Radiation Source Coordinate SystemYaw Angle Attribute
| Tag | (3010,0094) |
|---|---|
| Type | Conditionally Required (1C) |
| Keyword | RadiationSourceCoordinateSystemYawAngle |
| Value Multiplicity | 1 |
| Value Representation | Double (FD) |
Rotation angle in degrees of the Radiation Source Coordinate System about the z-axis of the Equipment Coordinate System, see Section C.36.12.2.2.
Required if RT Record Flag (300A,0639) is NO and the conditions in Section C.36.2.2.5.1.1 are satisfied.
May be present if RT Record Flag (300A,0639) is YES and the conditions in Section C.36.2.2.5.1.1 are satisfied.
Section C.36.12.2.2
C.36.12.2.2 Standard Robotic-Arm Coordinate System Frame of Reference
The Well-known Value of 1.2.840.10008.1.4.3.2 for Equipment Frame of Reference UID (300A,0675) identifies the Standard Robotic-Arm Coordinate System Frame of Reference to which each device is calibrated during installation.
This coordinate system definition requires that two X-Ray detectors are present at the same height and the X-ray beams intersect.
The right-handed coordinate system axes are oriented as follows, when viewed from the patient support device pedestal towards the delivery device:
-
the x-axis is increasing to the right, parallel to the line between the centers of the X-ray detectors and perpendicular to gravity
-
the z-axis is increasing away from the direction of gravity
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the y-axis is the cross-product of the z- and x-axis
The origin of the coordinate system is the intersection of the central beams from each X-ray source, where the central beam is the line from the X-ray source to the center of the corresponding detector. The coordinate system definition is independent of the location of the delivery device and the patient support system.
Movements of the robot head are described in the Standard Robotic-Arm Coordinate System. The rotation of the robot head is expressed by a rotation of the Radiation Source Coordinate System with respect to the Standard Robotic-Arm Coordinate System. The origin of the Radiation Source Coordinate System is defined at the RT Device Distance Reference Location. The axes of the Radiation Source Coordinate System coincide with the Standard Robotic-Arm Coordinate System under the following conditions:
-
the source position equals 0,0,0, and
-
the pitch, roll, and yaw angles equal zero.
The Radiation Source Coordinate System is the parent system of the Base Beam Modifier Coordinate System. The Base Beam Modifier Coordinate System is negatively offset along the z-axis of the Radiation Source coordinate system by the RT Beam Modifier Definition Distance (300A,0688).
Figure C.36.12.2-1. Standard Robotic-Arm Coordinate System
Section C.36.2.2.5.1.1
C.36.2.2.5.1.1 Requirements for Changing Values within RT Control Point Sequence Attributes
This Section specifies when individual Attributes shall be present in a Sequence.
The RT Control Point Sequence specifies a certain order of execution.
At each RT Control Point the value of various Attributes may be specified as an explicit value (which in the case of a type 2C Attribute may be a null value) and if absent remain at the same value as specified previously. There are physical and mechanical implications of specifying a new value as opposed to staying at the same value, for example gear lash, floating point jitter, etc.
At the first Sequence Item in RT Control Point Sequences (i.e., with an RT Control Point Index (300A,0600) equal to 1) all Attributes affected by this Section shall be present if applicable conditions are met.
For Sequence Items other than the first Sequence Item, Attributes shall be present if applicable conditions are met and the value is different from the previously populated value for the same Attribute (in the case of a type 2C Attribute, a null value is considered as a value). The previously populated value is the value from the Item where the Attribute was present with the greatest value of RT Control Point Index (300A,0600) less than the value of the RT Control Point Index (300A,0600) in the current Item.
This means that for an Item in which an Attribute is absent, the application stays at the value of the previously populated Item.
For Sequences inside a RT Control Point Sequence Item, the Sequence shall be present if any of the nested Attributes affected by this Section differ from the corresponding previously populated Item.
For multi-valued Attributes, such as Parallel RT Beam Delimiter Positions (300A,064A), all values shall be present if any value changes.
Section C.36.2.2.5.1.1
C.36.2.2.5.1.1 Requirements for Changing Values within RT Control Point Sequence Attributes
This Section specifies when individual Attributes shall be present in a Sequence.
The RT Control Point Sequence specifies a certain order of execution.
At each RT Control Point the value of various Attributes may be specified as an explicit value (which in the case of a type 2C Attribute may be a null value) and if absent remain at the same value as specified previously. There are physical and mechanical implications of specifying a new value as opposed to staying at the same value, for example gear lash, floating point jitter, etc.
At the first Sequence Item in RT Control Point Sequences (i.e., with an RT Control Point Index (300A,0600) equal to 1) all Attributes affected by this Section shall be present if applicable conditions are met.
For Sequence Items other than the first Sequence Item, Attributes shall be present if applicable conditions are met and the value is different from the previously populated value for the same Attribute (in the case of a type 2C Attribute, a null value is considered as a value). The previously populated value is the value from the Item where the Attribute was present with the greatest value of RT Control Point Index (300A,0600) less than the value of the RT Control Point Index (300A,0600) in the current Item.
This means that for an Item in which an Attribute is absent, the application stays at the value of the previously populated Item.
For Sequences inside a RT Control Point Sequence Item, the Sequence shall be present if any of the nested Attributes affected by this Section differ from the corresponding previously populated Item.
For multi-valued Attributes, such as Parallel RT Beam Delimiter Positions (300A,064A), all values shall be present if any value changes.