Abstract: Techniques are disclosed relating to buffer circuits. In one embodiment, a buffer circuit is disclosed that includes memory unit and an output register. The memory unit is configured to store a plurality of buffer entries and a first pointer to a current one of the plurality of buffer entries. The output register is coupled to an output of the memory unit. The buffer circuit is configured to perform a read operation by outputting a current value of the output register and storing a value of the current buffer entry in the output register. The buffer circuit is configured to update the first pointer in response to the read operation.

Abstract: An apparatus (4) and method of non-invasive monitoring of gut motility. An ingestible magnet (10, M) is swallowed by the patient (12) and then linear and rotational movement is directionally detected by an external compass (14, 16). In preferred form, movements of the magnet (10, M) are recorded by a memory means (18) and graphically presented (20) over a period of predetermined time. An alternate embodiment includes multiple compasses (C1, C2) for directionally locating the magnet (10, M) within the patient (12).