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                                                                 EXHIBIT 10(bbb)


                               THIRD AMENDMENT TO
                    1999 AMENDED AND RESTATED LOAN AGREEMENT

First Union National Bank
300 Main Street
Stamford, Connecticut 06904
(Hereinafter referred to as the "Bank")

Novametrix Medical Systems Inc.
5 Technology Drive, P.O. Box 690
Wallingford, Connecticut 06492
   ("Novametrix")

NTC Technology, Inc.
c/o Novametrix Medical Systems Inc.
5 Technology Drive, P.O. Box 690
Wallingford, Connecticut 06492
   ("NTC")

Children's Medical Ventures, Inc.
275 Longwater Drive
Norwell, Massachusetts 02061
("CMV"; Novametrix, NTC and CMV being,
individually and collectively "Borrower")


This Third Amendment to 1999 Amended and Restated Loan Agreement (the
"Amendment") is entered into as of March 30, 2001, by and between Borrower, each
of which are corporations organized under the laws of Delaware, and Bank. The
Amendment amends that certain 1999 Amended and Restated Loan Agreement, entered
into as of June 30, 1999, as amended by the First Amendment to 1999 Amended and
Restated Loan Agreement by and between Bank and Borrower entered into as of
April 28, 2000, and as amended by the Second Amendment to 1999 Amended and
Restated Loan Agreement by and between Bank and Borrower entered into as of
March 30, 2001 (said agreement being hereinafter referred to as the
"Agreement").

                                    RECITALS

Bank is the holder of, inter alia: (i) a certain 1999 Substitute Promissory Note
made by Borrower and payable to the order of the Bank, dated as of June 30, 1999
(the "Line of Credit Note"), as amended by that certain Allonge No. 1 to 1999
Substitute Promissory Note by and between the Borrower and Bank, dated as of
April 28, 2000 (the "First Allonge"), and by that certain Allonge No. 2 to 1999
Substitute Promissory Note by and


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between Borrower and Bank and dated as of March 30, 2001 (the "Second Allonge"),
in the maximum principal amount of up to $10,000,000.00, as amended, and as
further amended by that certain Allonge No. 3 to 1999 Substitute Promissory Note
by and between the Borrower and Bank, dated as of March 30, 2001 (the Line of
Credit Note as amended by each of the First Allonge, Second Allonge and Third
Allonge is hereinafter referred to as the "Line of Credit Note, as amended");
(ii) a certain 1999 Term Promissory Note in the original principal amount of
$4,800,000.00, dated as of June 30, 1999, from the Borrower to the Bank
(hereinafter referred to as the "1999 Term Note"); (iii) a certain 1998 Term
Promissory Note executed and delivered by Novametrix and NTC, dated December 11,
1998, in the original principal amount of $3,000,000.00, as modified by Allonge
No. 1 to 1998 Term Promissory Note, dated as of June 30, 1999, executed by
Novametrix, NTC and the Bank (as modified, hereinafter referred to as the "1998
Term Note") (the Line of Credit Note, as amended, the 1999 Term Note and the
1998 Term Note are sometimes collectively referred to hereinafter as the
"Notes"); and certain other Loan Documents, including the Agreement; and

Borrower and Bank have agreed to modify the terms of the Agreement by, inter
alia, replacing certain provisions contained therein with those contained in
this Agreement, as more particularly hereinafter set forth.

                                    AGREEMENT

In consideration of Bank's continued extension of credit and the agreements
contained herein, the parties agree as follows:

This Amendment amends the Agreement.

This Amendment applies to the Loan and all Loan Documents.

This Amendment and the Loans contemplated and covered herein are subject to that
certain Intercreditor Agreement by and between the Bank and Webster Bank, a
Connecticut banking association with a place of business at 80 Elm Street, New
Haven, CT 06510 ("Webster") dated as of June 30, 1999, as amended by that
certain First Amendment to Intercreditor Agreement dated as of April 28, 2000,
and by that certain Second Amendment to Intercreditor Agreement dated as of
March 30, 2001, as supplemented by a letter dated as of March 30, 2001. The
parties acknowledge and agree that Borrower has previously entered into a Loan
Agreement and related loan documents (the "Webster Loan Documents"), including
executing and delivering to Webster a certain Term Promissory Note in the
original principal amount of $4,800,000.00, dated as of June 30, 1999 (the
"Webster Note").

Relying upon the covenants, agreements, representations and warranties contained
in this Amendment and in the Agreement, Bank is willing to modify the terms on
which it will extend credit to Borrower as set forth in the Agreement, as more
particularly set forth herein, and Bank and Borrower agree as follows:


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ACKNOWLEDGMENT OF BALANCE. Borrower acknowledges that the most recent Commercial
Loan Invoice sent to Borrower with respect to the Obligations under the Notes is
correct.

LINE OF CREDIT NOTE. All references in the Loan Documents to the Line of Credit
Note shall be understood to mean the Line of Credit Note as amended by the First
Allonge, Second Allonge, and the Third Allonge, in the maximum principal amount
of up to $10,000,000.00.

LOAN AGREEMENT. All references in the Loan Documents to the Agreement shall be
understood to mean the Agreement, as amended by this Amendment.

ACKNOWLEDGMENTS AND REPRESENTATIONS. Borrower acknowledges and represents that
the Agreement and other Loan Documents, as amended hereby, and the Webster Loan
Documents, are in full force and effect without any defense, counterclaim, right
or claim of set-off; that, after giving effect to this Amendment, no default or
event that with the passage of time or giving of notice would constitute a
default under the Loan Documents or the Webster Loan Documents has occurred, all
representations and warranties contained in the Loan Documents and in the
Webster Loan Documents are true and correct as of this date, all necessary
action to authorize the execution and delivery of this Amendment has been taken;
and this Amendment is a modification of an existing obligation and is not a
novation.

COLLATERAL. Borrower acknowledges and confirms that there have been no changes
in the ownership of any collateral pledged to secure the Obligations (the
"Collateral") since the Collateral was originally pledged; Borrower acknowledges
and confirms that the Bank has, subject only to the Intercreditor Agreement,
existing, valid first priority security interests and liens in the Collateral;
and that such security interests and liens shall secure Borrower's Obligations
to Bank, including any modification of any of the Notes or Loan Agreement, if
any, and all future modifications, extensions, renewals and/or replacements of
the Loan Documents

CONDITIONS PRECEDENT. In addition to the Conditions Precedent identified in the
Agreement, the obligations of Bank to make any advances pursuant to the Loan
Documents or this Amendment (including, without limitation, under the Line of
Credit Note) are subject to the following conditions precedent: ADDITIONAL
DOCUMENTS. Receipt by Bank of such additional supporting documents as Bank or
its counsel may reasonably request. CONSENT AND AMENDMENT. The Borrower shall
have obtained the consent of Webster Bank to the modifications to the Loan and
the Loan Documents contemplated hereby and Webster Bank's agreement to the
inclusion of the increased amount under the Line of Credit Note, as amended as a
Loan (and not an Other Loan, as each of these terms is defined in the
Intercreditor Agreement) for purposes of the Intercreditor Agreement; Webster
Bank shall have executed an amendment to the Intercreditor Agreement reflecting
the foregoing. CERTIFICATE OF GOOD STANDING. Bank shall have received from
Borrower a certificate from the Secretary of State of the state of Borrower's
incorporation or organization, as applicable, as to the good standing of
Borrower. CERTIFICATE OF INCUMBENCY AND AUTHORIZATION. Bank shall have received


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from Borrower a certificate of an appropriate officer of Borrower as to the
incumbency and signatures of the officers of Borrower executing the Loan
Documents and as to the adoption of resolutions authorizing the amendments to
the Loan Documents including, without limitation, the increase to the amount of
the Line of Credit Note, as amended. OPINION OF COUNSEL. Bank shall have
received a written opinion of the counsel of Borrower acceptable to Bank that
includes confirmation of the following: (a) The Borrower is duly organized and
validly existing under the laws of the jurisdictions where Borrower is organized
and has full power and authority to undertake the activities contemplated by the
Loan; There have been no changes, since March 30, 2001, to the Charter Documents
or Operating Agreements of Borrower. (b) The Loan Documents, as modified by
documents executed in connection with this Amendment, create a perfected lien on
and security interest in the Collateral (as defined in the Loan Documents). (c)
The accuracy, as of the date hereof, of the representations set forth in the
Agreement in the Representations Subparagraphs entitled "Authorization;
Non-Contravention"; "Compliance with Laws" as to the transaction contemplated by
this Amendment and the documents pertaining thereto; and "Organization and
Authority." (d) This Amendment and other Loan Documents executed in connection
herewith have been duly executed and delivered by Borrower and constitute the
legal, valid and binding obligations of Borrower, enforceable in accordance with
their terms. (e) No registration with, consent of, approval of, or other action
by, any federal, state or other governmental authority or regulatory body to the
execution and delivery of this Agreement, the borrowing under this Agreement or
other Loan Documents, is required by law, or, if so required, such registration
has been made, and consent or approval given or such other appropriate action
taken. (f) The Loan and its terms do not violate any laws including, without
limitation, any usury laws of the jurisdictions where Borrower and any
Collateral are located; such other matters and opinions as the Bank reasonably
requests.

JOINT AND SEVERAL OBLIGATIONS. The obligations of the Borrower hereunder and
under the Loan Documents shall be joint and several.

MISCELLANEOUS. This Amendment shall be construed in accordance with and governed
by the laws of the State of Connecticut without reference to conflicts of laws
principles. This Amendment and the other Loan Documents constitute the sole
agreement of the parties with respect to the subject matter thereof and
supersede all oral negotiations and prior writings with respect to the subject
matter thereof. No amendment of this Amendment, no other amendment to the
Agreement, and no waiver of any one or more of the provisions hereof or thereof
shall be effective unless set forth in writing and signed by the parties hereto.
The illegality, unenforceability or inconsistency of any provision of this
Amendment shall not in any way affect or impair the legality, enforceability or
consistency of the remaining provisions of this Amendment, the Agreement, as
modified hereby, or the other Loan Documents. The Agreement, as modified by this
Amendment, and the other Loan Documents are intended to be consistent. However,
in the event of any inconsistencies among the Agreement, as modified by this
Amendment, and any of the Loan Documents, the terms of the Notes, and then the
Agreement, as modified by this Amendment, shall control. This Amendment may be
executed in any number of counterparts and by the different parties on separate
counterparts. Each such counterpart shall be deemed an original, but all such


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counterparts shall together constitute one and the same agreement. The terms
"Loan Documents" and "Obligations" shall have the meanings of such terms as
defined in the Agreement. Additional terms used in this Amendment which are
capitalized and not otherwise defined herein shall have the meanings ascribed to
such terms in the Loan Documents. Without limiting the generality of the
foregoing, the term "Loan Documents" does not include any swap agreements (as
defined in 11 U.S.C. Section 101); the term "Obligations" shall include, without
limitation, all obligations under any swap agreements as defined in 11 U.S.C.
Section 101 between Borrower and Bank whenever executed.

CONNECTICUT PREJUDGMENT REMEDY WAIVER. EACH BORROWER ACKNOWLEDGES THAT THE
TRANSACTIONS REPRESENTED BY THIS AMENDMENT ARE COMMERCIAL TRANSACTIONS AND
HEREBY VOLUNTARILY AND KNOWINGLY WAIVES ANY RIGHTS TO NOTICE OF AND HEARING ON
PREJUDGMENT REMEDIES UNDER CHAPTER 903a OF THE CONNECTICUT GENERAL STATUTES OR
OTHER STATUTES AFFECTING PREJUDGMENT REMEDIES, AND AUTHORIZES THE BANK'S
ATTORNEY TO ISSUE A WRIT FOR A PREJUDGMENT REMEDY WITHOUT COURT ORDER, PROVIDED
THE COMPLAINT SHALL SET FORTH A COPY OF THIS WAIVER.

WAIVER OF JURY TRIAL. THE PARTIES ACKNOWLEDGE THAT THEY HAVE IRREVOCABLY WAIVED
ANY RIGHT THEY MAY HAVE TO JURY TRIAL WITH REGARD TO A DISPUTE.

PLACE OF EXECUTION AND DELIVERY. Borrower hereby certifies that this Agreement
and the Loan Documents were executed in the State of Connecticut and State of
New York and delivered to Bank in the State of Connecticut.

                      [THE NEXT PAGE IS THE SIGNATURE PAGE]


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IN WITNESS WHEREOF, Borrower and Bank, on the day and year first written above,
have caused this Agreement to be executed.

                       BORROWER:

                       NOVAMETRIX MEDICAL SYSTEMS INC.

                       By:  /s/ William J. Lacourciere
                          ------------------------------------------------------
                            Name:    William J. Lacourciere
                            Title:   Chief Executive Officer

                       NTC TECHNOLOGY, INC.

                       By:  /s/ Thomas M. Haythe
                          ------------------------------------------------------
                            Name:    Thomas M. Haythe
                            Title: President

                       CHILDREN'S MEDICAL VENTURES, INC.

                       By:  /s/ Joseph A. Vincent
                          ------------------------------------------------------
                            Name:    Joseph A. Vincent
                            Title:   Vice President

                       BANK:

                       FIRST UNION NATIONAL BANK

                       By:  /s/ John H. Frost
                          ------------------------------------------------------
                            Name:    John H. Frost
                            Title:   Vice President


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