Systems and methods for applying vibration to the human body. In one embodiment, the jamb is formed from a first stud that has a web and two first flanges and a second stud with a second web and second flanges. The processor is configured to determine the social interaction between the participants based on the similarities between the first spatially filtered output and each of the second spatially filtered outputs and display an output that is representative of the social interaction between the participants. Techniques are provided for performing startup scans for radar, identifying backup channels for a possible channel switch, and efficiently changing channels in the event of radar detection in the operating channel. In an alternative, the microbubble suspension can be frozen.