JRM Vol.29 No.2 pp. 353-363
doi: 10.20965/jrm.2017.p0353

Development Report:

Excretion Detection System with Gas Sensor – Proposal and Verification of Algorithm Based on Time-Series Clustering –

Yoshimi Ui*, Yutaka Akiba**, Shohei Sugano**, Ryosuke Imai**, and Ken Tomiyama***

*aba Inc.
3-30-5 Maebara-Higashi, Funabashi, Chiba 274-0824, Japan

**Chiba Institute of Technology
2-17-1 Tsudanuma, Narashino, Chiba 275-0016, Japan

***Future Robotics Technology Center (fuRo), Chiba Institute of Technology
2-17-1 Tsudanuma, Narashino, Chiba 275-0016, Japan

September 30, 2016
February 6, 2017
April 20, 2017
excretion, care, gas sensor, clustering, non-wearing
In this study, we propose an excretion detection system, Lifi, which does not require sensors inside diapers, and we verify its capabilities. It consists of a sheet with strategically placed air intakes, a set of gas sensors, and a processing unit with a newly developed excretion detection algorithm. The gas sensor detects chemicals with odor in the excrement, such as hydrogen sulfide and urea. The time-series data from the gas sensor was used for the detection of not only excretion, but also of the presence/absence of the cared person on the bed. We examined two algorithms, one with a simple threshold and another based on the clustering of sensor data, obtained using the k-means method. The results from both algorithms were satisfactory and similar, once the algorithms were customized for each cared person. However, we adopted the clustering algorithm because it possesses a higher level of flexibility that can be explored and exploited. Lifi was conceived from an overwhelming and serious desire of caretakers to discover the excretion of bed-ridden cared persons, without opening their diapers. We believe that Lifi, along with the clustering algorithm, can help caretakers in this regard.
Standard Lifilm configuration

Standard Lifilm configuration

Cite this article as:
Y. Ui, Y. Akiba, S. Sugano, R. Imai, and K. Tomiyama, “Excretion Detection System with Gas Sensor – Proposal and Verification of Algorithm Based on Time-Series Clustering –,” J. Robot. Mechatron., Vol.29 No.2, pp. 353-363, 2017.
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Last updated on Sep. 21, 2023