.NET high precision busy wait timer

BusyWait.cs

                    while (running && Mode == TimerMode.Periodic)
                    {
                        var t = stopwatch.Elapsed;
                        var remainingTime = FInterval - (t - FOldTime);

                        if (remainingTime.Ticks > 2)
                        {
                            //if there is more time left than the wait accuracy
                            if (remainingTime.Ticks > FWaitAccuracy.Ticks)
                            {
                                Thread.Sleep(1);
                                continue;
                            }
                            else //busy wait last time < wait accuracy
                            {
                                while (remainingTime.Ticks > 2)
                                {
                                    //Thread.SpinWait(1)?
                                    t = stopwatch.Elapsed;
                                    remainingTime = FInterval - (t - FOldTime);
                                }
                            }
                        }

                        //if wait timer done, we arrive here
                        var interval = t - FOldTime;
                        LastIntervalDiff = interval - LastInterval;
                        LastInterval = interval;
                        FOldTime = t;

                        //do the actual work
                        if (FResetCounter)
                        {
                            FFramCounter = 0;
                            FResetCounter = false;
                        }
                        FFrameClock.Time = t.TotalSeconds;
                        FFrameClock.TimeDifference = interval.TotalSeconds;
                        FFrameClock.FrameCounter = FFramCounter++;
                        FSubject.OnNext(FFrameClock);
                    }