**Exhibit 31.2**

**CERTIFICATION**

I,Martin J. Joyce, certify that:

1.                 I have reviewedthis Annual Report on Form 10-K of BioSphere Medical, Inc.;

2.                 Based on myknowledge, this report does not contain any untrue statement of a material factor omit to state a material fact necessary to make the statements made, inlight of the circumstances under which such statements were made, notmisleading with respect to the period covered by this report;

3.                 Based on myknowledge, the financial statements, and other financial information includedin this report, fairly present in all material respects the financialcondition, results of operations and cash flows of the registrant as of, andfor, the periods presented in this report;

4.                 The registrant’sother certifying officer and I are responsible for establishing and maintainingdisclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and15d-15(e)) for the registrant and have:

a)               Designed suchdisclosure controls and procedures, or caused such disclosure controls andprocedures to be designed under our supervision, to ensure that materialinformation relating to the registrant, including its consolidatedsubsidiaries, is made known to us by others within those entities, particularlyduring the period in which this report is being prepared;

b)              [Not applicable.]

c)               Evaluated theeffectiveness of the registrant’s disclosure controls and procedures andpresented in this report ourconclusions about the effectiveness of thedisclosure controls and procedures, as of the end of the period covered by thisreport based on such evaluation; and

d)              Disclosed in thisreport any change in the registrant’s internal control over financial reportthat occurred during the registrant’s most recent fiscal quarter (the registrant’sfourth fiscal quarter in the case of an annual report) that has materiallyaffected, or is reasonably likely to materially affect, the registrant’sinternal control over financial reporting; and

5.                 The registrant’sother certifying officer and I have discussed, based on our most recentevaluation of internal control over financial reporting, to the registrant’sauditors and the audit committee of the registrant’s board of directors (orpersons performing the equivalent functions):

a)               All significant deficienciesand material weaknesses in the design or operation of internal control overfinancial reporting which are reasonably likely to adversely affect theregistrant’s ability to record, process, summarize and report financialinformation; and

b)              Anyfraud, whether or not material, that involves management or other employees whohave a significant role in the registrant’s internal control over financialreporting.
| Date: March 29, 2005 | /s/  MARTIN  J. JOYCE                    |
|---------------------------|-----------------------------------------------|
|                      | Martin J. Joyce                               |
|                      | *Vice  President and Chief Financial Officer* |
|                      | *(principal  financial officer)*              |

 

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