该产品的电阻值在其有效使用期限内，阻值是逐渐变大。
The resistance of elements increases gradually during their useful life.
耳背式助听器使用纽扣式电池，合格的产品使用寿命应在200小时左右，按每日使用12小时计算，有效使用期限约为两周。
BTE button battery life, the qualified products should be in 200 hours or so, is calculated by using 12 hours a day, period of validity for about two weeks.
我们有办法来保护现有干预措施的有效性和使用期限。
We have strategies in place for protecting the effectiveness and lifespan of existing interventions.
应用推荐