Sensors implantable into a patient's body, systems, and methods of using the same

A sensor configured to be implanted into a patient, the sensor comprising:

• a semiconductor strain gauge having a substrate and first, second, and third sensing elements carried by the substrate and each configured to detect one or both of torsional and bending forces, each sensing element having a respective first end and a respective second end that is offset from the first end along a respective central axis, and each sensing element comprising a respective resistor that is linear bar that extends between the respective first and second ends along the respective central axis, z wherein the first, second, and third sensing elements are disposed at an outer surface of the substrate, and the central axes of the first, second, and third sensing elements are non-parallel to one another;
• a measurement device in communication with the first to third sensing elements, the measurement device configured to generate a measurement value that is proportional to a value of an anatomical property of the patient observed by the sensor;
• an internal wireless communicator in communication with the measurement device, the wireless communicator configured to receive the measurement value;
• an antenna in communication with the internal wireless communicator and offset from the sensing elements along a select direction, the antenna having at least one antenna coil wound in a first winding direction about a respective central axis, the antenna coil configured to wirelessly transmit the measurement value through skin of the patient to an external wireless reader outside of the patient;
• and
• a shield having at least one inductive shield coil that is connected in series with the antenna and is wound in a second winding direction, opposite the first winding direction, about a respective central axis, wherein the shield is disposed entirely between the antenna and the at least one sensing element with respect to the select direction,
• wherein the substrate is a flexible printed circuit board having a first edge and a second edge spaced from the first edge along a first linear direction and the first end of each of the first, second, and third sensing elements are positioned between the first edge and the second end of each of the first, second, and third sensing elements with respect to the first linear direction, and
• wherein the substrate includes a third edge and a fourth edge spaced from the third edge along a second linear direction perpendicular to the first linear direction and a straight line extending from the third edge to the fourth edge passes through each of the first, second, and third sensing elements.

A sensor configured to be implanted into a patient, the sensor comprising:

• at least one sensing element;
• a measurement device in communication with the at least one sensing element, the measurement device configured to generate a measurement value that is proportional to a value of an anatomical property of the patient observed by the sensor;
• an antenna having at least one inductive antenna coil that is wound in a first direction about a respective centralaxis, the at least one antenna coil configured to wirelessly transmit the measurement value to a reader outside of the patient;
• and
• a shield having at least one inductive shield coil that is connected in series with the antenna coils and is wound in a second direction, opposite the first direction, about a respective central axis that is parallel to the respective central axis of the antenna, wherein the shield is configured to limit or substantially prevent magnetic flux from passing through the shield,
• wherein the shield is disposed entirely between the antenna and the at least one sensing element with respect to a direction along which the antenna and the at least one sensing element are separated from each other.