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Class III — Specially Controlled Medical Devices (High Risk)

Class III devices are categorised as "Specially Controlled Medical Devices" (高度管理医療機器) under the PMD Act — the same statutory category as Class IV. The distinction between Class III and Class IV is set by the Cabinet Order.

Characteristics​

Class III devices typically:

  • Contact internal body tissues or fluids for more than a transient period
  • Are implantable for periods of up to 30 days, or contact the central nervous system or cardiovascular system transiently
  • If defective, pose a serious risk to patient safety but are not in the absolute highest risk category
  • Include many life-sustaining and life-supporting devices

Examples of Class III devices​

Bone implant screws and plates, pacemaker leads, dialysis machines, mechanical ventilators (non-life-critical), certain diagnostic catheters, cochlear implant processors (external).

Regulatory pathway — Shonin (primarily)​

Most Class III devices must use the Shonin (approval) pathway via PMDA/MHLW. A subset of Class III devices that fall within MHLW-designated recognised standards may use Ninsho, but this is less common than for Class II.

The Shonin process for Class III devices typically requires:

  • Full technical documentation
  • Clinical evidence (which may include accepted foreign data)
  • QMS inspection of manufacturing sites
  • PMDA consultation is recommended for complex Class III devices

Re-examination period​

Class III devices approved via Shonin are subject to a re-examination period (usually 3 years but can be longer) during which the MAH collects and reports post-market use-results data to MHLW.