ABSTRACT
Objective To compare two verification tools for intensity modulated radiotherapy (IM-RT) and to investigate the feasibility of a new three dimensitional verification tool. Methods Five patients receiving IMRT were randomly chosen for the quality assurance plans with MapCHECK Model 1175 (SunNu-clear, Melbourne, FL,USA) and Delta4(ScandiDos, Sweden) by using Philips Pinnacle 8.0D treatment planning system. Dose verification was measured with the Varian Clinical 23EX LA. Results The overall average percentages of pass points in DD2% DTA2 mm, DD3% DTA3 mm and DD4% DTA4 mm were 84.7%, 97. 1% and 99.3% with MapCHECK Model 1175, 86.2%, 98.2% and 99.6% with Delta4 re-spectively. The differences were statisticically significant (t = 3.94, P = 0.003 ; t = 3.17, P = 0.011 ; t = 3.05 ,P =0.014,respectively). The gantry angle was changed to zero degree with MapCHECK, but not with Delta. The effects were embodied with Delta, such as the gravity on leaf position accuracy of MLC, the treat-ment table on dose distribution and the earth magnetism on dose system. Conclusion Delta4 is an ideal verification tool for intensity modulated radiotherapy.
ABSTRACT
Objective To transmit ECG signals through a portable dual-mcu ECG holter based dual-port RAM.Methods Dual-port RAM had two independent address,data and control buses,which allowed the two processors accessed it's resource independently at different time.The master processor buffered the acquired data on its RAM until the data accumulated to 200 Bytes.Then the 200 Bytes would be transferred into the dual-port RAM at one time.The slave processor was informed to fetch the data when it reached the flash's one whole page.Results Problems in such aspects were conquered as the port contention of dual-port RAM,limiting sampling frequency,data sharing between the master and slave processors as well as acquiring signals by the cache.Conclusion The portable dual-mcu ECG holter based dual-port RAM can be applied to transmission of ECG signals.