CALLABLE SECURED CONVERTIBLE NOTE

Exhibit 10.15

THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “ACT”). THE SECURITIES MAY NOT BE SOLD, TRANSFERRED OR ASSIGNED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT FOR THE SECURITIES UNDER SAID ACT, OR AN OPINION OF COUNSEL IN FORM, SUBSTANCE AND SCOPE CUSTOMARY FOR OPINIONS OF COUNSEL IN COMPARABLE TRANSACTIONS THAT REGISTRATION IS NOT REQUIRED UNDER SAID ACT OR UNLESS SOLD PURSUANT TO RULE 144 OR REGULATION S UNDER SAID ACT.

FOR VALUE RECEIVED , PEDIATRIC PROSTHETICS, INC. , an Idaho Corporation (hereinafter called the “ Borrower ”), hereby promises to pay to the order of AJW QUALIFIED PARTNERS, LLC or registered assigns (the “ Holder ”) the sum of $111,600, on February 16, 2010 (the “Maturity Date ”), and to pay interest on the unpaid principal balance hereof at the rate of six percent (6%) (the “ Interest Rate ”) per annum from February 16, 2007 (the “ Issue Date ”) until the same becomes due and payable, whether at maturity or upon acceleration or by prepayment or otherwise. Any amount of principal or interest on this Note which is not paid when due shall bear interest at the rate of fifteen percent (15%) per annum from the due date thereof until the same is paid (“ Default Interest ”). Interest shall commence accruing on the Issue Date, shall be computed on the basis of a 365-day year and the actual number of days elapsed and shall be payable quarterly provided that no interest shall be due and payable for any month in which the Trading Price (as such term is defined below) is greater than $.10375 for each Trading Day (as such term is defined below) of the month. All payments due hereunder (to the extent not converted into common stock, $.001 par value per share (the “Common Stock” ) in accordance with the terms hereof) shall be made in lawful money of the United States of America. All payments shall be made at such address as the Holder shall hereafter give to the Borrower by written notice made in accordance with the provisions of this Note. Whenever any amount expressed to be due by the terms of this Note is due on any day which is not a business day, the same shall instead be due on the next succeeding day which is a business day and, in the case of any interest payment date which is not the date on which this Note is paid in full, the extension of the due date thereof shall not be taken into account for purposes of determining the amount of interest due on such date. As used in this Note, the term “business day” shall mean any day other than a Saturday, Sunday or a day on which commercial banks in the city of New York, New York are authorized or required by law or executive order to

remain closed. Each capitalized term used herein, and not otherwise defined, shall have the meaning ascribed thereto in that certain Securities Purchase Agreement, dated May 30, 2006, pursuant to which this Note was originally issued (the “ Purchase Agreement ”).

This Note is free from all taxes, liens, claims and encumbrances with respect to the issue thereof and shall not be subject to preemptive rights or other similar rights of shareholders of the Borrower and will not impose personal liability upon the holder thereof. The obligations of the Borrower under this Note shall be secured by that certain Security Agreement and Intellectual Property Security Agreement, each dated May 30, 2006 by and between the Borrower and the Holder.

The following terms shall apply to this Note:

1.1   Conversion Right . The Holder shall have the right from time to time, and at any time on or prior to the earlier of (i) the Maturity Date and (ii) the date of payment of the Default Amount (as defined in Article III) pursuant to Section 1.6(a) or Article III, the Optional Prepayment Amount (as defined in Section 5.1 or any payments pursuant to Section 1.7, each in respect of the remaining outstanding principal amount of this Note to convert all or any part of the outstanding and unpaid principal amount of this Note into fully paid and non-assessable shares of Common Stock, as such Common Stock exists on the Issue Date, or any shares of capital stock or other securities of the Borrower into which such Common Stock shall hereafter be changed or reclassified at the conversion price (the “ Conversion Price ”) determined as provided herein (a “ Conversion ”); provided , however , that in no event shall the Holder be entitled to convert any portion of this Note in excess of that portion of this Note upon conversion of which the sum of (1) the number of shares of Common Stock beneficially owned by the Holder and its affiliates (other than shares of Common Stock which may be deemed beneficially owned through the ownership of the unconverted portion of the Notes or the unexercised or unconverted portion of any other security of the Borrower (including, without limitation, the warrants issued by the Borrower pursuant to the Purchase Agreement) subject to a limitation on conversion or exercise analogous to the limitations contained herein) and (2) the number of shares of Common Stock issuable upon the conversion of the portion of this Note with respect to which the determination of this proviso is being made, would result in beneficial ownership by the Holder and its affiliates of more than 4.99% of the outstanding shares of Common Stock and provided   further that the Holder shall not be entitled to convert any portion of this Note during any month immediately succeeding a Determination Date on which the Borrower exercises its prepayment option pursuant to Section 5.2 of this Note. For purposes of the proviso to the immediately preceding sentence, beneficial ownership shall be determined in accordance with Section 13(d) of the Securities Exchange Act of 1934, as amended, and Regulations 13D-G thereunder, except as otherwise provided in clause (1) of such proviso. The number of shares of Common Stock to be issued upon each conversion of this Note shall be determined by dividing the Conversion Amount (as defined below) by the applicable Conversion Price then in effect on the date specified in the notice of conversion, in the form attached hereto as Exhibit A (the “ Notice of Conversion ”), delivered to the Borrower by the Holder in accordance with Section 1.4 below; provided that the Notice of Conversion is submitted by facsimile (or by other means resulting in, or reasonably expected to result in, notice) to the Borrower before 6:00 p.m., New York, New York time on such conversion date (the “ Conversion Date ”).

  The term “ Conversion Amount ” means, with respect to any conversion of this Note, the sum of (1) the principal amount of this Note to be converted in such conversion plus (2) accrued and unpaid interest, if any, on such principal amount at the interest rates provided in this Note to the Conversion Date, provided, however, that the Company shall have the right to pay any or all interest in cash plus (3) Default Interest, if any, on the amounts referred to in the immediately preceding clauses (1) and/or (2) plus (4) at the Holder’s option, any amounts owed to the Holder pursuant to Sections 1.3 and 1.4(g) hereof or pursuant to Section 2(c) of that certain Registration Rights Agreement, dated as of May 30, 2006, executed in connection with the initial issuance of this Note and the other Notes issued on the Issue Date (the “ Registration Rights Agreement ”). The term “Determination Date” means the last business day of each month after the Issue Date.

1.2   Conversion Price .

(a)   Calculation of Conversion Price . The Conversion Price shall be the Variable Conversion Price (as defined herein) (subject, in each case, to equitable adjustments for stock splits, stock dividends or rights offerings by the Borrower relating to the Borrower’s securities or the securities of any subsidiary of the Borrower, combinations, recapitalization, reclassifications, extraordinary distributions and similar events). The “ Variable Conversion Price ” shall mean the Applicable Percentage (as defined herein) multiplied by the Market Price (as defined herein). “ Market Price ” means the average of the lowest three (3) Trading Prices (as defined below) for the Common Stock during the twenty (20) Trading Day period ending one Trading Day prior to the date the Conversion Notice is sent by the Holder to the Borrower via facsimile (the “ Conversion Date ”). “ Trading Price ” means, for any security as of any date, the intraday trading price on the Over-the-Counter Bulletin Board (the “ OTCBB ”) as reported by a reliable reporting service ( “Reporting Service” ) mutually acceptable to Borrower and Holder and hereafter designated by Holders of a majority in interest of the Notes and the Borrower or, if the OTCBB is not the principal trading market for such security, the intraday trading price of such security on the principal securities exchange or trading market where such security is listed or traded or, if no intraday trading price of such security is available in any of the foregoing manners, the average of the intraday trading prices of any market makers for such security that are listed in the “pink sheets” by the National Quotation Bureau, Inc. If the Trading Price cannot be calculated for such security on such date in the manner provided above, the Trading Price shall be the fair market value as mutually determined by the Borrower and the holders of a majority in interest of the Notes being converted for which the calculation of the Trading Price is required in order to determine the Conversion Price of such Notes. “ Trading Day ” shall mean any day on which the Common Stock is traded for any period on the OTCBB, or on the principal securities exchange or other securities market on which the Common Stock is then being traded. “ Applicable Percentage ” shall mean 50%; provided, however, that the Applicable Percentage shall be increased to (i) 55% in the event that the Registration Statement (as defined in the Registration Rights Agreement) is filed on or before the Filing Date (as defined in the in the Registration Rights Agreement) and (ii) 60% in the event that the Registration Statement (as defined in the Registration Rights Agreement) becomes effective on or before the Effectiveness Deadline (as defined in the Registration Rights Agreement). In addition, the Holder agrees that it will limit all of its conversions to no more than the greater of (1) $80,000 per calendar month; or (2) the average daily dollar volume calculated during the ten (10) business days prior to a conversion, per conversion.

(b)   Conversion Price During Major Announcements . Notwithstanding anything contained in Section 1.2(a) to the contrary, in the event the Borrower (i) makes a public announcement that it intends to consolidate or merge with any other corporation (other than a merger in which the Borrower is the surviving or continuing corporation and its capital stock is unchanged) or sell or transfer all or substantially all of the assets of the Borrower or (ii) any person, group or entity (including the Borrower) publicly announces a tender offer to purchase 50% or more of the Borrower’s Common Stock (or any other takeover scheme) (the date of the announcement referred to in clause (i) or (ii) is hereinafter referred to as the “ Announcement Date ”), then the Conversion Price shall, effective upon the Announcement Date and continuing through the Adjusted Conversion Price Termination Date (as defined below), be equal to the lower of (x) the Conversion Price which would have been applicable for a Conversion occurring on the Announcement Date and (y) the Conversion Price that would otherwise be in effect. From and after the Adjusted Conversion Price Termination Date, the Conversion Price shall be determined as set forth in this Section 1.2(a). For purposes hereof, “ Adjusted Conversion Price Termination Date ” shall mean, with respect to any proposed transaction or tender offer (or takeover scheme) for which a public announcement as contemplated by this Section 1.2(b) has been made, the date upon which the Borrower (in the case of clause (i) above) or the person, group or entity (in the case of clause (ii) above) consummates or publicly announces the termination or abandonment of the proposed transaction or tender offer (or takeover scheme) which caused this Section 1.2(b) to become operative.

1.3   Authorized Shares . Subject to Stockholder Approval (as such term is defined in Section 4(n) of the Securities Purchase Agreement), the Borrower covenants that during the period the conversion right exists, the Borrower will reserve from its authorized and unissued Common Stock a sufficient number of shares, free from preemptive rights, to provide for the issuance of Common Stock upon the full conversion of this Note and the other Notes issued pursuant to the Purchase Agreement. The Borrower is required at all times to have authorized and reserved two times the number of shares that is actually issuable upon full conversion of the Notes (based on the Conversion Price of the Notes or the Exercise Price of the Warrants in effect from time to time) (the “ Reserved Amount ”). The Reserved Amount shall be increased from time to time in accordance with the Borrower’s obligations pursuant to Section 4(h) of the Purchase Agreement. The Borrower represents that upon issuance, such shares will be duly and validly issued, fully paid and non-assessable. In addition, if the Borrower shall issue any securities or make any change to its capital structure which would change the number of shares of Common Stock into which the Notes shall be convertible at the then current Conversion Price, the Borrower shall at the same time make proper provision so that thereafter there shall be a sufficient number of shares of Common Stock authorized and reserved, free from preemptive rights, for conversion of the outstanding Notes. The Borrower (i) acknowledges that it has irrevocably instructed its transfer agent to issue certificates for the Common Stock issuable upon conversion of this Note, and (ii) agrees that its issuance of this Note shall constitute full authority to its officers and agents who are charged with the duty of executing stock certificates to execute and issue the necessary certificates for shares of Common Stock in accordance with the terms and conditions of this Note.

If, at any time a Holder of this Note submits a Notice of Conversion, and the Borrower does not have sufficient authorized but unissued shares of Common Stock available to effect such conversion in accordance with the provisions of this Article I (a “ Conversion Default ”), subject to Section 4.8, the Borrower shall issue to the Holder all of the shares of Common Stock which are then available to effect such conversion. The portion of this Note which the Holder included in its Conversion Notice and which exceeds the amount which is then convertible into available shares of Common Stock (the “ Excess Amount ”) shall, notwithstanding anything to the contrary contained herein, not be convertible into Common Stock in accordance with the terms hereof until (and at the Holder’s option at any time after) the date additional shares of Common Stock are authorized by the Borrower to permit such conversion, at which time the Conversion Price in respect thereof shall be the lesser of (i) the Conversion Price on the Conversion Default Date (as defined below) and (ii) the Conversion Price on the Conversion Date thereafter elected by the Holder in respect thereof. In addition, the Borrower shall pay to the Holder payments (“ Conversion Default Payments ”) for a Conversion Default in the amount of (x) the sum of (1) the then outstanding principal amount of this Note plus (2) accrued and unpaid interest on the unpaid principal amount of this Note through the Authorization Date (as defined below) plus (3) Default Interest, if any, on the amounts referred to in clauses (1) and/or (2), multiplied by (y) .24, multiplied by (z) (N/365), where N = the number of days from the day the holder submits a Notice of Conversion giving rise to a Conversion Default (the “ Conversion Default Date ”) to the date (the “ Authorization Date ”) that the Borrower authorizes a sufficient number of shares of Common Stock to effect conversion of the full outstanding principal balance of this Note. The Borrower shall use its best efforts to authorize a sufficient number of shares of Common Stock as soon as practicable following the earlier of (i) such time that the Holder notifies the Borrower or that the Borrower otherwise becomes aware that there are or likely will be insufficient authorized and unissued shares to allow full conversion thereof and (ii) a Conversion Default. The Borrower shall send notice to the Holder of the authorization of additional shares of Common Stock, the Authorization Date and the amount of Holder’s accrued Conversion Default Payments. The accrued Conversion Default Payments for each calendar month shall be paid in cash or shall be convertible into Common Stock (at such time as there are sufficient authorized shares of Common Stock) at the applicable Conversion Price, at the Borrower’s option, as follows:

(a)   In the event Holder elects to take such payment in cash, cash payment shall be made to Holder by the fifth (5 ^th ) day of the month following the month in which it has accrued; and

(b)   In the event Holder elects to take such payment in Common Stock, the Holder may convert such payment amount into Common Stock at the Conversion Price (as in effect at the time of conversion) at any time after the fifth day of the month following the month in which it has accrued in accordance with the terms of this Article I (so long as there is then a sufficient number of authorized shares of Common Stock).

The Holder’s election shall be made in writing to the Borrower at any time prior to 6:00 p.m., New York, New York time, on the third day of the month following the month in which Conversion Default payments have accrued. If no election is made, the Holder shall be deemed to have elected to receive cash. Nothing herein shall limit the Holder’s right to pursue actual damages (to the extent in excess of the Conversion Default Payments) for the Borrower’s failure to maintain a sufficient number of authorized shares of Common Stock, and each holder shall have the right to pursue all remedies available at law or in equity (including degree of specific performance and/or injunctive relief).

1.4   Method of Conversion .

(a)   Mechanics of Conversion . Subject to Section 1.1, this Note may be converted by the Holder in whole or in part at any time from time to time after the Issue Date, by (A) submitting to the Borrower a Notice of Conversion (by facsimile or other reasonable means of communication dispatched on the Conversion Date prior to 6:00 p.m., New York, New York time) and (B) subject to Section 1.4(b), surrendering this Note at the principal office of the Borrower.

(b)   Surrender of Note Upon Conversion . Notwithstanding anything to the contrary set forth herein, upon conversion of this Note in accordance with the terms hereof, the Holder shall not be required to physically surrender this Note to the Borrower unless the entire unpaid principal amount of this Note is so converted. The Holder and the Borrower shall maintain records showing the principal amount so converted and the dates of such conversions or shall use such other method, reasonably satisfactory to the Holder and the Borrower, so as not to require physical surrender of this Note upon each such conversion. In the event of any dispute or discrepancy, such records of the Borrower shall be controlling and determinative in the absence of manifest error. Notwithstanding the foregoing, if any portion of this Note is converted as aforesaid, the Holder may not transfer this Note unless the Holder first physically surrenders this Note to the Borrower, whereupon the Borrower will forthwith issue and deliver upon the order of the Holder a new Note of like tenor, registered as the Holder (upon payment by the Holder of any applicable transfer taxes) may request, representing in the aggregate the remaining unpaid principal amount of this Note. The Holder and any assignee, by acceptance of this Note, acknowledge and agree that, by reason of the provisions of this paragraph, following conversion of a portion of this Note, the unpaid and unconverted principal amount of this Note represented by this Note may be less than the amount stated on the face hereof.

(c)   Payment of Taxes . The Borrower shall not be required to pay any tax which may be payable in respect of any transfer involved in the issue and delivery of shares of Common Stock or other securities or property on conversion of this Note in a name other than that of the Holder (or in street name), and the Borrower shall not be required to issue or deliver any such shares or other securities or property unless and until the person or persons (other than the Holder or the custodian in whose street name such shares are to be held for the Holder’s account) requesting the issuance thereof shall have paid to the Borrower the amount of any such tax or shall have established to the satisfaction of the Borrower that such tax has been paid.

(d)   Delivery of Common Stock Upon Conversion . Upon receipt by the Borrower from the Holder of a facsimile transmission (or other reasonable means of communication) of a Notice of Conversion meeting the requirements for conversion as provided in this Section 1.4, the Borrower shall issue and deliver or cause to be issued and delivered to or upon the order of the Holder certificates for the Common Stock issuable upon such conversion within three (3) business days after such receipt (and, solely in the case of conversion of the entire unpaid principal amount hereof, surrender of this Note)

 (such third business day being hereinafter referred to as the “ Deadline ”) in accordance with the terms hereof and the Purchase Agreement (including, without limitation, in accordance with the requirements of Section 2(g) of the Purchase Agreement that certificates for shares of Common Stock issued on or after the effective date of the Registration Statement upon conversion of this Note shall not bear any restrictive legend).

(e)   Obligation of Borrower to Deliver Common Stock . Upon receipt by the Borrower of a Notice of Conversion, the Holder shall be deemed to be the holder of record of the Common Stock issuable upon such conversion, the outstanding principal amount and the amount of accrued and unpaid interest on this Note shall be reduced to reflect such conversion, and, unless the Borrower defaults on its obligations under this Article I, all rights with respect to the portion of this Note being so converted shall forthwith terminate except the right to receive the Common Stock or other securities, cash or other assets, as herein provided, on such conversion. If the Holder shall have given a Notice of Conversion as provided herein, the Borrower’s obligation to issue and deliver the certificates for Common Stock shall be absolute and unconditional, irrespective of the absence of any action by the Holder to enforce the same, any waiver or consent with respect to any provision thereof, the recovery of any judgment against any person or any action to enforce the same, any failure or delay in the enforcement of any other obligation of the Borrower to the holder of record, or any setoff, counterclaim, recoupment, limitation or termination, or any breach or alleged breach by the Holder of any obligation to the Borrower, and irrespective of any other circumstance which might otherwise limit such obligation of the Borrower to the Holder in connection with such conversion. The Conversion Date specified in the Notice of Conversion shall be the Conversion Date so long as the Notice of Conversion is received by the Borrower before 6:00 p.m., New York, New York time, on such date.

(f)   Delivery of Common Stock by Electronic Transfer . In lieu of delivering physical certificates representing the Common Stock issuable upon conversion, provided the Borrower’s transfer agent is participating in the Depository Trust Company (“ DTC ”) Fast Automated Securities Transfer (“ FAST ”) program, upon request of the Holder and its compliance with the provisions contained in Section 1.1 and in this Section 1.4, the Borrower shall use its best efforts to cause its transfer agent to electronically transmit the Common Stock issuable upon conversion to the Holder by crediting the account of Holder’s Prime Broker with DTC through its Deposit Withdrawal Agent Commission (“ DWAC ”) system.

(g)   Failure to Deliver Common Stock Prior to Deadline . Without in any way limiting the Holder’s right to pursue other remedies, including actual damages and/or equitable relief, the parties agree that if delivery of the Common Stock issuable upon conversion of this Note is more than three (3) business days after the Deadline (other than a failure due to the circumstances described in Section 1.3 above, which failure shall be governed by such Section) the Borrower shall pay to the Holder $1,000 per day in cash, for each day beyond the Deadline that the Borrower fails to deliver such Common Stock. Such cash amount shall be paid to Holder by the fifth day of the month following the month in which it has accrued or, at the option of the Holder (by written notice to the Borrower by the first day of the month following the month in which it has accrued), shall be added to the principal amount of this Note, in which event interest shall accrue thereon in accordance with the terms of this Note and such additional principal amount shall be convertible into Common Stock in accordance with the terms of this Note.

1.5   Concerning the Shares . The shares of Common Stock issuable upon conversion of this Note may not be sold or transferred unless (i) such shares are sold pursuant to an effective registration statement under the Act or (ii) the Borrower or its transfer agent shall have been furnished with an opinion of counsel (which opinion shall be in form, substance and scope customary for opinions of counsel in comparable transactions) to the effect that the shares to be sold or transferred may be sold or transferred pursuant to an exemption from such registration or (iii) such shares are sold or transferred pursuant to Rule 144 under the Act (or a successor rule) (“ Rule 144 ”) or (iv) such shares are transferred to an “affiliate” (as defined in Rule 144) of the Borrower who agrees to sell or otherwise transfer the shares only in accordance with this Section 1.5 and who is an Accredited Investor (as defined in the Purchase Agreement). Except as otherwise provided in the Purchase Agreement (and subject to the removal provisions set forth below), until such time as the shares of Common Stock issuable upon conversion of this Note have been registered under the Act as contemplated by the Registration Rights Agreement or otherwise may be sold pursuant to Rule 144 without any restriction as to the number of securities as of a particular date that can then be immediately sold, each certificate for shares of Common Stock issuable upon conversion of this Note that has not been so included in an effective registration statement or that has not been sold pursuant to an effective registration statement or an exemption that permits removal of the legend, shall bear a legend substantially in the following form, as appropriate:

“THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED. THE SECURITIES MAY NOT BE SOLD, TRANSFERRED OR ASSIG