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                                                                     Exhibit 3.1

                         CERTIFICATE OF DESIGNATION OF
                           RIGHTS AND PREFERENCES OF
                          SERIES B PREFERRED STOCK OF
                           SPECTRUMEDIX CORPORATION
                           ------------------------

          SpectruMedix Corporation, a corporation organized and existing under
the laws of the State of Delaware (the "Corporation"), hereby certifies as
follows:

          FIRST: That the name of the Corporation is SpectruMedix Corporation,
and the original certificate of incorporation of the Corporation was filed with
the Secretary of State of the State of Delaware on April 16, 1992 under the name
Premier American Technologies Corp. and the Second Amended and Restated
Certificate of Incorporation of the Corporation was filed with the Secretary of
State of the State of Delaware on September 16, 1997.

          SECOND: That the Certificate of Incorporation of the Corporation
authorizes the issuance of 2,000,000 shares of preferred stock, with the Board
of Directors of the Corporation authorized to establish the rights and
preferences thereof in accordance with Section 151(g) of the Delaware General
Corporation Law.

          THIRD:  That, on January 13, 2000, the Board of Directors of the
Corporation duly adopted resolutions setting forth the rights and preferences of
the Series B Preferred Stock.

          FOURTH:  That the rights and preferences of the Series B Preferred
Stock shall be as follows:

1.  Designation; Number of Shares.  The Corporation hereby authorizes the
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issuance of a series of preferred stock, par value $1,000 per share, to be
called the "Series B Preferred Stock."  The total number of shares of Series B
Preferred Stock that the Corporation shall have the authority to issue is 750.
The Corporation shall have the authority to issue fractional shares.

2.  Dividends; Ranking.  Holders of Series B Preferred Stock shall be entitled
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to receive dividends, whether such dividends are payable in cash, securities or
other property, only as and when the Corporation shall declare and pay dividends
in respect of its common stock, par value $.0015 per share (the "Common Stock"),
and absent such a declaration, no dividends shall be payable, accrue or
accumulate in respect of shares of Series B Preferred Stock.  If the Corporation
shall declare a dividend in respect of its Common Stock, each holder of Series B
Preferred Stock shall be paid in an amount equal to the dividend that would be
payable if such holder had converted his shares of Series B Preferred Stock into
shares of Common Stock immediately prior to the record date for the payment of
such dividend.  The Series B Preferred Stock shall rank (i) prior to the Common
Stock, and (ii) junior to the Series A Preferred Stock of the Corporation, in
each case, as to distributions of assets upon liquidation, dissolution or
winding up of the Corporation, whether voluntary or involuntary.

3.  Liquidation Preference.  In the event of any voluntary or involuntary
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liquidation, dissolution or winding-up of the Corporation, the holders of the
Series B Preferred
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Stock shall be entitled to receive out of the assets of the Corporation
available for distribution to stockholders, before any distribution of assets
shall be made to the holders of the Common Stock of the Corporation or any other
capital stock of the Corporation ranking junior to the Series B Preferred Stock
as to any such distribution, an amount in cash for each share equal to the par
value of the Series B Preferred Stock plus all declared and unpaid dividends for
each share of Series B Preferred Stock, if any (collectively, the
"Liquidation Preference"). If upon any voluntary or involuntary liquidation,
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dissolution or winding-up of the Corporation, the amounts payable with respect
to the Series B Preferred Stock and any other stock of the Corporation ranking
as to any such distribution on a parity with the Series B Preferred Stock shall
not be paid in full, then the holders of the Series B Preferred Stock and such
parity stock shall share ratably in any such distribution of assets of the
Corporation in proportion to the full preferential amounts to which they are
entitled. The merger of the Corporation with or into any other corporation, or
the sale of substantially all the assets of the Corporation in consideration for
the issuance of equity securities of another corporation, shall not be regarded
as a liquidation, dissolution or winding-up of the Corporation within the
meaning of this Section 3, but no merger or sale of assets shall in any way
impair the rights, preferences, privileges or priorities of the Series B
Preferred Stock.

4.  Conversion of Series B Preferred Stock.
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(a)  Right to Convert.  Each holder of Series B Preferred Stock shall have the
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     right, at such holder's option, to convert all or any portion of such
     holder's shares of Series B Preferred Stock into 8,000 fully paid and
     nonassessable share of Common Stock (the "Conversion Stock") for each share
     of Series B Preferred Stock presented for conversion, subject to adjustment
     as provided in Section 5 hereof.  The holder of any shares of Series B
     Preferred Stock converted in accordance with the provisions of this Section
     4 shall be entitled to payment of any declared but unpaid dividends thereon
     on the Series B Preferred Stock to be converted to the date of issuance by
     the Corporation of the shares of Conversion Stock.

(b)  Exercise of Conversion Right.  The holder of any shares of Series B
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     Preferred Stock may exercise the conversion right pursuant to Section 4(a)
     hereof by delivering to the Corporation during regular business hours, at
     the office of any transfer agent of the Corporation for the Series B
     Preferred Stock, or at such other place as may be designated by the
     Corporation, the certificate or certificates for the shares of the shares
     to be converted, duly endorsed or assigned in blank to the Corporation,
     accompanied by written notice (a "Conversion Notice") stating that such
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     holder elects to convert all or a specified portion of such shares and
     stating the name or names (with address) in which the certificate or
     certificates for the shares of Conversion Stock are to be issued and the
     class or classes of Conversion Stock to be issued; provided, however, that,
                                                        --------  -------
     if such name or names are other than that of the holder, such issuance of
     Conversion Stock is permitted by applicable Federal and state securities
     laws.  The date of receipt of such certificate or certificates and notice
     by the Corporation or transfer agent, as the case may be, shall be the
     conversion date (the "Conversion Date").  As soon as practicable after the
                           ---------------
     Conversion Date, the Corporation shall issue and deliver to the holder, or
     upon the written order of such holder, to the place designated by such
     holder, (i) a certificate or certificates for the number of full shares of
     Conversion Stock to which such holder is entitled, (ii) a check or cash in
     respect of any fractional interest in a share of Common Stock, as provided
     in Section 4(c) hereof, payable with respect to the shares of Series B
     Preferred Stock so converted up to and including
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     the Conversion Date and (iii) a check or cash representing declared but
     unpaid cash dividends, if any, on the Series B Preferred Stock converted in
     accordance with Section 4(a). The person in whose names the certificate or
     certificates for Conversion Stock are to be issued shall be deemed to have
     become a stockholder of record on the next succeeding date on which the
     transfer books are open. Upon conversion of only a portion of the number of
     shares covered by a certificate representing shares of Series B Preferred
     Stock surrendered for conversion, the Corporation shall issue and deliver
     to or upon the written order of the holder of the certificate so
     surrendered for conversion, at the expense of the Corporation, a new
     certificate covering the number of shares of Series B Preferred Stock
     representing the unconverted portion of the certificate so surrendered.

(c)  No Fractional Shares.  No fractional shares of Conversion Stock or scrip
     --------------------
     shall be issued upon conversion of shares of Series B Preferred Stock.  If
     more than one share of Series B Preferred Stock shall be surrendered for
     conversion at any one time by the same holder, the number of full shares of
     Conversion Stock issuable upon conversion thereof shall be computed using
     the aggregate number of shares of Series B Preferred Stock so surrendered.
     Instead of issuing any fractional shares of Conversion Stock that would
     otherwise be issuable upon conversion of any shares of Series B Preferred
     Stock, the Corporation shall make payment to such holder, in cash, of an
     amount equal to the fraction of a share of Conversion Stock otherwise
     issuable to such holder, multiplied by the Market Price on the Business Day
     immediately prior to conversion.

(d)  Stamp Taxes, Etc.  The Corporation shall pay all documentary, stamp or
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     other transactional taxes or governmental charges attributable to the
     issuance or delivery of shares of capital stock of the corporation upon
     conversion of any shares of Series B Preferred Stock; provided, however,
                                                           -----------------
     that the Corporation shall not be required to pay any taxes which may be
     payable in respect of any transfer involved in the issuance or delivery of
     any certificate of such shares in a name other than that of the holder of
     the shares of Series B Preferred Stock in respect of which such shares are
     being issued.

(e)  Reservation of Common Stock.  The Corporation shall reserve, free from
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     preemptive rights, out of its authorized but unissued shares of Common
     Stock, solely for the purpose of effecting the conversion of the shares of
     Series B Preferred Stock sufficient shares to provide for the conversion of
     all outstanding shares of Series B Preferred Stock.  The Corporation shall
     take all such actions as may be necessary to assure that all such shares of
     Common Stock may be so issued without violation of any applicable law or
     governmental regulation or any requirements of any domestic securities
     exchange upon which shares of Common Stock may be listed (except for
     official notice of issuance which shall be immediately delivered by the
     Corporation upon each such issuance).  The Corporation shall not take any
     action which would cause the number of authorized but unissued shares of
     Common Stock to be less than the number of such shares required to be
     reserved hereunder for issuance upon conversion of the Series B Preferred
     Stock.

(f)  No Liens.  All shares of Conversion Stock which may be issued in connection
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     with the conversion provisions set forth herein will, upon issuance by the
     Corporation, be validly issued, fully paid and nonassessable and free from
     all taxes, liens or charges with respect thereto created or imposed by the
     Corporation.
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(g)  No Impairment.  The Corporation shall not, by amendment of its Certificate
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     of Incorporation or through any reorganization, recapitalization, transfer
     of assets, consolidation, merger, dissolution, issue or sale of securities
     or any other voluntary action, avoid or seek to avoid the observance or
     performance of any of the terms to be observed or performed hereunder by
     the Corporation, but shall at all times in good faith assist in the
     carrying out of all provisions of Sections 4 and 5 hereof and in the taking
     of all such action as may be necessary or appropriate to protect the
     conversion rights of the holders of the Series B Preferred Stock against
     impairment.

5.  Adjustment of Number of Shares of Common Stock.  The applicable number of
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shares of Common Stock issuable upon conversion the Series B Preferred Stock
shall be subject to adjustment from time to time as hereinafter provided for in
this Section 5.

          Subdivision or Combination of Stock.  In case the Corporation shall at
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any time subdivide the outstanding shares of Common Stock into a greater number
of shares, the number of shares issuable upon conversion of the Series B
Preferred Stock immediately prior to such subdivision shall be proportionately
increased, and conversely, in case the outstanding shares of Common Stock shall
be combined at any time into a smaller number of shares, the number of shares
issuable upon conversion of the Series B Preferred Stock immediately prior to
such combination shall be proportionately reduced.

          Adjustments for Consolidation, Merger, Sale of Assets, Reorganization,
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etc.  In case the Corporation (i) consolidates or merges with or into any other,
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or (ii) transfers all or substantially all of its properties and assets to any
other corporation, or (iii) effects a capital reorganization or reclassification
of the capital stock of the Corporation in such a way that holders of Common
Stock shall be entitled to receive stock, securities, cash or assets with
respect to or in exchange for Common Stock, then, and in each such case, proper
provision, in form and substance reasonably satisfactory to the holders of 66-
2/3% of the Series B Preferred Stock then outstanding, shall be made so that,
upon the basis and upon the terms and in the manner provided in this Section
5(b), upon the conversion of the Series B Preferred Stock at any time after the
consummation of such consolidation, merger, transfer, reorganization or
reclassification, each holder shall be entitled to receive, in lieu of shares
issuable upon such conversion of the Series B Preferred Stock prior to such
consummation, the stock and other securities, cash and assets to which such
holder would have been entitled upon such consummation if such Holder had so
converted such Series B Preferred Stock immediately prior thereto.  The
Corporation shall not effect any such consolidation, merger or sale, unless
prior to the consummation thereof, the successor entity (if other than the
Corporation) resulting from consolidation or merger or the entity purchasing
such assets assumes by written instrument, the obligation to deliver to each
such holder such shares of stock, securities or assets as, in accordance with
the foregoing provisions, such holder may be entitled to acquire.

          Notice of Adjustment.  Whenever the number of shares issuable upon the
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conversion of the Series B Preferred Stock is adjusted, as provided in this
Section 5, the Corporation shall prepare and mail to each holder a certificate
setting forth (i) the number of shares issuable upon the conversion of the
Series B Preferred Stock after such adjustment, (ii) a brief statement of the
facts requiring such adjustment and (iii) the computation by which such
adjustment was made.
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          Treasury Shares.  The number of shares of Common Stock outstanding at
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any given time shall not include shares of Common Stock owned or held by or for
the account of the Corporation.  The disposition of any shares of Common Stock
owned or held by or for the account of the Corporation shall be considered an
issue of Common Stock for the purposes of this Section 5.

          Certain Adjustment Rules.  The provisions of this Section 5 shall
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similarly apply to successive transactions.

6.  Voting Rights.
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          Except to the extent the Delaware General Corporation Law requires a
separate vote of the holders of the Common Stock, each holder of outstanding
shares of Series B Preferred Stock shall vote together with the holders of the
Common Stock as a single class and each share of Series B Preferred Stock shall
be entitled to ten votes for each share of Common Stock issuable upon conversion
of a share of Series B Preferred Stock; provided, however, that if any Person
                                        --------  -------
other than Joseph Adlerstein or a member of his immediate family is a holder of
Series B Preferred Stock, each share of Series B Preferred Stock shall be
entitled to one vote for each share of Common Stock issuable upon conversion of
a share of Series B Preferred Stock.

          Notwithstanding the provisions of Section 6(a), so long as any shares
of Series B Preferred Stock shall be outstanding, the affirmative vote or
written consent of the holders of 66-2/3% of the Series B Preferred Stock then
outstanding, voting or consenting separately as a class, shall be required for
the Corporation to:

               (i) amend or repeal any provision of, or add any provision to,
     the Corporation's Certificate of Incorporation or By-laws if such action
     would change the preferences, rights, privileges or powers of, or the
     restrictions provided for the benefit of, the Series B Preferred Stock, or
     increase or decrease the number of shares of Series B Preferred Stock
     authorized hereby; or

               (ii) reclassify any class or series of any Common Stock into
     securities having any preference or priority as to the right to receive
     either dividends or amounts distributable upon liquidation, dissolution or
     winding up of the Corporation superior to any such preference or priority
     of the Series B Preferred Stock.

7.  Definitions.
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(a)  "Business Day" shall mean any day that is not a Saturday, a Sunday or a day
      ------------
     on which banks are required or authorized by law to be closed in the City
     of New York, New York.

(b)  "Convertible Securities" means any evidences of indebtedness, shares of
      ----------------------
     stock, or other securities directly or indirectly convertible into or
     exchangeable for Common Stock.

(c)  "Market Price" means the average of the closing prices of any security's
      ------------
     sales on the principal securities exchange on which such security may at
     the time be listed, or, if there
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     have been no sales on such exchange on any day, the average of the highest
     bid and lowest asked prices on such exchange at the end of such day, or, if
     on any day such security is not so listed, the average of the
     representative bid and asked prices quoted in the NASDAQ System as of 4:00
     P.M., New York time, or, if on any day such security is not quoted in the
     NASDAQ System, the average of the highest bid and lowest asked prices on
     such day in the domestic over-the-counter market as reported by the
     National Quotation Bureau, Incorporated, or any similar successor
     organization, in each such case averaged over a period of 21 days
     consisting of the day as of which "Market Price" is being determined and
     the 20 consecutive business days prior to such day. If at any time such
     security is not listed on any securities exchange or quoted in the NASDAQ
     System or the over-the counter market, the "Market Price" shall be the fair
     value thereof determined in good faith by the Board of Directors of the
     Corporation.

(d)  "Option" means any right, option, or warrant to subscribe for, purchase, or
      ------
     otherwise acquire Common Stock or Convertible Securities.

(e)  "Person" shall mean any corporation, natural person, firm, joint venture,
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     partnership, trust, unincorporated organization, enterprise, government or
     any department or agency of any government.

          8.  Registration of Transfer.  The Corporation shall keep at its
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principal office a register for the registration of Series B Preferred Stock.
Upon the surrender of any certificate representing Series B Preferred Stock at
such place, the Corporation shall, at the request of the record holder of such
certificate, execute and deliver (at the Corporation's expense) a new
certificate or certificates in exchange therefor representing in the aggregate
the number of shares represented by the surrendered certificate.  Each such new
certificate shall be registered in such name and shall represent such number of
shares as is requested by the holder of the surrendered certificate and shall be
substantially identical in form to the surrendered certificate, and dividends
shall accrue on the Series B Preferred Stock represented by such new certificate
from the date to which dividends have been fully paid on such Series B Preferred
Stock represented by the surrendered certificate.

          9.  Replacement.  Upon receipt of evidence reasonably satisfactory to
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the Corporation (an affidavit of the registered holder shall be satisfactory) of
the ownership and the loss, theft, destruction or mutilation of any certificate
evidencing shares of Series B Preferred Stock, and in the case of any such loss,
theft or destruction, upon receipt of indemnity reasonably satisfactory to the
Corporation (provided that if the holder is a financial institution or other
institutional investor its own agreement shall be satisfactory), or, in the case
of any such mutilation upon surrender of such certificate, the Corporation shall
(at its expense) execute and deliver in lieu of such certificate a new
certificate of like kind representing the number of shares of such class
represented by such lost, stolen, destroyed or mutilated certificate and dated
the date of such lost, stolen, destroyed or mutilated certificate, and dividends
shall accrue on the Series B Preferred Stock represented by such new certificate
from the date to which dividends have been fully paid on such lost, stolen,
destroyed or mutilated certificate.
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          IN WITNESS WHEREOF, the undersigned has executed this Certificate of
Amendment this 22nd day of February, 2000.

                              /s/ Joseph K. Adlerstein
                              ----------------------------------
                              Joseph K Adlerstein, Chairman and
                              Chief Executive Officer