Riker trapped in a stasis field
A stasis field was a field emitted by a stasis chamber. It caused complete immobilization of an object, also known as suspended animation. It had medical, tactical, and engineering uses. (VOY: "Innocence", "Renaissance Man"; DS9: "The Die is Cast"; Star Trek: Insurrection)
Bem, Spock, and Kirk held in a stasis field
In 2270, Captain Kirk, Commander Spock, and Ari bn Bem were held in a stasis field generated by the Delta Theta III entity. (TAS: "Bem")
In 2364, Commander William T. Riker was trapped in a stasis field which was created by an Echo Papa 607 drone on Minos. (TNG: "The Arsenal of Freedom")
In 2369, Deanna Troi's body was placed in a stasis field by Doctor Beverly Crusher after simulating her death with dylamadon so that Ambassador Ves Alkar would sever his link with her after he had used her body as a receptacle for his negative emotions. (TNG: "Man Of The People")
In a starship's sickbay, the morgue stasis fields were typically employed to slow or cease the rate of decomposition; this preserves dead bodies and tissues until they could be buried or until a postmortem was performed. (TNG: "Suspicions"; VOY: "Renaissance Man") It was also possible to set up such a field remotely. (VOY: "Innocence")
Starships also employed stasis fields to keep perishable food items fresh for weeks or months without spoilage.