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|                                                | kirsten             |
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| *By courier and e-mail: fdadockets@oc.fda.gov* | May 7, 2002         |
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|                                                | KER/KCH             |
+------------------------------------------------+---------------------+

Re: **Docket No. 01D-0577: Class II Special Controls Guidance Document:
Cutaneous Carbon Dioxide (PcCO~2~) and Oxygen (PcO~2~) Monitors; Draft
Guidance for Industry and FDA**

Gentlemen:

We hereby submit our comments to the above Draft Guidance.

We welcome the FDA's issuance of this draft guidance document, which
will help to remove the regulatory uncertainty that has been prevalent
in this field for years. We are concerned, however, that the draft
guidance does not reflect current standards applicable to devices
subject to this guidance. Specifically, the draft guidance refers to a
number of standards that have been discontinued, replaced, or amended
and, in some cases, fails to refer to the current standards in the
field. In order that the Guidance will reflect the state of the art, we
have proposed several revisions, as described below.

*1. Reference to Standards and Guidance Documents*

The Draft Guidance refers to the following standards/guidance documents
that either have been discontinued, replaced, or amended:

+-------------+---------+----------------------------------+----------+
| Standard    | Year    | Title                            | Status   |
| Id.         |         |                                  |          |
+=============+=========+==================================+==========+
| ASTM F      | 1986    | Standard Specifications for      | Disc     |
| 984-86      |         | Cutaneous Gas Monitoring Devices | ontinued |
|             | (rea    | for Oxygen and Carbon Dioxide    | 8/10/99  |
|             | pproved |                                  | without  |
|             | 1992)   |                                  | rep      |
|             |         |                                  | lacement |
+-------------+---------+----------------------------------+----------+
| IEC         | 1993    | Medical Electrical Equipment,    | O        |
| 60601-1-2   |         | Part 1: General Requirements for | bsolete, |
|             |         | Safety, 2. Collateral Standard:  |          |
|             |         | Electromagnetic Compatibility -  | Second   |
|             |         | Requirements and Tests           | Edition  |
|             |         |                                  | issued   |
|             |         |                                  | 2001;    |
|             |         |                                  |          |
|             |         |                                  | 2001     |
|             |         |                                  | Edition  |
|             |         |                                  | is an    |
|             |         |                                  | FDA      |
|             |         |                                  | Re       |
|             |         |                                  | cognized |
|             |         |                                  | C        |
|             |         |                                  | onsensus |
|             |         |                                  | Standard |
+-------------+---------+----------------------------------+----------+
| IEC         | 1996    | Medical electrical equipment -   | FDA      |
| 60601-3-1   |         | Part 3-1: Essential performance  | Re       |
|             |         | requirements for transcutaneous  | cognized |
|             |         | oxygen and carbon dioxide        | C        |
|             |         | partial pressure monitoring      | onsensus |
|             |         | equipment                        | Standard |
|             |         |                                  |          |
|             |         |                                  | Now      |
|             |         |                                  | included |
|             |         |                                  | in IEC   |
|             |         |                                  | 60       |
|             |         |                                  | 601-2-23 |
|             |         |                                  | (1999)   |
+-------------+---------+----------------------------------+----------+
| IEC         | 1993    | Medical electrical equipment -   | O        |
| 60601-2-23  |         | Part 2: Particular requirements  | bsolete. |
|             |         | for the safety of transcutaneous |          |
|             |         | partial pressure monitoring      | Second   |
|             |         | equipment                        | Edition  |
|             |         |                                  | issued   |
|             |         |                                  | Dec 1999 |
+-------------+---------+----------------------------------+----------+
| IEC         | 1999    | Electromagnetic Compatibility    | Amended  |
| 61000-4-2   |         | (EMC)-Part 4-2: Testing and      | 2000     |
|             |         | measurement                      |          |
|             |         | techniques-Electrostatic         |          |
|             |         | discharge immunity testing       |          |
+-------------+---------+----------------------------------+----------+
| IEC         | 1995    | Electromagnetic Compatibility    | Amended  |
| 61000-4-3   |         | (EMC)-Part 4-3: Testing and      | 2000     |
|             |         | measurement techniques-Radiated, |          |
|             |         | radio frequency, electromagnetic |          |
|             |         | field immunity test              |          |
+-------------+---------+----------------------------------+----------+
| IEC         | 1994    | Electromagnetic Compatibility    | Amended  |
| 61000-4-11  |         | (EMC)-Part 4-11: Testing and     | 2000     |
|             |         | measurement techniques-Voltage   |          |
|             |         | dips, short interruptions and    |          |
|             |         | voltage variations immunity      |          |
|             |         | tests                            |          |
+-------------+---------+----------------------------------+----------+
| IEC         | 1995    | Electromagnetic Compatibility    | Amended  |
| 61000-4-4   |         | (EMC)-Part 4-4: Testing and      | 2000     |
|             |         | measurement                      |          |
|             |         | techniques-Electrical fast       |          |
|             |         | transient/burst immunity test    |          |
+-------------+---------+----------------------------------+----------+
| IEC         | 1993    | Electromagnetic Compatibility    | Amended  |
| 61000-4-8   |         | (EMC)-Part 4: Testing and        | 2000     |
|             |         | measurement techniques-Section   |          |
|             |         | 8: Power frequency magnetic      |          |
|             |         | field immunity test              |          |
+-------------+---------+----------------------------------+----------+

*2. State of the Art Standards and Guidances*

IEC 60601-2-23: \"Medical Electrical Equipment - Part 2-23: Particular
requirements for the safety, including essential performance, of
transcutaneous partial pressure monitoring equipment\" has been issued
as a second edition in Dec. 1999. As noted above, this second edition
cancels and replaces the first edition published in 1993 and also covers
the scope of IEC 60601-3-1 published in 1996.

The 1999 edition of IEC 60601-2-23, together with the set of IEC
publications listed below, defines controls for all the risks identified
in Section 4 of the Draft Guidance, except Toxicity and Tissue
Reactivity:

-   IEC 60601-1:1988, Medical Electrical Equipment - Part 1: General
    requirements for safety, amendment 1, amendment 2;

-   IEC 60601-1-2:1993, Medical Electrical Equipment - Part 1: General
    requirements for safety - 2. Collateral Standard: Electromagnetic
    compatibility - Requirements and tests; and

-   IEC 60601-1-4:1996, Medical Electrical Equipment - Part 1: General
    requirements for safety - 4. Collateral Standard: Programmable
    electrical medical systems.

In addition, the 1999 edition of IEC 60601-2-23 is an FDA Recognized
Consensus Standard.

For that reason, Radiometer recommends that compliance with the 1999
edition of IEC 60601‑2‑23 should be the recommended mitigation measure
for the risks of electrical shock, electromagnetic interference, burns
and inaccurate measurement.

For the risks related to Toxicity and Tissue Reactivity, demonstration
of compliance with the relevant parts of ISO 10993, \"Biological
Evaluation of Medical Devices\" would appear to be adequate mitigation.
The ISO 10993 Series is also an FDA Recognized Consensus Standard.
Indirectly, the FDA supports compliance with ISO 10993 by referring to
General Program memorandum G95-1, but Radiometer would recommend a more
direct reference to ISO 10993**.**

*3. Other Comments*

> a\. Sections 1 and 5 of the Draft Guidance refer to the traditional
> 510(k) and the abbreviated 510(k) procedure. We believe that there
> should be a reference to the special 510(k) procedure as well.
>
> b\. MIL standards are developed for use by defense and aerospace
> related organizations. The compliance with the MIL standards referred
> to in the Draft Guidance and listed below should not be mandatory for
> normal situations and environments but only for such special uses
> requiring extreme reliability of the devices.

  ----------------- ------------ -----------------------------------------
  Standard Id.      Year         Title

  MIL-STD 461D      1993         Requirements for the Control of
                                 Electromagnetic Interference, Emissions
                                 and Susceptibility

  MIL-STD 462D      1993         Measurement of Electromagnetic
                                 Interference Characteristics
  ----------------- ------------ -----------------------------------------

> c\. Provided that the 1999 edition of IEC 60601-2-23 be relied upon as
> the primary risk mitigation measure we do not see any reason for
> maintaining a reference to the 1990 IFCC guidance document, Guidelines
> for Transcutaneous PO~2~ and PCO~2~ Measurement (1990). We understand
> the IFCC guidance document is cited only as support for the statements
> of Section 12.1 of the Draft Guidance and that no further compliance
> with the IFCC Guidance is requested. The 1999 edition of IEC
> 60601-2-23 has detailed provisions in Section Seven - Protection
> against Excessive Temperatures and other Safety Hazards - to ensure
> against skin burns, making reference to the 1990 IFCC guidance
> document superfluous. If the reference to the 1990 IFCC guidance
> document be maintained it should be clarified that the reference
> serves only to support the statements of Section 12.1 of the Draft
> Guidance.
>
> d\. For devices intended to be used in hyperbaric facilities
> Radiometer recommends that the FDA considers including a reference to
> NFPA 99-1999, Standard for Health Care Facilities CHAPTER 19 -
> Hyperbaric Facilities, or to the previous 1996 issue which is an FDA
> recognized consensus standard.

On the basis of the above comments, Radiometer recommends that the Draft
Guidance be redrafted so as to clarify what are the appropriate
standards. The Company believes that such clarification will be very
useful for the industry and ensure more relevant, consistent controls to
mitigate any risks associated with cutaneous carbon dioxide and oxygen
monitors.

Radiometer appreciates the opportunity to provide these comments on the
Draft Guidance. Because the Draft Guidance relies heavily on complicated
international standards, Radiometer stands prepared to discuss in
further detail any and all of these standards as part of the final
guidance drafting process. We encourage the FDA to contact us in this
regard and we also will be following up with the Agency on these issues.
In the meantime, please feel free to contact us at

+45 3827 3390 in the event that you should wish a clarification of any
of our comments.

Best regards,

RADIOMETER MEDICAL A/S

Kirsten Rønø

Director of Quality