Central Apnea???

I am a CPAP user that is still on a trial. I have trialed a Resmed Vantage 8 Machine and am no using a Remstar A flex unit. My oximetry levels have dramatically improved since being on a machine but have still not reduced my AHI numbers below 10 on a continuous basis. Also, I have not been able to use the machine throughout the entire night. I have been on a trial for about 5 weeks. I use a Swift Lt II breathing device. I have met with my DME numerous times and discussed my condition. I have completed one hospital sleep- over which became a disaster as the night progress. The person in charge of the lab was less than cooperative in the sharing of information and assisting with the visit. Although it wasn't very successful for a variety of reasons, my doctor believed, from the information gathered, that I could very well have Central Apnea. This, in my studies, didn't seem to be able to be reduced by the Resmed A10 algorithm thus the change in machines. I have an appointment this week with my Dr. to review the printouts that we have taken over the past five weeks from both machines and hopefully we will be able to come up with a solution to this on-going problem. The question I have is whether a Bi-Level machine is an option for treatment of this condition?? I have again read a variety of theories in this regard. I believe that I’m experiencing apneas that are not being preceded by snores or flow limitations and thus and are not being addressed in a rapid enough manner to prevent them from occurring. It seems that an apnea followed by another sudden or runaway apnea needs a specific treatment that doesn’t seem appropriate using a Remstar A Flex machine or a Resmed Series 8 machine that is not able to provide Bi-level therapy. Not trying to self diagnose here but need some options to take to my Dr. so we’re speaking the same language when I meet with him later this coming week. Any suggestions????