European MDD Classification of Medical Devices (Risk Class)

[temujin]

Dear Forum,

I have a question as to how to interpret the European MDD concerning
the classification of Medical Devices.

If a diagnostic device is both active AND surgically invasive,
which rule apply?

My advisor says as long as the device is active, the rules concerning
surgically invasive devices do not apply (!) even though the device would
have been in a higher risk class if the rules concerning surgically
invasive devises were considered.
Is this the current practice?

regards
temu

[Gert Sorensen]

Originally Posted by temujin

I have a question as to how to interpret the European MDD concerning
the classification of Medical Devices.

If a diagnostic device is both active AND surgically invasive,
which rule apply?

My advisor says as long as the device is active, the rules concerning
surgically invasive devices do not apply (!) even though the device would
have been in a higher risk class if the rules concerning surgically
invasive devises were considered.
Is this the current practice?

Hi Temu, and welcome to the Cove.

I do not interpret the MDD the same way as your advisor. The classification rules state:

CLASSIFICATION CRITERIA I. DEFINITIONS 1. Definitions for the classification rules

1.1. Duration

Transient

Normally intended for continuous use for less than 60 minutes.

Short term

Normally intended for continuous use for not more than 30 days.

Long term

Normally intended for continuous use for more than 30 days.

1.2. Invasive devices

Invasive device

A device which, in whole or in part, penetrates inside the body, either through a body orifice or through the surface of the body.

Body orifice

Any natural opening in the body, as well as the external surface of the eyeball, or any permanent artificial opening, such as a stoma.

Surgically invasive device

An invasive device which penetrates inside the body through the surface of the body, with the aid or in the context of a surgical operation.

For the purposes of this Directive devices other than those referred to in the previous subparagraph and which produce penetration other than through an established body orifice, shall be treated as surgically invasive devices.

Implantable device

Any device which is intended:

- to be totally introduced into the human body or,

- to replace an epithelial surface or the surface of the eye,

by surgical intervention which is intended to remain in place after the procedure.

Any device intended to be partially introduced into the human body through surgical intervention and intended to remain in place after the procedure for at least 30 days is also considered an implantable device.

1.3. Reusable surgical instrument

Instrument intended for surgical use by cutting, drilling, sawing, scratching, scraping, clamping, retracting, clipping or similar procedures, without connection to any active medical device and which can be reused after appropriate procedures have been carried out.

1.4. Active medical device

Any medical device operation of which depends on a source of electrical energy or any source of power other than that directly generated by the human body or gravity and which acts by converting this energy. Medical devices intended to transmit energy, substances or other elements between an active medical device and the patient, without any significant change, are not considered to be active medical devices.

1.5. Active therapeutical device

Any active medical device, whether used alone or in combination with other medical devices, to support, modify, replace or restore biological functions or structures with a view to treatment or alleviation of an illness, injury or handicap.

1.6. Active device for diagnosis

Any active medical device, whether used alone or in combination with other medical devices, to supply information for detecting, diagnosing, monitoring or treating physiological conditions, states of health, illnesses or congenital deformities.

1.7. Central circulatory system

For the purposes of this Directive, 'central circulatory system' means the following vessels:

arteriae pulmonales, aorta ascendens, arteriae coronariae, arteria carotis communis, arteria carotis externa, arteria carotis interna, arteriae cerebrales, truncus brachicephalicus, venae cordis, venae pulmonales, vena cava superior, vena cava inferior.

1.8. Central nervous system

For the purposes of this Directive, 'central nervous system' means brain, meninges and spinal cord.

II. IMPLEMENTING RULES 2. Implementing rules

2.1. Application of the classification rules shall be governed by the intended purpose of the devices.

2.2. If the device is intended to be used in combination with another device, the classification rules shall apply separately to each of the devices. Accessories are classified in their own right separately from the device with which they are used.

2.3. Software, which drives a device or influences the use of a device, falls automatically in the same class.

2.4. If the device is not intended to be used solely or principally in a specific part of the body, it must be considered and classified on the basis of the most critical specified use.

2.5. If several rules apply to the same device, based on the performance specified for the device by the manufacturer, the strictest rules resulting in the higher classification shall apply.

As you can see in 2.4 and 2.5, the strictest rule apply. This i basic good sense, since it would be easy to classify your product in a category that does not reflect the risk involved in the use, if you could choose freely.

[temujin]

Thanks Gerd,... that was my own interpretation as well.

However, my "advisor" claims that the current practice by Notified Bodies is that as long as a device is active only the "active" rules are to be applied. I have not seen any examples of this current practice.
Moreover, he claims that Annex 9/ Rule 7 (on surgically invasive devices) is only about PASSIVE invasive devices.

Do you or anyone else have any examples of other active, surgically invasive devices for short term use (that would get the Class III classification)?


regards
temu

[Gert Sorensen]

Originally Posted by temujin

Thanks Gerd,... that was my own interpretation as well.

However, my "advisor" claims that the current practice by Notified Bodies is that as long as a device is active only the "active" rules are to be applied. I have not seen any examples of this current practice.
Moreover, he claims that Annex 9/ Rule 7 (on surgically invasive devices) is only about PASSIVE invasive devices.

Do you or anyone else have any examples of other active, surgically invasive devices for short term use (that would get the Class III classification)?


regards
temu

Can you elaborate on the type of device you are producing?

[temujin]

a system (ultrasound) with a probe for measuring coronar flow on an open heart.

[Gert Sorensen]

Originally Posted by temujin

a system (ultrasound) with a probe for measuring coronar flow on an open heart.

If I understand you correctly, the probe is inserted in the coronary system and generates a signal that is transmitted to some sort of monitoringsystem? Where does the probe go?

[temujin]

Yep,

1 end of the probe is connected to the coronary artery (ies)
2 end of probe is connected to an ultrasound scanner.

temu

[Gert Sorensen]

Originally Posted by temujin

Yep,

1 end of the probe is connected to the coronary artery (ies)
2 end of probe is connected to an ultrasound scanner.

temu

If I produced something that went into the coronary artery, then I would not have any doubt whatsoever, that I would have to apply the highest risk.