AMENDED AND RESTATED SECURITY AGREEMENT

EXHIBIT 10.17

A MENDED AND R ESTATED S ECURITY A GREEMENT

T HIS A MENDED AND R ESTATED S ECURITY A GREEMENT (this “ Agreement ”) is entered into as of February 19, 2009, by N ATUS M EDICAL I NCORPORATED , a Delaware corporation (“ Debtor ” or the “ Company ”), in favor of W ELLS F ARGO B ANK , N ATIONAL A SSOCIATION (“ Secured Party ”).

R ECITALS :

A. The Company and Secured Party have previously entered into that certain Security Agreement, dated as of November 28, 2007 (as amended, restated, modified and/or supplemented prior to the date hereof, the “ Existing Agreement) .

B. The Company has requested that Secured Party provide and continue to provide the Company with certain financial accommodations as evidenced by one or more promissory notes or other instruments executed and delivered by the Company to Secured Party and other agreements entered into from time to time between the Company and Secured Party, including, without limitation, that certain Standby Letter of Credit Agreement, dated as of the date hereof (the “ L/C Agreement ”) and that certain Amended and Restated Credit Agreement, dated as of November 28, 2007 (the “Loan Agreement” ) (together with this Agreement, the L/C Agreement, the Amended and Restated Revolving Line of Credit Note, in the maximum aggregate principal amount of U.S. $25,000,000.00, executed by the Company in favor of Secured Party, and any and all documents or agreements executed by Debtor in connection with any of foregoing, as any of them may be amended, modified or extended from time to time, collectively, the “ Loan Documents”) .

C. In order to induce Secured Party to provide and continue to provide financial accommodations to the Company under the L/C Agreement and the Loan Agreement and to enter into the L/C Agreement and other Loan Documents to which it is a party, the Debtor wishes and has agreed (i) to amend and restate the Existing Agreement and (ii) to secure its obligations to Secured Party under Loan Documents by granting to Secured Party a first priority security interest in the Collateral (as defined below).

D. All capitalized terms used but not otherwise defined herein shall have the meanings assigned to them in the Loan Agreement.

NOW, THEREFORE, in consideration of the premises and the mutual covenants and conditions contained herein, and for other good and valuable consideration, the receipt and sufficiency of which are hereby specifically acknowledged, Secured Party and Debtor agree as follows:

1. G RANT OF S ECURITY I NTEREST . To secure the prompt and complete payment, observance and performance of each covenant, condition or obligation of whatsoever nature to be performed or observed by the Company under the Loan Documents, including repayment of all future loans extended by and reimbursement obligations owing to Secured Party (the “ Secured Obligations ”), the Company hereby grants Secured Party a first priority security interest (except for Permitted Liens that are senior to Bank’s security interest) in and to all assets of the Company whether now existing or hereafter arising or acquired, including without limitation the following (collectively, the “ Collateral ”):

(a) all accounts, deposit accounts, contract rights, chattel paper, (whether electronic or tangible) instruments, promissory notes, documents, general intangibles, payment intangibles, software, letter of credit rights, health-care insurance receivables and other rights to payment of every kind now existing or at any time hereafter arising;

(b) all inventory, goods held for sale or lease or to be furnished under contracts for service, or goods so leased or furnished, raw materials, component parts, work in process and other materials used or consumed in Debtor’s business, now or at any time hereafter owned or acquired by Debtor, wherever located, and all products thereof, whether in the possession of Debtor, any warehousemen, any bailee or any other person, or in process of delivery, and whether located at Debtor’s places of business or elsewhere;

(c) all warehouse receipts, bills of sale, bills of lading and other documents of every kind (whether or not negotiable) in which Debtor now has or at any time hereafter acquires any interest, and all additions and accessions thereto, whether in the possession or custody of Debtor, any bailee or any other person for any purpose;

(d) all money and property heretofore, now or hereafter delivered to or deposited with Secured Party or otherwise coming into the possession, custody or control of Secured Party (or any agent or bailee of Secured Party) in any manner or for any purpose whatsoever during the existence of this Agreement and whether held in a general or special account or deposit for safekeeping or otherwise;

(e) all right, title and interest of Debtor under licenses, guaranties, warranties, management agreements, marketing or sales agreements, escrow contracts, indemnity agreements, insurance policies, service or maintenance agreements, supporting obligations and other similar contracts of every kind in which Debtor now has or at any time hereafter shall have an interest;

(f) all goods, tools, machinery, furnishings, furniture and other equipment and fixtures of every kind now existing or hereafter acquired, and all improvements, replacements, accessions and additions thereto and embedded software included therein, whether located on any property owned or leased by Debtor or elsewhere, including without limitation, any of the foregoing now or at any time hereafter located at or installed on the land or in the improvements at any of the real property owned or leased by Debtor, and all such goods after they have been severed and removed from any of said real property;

(g) all motor vehicles, trailers, mobile homes, manufactured homes, boats, other rolling stock and related equipment of every kind now existing or hereafter acquired and all additions and accessories thereto, whether located on any property owned or leased by Debtor or elsewhere;

(h) all of the following (collectively, “ Intellectual Property Collateral”):

(i) all patents and patent applications and all patent rights with respect thereto throughout the world, including without limitation all license royalties, foreign filing rights, and rights to extend such patents and patent rights, and all rights in all patentable inventions, and to file applications for patent under federal patent law or under the laws or regulations of any foreign country (collectively, the “ Patents ”);

(ii) all copyrights (whether or not registered with the United States Copyright Office), and all applications for copyright registration (including without limitation, applications for copyright registrations of derivative works and compilations), all license royalties, foreign filing rights, and extension rights (collectively, the “ Copyrights ”);

(iii) all trademarks and rights and interests which are capable of being protected as trademarks (including without limitation trademarks, service marks, designs, logos, indicia, tradenames, corporate names, company names, business names, fictitious business names, trade styles, and other source or business identifiers, and the goodwill related thereto and represented thereby, and applications pertaining thereto, and all rights to register trademark claims under any state or federal trademark law or regulation of any foreign country, and to apply for, renew, and extend trademark registrations and trademark rights (collectively, “ Trademarks ” );

(iv) all computer programs, software, source codes, object codes, data bases, processes and trade secrets and all other intellectual property in which Debtor now has or hereafter creates or acquires any interest; and

(v) all applications for any of the foregoing and all licenses with respect to any of the foregoing;

(i) all commercial tort claims in existence on the date of this Agreement or at any time hereafter arising and identified by the Debtor to Secured Party;

together with whatever is receivable or received when any of the foregoing or the proceeds thereof are sold, leased, collected, exchanged or otherwise disposed of, whether such disposition is voluntary or involuntary, including without limitation, all rights to payment, including returned premiums, with respect to any insurance relating to any of the foregoing, any infringement claims or causes of action and all rights to payment with respect to any claim or cause of action affecting or relating to any of the foregoing.

Notwithstanding the foregoing, the Collateral shall not include: (a) interests as a lessee under real property and personal property leases, (b) more than 65% of the voting securities of any Foreign Subsidiary of Debtor; or (c) equipment and related software encumbered by a Permitted Lien covered by paragraph (d) of the definition of Permitted Liens, and any rights of Debtor as licensee, to the extent the granting of a security interest in such equipment or license rights (A) is prohibited by the terms of or would constitute a default under any agreement or document governing such equipment or license right (but only to the extent such prohibition is enforceable under applicable law), or (B) is contrary to applicable law; provided that, upon the cessation of any such restriction or prohibition, such equipment and/or license rights shall automatically become part of the Collateral; and provided further that the provisions of this Section 1 shall in no case exclude from the definition of Collateral any accounts receivables, other rights to payment, general intangibles or proceeds of the disposition of any property. Except as disclosed to Secured Party in writing prior to the date hereof, Debtor represents and warrants to Secured Party that it is not presently a party to, nor is it bound by, any material license, contract or agreement which prohibits Debtor from granting a security interest therein (to the extent such prohibition is enforceable under applicable law). Debtor shall not, hereafter, without Secured Party’s prior written consent, enter into any material license which prohibits Debtor from granting a security interest therein to Secured Party (to the extent such prohibition is enforceable under applicable law), unless Debtor uses commercially reasonable efforts to have such prohibition removed, and in the event Debtor is not successful in having such prohibition removed, Debtor shall give prompt written notice thereof to Secured Party.

Debtor agrees that this Agreement shall create a continuing security interest in the Collateral which shall remain in effect until the payment and performance in full of all of the Secured Obligations.

2. D EBTOR ’ S R EPRESENTATIONS , W ARRANTIES AND C OVENANTS . Debtor represents, warrants and covenants as follows:

(a) Permitted Liens . Debtor has rights in and good title to all of the Collateral. Other than any of the Intellectual Property Collateral for which Debtor is a licensee, Debtor is and will continue to be the sole and exclusive owner of the Collateral, free and clear of all security interests, liens or encumbrances or other rights or claims of third parties (“ Liens ”), other than Permitted Liens. For any of the Intellectual Property Collateral for which Debtor is a licensee, each such license or licensing agreement is in full force and effect and Debtor is not in default of any of its material obligations thereunder.

(b) Organization . Debtor is a registered