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, 11 (1), e0147531

Capsule Design for Blue Light Therapy Against Helicobacter Pylori


Capsule Design for Blue Light Therapy Against Helicobacter Pylori

Zhangyong Li et al. PLoS One.


A photo-medical capsule that emits blue light for Helicobacter pylori treatment was described in this paper. The system consists of modules for pH sensing and measuring, light-emitting diode driver circuit, radio communication and microcontroller, and power management. The system can differentiate locations by monitoring the pH values of the gastrointestinal tract, and turn on and off the blue light according to the preset range of pH values. Our experimental tests show that the capsule can operate in the effective light therapy mode for more than 32 minutes and the wireless communication module can reliably transmit the measured pH value to a receiver located outside the body.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.


Fig 1
Fig 1. Architecture inside the capsule.
Fig 2
Fig 2. PCB LEDs and LED driver.
Fig 3
Fig 3. Circuit configuration of nRF24L01 at 2.4GHz.
Fig 4
Fig 4. Flow diagram of the system operation.
Fig 5
Fig 5. System packaging.
①RF Antenna, ②pH Sensor, ③RF Circuit, ④Micro-controller, ⑤Power Management, ⑥Battery, ⑦LED Driver, ⑧Blue LEDs, ⑨Shell.
Fig 6
Fig 6. The relationship between the average voltage and pH value measured for the eight testing vessels.
This line is used to convert voltage measured by the antimony electrode of the capsule into pH reading.
Fig 7
Fig 7. Current efficiency of the therapy unit.
Fig 8
Fig 8. Efficiency of the therapy unit as a function of time for different power modes.

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Grant support

This project is supported by the National Natural Science Foundation of China (No. 60901045), Science Fund of Chongqing China (No. cstc2012jjA10148 and No. KJ1400427). The author Zhangyong Li plays a role in charge for both the funders.

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