Kamrava said Suleman volunteered for the study and she signed a consent form listing risks of the procedure.
During the experimental procedure, Kamrava used a camera-guided catheter to implant the 12 embryos in Suleman. The goal was to prevent scratching on her uterine walls.
Kamrava took the stand after a Food and Drug Administration investigator first told the state medical board that Kamrava was using an experimental procedure for Suleman's implantation.
In closing arguments, prosecutors said the fertility experiment is proof that Kamrava had acted irresponsibly and that he was using Suleman as a guinea pig.
They say there are no documents showing Suleman agreed to the experiment and that this study was performed after Suleman gave birth to six other children - also the result of embryos implanted by Kamrava.
Kamrava's defense attorney said his client's decision to use Suleman in this experiment is not enough to revoke his medical license.
During the hearing, Kamrava admitted he only planted so many embryos in Suleman because she had bad ovaries and she couldn't get pregnant.
He also said Suleman's decision to have a large family was a personal one and that he never believed she had psychological problems.
The board is trying to revoke Kamrava's medical license, alleging gross negligence in his treatment of Suleman and two other patients.
Now, the judge has 60 days to submit his recommendation to the state medical board for a final decision.
The Associated Press contributed to this report.