Exhibit
31.1

# CERTIFICATION BY DAVID
L. SCHLOTTERBECK PURSUANT TO SECURITIES EXCHANGE
ACT RULE 13a-15

I, David L. Schlotterbeck, certify
that:

1.
          I have reviewed this quarterly report on Form 10-Q of ALARIS Medical Systems,
          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)) 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) 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

c) 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 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 controls           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: October 28, 2003 /s/ DAVID L. SCHLOTTERBECK
David L. SchlotterbeckPresident and Chief Executive Officer |  | 
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