Patent ID: 11944423
Assignee: CALIFORNIA INSTITUTE OF TECHNOLOGY
Field: Medical technology (Instruments)
Classification: CPC A  G | IPC A  G

Claim 9:
10. A system for in-vivo monitoring of an internal volume of a mammal, comprising:
a three-dimensional magnetic field generator configured to sequentially produce:
a first localization magnetic field gradient along a first axis, a portion of the magnitude of the first localization magnetic field gradient being monotonically-varying along the first axis through the target internal volume and uniquely encoding a position along said first axis corresponding to a strength of said monotonically-varying first localization magnetic field in said target internal volume,
a second localization magnetic field gradient along a second axis that is orthogonal to the first axis, portion of the magnitude of the second localization magnetic field gradient being monotonically-varying along the second axis through the target internal volume and uniquely encoding a position along said second axis corresponding to a strength of said monotonically-varying second localization magnetic field in said target internal volume, and
a third localization magnetic field gradient along a third axis that is orthogonal to the first and second axes, a portion of the magnitude of the third localization magnetic field gradient being monotonically-varying along the third axis through the target internal volume and uniquely encoding a position along said third axis corresponding to a strength of said monotonically-varying third localization magnetic field in said target internal volume; and

an ingestible magnetic sensor comprising:
a three-dimensional magnetic sensor that outputs measurements of respective magnetic fields corresponding to the first, second, and third localization magnetic field gradients, respectively;
a first controller electrically coupled to the three-dimensional magnetic sensor, the controller generating a magnetic sensor output signal that encodes the measurements of the respective magnetic fields;
an antenna electrically coupled to the first controller, the antenna broadcasting the magnetic sensor output signal;
a power source electrically coupled to the three-dimensional magnetic sensor and the first controller; and
an ingestible capsule having an internal cavity in which the three-dimensional magnetic sensor, the first controller, the antenna, and the power source are disposed,
wherein:
the three-dimensional magnetic field generator comprises:
a first planar electromagnet coil set configured to generate a first magnetic field having a first magnetic field gradient along the first axis;
a second planar electromagnet coil set configured to generate a second magnetic field having a second magnetic field gradient along the second axis;
a third planar electromagnet coil set configured to generate a third magnetic field having a third magnetic field gradient along the third axis; and
a second controller configured to selectively provide power to the first electromagnet coil set, the second electromagnet coil set, and/or the third electromagnet coil set to sequentially produce the first, second, and third localization magnetic field gradients,

the second controller selectively provides power to only the first and third planar electromagnet coil sets to simultaneously generate only the first and third magnetic fields, wherein the first localization magnetic field gradient comprises a total magnetic field of the first and third magnetic fields, and
the three-dimensional magnetic sensor measures the respective magnetic field corresponding to the first localization magnetic field gradient while only the first and third magnetic fields are generated.