Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
In addition to editorial changes, the following main technical changes have been made with respect to YY 0592-2005:
This standard replaces YY 0592-2005 High intensity focused ultrasound (HIFU) treatment system.
——Some terms and definitions repeated in other reference standards are deleted (3.2, 3.3, 3.4, 3.5, 3.6, 3.7 of Edition 2005);
——Requirements of longitudinal positioning accuracy are added (see 5.5.2);
——Relevant requirements of electromagnetic compatibility are added (see 5.11);
——Annex A of Edition 2005 is deleted.
This standard was proposed by the China Food and Drug Administration.
This standard is under the jurisdiction of Subcommittee of Medical Ultrasonic Equipment of the National Technical Committee on Medical Electrical Equipment of Standardization Administration of China (SAC/TC 10/SC 2).
This standard was issued in December, 2005 for the first time.
High intensity focused ultrasound therapy system
1 Scope
This standard specifies terms and definitions, classification, requirements, test methods, inspection rules as well as marking, packaging, transportation and storage of high intensity focused ultrasound therapy system.
It is applicable to extracorporeal focused high intensity focused ultrasound therapy system (hereinafter referred to as HIFU therapy system) which is used for extracorporeal high intensity focused ultrasound ablation therapy.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 191 Packaging - Pictorial marking for handling of goods
GB/T 3947-1996 Acoustical terminology
GB 9706.1-2007 Medical electrical equipment - Part 1: General requirements for safety
GB/T 14710 The environmental requirement and test methods for medical electrical equipment
GB/T 19890-2005 Acoustics - High intensity focused ultrasound (HIFU) - Measurements of acoustic power and field characteristics
YY/T 0162.1-2009 Medical ultrasound equipment class series - Part 1: B mode ultrasound diagnostic equipment
YY 0505 Medical electrical equipment - Part 1-2: General requirements for safety - Collateral standards: Electromagnetic compatibility - Requirements and tests
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 3947-1996 and GB/T 19890-2005 as well as the followings apply.
3.1
high intensity focused ultrasound therapy system
a therapy system, in which the ultrasound sent out by the focused ultrasound sound source composed of single-element or multi-element transducer array penetrates through patient's body surface at the sound intensity acceptable for human's normal structure after passing through acoustic transmission medium and gathers energy on target tissue to cause its coagulative necrosis (or instant inactivation)
3.2
acoustic pressure focal region
space enclosed by interface that includes acoustic pressure focal point and the acoustic pressure 6dB less than acoustic pressure peak (0dB)
3.3
acoustic pressure focal area
area in acoustic pressure focal plane and around the acoustic pressure focal point, enclosed by the boundary with acoustic pressure 6dB less than acoustic pressure peak (0dB)
Unit: mm2
3.4
transverse size of focal region
distance between two intersection points where a straight line penetrates the acoustic pressure peak point and intersects with focal region interface in acoustic pressure focal plane
Unit: mm
Note: In GB/T 19890-2005, transverse size of pressure focal and longitudinal size of pressure focal are collectively referred to "-6dB focal region size (FWHM)".
3.5
longitudinal size of focal region
distance between two intersection points on beam axis intersected with focal region interface
Unit: mm
3.6
major lobe (main lobe)
wave lobe that includes maximum pulse-pressure-squared integral in acoustic pressure distribution on acoustic pressure focal plane
3.7
side lobe
all wave lobes except major lobe (main lobe) in acoustic pressure distribution on acoustic pressure focal plane
3.8
secondary maximum acoustic pressure on beam axis
maximum pressure beyond acoustic pressure focal region on beam axis
Unit: Pa
3.9
localization device
medical imaging equipment and relevant device used for determining spatial position of target tissue and monitoring during therapy
3.10
target location
preset position of target tissue provided by the manufacturer to operator by certain positioning sign
3.11
positioning device
device that superposes the target tissue and target location by adjusting patient position or position of ultrasonic source or ultrasonic beam
3.12
treatment head
component composed of transducer and relevant parts that act ultrasound on partial areas of patients
4 Classification
4.1 Product classification
4.1.1 According to ultrasound output waveform: continuous wave, pulse modulated wave and impulse wave.
4.1.2 According to focused transducer structure: single-element focus and multi-element focus.
4.2 Product composition
HIFU therapy system is generally composed of the following devices (or parts):
a) treatment head and acoustic coupling device;
b) ultrasound power generator;
c) localization device;
d) positioning device;
e) control device;
f) patient carrying device;
g) water treatment and water temperature control device;
h) software.
5 Requirements
5.1 Acoustic field characteristic
5.1.1 Acoustic pressure focal area (transverse size of focal region)
It shall not be greater than the nominal value published by the manufacturer. The acoustic pressure focal area is obtained according to the following method:
Select the direction including maximum transverse size of focal region as x-axis and select its perpendicular direction as y-axis, then express the area by the equation of multiplying the transverse size of focal regions of x-axis and y-axis.
5.1.2 Longitudinal size of focal region
It shall not be greater than nominal value published by the manufacturer.
5.1.3 Maximum side lobe level
The amplitude of side lobe on acoustic pressure focal plane shall be at least 8dB less than that of the major lobe (main lobe).
5.1.4 Secondary maximum level on beam axis
The secondary maximum acoustic pressure on beam axis shall be at least 8dB less than acoustic pressure of focal point.
5.1.5 Maximum acoustic intensity of focal region
The spatial-peak temporal-average intensity (Ispta) shall not be less than 1 000W/cm2. The manufacturer shall publish the maximum acoustic intensity of focal region and deviation under the condition of maximum output acoustic power.
Note: If limited by testing conditions (particularly ultrasonic output equipment of continuous wave), spatial temporal-average intensity (ISAL) within -6dB acoustic beam area may be adopted to replace spatial-peak temporal-average intensity.
5.2 Acoustic-working frequency deviation
The manufacturer shall publish the nominal value of the acoustic-working frequency of the transducer. Maximum acoustic-working frequency deviation shall not exceed ±15% of nominal value.
5.3 Ultrasonic power and control
5.3.1 The manufacturer shall publish the maximum output acoustic power and deviation.
5.3.2 HIFU therapy system must have ultrasonic output energy control function to make acoustic intensity or acoustic power within focal region drop to 20% or less of the maximum value.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Classification
5 Requirements
6 Test methods
7 Inspection rules
8 Marking, packaging, transportation and storage
