Biocompatibility evaluation for Hardware/Interface Components?

[Freddo]

Hi All,

Let's say we have a heart-lung machine that is used with a disposable part. Only the disposable part has contact to the patient. The heart-lung machine has interfaces that the user needs to touch in order to operate the machine during the procedure.

No, obviously, in the scope of ISO10993-1:2018 it says that this standard applies to medical devices that have direct or indirect contact to the patient. So the heart-lung machine would not be in scope. Furthermore it says that if the medical devcie is used for protection (e.g. gloves, masks etc) also the contact with the user's body needs to be evaluated. Again, our machine is not in scope.

Figure 1 also clearly states that ISO 10993-1 does not apply if there is np patient contact.

However: In section 5.2.2 there is a note that says:

"Some medical devices used in either sterile or non-sterile environments include components that can come into contact with a user’s ungloved hands such as human interfaces for electronic equipment (e.g. computer keyboards, dials or buttons, touch screens, SD cards, USB sticks); housings for electronic monitors or programmers that can come into contact with any intact skin (e.g. electronic devices like cell phones, tablets); or components that can come into contact with a user’s gloved hand (e.g. catheter handles).If these types of components can be shown to be made from materials in common use for other consumer products with a similar nature of contact, no further biological evaluation is needed."

How am i to understand this section? Isn't that contradictory to what the scope and figure 1 says? Do I now have to prepare a document for our heart-lung machine? If so, I am guessing it is not a full biocompatibility evaluation, but rather a list of materials used with the concluding statment that these are all "materials in common use for consumer products"? But how do i prove that?

Anybody asked themselves this question before?

Thanks a lot

Freddo

 

[planB]

Freddo,

unfortunately, ISO 10993-1:2018 (Part 1: Evaluation and testing within a risk management process) is not entirely consistent in defining body contact throughout the standard. You are safe if you consider both patient and any (professional) user contact in your biological evaluation report (BER).

Regarding section 5.2.2, I would recommend to directly address your NB and explore their expectations: I have seen reviewers of the very same NB having different expectations, ranging from a simple statement in the BER without further substantiation, to actually listing consumer product examples for each used (base) material.

HTH,

 

[Freddo]

Thanks for your comment.
Unfortunately (or, maybe, fortunately) its not something that comes from our NB but rather from my collegues from the hardware department that insist they need it, and my interpretation of the standard always was that we do not need it (and the NB never requested it). Then they pointed me to section 5.2.2 and i was out of arguments.... Let's hope this gets clarified in the next update of ISO 10993-1.

Regards

Freddo

 

[ThatSinc]

a list of materials used with the concluding statment that these are all "materials in common use for consumer products"? But how do i prove that?

Anybody asked themselves this question before?

Thanks a lot

Freddo

I've recently documented a 10993-1 biocompatibility report that had the same situation - no parts of the product came into contact with the patient by design, or in any reasonably foreseeable situation.

But it has a touch screen (corning gorilla glass), control knobs and handles that are made of ABS.

Literally it was a decision tree that showed the standard was considered, but determined as not applicable based on no patient contact, but as it is user contact, a reference to the technical drawings of the contact parts confirming the materials, and then a list of consumer products made from ABS that are held for the same amount of time or longer than the handles on the product.
It's likely that the interface is of common materials that are used on every day products - the same glass touchscreen used on a mobile phone etc.

 

[Tidge]

Do I now have to prepare a document for our heart-lung machine? If so, I am guessing it is not a full biocompatibility evaluation, but rather a list of materials used with the concluding statment that these are all "materials in common use for consumer products"? But how do i prove that?

Anybody asked themselves this question before?

I have some experience with medical devices used in a surgical theater, but are not 'patient contact'. These devices have risk files which include lines of analysis for biological hazards (typically to users) and the most common P1 (probability of the hazardous situation occurring) is some biological agent present on the device introduced from elsewhere. The risk control is implemented by surgical staff (cleaning) at our direction/reminder (IFU). We maintain an awareness of the products used by hospital staff to clean equipment, and so we choose (i.e. specify) materials which tolerate the cleaning agents and design (again, specify) elements of the device to allow for cleaning (i.e. no areas which trap biohazards). We further disclose (IFU) which cleaning materials/processes have been tested by us to be appropriate.

I should disclosure this: The risk management process I use leverages a checklist as a sort of pre-cursor to the use scenarios that includes high-level design theory of the device. The checklist allows for the possibility that our devices would be subject to 10993 (from concept) but it has not been the case that we've had to ever explicitly make statements about 10993 compliance.

It should be noted: there are some medical devices used in surgical suites that were once not considered as a contributing factor in transmission of biological hazards have been implicated as contributing to such hazards: Heater-coolers and NTM infections is one such device.

 

[Kuldeep Singh]

During an audit, we have debate on applicability of biocompatibility of parts which comes in contact with user. We give the reference of ISO 10993-1:2018 , scope of this standard only talks about patient , although this standard applicable on parts contact with user if the device is intended for protection such as surgical mask etc.

But Auditor didn't convince and give the reference of EU MDD 93/42/EEC , ER 7.1
7.1. The devices must be designed and manufactured in such a way as to guarantee the characteristics and performances referred to in Section I on the ‘General requirements’.
Particular attention must be paid to:
— the choice of materials used, particularly as regards toxicity and, where appropriate, flammability,
— the compatibility between the materials used and biological tissues, cells and body fluids, taking account of the intended purpose of the device,
— where appropriate, the results of biophysical or modelling research whose validity has been demonstrated beforehand.

Can anyone discuss this, is this bold line indicates that we should consider the biocompatibility for parts which comes in contact with user???

IMO , ER 7.1 didin't require biocompatibility for user contactable part. please guide if i am wrong.

your help will be appreciated.

 

[planB]

Kuldeep Singh,

as pointed out above, ISO 10993-1:2018 is not entirely consistent in defining body contact throughout the standard. Yes, you should consider any body contact, be it patient or any (professional) user contact, according to your intended use.

Hope this helps,

 

[Tidge]

But Auditor didn't convince and give the reference of EU MDD 93/42/EEC , ER 7.1
7.1. The devices must be designed and manufactured in such a way as to guarantee the characteristics and performances referred to in Section I on the ‘General requirements’.
Particular attention must be paid to:
— the choice of materials used, particularly as regards toxicity and, where appropriate, flammability,
— the compatibility between the materials used and biological tissues, cells and body fluids, taking account of the intended purpose of the device,
— where appropriate, the results of biophysical or modelling research whose validity has been demonstrated beforehand.

Can anyone discuss this, is this bold line indicates that we should consider the biocompatibility for parts which comes in contact with user???

My advice is to update your risk management files to include lines of analysis which specifically consider biocompatibility for the users. Implementing materials 'generally considered safe for use' or 'state of the art' for pieces that the user physically touches (with or without PPE) should be enough to reach an acceptable level of risk, unless the auditor has specific knowledge about a particular risk or is playing some sort of "what if" game.

The next level of effort would again involve the risk files: A manufacturer of ME devices does have to balance risks. The biological hazards with the greatest user risks for an HLM interface are from contamination and not from exposure to materials. The risks of contamination is mitigated by choosing materials which resist the commonly used cleaning materials in the environment. Don't waste your time with ISO 10993 assessments of user materials unless (a) you are making some radical choice in materials or (b) the knowledge of 'the state of the art' material changes (possibly due to regulation)'. Your risk files can make all of this clear.

 

[Kuldeep Singh]

Thank You Tidge

Material used in our devices is plastic , ABS, which generally comes in contact with user. There is no user claim for biological effect for last 15 years . As per my opinion , material used in devices in safe enough. Is there any literature or any trustworthy document which can prove that these material are safe, biocompatible and commonly used material and no biological testing is required.

 

[monoj mon]

Is there any literature or any trustworthy document which can prove that these material are safe, biocompatible

See here for a more specific document. Also see here for many more like that.