getYkgwHdrChanne
This function retrieves information about channel.
channel_info
= getYkgwHdrChannel(
filepath
);
Arguments:
filepath
string [in] File path
Return values:
channel_info
structure [out] The structure of channel information.
.channel_count
double The number of whole channels.
.channel
structure array The detail information of channels. ('index 1' corresponds to 'channel 0')
.type
double Channel type as follow table:
NullChannel = 0;
MagnetoMeter = 1;
AxialGradioMeter = 2;
PlanarGradioMeter = 3;
Axial2ndOrderGradioMeter = 4;
ReferenceMagnetoMeter = 257;
ReferenceAxialGradioMeter = 258;
ReferencePlanarGradioMeter = 259;
ReferenceAxial2ndOrderGradioMeter = 260;
TriggerChannel = -1;
EegChannel = -2;
EcgChannel = -3;
EtcChannel = -4;
.data
structure The geometrical information of a channel.
These fields is based on MEG device coordinate system.
These fields of each channel type are as follows:
See Figure.1 and Figure.2.
If channel type is AxialGradioMeter or ReferenceAxialGradioMeter (see Figure.3),
.x
double x coordinate of inner coil position [meter]
.y
double y coordinate of inner coil position [meter]
.z
double z coordinate of inner coil position [meter]
.zdir
double Sensor orientation from z-axis [degree]
.xdir
double Sensor orientation from x-axis [degree]
.baseline
double Baseline length [meter]
.size
double Inner coil size [meter]
.name
string Abbreviation name
If channel type is PlanarGradioMeter or ReferencePlanarGradioMeter (see Figure 4),
.x
double x coordinate of inner coil position [meter]
.y
double y coordinate of inner coil position [meter]
.z
double z coordinate of inner coil position [meter]
.zdir1
double Sensor orientation from z-axis [degree]
.xdir1
double Sensor orientation from x-axis [degree]
.zdir2
double Baseline orientation from z-axis [degree]
.xdir2
double Baseline orientation from x-axis [degree]
.baseline
double Baseline length [meter]
.size
double Inner coil size [meter]
If channel type is MagnetoMeter or ReferenceMagnetoMeter,
.x
double x coordinate of coil position [meter]
.y
double y coordinate of coil position [meter]
.z
double z coordinate of coil position [meter]
.zdir
double Sensor orientation from z-axis [degree]
.xdir
double Sensor orientation from x-axis [degree]
.size
double Inner coil size [meter]
.name
string Abbreviation name
If channel type is Axial2ndOrderGradioMeter or ReferenceAxial2ndOrderGradioMeter (see Figure.5),
.x
double x coordinate of inner coil position [meter]
.y
double y coordinate of inner coil position [meter]
.z
double z coordinate of inner coil position [meter]
.zdir
double Sensor orientation from z-axis [degree]
.xdir
double Sensor orientation from x-axis [degree]
.baseline1
double Baseline1 length [meter]
.baseline2
double Baseline2 length [meter]
.size
double Inner coil size [meter]
.name
string Abbreviation name
If channel type is EegChannel or EcgChannel,
.type
double Type (0: Analog input, 1: Nihon-Kohden EEG)
.id
double ID
.name
string Abbreviation name
.gain double Gain (This field exists if type=0)
If channel type is TriggerChannel or EtcChannel,
.type
double Type
.id
double ID
.name
string Abbreviation name
If channel type is NullChannel, there is no field.
Orientation vector
xdir
zdir
x = sin(zdir)cos(xdir)
y = sin(zdir)sin(xdir)
z = cos(zdir)
x
y
z
Figure.1 Orientation vector
Inner coil size
Baseline
Sensor
orientation
(zdir, xdir)
Inner coil position
Inner(Pickup) coil
Outer(Reference) coil
Figure.3 AxialGradioMeter parameter
Baseline
Figure.4 PlanarGradioMeter parameter
Inner coil
position
Inner coil size
Outer(Reference) coil
Inner (Pickup) coil
Sensor
orientation
(zdir1, xdir1)
Baseline
orientation
(zdir2, xdir2)
Figure.2 Sensor orientation in the dewar
: Sensor and its
forward orientation
Inner coil size
Baseline2
Sensor
orientation
(zdir, xdir)
Inner coil position
Inner(Pickup) coil
1st compensating coil
Figure.5 Axial2ndOrderGradioMeter parameter
Baseline1
2nd compensating coil
MEG-A20035
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