SEVENTH AMENDMENT TO AMENDED AND RESTATED CREDITAGREEMENT

Exhibit 10.21

SEVENTH AMENDMENT TO

AMENDED AND RESTATED CREDIT AGREEMENT

This seventh amendment to Amended and Restated Credit Agreement (this “Amendment”) is entered into as of February 27, 2010, between Natus Medical Incorporated a Delaware corporation (“Borrower”), and Wells Fargo Bank, National Association (“Bank”).

Whereas Borrower is currently indebted to Bank pursuant to the terms and conditions of the Amended and Restated Credit Agreement, dated as of November 28, 2007 (as amended, amended and restated, modified or supplemented prior to the date hereof, the “Credit Agreement”), between Borrower and Bank; and whereas Bank and Borrower have agreed to certain changes in the terms and conditions set forth in the Credit Agreement and have agreed to amend the Credit Agreement to reflect such changes;

Now, therefore, for valuable consideration, the receipt and sufficiency of which are hereby acknowledged, Bank and Borrower hereby agree that the Credit Agreement shall be amended as follows; provided that nothing contained herein shall terminate any security interests, guaranties, subordinations or other documents in favor of Bank, all of which shall remain in full force and effect unless expressly amended hereby:

Section 1. Definitions. Each capitalized term used but not otherwise defined herein has the meaning assigned to it in the Credit Agreement.

Section 2. Amendments to Credit Agreement. Subject to Section 3 hereof, the Credit Agreement is hereby amended as follows:

(a) The definition of “Revolving Credit Maturity Date” in Section 1.1 of the Credit Agreement is hereby amended and restated in its entirety to read as follows:

“Revolving Credit Maturity Date” means April 30, 2010.

(b) Section 6.9(a) of the Credit Agreement is amended and restated in its entirety to read as follows:

(a) As of each fiscal quarter end of Borrower, Consolidated EBITDA not less than the amount set forth below:

For each quarterly period ending as of each fiscal quarter end of Borrower ending on or before September 30, 2008: $5,000,000

For the four consecutive fiscal quarters ending as of each fiscal quarter end of Borrower ending on December 31, 2008 and March 31, 2009: $35,000,000 For the four consecutive fiscal quarters ending as of each fiscal quarter end of Borrower ending on June 30, 2009 and September 30, 2009: $32,000,000 For the four consecutive fiscal quarters ending as of each fiscal quarter end of Borrower ending on December 31, 2009 and March 31, 2010: $28,000,000.

Section 3. Conditions Precedent. This Amendment, including, without limitation the amendments to the Credit Agreement contained herein, shall become effective as of the date first set forth above (the “Effective Date”) upon satisfaction of all of the conditions set forth in this Section 3 to the satisfaction of Bank; provided that, in the event such conditions are not so satisfied on or before February 27, 2010, then this Amendment shall be of no further force and effect:

(a) Bank shall have received each of the following, duly executed and delivered by each of the applicable parties thereto:

(i) this Amendment together with the Consent and Reaffirmation attached hereto; and

(ii) such other documents as Bank may require under any other Section of this Amendment; and

(b) No Event of Default or event which, with the giving of notice, the lapse of time or both would constitute an Event of Default, shall have occurred and be continuing.

Section 4. Interpretation. Except as specifically provided herein, all terms and conditions of the Credit Agreement remain in full force and effect, without waiver or modification. This Amendment and the Credit Agreement shall be read together, as one document. The Recitals hereto, including the terms defined therein, are incorporated herein by this reference and acknowledged by Borrower to be true, correct and complete.

Section 5. Representations, Warranties and Covenants. Borrower hereby remakes all representations and warranties contained in the Credit Agreement and reaffirms all covenants set forth therein (as amended hereby) as of the date of this Amendment. Borrower further certifies that as of the date of this Amendment there exists no Event of Default, nor any condition, act or event which with the giving of notice or the passage of time or both would constitute an Event of Default.

Section 6. Further Assurances. Borrower will make, execute, endorse, acknowledge, and deliver any agreements, documents, or instruments, and take any and all other actions, as may from time to time be reasonably requested by Bank to perfect and maintain the validity and priority of the liens and security interests granted to Bank pursuant to the Credit Agreement and the other Loan Documents and to effect, confirm, or further assure or protect and preserve the interests, rights, and remedies of Bank under the Credit Agreement (as amended hereby) and the other Loan Documents.

Section 7. Counterparts. This Amendment may be executed in any number of identical counterparts, any set of which signed by all the parties hereto shall be deemed to constitute a complete, executed original for all purposes. Delivery of an executed counterpart of a signature page of this Amendment by telefacsimile transmission shall be as effective as delivery of a manually executed counterpart hereof.

Section 8. Governing Law. This Amendment shall be governed by and construed in accordance with the internal laws of the State of California.

[Signatures follow on next page.]

In witness whereof, the parties hereto have caused this Amendment to be executed as of the date first written above.

Natus Medical Incorporated, a Delaware corporation

Wells Fargo Bank, National Association

Seventh Amendment to Amended and Restated Credit Agreement

Consent and Reaffirmation

Each of the undersigned, a subsidiary of Natus Medical Incorporated (“Borrower”) who has executed both a Continuing Guaranty and a Third Party Security Agreement, each in favor of Wells Fargo Bank, National Association (“Bank”), hereby: (i) consents to the foregoing Seventh Amendment to Amended and Restated Credit Agreement; (ii) reaffirms its obligations under its respective Continuing Guaranty and its. respective Third Party Security Agreement; (iii) reaffirms the waivers of each and every one of the defenses to such obligations as set forth in such Continuing Guaranty and such Third Party Security Agreement; and (iv) reaffirms that its obligations under such Continuing Guaranty and such Third Party Security Agreement are separate and distinct from the obligations of any other party under the Credit Agreement (as modified by the Seventh Amendment to Amended and Restated Credit Agreement) and the other Loan Documents.

Dated as of February 27, 2010

Guarantor:

Natus Acquisition Corporation

NeuroCom International, Inc.

Alpine Biomed Holdings Corp.