Strategy to allow for OTS computer use as part of a Medical Equipment System

[mr.mike]

Hi Covers!

This thread is a followup to the thread Options for OTS Computer as part of Medical Equipment System in the 60601 series sub-forum.

Basically, we are discussing a Class I system that involves a USB-powered device, connected to an Off-the-Shelf (OTS) computer.

Here, I want to get away from the 60601 harmonized standard, and ask if there are other strategies for meeting MDD essential-requirements, that allows users the freedom to use their OWN computer (and associated power-supply adaptor, monitor, mouse, keyboard, etc.).

The strategy would hinge on risk-analysis - i.e. what is the worst-case hazards of someone using their own computer?

Seeking advice & suggestions... Some concerns that come to mind:

- Computer is supplying power to the device (via USB). Control: Device is fused?
- Software unstable on user system. Control: Clear system requirements?
- Software affects user system. Control: Use disclaimer?

Any input appreciated!

 

[yodon]

I don't know how these might affect risk but just thinking through some possible use scenarios:
* plugs into a USB hub (powered? unpowered?) that has multiple devices attached
* old computer, old USB standards (1.x -v- 2.0 -v- ...)
* old computer, old OS
* use of one of those USB cable extenders (for lack of a better term)

And you're also then relying on the users' equipment and relying on the users properly plugging it in correctly (sounds trivial but we've all heard the story about using the CD drive as a drink holder). You may need to account for a varied level of user expertise.

Your last note about using a disclaimer to control (mitigate) how the software could affect the user system would be considered pretty weak (and if you were trying to comply with the harmonized version of 14971 you couldn't reduce the risk that way).

 

[mr.mike]

Yes, this is tricky because there is really no way to control the user's computer system. Other than meeting basic system requirements from the software, there's no telling what other stuff (e.g. other software, malware...) might be on the computer.

In terms of software, however, it can be demonstrated that even under worst case (the software totally fails or becomes totally unpredictable), there are no hazards.

My main concern is more to do with power. USB is inherently low-power, and version compatibility and hubs are not a problem, but the concern is the simple fact that the device would be powered by the user's computer & power-supply. In otherwords, the system depends on a power-supply from the user and this may be defective/hazardous. Strictly speaking it would not be our device that is potentially hazardous, but rather the user's computer/power-supply...

Curious if anyone out there has a CE-marked medical device that connects to a user's computer/power-supply (& peripherals)? If so, what strategy was employed?

 

[shimonv]

mr.mike

There are two thing you should consider:
1. Does your product meet the definition of medical electrical equipment as appears in the IEC 60601-1 standard. The strict requirements of 60601-1 apply to medial electrical device in the patient environment.

3.63
* MEDICAL ELECTRICAL EQUIPMENT
ME EQUIPMENT
electrical equipment having an APPLIED PART or transferring energy to or from the PATIENT or
detecting such energy transfer to or from the PATIENT and which is:
a) provided with not more than one connection to a particular SUPPLY MAINS; and
b) intended by its MANUFACTURER to be used:
1) in the diagnosis, treatment, or monitoring of a PATIENT; or
2) for compensation or alleviation of disease, injury or disability

3.79
* PATIENT ENVIRONMENT
any volume in which intentional or unintentional contact can occur between a PATIENT and
parts of the ME EQUIPMENT or ME SYSTEM or between a PATIENT and other persons touching
parts of the ME EQUIPMENT or ME SYSTEM

2. Another option is to offer your product without the OTS computer. This way you roll over the responsibility to the customer or third part who will be suppling the computer. Since your device feeds on the USB port I presume most all computers will be fine for the job. Of course you will need to include minimum requirements in your labeling.

Shimon

 

[MIREGMGR]

This way you roll over the responsibility to the customer or third part who will be suppling the computer.

I think this may be incorrect in the presented scenario.

Per the OP's third paragraph, I gather that we are analyzing a software-plus-patient-interface device. I don't know of a specific guidance or precedent on this point within the MDD regulatory system. Under the US FDA approach as I understand it, though, if your product were software-only, it would be a device as such. If your IFU and marketing instruct the user to install it on their computer, I believe that computer becomes an accessory to your device. I don't see how the additional presence of a patient-interface hardware element provided by you will change any of that in your favor.

My understanding thereby is that you thereby take on responsibility for the performance of the user-computer accessory that you've directed be used. Basically, you have at least some measure of responsibility for whatever your IFU directs the user to do; and in this case, it will direct the use of unknown equipment for the operation of your medical device.

That would present an interesting risk analysis conundrum, since as you note you essentially have no idea of the state of that accessory, including safety and effectiveness. It seems on its face that your risk analysis would have to consider everything that could go wrong, which could be an extensive process. It also seems that anything that does go wrong will come back to you in terms of device failure responsibility because of that device-accessory relationship, and adverse event reportability if the nature of your device's intended performance is such that its failure to perform can have an adverse patient effect.

 

[shimonv]

Hi MIREGMGR,
As I wrote - "There are two thing you should consider..."

Neither of us knows what the device does and what are the potential risks. My thought was to specify minimum requirements for the OTS computer which includes compliance to 60601 if deemed necessary.
Being a class I device it?s fair to assume it?s a low risk device and so I thought this could be a valid option. Anyhow, mr.mike will need to take it from here.

Shimon

 

[mr.mike]

Does your product meet the definition of medical electrical equipment as appears in the IEC 60601-1 standard.

Yes it is a medical device for rehabilitation. Basically passively monitors movement and logs progress via software.

I gather that we are analyzing a software-plus-patient-interface device.

That is correct. The device needs a computer to both power it (via USB) and to run the software. The software alone can't do anything (it needs the device), so it is not a standalone "device".

My thought was to specify minimum requirements for the OTS computer which includes compliance to 60601 if deemed necessary.

We had considered this as well. However, because the device is intended for home-use, it seems just a source of user confusion. Even in a clinical setting, how many clinicians know what a "60601 compliant system" is?

It also seems that anything that does go wrong will come back to you in terms of device failure responsibility because of that device-accessory relationship...

Two major concerns we are considering:
1. The user's power-supply is defective and causes fire or electrocution.
2. The user's system crashes (this would likely be due to any of common reasons: hardware failures, malware/viruses...).

In either case, this would not be the fault of using our device and software, but rather issues with the user's computer system that would have happened anyways. Surely there's a way to show we are not responsible for such events?

 

[shimonv]

okay...
few more suggestions for you:
1. Did you try looking into USB isolators? I saw on the Internet an example of one which is 'medical grade'. If it is as good as they say than you have a mitigation for power supply failure without a need to go for 60601 and repeat again when a new PC comes out...

2. The risk management file is the essence of your safety and effectiveness planning. You might want to consider adding a software "watch dog" or some hardware mechanism (maybe even with battery) that alerts the user when hazardous situation occurs.

Good luck.

Shimon

 

[MIREGMGR]

The software alone can't do anything (it needs the device), so it is not a standalone "device".

You may want to review MedDev 2.1/6. https://ec.europa.eu/health/medical-devices/files/meddev/2_1_6_ol_en.pdf If I'm correctly understanding your description of your product's use, it sounds to me as if it's a device under MDD.

I believe it's also a device per FDA.

Fundamentally, "medical device" does not necessarily mean "hardware".

 

[dgrainger]

As it is a medical device you need look at the relevant essential requirements.
9.1 is appropriate:

9.1. If the device is intended for use in combination with other devices or
equipment, the whole combination, including the connection system
must be safe and must not impair the specified performances of the
devices. Any restrictions on use must be indicated on the label or in the
instructions for use.

You need to ensure that the combination is safe.