Selected results on micromechatronics of the Micro- and Nanorobotics group
In vivo wireless capsule for bowel monitoring
Swallowable capsule with wireless data transferring enables diagnostic of whole gastrointestinal track (GI) without invasive surgical operation. The capsule travels through GI driven by natural perilstatics. Sensors in the capsule collect data and send them wirelessly to receiver unit which hangs on the patient’s belt. The capsule includes two sensors: 3D-accelerometer and microphone. The detection of peristaltic motion and sounds are collected and sent to outside of body for analysis. Both of the sensors measure vibration of environment and large frequency range can be measured with pooling of data sets. The analysis is done in the receiving module.
The capsule has been tested in animal tests in 20 pigs. The bowel conditions of the pigs were artificially modified by inducing constipation or diarrhea. The analysis can be divided to three parts: filtering, feature extraction and classification. In the filtering the noise is filtered off from data and sounds are separated. After the filtering, interesting features is calculated out of the data. The idea is to set n-dimensional map about collected data where n is number of the features. The last step is to classify the signals based on the extracted features. In the classification process is used neural network which is trained by experts.
- Hänninen, P., Liimatainen, V., Sariola, V., Zhou, Q., and Koivo, H.N., “Swallowable Biotelemetry Device for Analysis of Irritable Bowel Syndrome”, Proceedings of 2008 International Symposium on Micro-NanoMechatronics and Human Science, MHS’08, Nagoya, Japan, 2008.
Microhopping robot using voicecoil actuator
Hopping is a very efficient locomotion method for a robot in an unconstructed environment or a complicated terrain. Small hopping robots have many interesting properties in comparison to the larger ones. However, relatively little research has been reported on hopping microrobot, while most of existing designs of hopping robots are not suitable for scaling down. We have invented a novel hopping mechanism based on the working principle of voice coil actuator. This mechanism is relatively easy to miniaturize and the hopping performance improves in a smaller scale. Two prototypes have been developed based on electromagnetic simulation and an analytic model of hopping process. The first prototype has a dimension of Φ30 mm × 10 mm and a mass of 41.59 g, with a hopping height of about 73 mm. The second one has a dimension of Φ14 mm × 6 mm and a mass of 4.94 g, and achieves a maximum hopping height of about 100 mm.
- Zhang, P.F., Zhou, Q., “Voice Coil Based Hopping Mechanism for Microrobot”, to be published in 2009 IEEE International Conference on Robotics and Automation, ICRA’09, Kobe, Japan, 2009.