Материал: part03

C.29.1.1.1 Generic Implant Template Description Attribute Descriptions​

C.29.1.1.1.1 Implant Size​

Implant Size (0068,6210) is the descriptor defined by the manufacturer to distinguish between different sizes of one kind of implant,​ e.g., size S/M/L/XL.​

C.29.1.1.1.2 Frame of Reference​

The Frame of Reference UID (0020,0052) Attribute is used as an identifier for spatial registration in 3D. The Frame Of Reference​ UID uniquely identifies the spatial Frame of Reference of all 3D models contained in an Implant Template UID Instance.​

IftheFrameOfReferenceUIDsintwoinstancesareidentical,thecontained3DModelsaredefinedinthesame3Dspace,i.e.,require​ no additional registration.​

C.29.1.2 Generic Implant Template 2D Drawings Module​

Table C.29.1.2-1 defines the general Attributes of the Generic Implant Template 2D Drawings Module. This Module contains all At-​ tributesrequiredfortheinclusionoftechnical2DdrawingsinanIOD,e.g.,theImplantTemplateIOD.TheModulespecificationcontains​ the definition of a subset of the HPGL plotter language that is used for the graphical definition of the drawings.​

Table C.29.1.2-1. Generic Implant Template 2D Drawings Module Attributes​

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C.29.1.2.1 Generic Implant Template 2D Drawings Attribute Descriptions​

C.29.1.2.1.1 HPGL Document Scaling and Coordinate System​

HPGL Documents use integer coordinates based on a 25µm grid in the printing space - i.e., the paper to print on - rather than the​ object space. HPGL Document Scaling (0068,62F2) is used to scale the printed dimensions measured in millimeters to match the​ real dimensions of the implant measured in millimeters.​

Note​

1.​For example, if HPGL Document Scaling is 2.5, then a line in HPGL that goes from (0,0) to (0,500) that is 12.5 mm long​ when printed represents 31.25 mm in the real world.​

2.​InHPGL,theoriginoftheprintingspaceisplacedinthelowerleftcornerwiththex-axispointingtotheright.Nonegative​ coordinates are allowed.​

This Attribute does not compensate for any radiographic geometric magnification effect caused by the diverging X-Ray beam in the​ projection patient images used for planning. Such compensation is the responsibility of the application based on calibration of the​ imaging process.​

C.29.1.2.1.2 HPGL Document​

The HPGL files encapsulated in the Attribute HPGL Document (0068,6300) is restricted to a subset of HPGL commands called​ DICOM-HPGL specified in this section.​

C.29.1.2.1.2.1 Scope​

The aim of DICOM-HPGL is to facilitate the storage of 2D template graphics in DICOM implant objects. DICOM-HPGL is a subset of​ HPGL-2 that is kept as minimal as possible to comply with the needs of 2D implant templates.​

C.29.1.2.1.2.2 Syntax​

DICOM-HPGL documents consist of valid HPGL commands terminated by a semicolon. Commands consist of a two-letter mnemonic​ and zero or more numeric parameters separated by commas. To separate between commands, line breaks (x0D, x0A or x0Dx0A)​ or whitespaces (x20) may be used but are not mandatory.​

Only the following commands shall be used in a DICOM-HPGL document​

Table C.29.1.2-2. Permitted HPGL Commands​

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According to the parameter definition in HPGL, [] indicate optional parameters. The expression [X,Y,…[,X,Y]] indicates a sequence​ of arbitrary length of paired parameters X and Y. The commands and their parameters shall be interpreted as specified in the HP​ PCL/PJL Reference.​

Note​

ThisdocumentcanbeobtainedfromURL:http://h20000.www2.hp.com/bc/docs/support/SupportManual/bpl13211/bpl13211.pdf​

The coordinates in a DICOM-HPGL document are absolute values with respect to the lower left corner of the drawing space. The​ units of length within HPGL are 25 µm with respect to pen movements in the drawing space.​

The DICOM-HPGL Document shall be structured as shown in Figure C.29.1.2-1.​

Figure C.29.1.2-2 shows an example for a DICOM-HPGL Document in plain text (as byte stream), and plotted.​

IN

PA

PC

SP

PU PD

Figure C.29.1.2-1. DICOM-HPGL Document​

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IN;

PA;

PC2,255,0,0;

PC255,0,255,0;

SP2;

PU500,500;

PD745,255,255,255;

PD500,500;

SP255;

PU500,600;

PD500,100;

Figure C.29.1.2-2. DICOM-HPGL Document - Example​

C.29.1.3 Generic Implant Template 3D Models Module​

Table C.29.1.3-1 defines the general Attributes of the Generic Implant Template 3D Models Module. This Module contains Attributes​ that add context and scaling information to surfaces specified in the Surface Mesh Module, for 3D Models in an Implant Template​ Instance.​

Table C.29.1.3-1. Generic Implant Template 3D Models Module Attributes​

C.29.1.3.1 Generic Implant Template 3D Models Attribute Descriptions​

C.29.1.3.1.1 Surface Model Scaling Factor​

SurfaceModelScalingFactor(0068,6390)isusedtoscaledimensionsofthesurfacemeshrepresentationtomatchtherealdimensions​ of the implant measured in millimeters.​

This Attribute does not compensate for any radiographic geometric magnification effect caused by the diverging X-Ray beam in the​ projection patient images used for planning. Such compensation is the responsibility of the application based on calibration of the​ imaging process.​

C.29.1.4 Generic Implant Template Mating Features Module​

TableC.29.1.4-1definesthegeneralAttributesoftheGenericImplantTemplateMatingFeaturesModule.ThisModuleaddscoordinate​ systemsthatcanbeutilizedtogeometricallyconstrainmatingofImplantTemplateswhenplanningtheimplantationofamodularimplant.​

Note​

An Implant Template may contain 2D drawings of the described implant, 3D surface models of the described implant, or​ both. In this Module mating features that constrain the geometric matching of implants in multi-component assemblies are​

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specified. These geometric features (points and axes) can be specified in the 2D drawings as well as the 3D models. Mating​ features are grouped into mating feature sets (see PS3.17). Based on the existence of 2D drawings and/or 3D models in​ the Instance, either or both is possible. In this Module, there are a number of conditions on Attribute use to support the fol-​ lowing cases:​

•​Specification of 2D mating features is only possible if at least one 2D drawing is present in the instance.​

•​Specification of 3D mating features is only possible if at least one 3D model is present in the instance.​

Table C.29.1.4-1. Generic Implant Template Mating Features Module Attributes​

Shall be unique within the Sequence.​

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