Exhibit 31.1  CERTIFICATIONS  I, Sherri C. Oberg,
certify that:  1. I have reviewed this
annual report on Form 10-K of Acusphere, Inc.;  2. Based on my knowledge,
this report does not contain any untrue statement of a material fact or omit to
state a material fact necessary to make the statements made, in light of the
circumstances under which such statements were made, not misleading with
respect to the period covered by this report;  3. Based on my knowledge,
the financial statements, and other financial information included in this
report, fairly present in all material respects the financial condition,
results of operations and cash flows of the registrant as of, and for, the
periods presented in this report;  4. The registrants other
certifying officer and I are responsible for establishing and maintaining
disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and
15d-15(e)) and internal control over financial reporting  (as defined in Exchange Act Rules 13a-15(f) and
15d-15(f)) for the registrant and we have:  a) Designed such
disclosure controls and procedures, or caused such disclosure controls and
procedures to be designed under our supervision, to ensure that material
information relating to the registrant, including its consolidated
subsidiaries, is made known to us by others within those entities, particularly
during the period in which this report is being prepared;  b) Designed such internal
control over financial reporting, or caused such internal control over
financial reporting to be designed under our supervision, to provide reasonable
assurance regarding the reliability of financial reporting and the preparation
of financial statements for external purposes in accordance with generally
accepted accounting principles;  c) Evaluated the
effectiveness of the registrants disclosure controls and procedures and
presented in this report our conclusions about the effectiveness of the
disclosure controls and procedures, as of the end of the period covered by this
report based on such evaluation; and  d) Disclosed in this
report any change in the registrants internal control over financial reporting
that occurred during the registrants most recent fiscal quarter (the
registrants fourth fiscal quarter in the case of an annual report) that has
materially affected, or is reasonably likely to materially affect, the
registrants internal control over financial reporting; and  5. The registrants other
certifying officer and I have disclosed, based on our most recent evaluation of
internal control over financial reporting, to the registrants auditors and the
audit committee of the registrants board of directors (or persons performing
the equivalent functions):  a) All significant
deficiencies and material weaknesses in the design or operation of internal
control over financial reporting which are reasonably likely to adversely
affect the registrants ability to record, process, summarize and report
financial information; and  b) Any fraud, whether or
not material, that involves management or other employees who have a
significant role in the registrants internal control over financial reporting.  Date:
  
  March 17, 2008
  
  /s/ SHERRI C. OBERGSherri C. ObergChief Executive Officer(Principal Executive
  Officer)