Exhibit 24

                                POWER OF ATTORNEY

         KNOW ALL BY THESE PRESENTS, that the undersigned hereby constitutes and
appoints Jay Spitzen and William Zerella, and each of them, his true and lawful
attorney-in-fact to:

         (1)  execute for and on behalf of the undersigned, in the undersigned's
capacity as a representative of Vocera Communications, Inc. ("Company"), any and
all Form 3, 4 or 5 reports required to be filed by the undersigned in accordance
with Section 16(a) of the Securities Exchange Act of 1934, as amended ("Exchange
Act"), and the rules thereunder with respect to transactions in securities of
Vocera Communications, Inc.;

         (2)  do and perform any and all acts for and on behalf of the
undersigned which may be necessary or desirable to complete and execute any such
Form 3, 4 or 5 report and timely file such report with the U.S. Securities and
Exchange Commission and any stock exchange or similar authority; and

         (3)  take any other action of any type whatsoever in connection with the
foregoing which, in the opinion of such attorney-in-fact, may be of benefit to,
in the best interest of, or legally required by, the undersigned, it being
understood that the documents executed by such attorney-in-fact on behalf of the
undersigned, pursuant to this Power of Attorney, shall be in such form and shall
contain such terms and conditions as such attorney-in-fact may approve in his
discretion.

         The undersigned hereby grants to each such attorney-in-fact full power
and authority to do and perform each and every act and thing whatsoever
requisite, necessary and proper to be done in the exercise of any of the rights
and powers herein granted, as fully to all intents and purposes as the
undersigned might or could do if personally present, with full power of
substitution or revocation, hereby ratifying and confirming all that such
attorney-in-fact, or her substitute or substitutes, shall lawfully do or cause
to be done by virtue of this Power of Attorney and the rights and powers herein
granted. The undersigned acknowledges that no such attorney-in-fact, in serving
in such capacity at the request of the undersigned, is hereby assuming, nor is
the Company hereby assuming, any of the undersigned's responsibilities to comply
with Section 16 of the Exchange Act.

         This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Form 3, 4 or 5 reports with respect to
the undersigned's holdings of and transactions in securities issued by the
Company, unless earlier revoked by the undersigned in a signed writing delivered
to the foregoing attorneys-in-fact.

         IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney
to be executed as of the 6th day of March, 2012.

                                            /s/ Howard E. Janzen
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                                            Howard E. Janzen