[{"timestamp":1553168075444,"content":[{"name":"temperature_x","value":2},{"name":"temperature_y","value":2},{"name":"temperature_z","value":0}]},{"timestamp":1553168075444,"content":[{"name":"temperature_x","value":2},{"name":"vibration_x","value":21},{"name":"vibration_z","value":10}]}]

db.collection.aggregate([{$replaceRoot:{newRoot:{$mergeObjects:["$$ROOT",{$arrayToObject:{$map:{input:"$content",in:{k:"$$this.name",v:"$$this.value"}}}}]}}}])