An ingestible capsule system for in‐body core temperature monitoring

Abstract

An ingestible capsule system monitoring in‐body core temperature is presented and an in vitro measurement is carried out. The capsule system composed of essential electrical components, antenna, and power supply is codesigned for the sake of minimizing the overall size and maximizing the transmission distance. To meet these properties, a multilayered PIFA antenna is applied to be integrated with the circuit. The proposed capsule antenna is demonstrated experimentally at 433‐MHz industrial, scientific and medical (ISM) band. The total length of capsule is 31.4 mm and the volume of capsule antenna is 147 mm3. Experimental results are well agreed with theoretical predictions.

Multiband antenna design based on Gosper fractal for implantable biomedical devices

“…Secondly, a wide impedance bandwidth is required as the antenna is surrounded by frequency-dependent tissues (high permittivity medium) and can experience wide permittivity diversity for different body tissue environments or even permittivity of tissue can vary from person to person. However, antennas with small bandwidth have also been proposed in [1, 2], which can be reliable for only a single tissue environment. Thirdly, as the human tissue has a high absorption capability ( σ ≠ 0) of electromagnetic waves, an antenna must communicate well inside the human tissue environment in prescribed safety specific absorption rate (SAR) limit.…”