
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Application NumberUS09/494,020Time in Patent Office1,103 DaysField of Search600/509, 600/523, 600/547, 600/483, 600/513, 600/484, 128/902, 128/901US Class Current600/509CPC Class CodesA61B 5/0809 by impedance pneumographyA61B 5/276 Protection against electrod...A61B 5/6843 Monitoring or controlling s...
