Low power receiver for in vivo channel sensing and ingestible sensor detection with wandering frequency

A wearable device comprising:

• a disposable component configured to attach to a patient and receive discontinuous data comprising frames of ingestible sensor data and frames of physiological data of the patient interspersed in time gaps between the frames of the ingestible sensor data;
• a reusable component coupled to the disposable component and comprising:
• a processor;
• a non-transitory memory coupled to the processor and configured to store the discontinuous data, wherein the non-transitory memory comprises machine executable instructions that when executed by the processor, cause the processor to:
• extract accelerometer data from the physiological data;
• enhance the accelerometer data;
• calculate a number of level crossings in the enhanced accelerometer data by:
• computing initial level crossings in portions of the accelerometer data that are uninterrupted by the ingestible sensor data;
• identifying boundary conditions in the discontinuous data where the physiological data switches to the ingestible sensor data, and the ingestible sensor data switches to the physiological data;
• determining a direction of the level crossing of the accelerometer data at each of the boundary conditions;
• and
• incrementing the number of level crossings responsive to a determination a level crossing at the end of a first frame of physiological data is in the same direction as a level crossing at the start of a second frame of physiological data, the first and second frames being sequentially positioned in the physiological data;
• and
• determine a step count of the patient in a speed range of 80 to 150 steps per minute using the calculated number of level crossings with a mean error of plus or minus 3 percent as measured over at least 1000 steps.

A method of a wearable device for determining a step count of a patient from discontinuous data, the method comprising:

• receiving, by the wearable device, discontinuous data derived from the patient, the discontinuous data comprising frames of ingestible sensor data and frames of physiological data of the patient interspersed in time gaps between the frames of the ingestible sensor data;
• extracting accelerometer data from the physiological data;
• enhancing the accelerometer data;
• calculating a number of level crossings in the enhanced accelerometer data by:
• computing initial level crossings in portions of the accelerometer data that are uninterrupted by the ingestible sensor data;
• identifying boundary conditions in the discontinuous data where the physiological data switches to the ingestible sensor data, and the ingestible sensor data switches to the physiological data;
• determining a direction of the level crossing of the accelerometer data at each of the boundary conditions;
• and
• incrementing the number of level crossings responsive to a determination a level crossing at the end of a first frame of physiological data is in the same direction as a level crossing at the start of a second frame of physiological data, the first and second frames being sequentially positioned in the physiological data;
• and
• determining the step count in a speed range of 80 to 150 steps per minute using the calculated number of level crossings with a mean error of plus or minus 3 percent as measured over at least 1000 steps.