Prediction-Based Compensation for Gate On/Off Latency during Respiratory-Gated Radiotherapy

Figure 2

Smoothing of a respiratory signal. The phantom’s signal was measured for 20 s, and an artificial noise was added (13.65–13.7 s), forming a signal tuple . Then was calculated (Equations (8a)–(8d)), setting to filter out high frequency ( Hz) components. Note that indicates , where , denotes the absolute value of , and is the largest integer smaller than or equal to . The units of signal value, time, and frequency are mm, s, and Hz, respectively.