he was learning the lifesaving technique called cpr, cardio pulmonary resuscitation. >> we were required to take a cpr course at our high school in gym class, and when people were trying to perform cpr on the mannequins, i found that most people weren't able to do it. >> reporter: cpr can save someone whose heart has stopped beating, but only if air gets into the victim's lungs. that's called ventilation. the usual technique is mouth-to-mouth resuscitation, but john noticed his classmates were resisting. >> they either didn't want to perform cpr cause they didn't want to have their mouth touch the mannequin, 'cause it's kind of gross. or they just weren't able to create a proper seal around the mouth of the mannequin. >> and johnny looked at what are the other things that we could do to replace mouth-to-mouth resuscitation. >> reporter: john did his research with people of all ages, which he recreates here with his sister and brother. he tested peoples' ability to learn cpr the traditional way. then he had his subjects try using a device called a bag mask ventilator. finally, he had them