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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This standard was proposed by the National Medical Products Administration of the People’s Republic of China.
This standard is under the jurisdiction of Subcommittee on Radiation Therapy, Nuclear Medicine and Radiodosimetry Equipment of National Technical Committee on Medical Electrical Equipment of Standardization Administration of China (SAC/TC 10/SC 3).
Gating interface used in radiation therapy
1 Scope
This standard specifies the technical requirements and test methods for gating interface used in radiation therapy.
This standard is applicable to gating interface used in radiation therapy. Each manufacturer may provide other safety design and functional design schemes.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB 9706.5-2008 Medical electrical equipment — Part 2: Particular requirements for the safety of electron accelerators in the range 1 MeV to 50 MeV
GB 9706.17-2009 Medical electrical equipment — Part 2: Particular requirements for the safety of gamma beam therapy equipment
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB 9706.5-2008 and GB 9706.17-2009 and the following apply.
3.1
beam hold
condition in which a system is ready to quickly recover the beam on but has not been in the beam on state
Note 1: Beam hold is different from the interrupt irradiation (equipment is shifted into beam off).
Note 2: Beam hold, a sub-state of the irradiation state, is intended to quickly change into the expected irradiation therapy state.
Note 3: It is usually used for gating, IMRT, etc.
3.2
beam off
condition in which the radiation source(s) is fully shielded, and is also in a position in which it can be secured
[Definition 2.101, GB 9706.17-2009]
3.3
beam termination/terminate irradiation
signal to stop to start or immediately terminate irradiation from the Patient Position Monitoring System (PPMS) to the Treatment Delivery Device (TDD)
Note: TDD described in this standard mainly includes medical electron accelerator, light ion therapy system, gamma beam stereotactic radiotherapy system, Co-60 remote machine and other equipment; PPMS mainly includes optical surface, X-ray transmission, abdominal pressure, magnetic field signal, ultrasound imaging, magnetic resonance imaging and other position monitoring systems.
3.4
gating interface
gating interface is designed to enable TDD and PPMS to provide the following capabilities:
a) Perform the beam hold or beam termination/terminate irradiation based on movement of the target area in the patient body or the position of the patient without operator's intervention.
b) Turn off the beam in case of error or the patient state exceeding the deviation limit.
Note: PPMS can change the beam generation state of TDD by two control ways. Both need to be implemented by hard wire between PPMS and TDD. The first way is beam gating connection, that is, beam hold, which allows PPMS to temporarily hold the beam without causing beam off. The second is gating interlock, which allows PPMS to require beam termination (i.e. "beam turn-off" described in GB 9706.5-2008) or prohibit beam on when an error is detected.
3.5
interlock
setting preventing the start or the continued operation of equipment unless certain predetermined conditions prevail
Note: It is a signal that enables the gating equipment to stop the beam. Please note that when the interlock occurs, the operator is required to take action to confirm it, and then resume treatment after it is cleared.
[IEC/TR 60788: 2004]
3.6
interrupt irradiation
interrupt irradiation signal sent by PPMS to TDD, which requires user's intervention to restart irradiation
Note: There can only be one interface for interruption, and the TDD manufacturer should determine (and describe in random files) the impact of this interface.
3.7
fail-safe
emergency response for minimizing the harm or mechanism to prevent an unsafe state in the event of a failure
Example: Providing a redundant safety design.
4 Requirements and test methods
4.1 Electrical interface
Details of the electrical signal specification and interface protocol specification for the gating interface shall be described in the TDD and PPMS random files, where applicable, and the verification function shall be included in the interface protocol.
4.2 Conditions for normal operation of beam termination function
PPMS and TDD manufacturers shall ensure that the following functions (if provided) are normal:
a) Gating interlock works normally.
b) Dose interlock works normally.
c) Beam termination works normally in using fail-safe and redundancy.
4.3 Delay time of beam hold and switch action
The PPMS and TDD manufacturers shall have their respective system detection and action delay time provided in a random document:
a) The TDD manufacturer shall provide the delay time from the receipt of the beam hold request to the beam hold state.
b) The TDD manufacturer shall provide the delay time from the receipt of release beam hold request to the beam output state.
c) The PPMS manufacturer shall provide the delay time from the availability of the beam hold condition to the issuance of the beam hold request.
4.4 Gating time
The TDD manufacturer shall give the minimum limit of beam hold time and other limitations, and the PPMS manufacturer shall provide the corresponding configuration.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Requirements and test methods
4.1 Electrical interface
4.2 Conditions for normal operation of beam termination function
4.3 Delay time of beam hold and switch action
4.4 Gating time
4.5 Error handling and recovery
4.6 Basic operations and basic performance
Bibliography
