技術記事

  • Introduction to IEC60601-1-8 Regulations and Medical Product Applications


    The purpose of the IEC60601-1-8 standard is to define the safety and performance requirements for audible or visual alarm systems used in medical electrical equipment. This article only uses the sound alarm as the main description. This standard specifies minimum sound pressure limits and duration for sirens. It is required that the alarm volume be heard in a noisy environment, and the alarm time must be long enough to attract the attention of medical personnel to ensure that correct responses and judgments can be made promptly without causing confusion, misjudgment, or disturbing the patient. Suffer. Therefore, if the alarms in medical equipment can comply with this standard, it will be a guarantee for the medical staff and patients in the hospital.

    【 Main requirements of IEC 60601-1-8 standard 】
    The alarm's pulse frequency must be between 150Hz and 1KHz and the pulse signal must be a square wave. Suppose the alarm is a speaker (usually using a sine wave as the signal input). In that case, it must be ensured that the speaker maintains sufficient power to keep the pulse signal conditions.

    Figure 1, the pulse signal defined in IEC 60601-1-8

    In addition, the speaker's resonant frequency ( fo ) must not be higher than 400Hz to meet the frequency requirement that the pulse frequency between 300Hz and 4 KHz has at least four harmonics (that is, the highest odd number is the ninth harmonic). Since the available space of the speaker equipment will directly affect the sound pressure (in-box resonance), if relevant information such as the size of the space reserved for the speaker in the equipment can be provided, products with suitable specifications can be found more effectively.

    When choosing a speaker as a medical alarm, you should choose a model with a relatively flat frequency response curve to better meet the sound pressure levels at the four resonant frequency points required by regulations ( the sound pressure level error value is within ± 15d B ).

    Figure 2, as smooth as possible frequency response

    【 Applications】

    Table 1 The products applicable IEC60601-1-8

    The above table shows K INGSTATE's speaker products that comply with the IEC60601-1-8 standard. They are widely used in medical equipment such as medical devices, ventilators, blood pressure machines, and medical mattresses. Customers can choose the appropriate model according to the size or form of the medical product they require. K INGSTATE also provides simulation systems that match speakers and products to assist customers in design and development. 

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