本文介紹了一種界面友好可與醫(yī)院聯(lián)網(wǎng)的便攜式強迫振蕩呼吸阻抗測試系統(tǒng)。該系統(tǒng)采用STM32產(chǎn)生單頻率或復頻率的正弦振蕩信號，經(jīng)放大電路放大后驅(qū)動揚聲器產(chǎn)生正弦振蕩氣流于受試者口腔中，應用STM32的模數(shù)據(jù)轉(zhuǎn)換器（ADC）模塊分別測量由壓力傳感器和流量傳感器得到的模擬電壓信號，再經(jīng)運算后將得到的參數(shù)顯示在觸摸顯示屏上，同時可通過GPRS將數(shù)據(jù)上傳到上位機進行保存和顯示。最后使用模擬肺和征集志愿者等方式來評價該系統(tǒng)的可靠性。測試結果表明該系統(tǒng)穩(wěn)定可靠，可以達到監(jiān)測呼吸阻抗狀況的目的。
【摘要】 目的 調(diào)強放射治療（IMRT）能較好的保護危及器官并給予腫瘤足夠的致死劑量，基于多葉準直器（MLC）分步照射的IMRT技術對復雜病例需要更多子野。研究對直腸癌術后放射治療使用不同子野數(shù)目的IMRT計劃進行比對，選擇合理的子野數(shù)。 方法 選取2010年4-8月入院的直腸癌術后患者10例，保持射野入射角度及優(yōu)化目標參數(shù)相同，僅改變MLC子野數(shù)目，設計不同IMRT對每一患者治療計劃的靶區(qū)適形指數(shù)（CI）、均勻性指數(shù)、最大劑量、最小劑量、平均劑量，危及器官關注體積的受照劑量，機器跳數(shù)及治療時間進行分析?！〗Y果 所有治療計劃中靶區(qū)及危及器官的劑量學評估指標無統(tǒng)計學意義（Pgt;0.05），只有亞臨床計劃靶區(qū)（PTV）CI在15個子野的方案中（0.74±0.06）明顯差于25個子野方案（0.82±0.03）、40個子野方案（0.81±0.06）及60個子野方案（0.84±0.03），有統(tǒng)計學意義（Plt;0.05）；治療機器跳數(shù)（MU）隨子野數(shù)目增多明顯增大，15、20、40及60個子野方案所需MU分別為（458±56）、（559±62）、（614±74）、（622±82），有統(tǒng)計學意義（Plt;0.05），但40個子野方案與60個子野方案間無統(tǒng)計學意義。治療時間明顯隨子野數(shù)增加而增大?！〗Y論 直腸癌術后IMRT計劃使用25個子野能滿足臨床劑量要求，同時能有效降低治療時間，可作為臨床應用參考值。【Abstract】 Objective The intensity modulated radiotherapy (IMRT) can deliver tumor enough doses and protect risk organs as much as possible at the same time. The MLC-based step and shoot IMRT(sIMRT) plan needs much more segment member to meet clinical aims. In this study, several sIMRT plans using different segment number for postoperative rectal cancer were compared to find out the most reasonable segment number setting. Methods Ten patients with rectal carcinoma underwent postoperative adjuvant radiotherapy for rectal cancer from April to August 2010 were selected. For each patient, the angle of field, the prescription expected and the physical parameters optimized were kept the same, while only the number of segments was changed in sIMRT plans. The dose volume histogram-based parameters [conformity index (CI) and homogeneous index (HI)] and other parameters concerned were compared and analyzed. Results The indexes of dosimetry associated with the targets and risk organs showed no significant statistical difference among the 4 sIMRT plans with different segment numbers. The index CI of PTV in the sIMRT plan with 15 segments (CI 0.74±0.06) was less than that in the sIMRT plan with 25 segments (CI 0.82±0.03), the sIMRT plan with 40 segments plan (CI 0.81±0.06), and the sIMRT plan with 60 segments (CI 0.84±0.03) (Plt;0.05). There were significant differences in MU among the sIMRT plans with 15 segments (average MU: 458±56) , with 25 segments (average MU: 559±62 ), and with 40 segments (average MU: 614±74)or with the 60 segments (average MU: 622±82 (Plt;0.05). The more segments meant more MU and more irradiation time. Conclusion The sIMRT plan for patients of rectal cancer to receive postoperative adjuvant radiotherapy may require at least 25 segments to balance the accepted dose results and efficient delivering.