Just in case, however, I will be keeping him under observation for another month.
This would suggest that you or your house at least have been kept under observation.
After treatment and being kept under observation, she was released.
All exposed individuals should be kept under observation for 8 hours.
All of whom have been kept under observation in a hospital.
Ask the patient to remain in bed, leave him to rest but keep under observation.
"We can keep her under observation if she is actually living in the house."
I will check your wife into the hospital and keep her under close observation.
"I'd really like to keep her under observation for another hour or so hey!"
She was kept under observation, but nothing of interest happened until yesterday evening.