Exhibit 15
Acknowledgement of Ernst & Young LLP

Board of Directors
Respironics, Inc. and Subsidiaries

We are aware of the incorporation by reference in the Registration Statements
(Post Effective Amendment No.1 on Form S-8 to Form S-4 No. 333-43703) pertaining
to the Healthdyne Technologies, Inc. 1996 Stock Option Plan, Healthdyne
Technologies, Inc. Stock Option Plan, Healthdyne Technologies, Inc. Nonemployee
Director Stock Option Plan, and Healthdyne Technologies, Inc. Stock Option Plan
II; (Form S-8 No. 333-22639) pertaining to the 1997 Employee Stock Purchase
Plan; (Form S-8 No. 333-16721) pertaining to the Respironics, Inc. Retirement
Savings Plan; (Form S-8 No. 33-89308 and Form S-8 No. 333-74510) pertaining to
the 1992 Stock Incentive Plan; (Form S-8 No. 33-44716 and Form S-8 No. 333-
74504) pertaining to the 1991 Nonemployee Directors' Stock Option Plan; (Form S-
8 No. 33-36459) pertaining to the Amended and Restated Incentive Stock Option
Plan of Respironics, Inc. and Gerald E. McGinnis and the Consulting Agreement
dated July 1, 1988 between Respironics, Inc. and Mark H. Sanders, M.D.; (Form S-
8 No. 333-87335) pertaining to the Respironics, Inc. 1997 Non-Employee
Directors' Fee Plan; (Form S-8 No. 333-56812) pertaining to the Respironics,
Inc. 2000 Stock Incentive Plan; and (Form S-8 No. 333-74506) pertaining to the
Respironics, Inc. 2002 Employee Stock Purchase Plan of our report dated January
22, 2002 relating to the unaudited condensed consolidated interim financial
statements of Respironics, Inc. and Subsidiaries that are included in its Form
10-Q for the three-month and six-month periods ended December 31, 2001.

                                         /s/ Ernst & Young LLP

Pittsburgh, Pennsylvania
February 14, 2002