Medical FAQ & Glossary

Medical FAQ Medical Safety Glossary

Medical FAQ

What is IEC 60601-1 and why does every medical-power design start with it?

IEC 60601-1 is the global baseline for basic safety and essential performance of medical electrical equipment. Conformance is required for FDA clearance, CE marking in the EU, and most other international markets.

Key takeaway:

Choosing a power supply with an IEC 60601-1 CB certificate reduces your system-level test burden significantly.

What do MOP, MOOP, and MOPP mean?

  • Means of Protection (MOP): Safeguards against electric shock.
  • MOOP: Protects operators.
  • MOPP: Protects patients and is stricter (double/reinforced insulation, ≥ 4 kVAC dielectric test, ≥ 8 mm creepage at 250 VAC).
Key takeaway:

Devices with patient contact typically require 2 × MOPP.

Which edition should I design to today?

IEC 60601-1 evolved from 2nd Ed. (1988) → 3rd Ed. (2005) → Amendment 1 (2012) → Amendment 2 (2020–2023 rollout).

Key takeaway:

Design to Edition 3.2 to avoid costly re-qualification when regional transition deadlines arrive.

What is IEC 60601-1-2 (4th Ed.) and why does EMC matter?

Edition 4 introduces stricter EMI immunity and defines three environments (professional, home, special). Since 2018 (EU) and recent FDA updates, all new devices must comply.

Key takeaway:

Medical devices must comply with this standard. All Bel medical products, since the publication of the 4th edition, are designed to meet IEC 60601-1-2 4th Ed.

How does IEC 60601-1-11 (home healthcare) affect PSU choice?

Home-use equipment must tolerate less controlled environments including wider mains fluctuations, higher ESD and surge potential, IP21 drip protection, increased shock and vibration, and more.

Key takeaway:

Use the parametric search to find suitable products designed to meet IEC 60601-1 and the additional home medical requirements.

What leakage-current limits apply?

  • BF class: ≤ 100 µA (normal) / 500 µA (single fault)
  • CF class: ≤ 10 µA / 50 µA
Key takeaway:

Bel typically designs products to exceed BF leakage requirements.

Which Bel families carry full medical approvals?

Bel has a wide range of internal and external power supplies that have been designed and approved to IEC 60601-1. This includes open-frame, enclosed, board mount, chassis mount, and external adapters.

Key takeaway:

Use Bel’s parametric search to filter by medical industry and other specific product requirements to quickly find suitable products.

How do I verify 2 × MOPP isolation on a Bel unit?

Datasheets show dielectric test voltages.

Key takeaway:

Bel typically designs to 2 × MOPP.

What does a typical IEC 60601 approval path look like?

A 15-step flow covers risk files, pre-compliance, CB testing, country deviations, and regulatory submission.

Key takeaway:

Using pre-certified PSUs can cut months off approval timelines.

Who can certify my product?

Nationally Recognized Testing Labs (NRTLs), such as UL Solutions, Intertek, and Compliance Testing LLC.

Key takeaway:

Work with an NRTL early to avoid surprises.

Any special PSU concerns for telehealth / remote monitoring?

Yes—these require hospital-grade safety plus home EMC performance.

Key takeaway:

Home EMC performance is required to meet CISPR 11 Class B.

What documentation does Bel deliver for submissions?

  • CB report
  • UL/CSA card
  • EU Declaration of Conformity
  • ISO 13485 / ISO 9001 certs
  • RoHS/REACH
  • 3D STEP files
Key takeaway:

Bel provides ready-to-file documentation.

Can Bel customize voltages, connectors, or mechanics?

Yes—Bel’s engineering team can tailor harnesses, coatings, and mechanics; often without invalidating safety files.

Key takeaway:

Customization is possible without starting from scratch.

Where do I get samples, MTBF data, or thermal models?

Request a sample or additional information from the Technical Support tab on any product webpage.

Key takeaway:

Resources are available early in design.

If my device uses multiple PSUs, how is leakage current budgeted?

IEC 60601 requires leakage to be added arithmetically.

Key takeaway:

PSU leakage requirements depend on the system as a whole; other devices may need to be factored in when determining the allowable leakage from a power supply.

What IP rating is mandatory for external adapters in home healthcare?

At least IP21 (finger-safe, vertical drip-proof). Must appear on the label.

Key takeaway:

IEC 60601-1-11 mandates IP21 minimum.

How does ISO 14971 risk management tie into PSU compliance?

Every PSU failure mode must be documented and mitigated per ISO 14971.

Key takeaway:

Risk management is reviewed before type testing.

What changed for power supplies in Edition 3.2 (2020)?

Updates include creepage for coated PCBs, functional earth labeling, and DC-output test voltages.

Key takeaway:

Design to Ed. 3.2 to future-proof.

Home-use gear sees brown-outs—what must a PSU survive?

PSUs must handle mains dips of -15% for non-life-supporting applications and –20% for life-supporting applications.

Key takeaway:

For universal inputs (100-240 VAC nominal) this equates to 85 VAC and 80 VAC.

Do BF/CF devices need defibrillator-surge immunity?

Yes—must survive a 5 kV, 360 J pulse without unsafe leakage.

Key takeaway:

Applied parts must pass Figure 24 test.

Can I power a medical device with a USB-C PD adapter?

Yes—if it’s certified for IEC 60601, up to 100 W.

Key takeaway:

Verify 2 × MOPP, leakage, and connector retention.

When should EMC planning start?

At the architecture stage. Early planning avoids late-stage fixes that break creepage or thermal rules.

Key takeaway:

Plan EMC early—don’t bolt it on.

Medical Safety Glossary (IEC 60601 & Related Standards)

Applied Part (AP)

Any conductive or non-conductive part of medical equipment that, in normal use, touches the patient. IEC 60601 classifies APs to set leakage-current and insulation requirements.

Key takeaway:

Classification determines how strict leakage and insulation barriers must be.

Basic Safety

Freedom from unacceptable risk due to hazards (electrical, mechanical, thermal, fire, radiation) under normal and single-fault conditions. Defined in IEC 60601-1, separate from essential performance.

Key takeaway:

Baseline safety requirement before considering performance.

BF Applied Part

“Body-Floating” part in contact with the patient’s skin (e.g., ECG electrodes). Must be isolated from earth ground and meet leakage limits ≤ 100 µA (normal), 500 µA (single fault).

Key takeaway:

Stricter leakage limits than operator-only equipment.

CB Scheme (IECEE)

Global IEC program allowing one CB Test Certificate/Report to be accepted for national marks worldwide—reduces duplicate testing.

Key takeaway:

Speeds approval of IEC 60601-compliant devices.

CF Applied Part

“Cardiac-Floating” part that can contact the heart or blood. Requires the lowest patient-leakage levels: ≤ 10 µA (normal), 50 µA (single fault).

Key takeaway:

Highest isolation requirements in IEC 60601.

Clearance

Shortest air gap between conductive parts. For 2 × MOPP at 250 VAC: ≥ 5 mm (less for MOOP).

Key takeaway:

Clearance prevents breakdown through air.

Creepage

Shortest path along an insulating surface between conductive parts. For 2 × MOPP at 250 VAC: ≥ 8 mm.

Key takeaway:

Creepage prevents tracking along insulation surfaces.

EMC (Electromagnetic Compatibility)

Ability of equipment to function without causing or being disturbed by electromagnetic emissions. IEC 60601-1-2 (4th Ed.) increases immunity and defines professional, home, and special environments.

Key takeaway:

EMC compliance is mandatory for medical approval.

Essential Performance

Performance necessary to avoid unacceptable risk; loss would compromise safety (e.g., infusion rate accuracy). Separate from basic safety.

Key takeaway:

If it fails, the patient may be harmed.

IEC 60601-1 (General Standard)

Cornerstone standard for basic safety and essential performance of medical electrical equipment. Current baseline: 3rd Ed. + A1 (2012); A2 (2020) rolling out regionally.

Key takeaway:

All medical PSUs must align to IEC 60601-1.

IEC 60601-1-2 (EMC Collateral)

Defines emission and immunity requirements. The 4th Ed. (2014/2020) is mandatory for new FDA and EU approvals.

Key takeaway:

4th Ed. EMC is now the global norm.

IEC 60601-1-11 (Home Healthcare Collateral)

Adds safety/EMC rules for non-clinical environments: mains brown-outs, higher ESD, ingress protection, rugged housing.

Key takeaway:

Required for devices used outside hospitals.

ISO 13485

QMS standard specific to medical devices; required by many regulators and notified bodies.

Key takeaway:

Certification is mandatory for most medical manufacturers.

ISO 9001

Generic QMS standard for all industries. Supports continual improvement and complements ISO 13485.

Key takeaway:

ISO 9001 underpins Bel’s broader quality framework.

Leakage Current

Unintended current through protective earth, enclosure, or patient. IEC 60601 caps:

  • BF: ≤ 100 µA (normal)
  • CF: ≤ 10 µA (normal)
Key takeaway:

Multiple PSUs add leakage arithmetically, requiring margin.

Means of Protection (MOP)

Insulation, spacing, or isolation that guards against electric shock. IEC 60601 defines:

  • MOOP: Operator protection
  • MOPP: Patient protection
Key takeaway:

Patient protection (MOPP) is stricter.

MOOP (Means of Operator Protection)

Protection for trained users. Requirements are similar to IT equipment under IEC 60950.

Key takeaway:

Less stringent than MOPP.

MOPP (Means of Patient Protection)

Highest protection level. Requires double/reinforced insulation, 4 kVAC dielectric strength, 8 mm creepage at 250 VAC.

Key takeaway:

Always required for patient-applied parts.

NRTL (Nationally Recognized Testing Laboratory)

U.S. OSHA-recognized lab (e.g., UL, Intertek) authorized to certify to standards like IEC 60601.

Key takeaway:

Necessary for U.S. market access.

Patient Environment / Vicinity

1.5 m radius around a patient within which medical equipment may contact them. Equipment in this zone must meet IEC 60601 leakage/insulation limits.

Key takeaway:

Defines stricter design requirements.

2 × MOPP

Two independent means of patient protection—typically reinforced insulation, 4 kVAC isolation, 8 mm creepage.

Key takeaway:

Represents the highest electrical safety level in IEC 60601.

Related Product FAQs

Railway FAQ & Glossary

Product FAQ

Railway FAQ & Glossary

Read Product FAQ
Power FAQ

Product FAQ

Power FAQ

Find answers to power supply questions, including testing and measurement, safety standards, and efficiency regulations.

Read Product FAQ
Back To Resource Library