Target participant that is substantially present in the act and which is directly involved in the action (includes consumed material, devices, etc.).

The target of an Observation action. Links an observation to a Role whose player is the substance or most specific component entity (material, micro-organism, etc.) being measured within the subject.

Examples: A "plasma porcelain substance concentration" has analyte a Role with player substance Entity "porcelain".

UsageNotes: The Role that this participation connects to may be any Role whose player is that substance measured. Very often, the scoper may indicate the system in which the component is being measured. E.g., for "plasma porcelain" the scoper could be "Plasma".

In an obstetric service, the baby.

The catalyst of a chemical reaction, such as an enzyme or a platinum surface. In biochemical reactions, connects the enzyme with the molecular interaction

Participant material that is taken up, diminished, altered, or disappears in the act.

Something incorporated in the subject of a therapy service to achieve a physiologic effect (e.g., heal, relieve, provoke a condition, etc.) on the subject. In an administration service the therapeutic agent is a consumable, in a preparation or dispense service, it is a product. Thus, consumable or product must be specified in accordance with the kind of service.

Participant used in performing the act without being substantially affected by the act (i.e. durable or inert with respect to that particular service).

Examples: monitoring equipment, tools, but also access/drainage lines, prostheses, pace maker, etc.

A device that changes ownership due to the service, e.g., a pacemaker, a prosthesis, an insulin injection equipment (pen), etc. Such material may need to be restocked after he service.

A device that does not change ownership due to the service, i.e., a surgical instrument or tool or an endoscope. The distinction between reuseable and non-reuseable must be made in order to know whether material must be re-stocked.

In some organ transplantation services and rarely in transfusion services a donor will be a target participant in the service. However, in most cases transplantation is decomposed in three services: explantation, transport, and implantation. The identity of the donor (recipient) is often irrelevant for the explantation (implantation) service.

Description: The entity playing the associated role is the physical (including energy), chemical or biological substance that is participating in the exposure. For example in communicable diseases, the associated playing entity is the disease causing pathogen.

**Description:**Direct participation in an exposure act where it is unknown that the participant is the source or subject of the exposure. If the participant is known to be the contact of an exposure then the SBJ participation type should be used. If the participant is known to be the source then the EXSRC participation type should be used.

Description: The entity playing the associated role is the target (contact) of exposure.

**Description:**The entity playing the associated role is the source of exposure.

Participant material that is brought forth (produced) in the act (e.g., specimen in a specimen collection, access or drainage in a placement service, medication package in a dispense service). It does not matter whether the material produced had existence prior to the service, or whether it is created in the service (e.g., in supply services the product is taken from a stock).

The principle target on which the action happens.

Examples: The patient in physical examination, a specimen in a lab observation. May also be a patient's family member (teaching) or a device or room (cleaning, disinfecting, housekeeping).

UsageNotes: Not all direct targets are subjects. Consumables and devices used as tools for an act are not subjects. However, a device may be a subject of a maintenance action.

The subject of non-clinical (e.g. laboratory) observation services is a specimen.