A cassette is disclosed that comprises an interface element having a first position and a second position, the interface element configured to be driven from the first position to the second position and back to the first position by unidirectional rotary motion of a driving element, and a first and a second pumping chamber each having a volume and each coupled to the interface element such that the volume of the first pumping chamber is increasing while the volume of the second pumping chamber is decreasing as the interface element moves from the first position to the second position and the volume of the first pumping chamber is decreasing while the volume of the second pumping chamber is increasing as the interface element moves from the second position to the first position.本發明揭示出一種卡匣，其包含一具有第一位置及第二位置的介面元件，該介面元件組配成藉由一驅動元件的單向旋轉運動從第一位置驅動至第二位置及回至第一位置；及一第一及第二泵取艙，其每個具有一體積及每個連結至該介面元件，如此當該介面元件從第一位置移動至第二位置時，該第一泵取艙的體積增加同時該第二泵取艙的體積減少，及當該介面元件從第二位置移動至第一位置時，該第一泵取艙的體積減少同時該第二泵取艙的體積增加。
