A Gaithersburg woman charged in connection with the beating of an infant during and "exorcism" last year was sentenced yesterday to two concurrent seven-year prison terms with all but 18 months suspended.

Montgomery County Circuit Court Judge Phillip M. Fairbanks imposed the sentence after finding Joyce Lillian Pope, 28, of 7348 Damascus Rd. guilty of child abuse and misprision of a felony. The latter offense is defined as failing to report or attempt to prevent a crime that occurs in one's presence.

The charges resulted from the death of 3-month-old Dmiko Loo Norris, who dies at Pope's home last April 11. The infant's mother, Melissa Norris, 20, who told investigator Demiko dies while she was attempting to rid him of a demon that possessed him, was charged with murder but was freed Sept. 14 after found innocent by reason of insanity.

Pope was never accused of actually striking the boy, but was present which was played at her trial, Pope said that Norris, "whose eyes never blinked," addressed the child as Satan and referred to herself as God as she beat him.

The beating occured in the bedroom of Pope's home. Pope testified that during the beating she "couldn't move . . . I know she was hurting the baby, but it was as if there was a shield between us" preventing her from stopping the beating.

Judge Fairbanks, who heard the case without a jury, ordered Pope to serve the 18 months at the Montgomery County Detention Center and said she is to be granted work release if she finds a job. The judge ordered her to undergo psychiatric treatment while on probation.