Embodiments isolate exposed surfaces to increase the effectiveness of different treatment modalities. Embodiments isolate hollow spaces within the body to increase the effectiveness of ultrasound energy and/or other treatments. Such hollow spaces within the body may include nasal surfaces, and recessed or sequestered surfaces, e.g. sinus cavity surfaces or other anatomical structures, such as upper and lower gastrointestinal tract, airways, uterine and vaginal cavities and the anorectal canal, for example. Isolating the area to be treated reduces the volume of the enclosed and delimited space and reduces the tissue surface against which the ultrasound and/or biologically active substances act. For example, isolating a hollow passageway within the body enhances the effectiveness of ultrasound within the isolated space, and constrains the biologically active fluid and/or the gel or fluid configured to conducts the ultrasonic energy from the emitter thereof (e.g., an ultrasound waveguide) to the surfaces to be treated.
