Five Tests for Medical Lasers

Medical laser marking must pass biocompatibility tests to ensure the safety of the materials.The five tests are cytotoxicity, skin irritation, sensitization, systemic toxicity, and blood compatibility. The guide helps companies to efficiently complete the certification process and comply with the standards of the medical device industry.

Why is biocompatibility testing so important?

Whether surgical instruments or implanted medical devices, if they are to be laser marked, the materials must be safe.After all, these devices may be in contact with human tissue or even blood for long periods of time. If the materials release harmful substances, the consequences are not to be taken lightly.So biocompatibility tests are like a physical, to make sure that a material will not have a negative effect on the human body.

Five essential biocompatibility tests.

Cell toxicity testing.

In other words, they look to see if the material will "poison" the cells.The lab uses liquid extracts of the material to culture cells, and then observes the survival rate of the cells.If the cells die in mass, it indicates that the material may have released harmful components, and the formula has to be adjusted.

Skin irritation test.

The standards primarily apply to devices which come into contact with the skin, such as external monitoring devices.During testing, the materials are attached to animals or artificial skin and then examined to see if they cause inflammation or other adverse reactions.This step is able to discover potential allergic risks in advance.

Allergic reaction tests.

Some materials may not cause a problem with a single exposure, but repeated exposure may trigger an allergy.The test involves multiple exposures to the allergen, and observation of any abnormal reactions from the immune system, such as rashes or inflammation.

A whole-body toxicity test.

These are designed specifically for devices that might enter the bloodstream or the internal environment of the body, such as heart stents.The second stage of testing is in animals, to determine if the material will cause fever or damage to organs.

Blood compatibility test.

The key is how well the material interacts with the blood.For example, would they cause blood clots, hemolysis (the breaking of red blood cells) or change the composition of the blood.This is especially critical for intravenous and dialysis equipment.

Three things to consider before taking the test.

Selecting the Right Test

Don't just focus on ISO 10993. Different countries may have additional requirements.For example, the FDA stresses clinical data, while the MDR focuses more on long-term risks.

They are also able to screen for materials in advance.

The company uses spectral analysis and chemical tests to check for heavy metals and residual solvents, saving a lot of time and money.

Leave enough time for budgeting.

The testing period generally takes 4-8 weeks, and if a second test is required, it's even more troublesome.It is recommended that planning be done at least six months in advance, so that testing does not slow the introduction of a product to market.

What happens if a student fails?

Don't panic. Most of the problems are due to the formulation of the raw materials or to the manufacturing process.For example, if the temperature is too high during laser marking, the material could decompose, or the cleaning agent could leave a residue.At this point we need to work closely with the testing organization to analyze the data and adjust the parameters, and then send samples back for retesting.As long as the basic materials are chosen correctly, there is usually a solution.