SC 13D/A


                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  Schedule 13D

                    Under the Securities Exchange Act of 1934
                                (Amendment No. 4)

                             Criticare Systems, Inc.
                                (Name of Issuer)


                                  Common Stock
                         (Title of Class of Securities)

                                    226901106
                                 (CUSIP Number)

                                 Scott A. Shuda
                             BlueLine Partners, LLC
                     4115 Blackhawk Plaza Circle, Suite 100
                           Danville, California 94506

                  (Name, Address and Telephone Number of Person
                Authorized to Receive Notices and Communications)

                                    Copy to:

                                 James C. Creigh
                       Blackwell Sanders Peper Martin LLP
                          1620 Dodge Street, Suite 2100
                              Omaha, Nebraska 68102
                                 (402) 964-5000

                                February 7, 2006
                      (Date of Event which Requires Filing
                               of this Statement)


If the filing person has previously  filed a statement on Schedule 13G to report
the  acquisition  that is the subject of this  Schedule  13D, and is filing this
schedule  because of Rule 13d-1(e),  Rule 13d-1(f) or Rule  13d-1(g),  check the
following box [ ].


                                  Page 1 of 10





----------------------------
CUSIP No.  226901106       -
----------------------------

---------- ---------------------------------------------------------------------
    1      NAME OF REPORTING PERSON/
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (entities only)
           BlueLine Catalyst Fund VII, L.P.
---------- ---------------------------------------------------------------------
           CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See
    2      Instructions) (a) [   ]
                         (b) [ X ]
---------- ---------------------------------------------------------------------
    3      SEC USE ONLY

---------- ---------------------------------------------------------------------
    4      SOURCE OF FUNDS (See Instructions)
           WC
---------- ---------------------------------------------------------------------
    5      CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
           ITEMS 2(d) or 2(e)   [    ]
---------- ---------------------------------------------------------------------
    6      CITIZENSHIP OR PLACE OF ORGANIZATION
           Delaware
--------------------------- ----- ----------------------------------------------
                          -   7    SOLE VOTING POWER
                          -            0
      NUMBER OF           - ----- ----------------------------------------------
       SHARES             -   8    SHARED VOTING POWER
    BENEFICIALLY          -            449,800
    OWNED BY EACH         - ----- ----------------------------------------------
      REPORTING           -   9    SOLE DISPOSITIVE POWER
       PERSON             -            0
        WITH              - ----- ----------------------------------------------
                          -   10   SHARED DISPOSITIVE POWER
                          -            449,800
--------------------------- ----- ----------------------------------------------
   11      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                974,600
---------- ---------------------------------------------------------------------
   12      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
           SHARES [ ]
                (See Instructions)
---------- ---------------------------------------------------------------------
   13      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
                8.1%
---------- ---------------------------------------------------------------------
   14      TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
                                       PN
---------- ---------------------------------------------------------------------


                                  Page 2 of 10





----------------------------
CUSIP No.  226901106       -
----------------------------

---------- ---------------------------------------------------------------------
    1      NAME OF REPORTING PERSON/
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (entities only)
           BlueLine Partners, L.L.C.
---------- ---------------------------------------------------------------------
           CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See
    2      Instructions) (a) [   ]
                         (b) [ X ]
---------- ---------------------------------------------------------------------
    3      SEC USE ONLY

---------- ---------------------------------------------------------------------
    4      SOURCE OF FUNDS (See Instructions)
           WC
---------- ---------------------------------------------------------------------
    5      CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
           ITEMS 2(d) or 2(e)   [    ]
---------- ---------------------------------------------------------------------
    6      CITIZENSHIP OR PLACE OF ORGANIZATION
           California
--------------------------- ----- ----------------------------------------------
                          -   7    SOLE VOTING POWER
                          -            0
      NUMBER OF           - ----- ----------------------------------------------
       SHARES             -   8    SHARED VOTING POWER
    BENEFICIALLY          -            449,800
    OWNED BY EACH         - ----- ----------------------------------------------
      REPORTING           -   9    SOLE DISPOSITIVE POWER
       PERSON             -            0
        WITH              - ----- ----------------------------------------------
                          -   10   SHARED DISPOSITIVE POWER
                          -            449,800
--------------------------- ----- ----------------------------------------------
   11      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                974,600
---------- ---------------------------------------------------------------------
   12      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
           SHARES [ ]
                (See Instructions)
---------- ---------------------------------------------------------------------
   13      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
                8.1%
---------- ---------------------------------------------------------------------
   14      TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
                                       OO
---------- ---------------------------------------------------------------------


                                  Page 3 of 10





----------------------------
CUSIP No.  226901106       -
----------------------------

---------- ---------------------------------------------------------------------
    1      NAME OF REPORTING PERSON/
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (entities only)
           BlueLine Capital Partners, L.P.
---------- ---------------------------------------------------------------------
           CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See
    2      Instructions) (a) [   ]
                         (b) [ X ]
---------- ---------------------------------------------------------------------
    3      SEC USE ONLY

---------- ---------------------------------------------------------------------
    4      SOURCE OF FUNDS (See Instructions)
           WC
---------- ---------------------------------------------------------------------
    5      CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
           ITEMS 2(d) or 2(e)   [    ]
---------- ---------------------------------------------------------------------
    6      CITIZENSHIP OR PLACE OF ORGANIZATION
           Delaware
--------------------------- ----- ----------------------------------------------
                          -   7    SOLE VOTING POWER
                          -            0
      NUMBER OF           - ----- ----------------------------------------------
       SHARES             -   8    SHARED VOTING POWER
    BENEFICIALLY          -            524,800
    OWNED BY EACH         - ----- ----------------------------------------------
      REPORTING           -   9    SOLE DISPOSITIVE POWER
       PERSON             -            0
        WITH              - ----- ----------------------------------------------
                          -   10   SHARED DISPOSITIVE POWER
                          -            524,800
--------------------------- ----- ----------------------------------------------
   11      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                974,600
---------- ---------------------------------------------------------------------
   12      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
           SHARES [ ]
                (See Instructions)
---------- ---------------------------------------------------------------------
   13      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
                8.1%
---------- ---------------------------------------------------------------------
   14      TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
                                       PN
---------- ---------------------------------------------------------------------


                                  Page 4 of 10





----------------------------
CUSIP No.  226901106       -
----------------------------

---------- ---------------------------------------------------------------------
    1      NAME OF REPORTING PERSON/
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (entities only)
           BlueLine Partners, L.L.C.
---------- ---------------------------------------------------------------------
           CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See
    2      Instructions) (a) [   ]
                         (b) [ X ]
---------- ---------------------------------------------------------------------
    3      SEC USE ONLY

---------- ---------------------------------------------------------------------
    4      SOURCE OF FUNDS (See Instructions)
           WC
---------- ---------------------------------------------------------------------
    5      CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
           ITEMS 2(d) or 2(e)   [    ]
---------- ---------------------------------------------------------------------
    6      CITIZENSHIP OR PLACE OF ORGANIZATION
           Delaware
--------------------------- ----- ----------------------------------------------
                          -   7    SOLE VOTING POWER
                          -            0
      NUMBER OF           - ----- ----------------------------------------------
       SHARES             -   8    SHARED VOTING POWER
    BENEFICIALLY          -            524,800
    OWNED BY EACH         - ----- ----------------------------------------------
      REPORTING           -   9    SOLE DISPOSITIVE POWER
       PERSON             -            0
        WITH              - ----- ----------------------------------------------
                          -   10   SHARED DISPOSITIVE POWER
                          -            524,800
--------------------------- ----- ----------------------------------------------
   11      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                974,600
---------- ---------------------------------------------------------------------
   12      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
           SHARES [ ]
                (See Instructions)
---------- ---------------------------------------------------------------------
   13      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
                8.1%
---------- ---------------------------------------------------------------------
   14      TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
                                       OO
---------- ---------------------------------------------------------------------


                                  Page 5 of 10





     This  Amendment  No.  4  (this  "Amendment")  amends  and  supplements  the
statement on Schedule 13D filed by BlueLine  Catalyst Fund VII, L.P.  ("BlueLine
Catalyst") and BlueLine Partners, L.L.C. ("BlueLine California") on December 14,
2004 (the  "Schedule  13D") and  Amendment No. 1 to such filing made by the same
entities on April 11, 2005 and  Amendment  No. 2 filed on September 28, 2005 and
Amendment  No. 3 filed on  December  14, 2005 by the above  named  entities  and
BlueLine Capital Partners, L.P ("BCP") and BlueLine Partners, L.L.C., a Delaware
limited  liability  company  and the  sole  general  Partner  of BCP  ("BlueLine
Partners")  relating  to the common  stock  (the  "Common  Stock") of  Criticare
Systems, Inc. (the "Company"). Items designated as "no change" indicate that the
information  previously  included in the Schedule 13D remains  current as of the
date of this Amendment.

Item 1. Security and Issuer

No change.

Item 2. Identity and Background

No change.

Item 3. Source and Amount of Funds

Item 3 is hereby amended and restated to read as follows:

As of the date hereof, the Reporting  Entities may, in the aggregate,  be deemed
to beneficially  own 974,600 shares of Common Stock (the  "Shares").  The Shares
were  purchased  by  BlueLine  Catalyst  and BCP in the open  market  with their
investment capital.

Item 4. Purpose of the Transaction

Item 4 is hereby amended to include the following:

The Reporting Entities invest in companies they believe are undervalued relative
to their potential.  These are not companies that are broken, but rather,  those
in situations  where if certain issues were  addressed and  identified  problems
fixed, the companies could be expected to trade at significantly  higher values.
As part of each  investment,  the Reporting  Entities  identify these issues and
seek to work with management,  the board of directors and other  shareholders to
address and correct the problems and thereby create shareholder  value.  Because
BlueLine's perspective and advice relate to operational issues and not financial
engineering,   BlueLine's  participation  is  usually  well  received  by  other
stakeholders.

The  Company is clearly  performing  better now than it did prior to  BlueLine's
investment.  Published  analyst  reports project that revenues will reach record
levels in fiscal  year  2006 and the  Company  has  reported  three  consecutive
quarters of profitable  operations.  In addition,  management is to be commended
for the job it has done in creating opportunities around new products and recent
developments in the marketplace.  There remains,  however,  significant room for
improvement  in the areas of cost  controls,  financial  planning  and  investor
relations.  The Company must leverage top line growth to improve net margins and
increase its profitability.


                                  Page 6 of 10





The Company must also exhibit  greater control over its business and the message
it communicates to investors.

The Company's  management has been promoting its product initiatives and new OEM
relationships  for some time.  Investors are growing  impatient with promises of
future  performance and the Company's  management must begin delivering  against
the  expectations  that it has set. To this end,  the  Reporting  Entities  have
advocated  governance  reforms  and a greater  role for the  Company's  board of
directors.  A more active board should help management set  priorities,  produce
budgets and financial  projections,  develop a better defined investor  message,
and,  most  importantly,  hold  management  accountable  if it fails to  achieve
established  performance  metrics.  This last item could be effectively  done by
creating an executive compensation plan that links pay to performance.  BlueLine
takes some  encouragement  from the recent  appointment  of a new director  with
public company  experience,  but will continue to press for  governance  reforms
until it  believes  that the board  will  adhere to its own  written  governance
policies as well as accepted norms of good corporate governance.

Depending on market conditions,  general economic  conditions and other factors,
including the degree of their  participation in the Company's  business affairs,
the  Reporting  Entities may purchase  additional  shares of Common Stock in the
open  market or in private  transactions,  or may dispose of all or a portion of
the  shares  of  Common  Stock  that  they or any of them  presently  own or may
hereafter acquire.

Item 5. Interest in Securities of the Issuer

Item 5 is hereby amended and restated to read as follows:

(a)  As of the date of this  Amendment,  each of the  Reporting  Entities may be
     deemed  to own  974,600  shares  of  Common  Stock.  The  Shares  represent
     approximately  8.1% of the  shares of  Common  Stock  outstanding  based on
     12,062,268  shares of the Company's Common Stock outstanding as reported in
     the Company's  report on Form 10-Q for the Company's  fiscal  quarter ended
     September 30, 2005 as filed with the Securities and Exchange  Commission on
     November 10, 2005.

     The Reporting  Entities are making this single,  joint filing  because they
     may be deemed to  constitute  a  "group"  within  the  meaning  of  Section
     13(d)(3) of the Act. Each Reporting Entity expressly  disclaims  beneficial
     ownership  of any of the shares of Common  Stock other than those  reported
     herein as being owned by it.

(b)  As of the  date of this  Amendment  No. 4 to  Schedule  13D:  (i)  BlueLine
     Catalyst  beneficially  owns  449,800  shares of Common  Stock  with  which
     BlueLine Catalyst has shared voting power and shared dispositive power with
     the other Reporting Entities;  (ii) BlueLine  California  beneficially owns
     449,800  shares of Common Stock with which  BlueLine  California has shared
     voting  power  and  shared  dispositive  power  with  the  other  Reporting
     Entities;  (iii) BCP beneficially  owns 524,800 shares of Common Stock with
     which BCP has shared  voting  power and shared  dispositive  power with the
     other Reporting  Entities;  and (iv) BlueLine  Partners  beneficially  owns
     524,800 shares of Common Stock with which BlueLine


                                  Page 7 of 10





     Partners  has shared  voting  power and shared  dispositive  power with the
     other Reporting Entities.

(c)  Information  concerning  transactions  in the Common Stock  effected by the
     Reporting  Entities  during  the past  sixty days is set forth in Exhibit B
     hereto and is incorporated by this reference.  All of the  transactions set
     forth in Exhibit B were open market transactions for cash.

(d)  No person (other than the Reporting Entities) is known to have the right to
     receive  or the power to direct  the  receipt  of  dividends  from,  or the
     proceeds from the sale of, the Shares.

(e)  Not applicable.

Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to
Securities of the Issuer

No change.

Item 7. Materials to be Filed as Exhibits

     1.   Exhibit A - Joint Filing Agreement dated September 28, 2005, signed by
          each of the Reporting Entities.*
     2.   Exhibit B - Transactions in the Common Stock by the Reporting Entities
          during the past 60 days.

*  Incorporated  by  reference  to the  Amendment  No. 2  Schedule  13D filed on
September 28, 2005.


                                  Page 8 of 10





SIGNATURES

     After  reasonable  inquiry and to the best of my  knowledge  and belief,  I
certify that the information  set forth in this statement is true,  complete and
correct.

Date:  February 15, 2006

                                       BlueLine Catalyst Fund VII, L.P.

                                       By:  BlueLine Partners, L.L.C.
                                               Its:  General Partner

                                       By:     /s/ Scott Shuda
                                          --------------------------------------
                                       Name:   Scott Shuda
                                       Title:  Manager


                                       BlueLine Partners, L.L.C.


                                       By:     /s/ Scott Shuda
                                          --------------------------------------
                                       Name:   Scott Shuda
                                       Title:  Manager

                                       BlueLine Capital Partners, L.P.

                                       By:  BlueLine Partners, L.L.C.
                                               Its:  General Partner

                                       By:     /s/ Scott Shuda
                                          --------------------------------------
                                       Name:   Scott Shuda
                                       Title:  Manager


                                       BlueLine Partners, L.L.C.


                                       By:     /s/ Scott Shuda
                                          --------------------------------------
                                       Name:   Scott Shuda
                                       Title:  Manager


                                  Page 9 of 10





                                    EXHIBIT B

Transactions  in the Common Stock effected by the Reporting  Entities during the
past sixty days.


                             BCP                       BlueLine Catalyst
  Date         No. of Shares    Price per Share   No. of Shares  Price per Share
12/12/2005        -1,000             $4.70
12/12/2005       340,000             $4.54
12/16/2005         1,500             $4.94
12/27/2005        -3,000             $5.11
  1/4/2006           500             $4.95
  1/5/2006         1,000             $4.90
  1/6/2006         1,000             $4.85
  1/9/2006         1,000             $4.75
 1/10/2006         1,000             $4.70
 1/13/2006         1,700             $4.48
 1/19/2006         2,000             $4.56
 1/26/2006                                            -3,000          $4.59
 1/27/2006                                            -3,000          $4.62
  2/1/2006                                            -7,000          $5.18
  2/6/2006                                            -6,000          $5.11
  2/7/2006                                          -206,500          $5.30
  2/9/2006         4,000             $4.88
 2/13/2006         5,000             $4.80


                                 Page 10 of 10