UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)*

ACUSPHERE, INC.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

00511R 87 0

                                (CUSIP Number)                                

December 31, 2004

(Date of Event, Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

¨ Rule 13d-1(b)

¨ Rule 13d-1(c)

¨ Rule 13d-1(d)

* The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. 00511R 87 0 Page 2 of 5 Pages

(1)	Names of Reporting Persons. SS or I.R.S. Identification Nos. of Above Persons             Burr, Egan, Deleage & Co.             04-2758272
(2)	Check The Appropriate Box If A Member Of A Group (a) (b)
(3)	SEC Use Only
(4)	Citizenship or Place of Organization             Massachusetts

Number Of Shares Beneficially Owned By Each Reporting Person With   (5)    Sole Voting Power                 -0-   (6)    Shared Voting Power                 202,383    Please also refer to Attachment A   (7)    Sole Dispositive Power                 -0-   (8)    Shared Dispositive Power                 202,383    Please also refer to Attachment A

(9)	Aggregate Amount Beneficially Owned By Each Reporting Person             202,383    Please also refer to Attachment A
(10)	Check If The Aggregate Amount In Row (11) Excludes Certain Shares*
(11)	Percent Of Class Represented By Amount In Row (11)             1.1%    Please also refer to Attachment A
(12)	Type Of Reporting Person             IA

* SEE INSTRUCTION BEFORE FILLING OUT!

Item 1.	(a)	Name of Issuer:
		Acusphere, Inc. (“Issuer”)
	(b)	Address of Issuer’s Principal Executive Offices: 500 Arsenal Street Watertown, MA 02472
Item 2.	(a)	Name of Person Filing: Burr, Egan, Deleage & Co.
	(b)	Address of Principal Business Office: 200 Clarendon St. Floor 51 Boston, MA 02116
	(c)	Citizenship/Place of Organization: Massachusetts
	(d)	Title of Class of Securities: Common Stock
	(e)	CUSIP Number: 00511R 87 0
Item 3.	Not applicable

Item 4.	Ownership.
	(a)	Amount Beneficially Owned:
		202,383
	(b)	Percent of Class:
		1.1%
	(c)	Number of shares as to which such person has:
		(i)	sole power to vote or to direct the vote:
			N/A
		(ii)	shared power to vote or to direct the vote:
			202,383 Please also refer to Attachment A
		(iii)	sole power to dispose or to direct the disposition of:
			N/A
		(iv)	shared power to dispose or to direct the disposition of:
			202,383 Please also refer to Attachment A
Item 5.	Ownership of Five Percent or Less of a Class Exit Filing—Total beneficial ownership is significantly less than 5% of the class of securities of the Company
Item 6.	Ownership of More than Five Percent on Behalf of Another Person Not applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company. Not applicable
Item 8.	Identification and Classification of Members of the Group No reporting person is a member of a group as defined in Section 240.13d-1(b)(1)(ii)(H) of the Act.
Item 9.	Notice of Dissolution of Group Not applicable
Item 10.	Certification Not applicable

SIGNATURE

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 10, 2005

Burr, Egan, Deleage & Co.

By:	/s/ Eileen McCarthy
	Eileen McCarthy
	Vice President

ATTACHMENT A / ACUSPHERE, INC.

Burr, Egan, Deleage & Co. directly or indirectly provides investment advisory services to several venture capital funds including Alta V Limited Partnership, Alta V Management Partners, L.P. and Customs House Partners. At December 31, 2004, the beneficial ownership is as follows:

Fund	Common Shares	Warrant Common Shares	Total Common Shares
Alta V Limited Partnership	0	40,195	40,195
Alta V Management Partners, L.P. (1)	152,817	0	152,817
Customs House Partners	8,949	422	9,371
Total:	161,766	40,617	202,383

(1) Alta V Management Partners, L.P. is the General Partner of Alta V Limited Partnership. On 5/11/04 and 11/30/04, Alta V Limited Partnership made stock distributions in the amounts of 421,379 shares and 430,265 shares, respectively to its General and Limited Partners, which liquidated Alta V Limited Partnership’s stock holdings to zero. As a result of these distributions, Alta V Management Partners, L.P. received a total of 152,817 shares which they continued to hold at December 31, 2004.

The respective general partners of these funds exercise sole voting and investment power with respect to the shares owned by such funds.

The principals of Burr, Egan, Deleage & Co. are general partners of Alta V Management Partners, L.P. (the General Partner of Alta V Limited Partnership) and Customs House Partners. As general partners of these funds, they may be deemed to share voting and investment powers for the shares held by the funds. These principals disclaim beneficial ownership of all such shares held by the aforementioned funds except to the extent of their proportionate pecuniary interests therein.

Terrance McGuire, a former director of the Company (who retired from the board on June 10, 2004) is a general partner of Alta V Management Partners, L.P. As a general partner of the fund, he may be deemed to share voting and investment powers with respect to the shares held by Alta V Limited Partnership. Mr. McGuire disclaims beneficial ownership of all the shares held by Alta V Limited Partnership except to the extent of his proportionate pecuniary interest therein. Mr. McGuire also disclaims beneficial ownership to all the shares of Customs House Partners.

Additionally, Mr. McGuire is a member of Polaris Venture Management Co., LLC which is the General Partner of both Polaris Venture Partners L.P. and Polaris Venture Partners Founders’ Fund, L.P., two other shareholders of the Company (please refer to Polaris’ filings for further disclosure of Mr. McGuire’s beneficial ownership relating to the two aforementioned funds). Mr. McGuire’s address is c/o Polaris Ventures.