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                                                                 EXHIBIT 10(aaa)


                               SECOND 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 Second 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 (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 as further amended by that certain
Allonge No. 2 to 1999 Substitute Promissory Note by and between Borrower and
Bank and dated as of even date herewith (the "Second Allonge"), in the maximum
principal amount of up to $10,000,000.00, as amended (the Line of Credit Note as
amended by each of the First Allonge and the Second Allonge is hereinafter
referred to as the "Line of Credit Note, as amended"); (ii) a


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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 as further amended by that certain Second Amendment to Intercreditor
Agreement dated as of even date herewith. 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:

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


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Allonge and as further amended by the Second 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

Borrower acknowledges and agrees that, in applying the law of any jurisdiction
that at any time enacts all or substantially all of the uniform provisions of
Revised Article 9 of the Uniform Commercial Code (1999 Official Text), the
Collateral described in the 1999 Amended and Restated Security Agreement by the
Borrower and in favor of the Bank and dated as of June 30, 1999, is intended to
cover all of the assets described therein, regardless of how such assets may be
defined or categorized under the uniform provisions of the Revised Article 9.
Borrower hereby authorizes the Bank, at any time and from time to time, to file
financing and continuation statements and amendments thereto reflecting the
same.

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. PAYMENT OF COMMITMENT FEE. Borrower shall
have paid to the Bank a one time commitment fee of $2,500 for the amendments to
the Loan as contemplated herein (including, without limitation, to the Line of
Credit Note, as amended). 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


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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 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 April 28,
2000, 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


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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 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/ Thomas M. Patton
                                   ---------------------------------------------
                                    Name:    Thomas M. Patton
                                    Title:   President

                                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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