A cap like suction device is applied to the fetal head to facilitate extraction
Suction is used to assist in delivery of the fetal head.
Vento use is an instrumental device designed to assist delivery by erecting a vacuum b/w it & fetal scalp
Metal cap were initially used
Now a day’s silk cup (Silicon rubber) are used because they could be folder & introduced in to the vagina
4 sizes- 30, 40, 50 & 60 mm
Should be placed near to the occipital region
A vacuum of 0.2 kg/cm2 is induced b the pump slowly taking at least 2 minutes. This pressure is gradually raised at the rate 0.1 kg/cm2 per minute until the effective vacuum of 0.8 kg/cm2 is achieved in about 10 minutes times.
The scalp is sucked in to the cup & an artificial caput succedaneum (chignon) is produced this chignon is usually disappearing & in few hours
The suction dance should not be kept in place any longer then 25 minutes
Vacuum extraction should by apply after engagement of the head.
Either way the teacher or student will get the solution to the problem within 24 hours.