(written from a Production point of view)
Canadian actor Derek McGrath (born 4 June 1951; age 71) played Chell in the Star Trek: Voyager first and seventh season episodes "Learning Curve" and "Repression". He also voiced the character in the video game Star Trek: Voyager - Elite Force.
McGrath is best known for his role as Andy Schroder in four episodes of the hit television sitcom Cheers. Kirstie Alley, Kelsey Grammer, and Bebe Neuwirth were all regulars on that series. He is also well known for playing Dr. Benjamin Jeffcoate in the TV series My Secret Identity (starring Jerry O'Connell) from 1988 to 1991.
He voiced the character of Knuckles, Muggsy, Spike and additional voices on the animated series Heathcliff from 1984 through 1987. He also had a recurring role as Ozwald Valentine on the series Dallas from 1986 through 1988. Glenn Corbett also had a role on this series during this time. He later starred in the medical drama Doc, which was on the air from 2001 through 2004.
McGrath's motion picture credits include Nothing Personal (1980, with Saul Rubinek), Mr. Mom (1983, with Terri Garr, Christopher Lloyd, Michael Ensign and Carolyn Seymour), Police Academy 4: Citizens on Patrol (1987, with David Graf and Brian Tochi), She's Out of Control (1989, with Catherine Hicks and Wallace Shawn), Freaked (1993, with William Sadler and Lee Arenberg), and Hologram Man (1995, with Tommy "Tiny" Lister, Jr.).
McGrath was a regular on the first three seasons of CBC's Little Mosque on the Prairie (2006 – 2009) as Reverend Duncan McGee. The series also starred Sheila McCarthy. He appeared on Kim's Convenience (2016-17, with Ali Momen and Shaleen Mulvany).