Electrocardiograph device having additional lead function and method for obtaining additional-lead electrocardiogram

Abstract

There are provided an electrocardiograph with an extended lead function and an extended lead ECG deriving method capable of easily deriving an ECG signal of an extended lead ECG by an arithmetic operation, based on ECG signals of a standard 12-lead ECG measured by a potential detector 10 . An ECG memory 12 stores the ECG signals measured as the standard 12-lead ECG by the potential detector 10 . An extended lead ECG calculator 16 calculates extended lead ECGs V 7 -V 9 from the ECG signals stored in the ECG memory 12 , using coefficients α representing a relationship among leads. The extended lead ECGs V 7 -V 9 calculated are displayed through an extended lead ECG waveform outputting device 18 on a display monitor 20.

1 . An electrocardiograph with an extended lead function comprising: 
 a potential detector for measuring at least certain lead potentials out of lead potentials of a 12-lead electrocardiogram (ECG); and    extended lead potential calculating means for calculating an extended lead potential, based on the lead potentials of the 12-lead ECG measured by the potential detector.    
   
   
       2 . The electrocardiograph with the extended lead function according to  claim 1 , wherein the extended lead potential calculating means uses a relationship among the lead potentials, a heart vector, and lead vectors to determine the heart vector on the basis of the lead potentials measured by the potential detector, and calculates the extended lead potential by use of the heart vector thus determined.  
   
   
       3 . The electrocardiograph with the extended lead function according to  claim 1 , wherein the extended lead potential calculating means calculates the extended lead potential on the basis of the lead potentials measured by the potential detector, using transfer coefficients α representing a relationship among leads.  
   
   
       4 . The electrocardiograph with the extended lead function according to  claim 3 , wherein the transfer coefficients α are defined by the following equation:  
     
       
         
           
             
               
                 V 
                 i 
               
               = 
               
                 
                   ∑ 
                   j 
                 
                 ⁢ 
                 
                   
                     α 
                     
                       i 
                       , 
                       j 
                     
                   
                   ⁢ 
                   
                     V 
                     j 
                   
                 
               
             
             , 
           
         
       
       where i is a lead number of an extended lead and j a lead number of one of 12 leads.  
     
   
   
       5 . The electrocardiograph with the extended lead function according to any one of  claims 1  to  4 , wherein the potential detector measures at least two lead potentials out of limb leads and measures at least two lead potentials out of chest leads.  
   
   
       6 . The electrocardiograph with the extended lead function according to any one of  claims 1  to  4 , wherein the extended lead potential comprises at least one lead out of Leads V 7 -V 9  and Leads V 3R , V 4R , V 5R , and V 6R .  
   
   
       7 . An extended lead ECG deriving method comprising: 
 a first step of measuring at least certain lead potentials out of lead potentials of a 12-lead ECG; and    a second step of calculating an extended lead potential, based on the lead potentials of the 12-lead ECG measured.    
   
   
       8 . The extended lead ECG deriving method according to  claim 7 , wherein the second step comprises using a relationship among the lead potentials, a heart vector, and lead vectors to determine the heart vector on the basis of the lead potentials measured, and calculating the extended lead potential by use of the heart vector thus determined.  
   
   
       9 . The extended lead ECG deriving method according to  claim 7 , wherein the second step comprises calculating the extended lead potential on the basis of the lead potentials measured, using transfer coefficients α representing a relationship among leads.  
   
   
       10 . The extended lead ECG deriving method according to  claim 9 , wherein the transfer coefficients α are defined by the following equation:  
     
       
         
           
             
               
                 V 
                 i 
               
               = 
               
                 
                   ∑ 
                   j 
                 
                 ⁢ 
                 
                   
                     α 
                     
                       i 
                       , 
                       j 
                     
                   
                   ⁢ 
                   
                     V 
                     j 
                   
                 
               
             
             , 
           
         
       
       where i is a lead number of an extended lead and j a lead number of one of 12 leads.  
     
   
   
       11 . The extended lead ECG deriving method according to any one of  claims 7  to  10 , wherein the first step comprises measuring at least two lead potentials out of limb leads and at least two lead potentials out of chest leads.  
   
   
       12 . The extended lead ECG deriving method according to any one of  claims 7  to  10 , wherein the extended lead potential comprises at least one lead out of Leads V 7 -V 9  and Leads V 3R , V 4R , V 5R , and V 6R .  
   
   
       13 . A method of deriving an extended lead ECG, comprising performing an arithmetic operation to calculate a lead potential at an extended lead location except for a standard 12-lead ECG, based on ECG signals measured as standard lead potentials of the standard 12-lead ECG by a potential detector comprised of ten or less electrodes.  
   
   
       14 . A method of deriving an extended lead ECG, comprising, based on ECG signals measured as standard lead potentials of a standard 12-lead ECG by a potential detector comprised of ten or less electrodes, using a relationship among potentials [V], lead vectors [L], and a heart vector [H] to determine the heart vector [H] on the basis of the ECG signals as the standard lead potentials of the standard 12-lead ECG measured, and performing an arithmetic operation to calculate an extended lead potential of the extended lead ECG, using the heart vector [H] thus determined.  
   
   
       15 . A method of deriving an extended lead ECG, comprising storing ECG signals measured as standard lead potentials of a standard 12-lead ECG by a potential detector comprised of ten or less electrodes, performing an arithmetic operation to set transfer coefficients α for calculation of an extended lead potential on the basis of the standard lead potentials of the standard 12-lead ECG and extended lead potentials of the extended lead ECG measured in advance, and performing an arithmetic operation to calculate the extended lead potential of the extended lead ECG from the ECG signals measured as the standard lead potentials of the standard 12-lead ECG, using the transfer coefficients α set by the arithmetic operation.  
   
   
       16 . A method of deriving an extended lead ECG, comprising storing ECG signals measured as a standard 12-lead ECG by a potential detector, performing an arithmetic operation to set parameters for calculation of an extended lead ECG on the basis of lead potentials of the standard 12-lead ECG and lead potentials of the extended lead ECG measured in advance, and performing an arithmetic operation to calculate a lead potential of the extended lead ECG from the ECG signals measured as the standard 12-lead ECG, using the parameters set by the arithmetic operation.  
   
   
       17 . The method according to any one of  claims 13  to  16 , wherein the potential of the extended lead comprises at least one lead out of Leads V 7 -V 9  and Leads V 3R , V 4R , V 5R , and V 6R .  
   
   
       18 . An electrocardiograph with an extended lead function comprising: 
 electrodes to be mounted on a body surface of a living body in order to obtain lead waveforms of a standard 12-ECG;    a potential detector for measuring ECG signals of the standard 12-lead ECG from the respective electrodes;    an ECG signal memory for storing each of the ECG signals of the standard 12-lead ECG measured by the potential detector;    standard 12-lead ECG waveform means for performing waveform processing of the standard 12-lead ECG with input of the ECG signals obtained via the ECG signal memory;    extended lead ECG signal calculating means for calculating an ECG signal of an extended lead ECG on the basis of calculation parameters α preliminarily set by an arithmetic operation with input of the ECG signals obtained via the ECG signal memory;    extended lead ECG waveform outputting means for performing waveform processing of the extended lead ECG with input of the ECG signal calculated by the extended lead ECG signal calculating means; and    a display monitor for simultaneously displaying on a screen, the ECG waveform outputs from the standard 12-lead ECG waveform outputting means and from the extended lead ECG waveform outputting means.    
   
   
       19 . The electrocardiograph with the extended lead function according to  claim 18 , wherein the signal potential of the extended lead ECG comprises at least one lead out of Leads V 7 -V 9  and Leads V 3R , V 4R , V 5R , and V 6R .  
   
   
       20 . The electrocardiograph with the extended lead function according to  claim 5 , wherein the extended lead potential comprises at least one lead out of Leads V 7 -V 9  and Leads V 3R , V 4R , V 5R , and V 6R .  
   
   
       21 . The extended lead ECG deriving method according to  claim 11 , wherein the extended lead potential comprises at least one lead out of Leads V 7 -V 9  and Leads V 3R , V 4R , V 5R , and V 6R .