A wearable system to detect urine leakage based on a textile sensor. Marc Martínez-Estrada, Raul Fernández-García, Ignacio Gil Universitat Politècnica de Catalunya, Dept. Electronic Engineering, Terrassa, Spain marc.martinez.estrada@upc.edu Abstract—. In this work, a wearable system to detect urine leakage based on a textile sensor is proposed. The system consists of a capacitive sensor embroidered with a conductive yarn in a cotton/polyester substrate. A microcontroller (MCU) with a wireless module for signal acquisition and a smartphone for monitoring complete the overall system. The capacitive sensor behaviour was tested in a climatic chamber between 30 % and 80% of relative humidity (RH) with a LCR meter and charge/discharge method directly connected to the MCU. The results show that the proposed system is able to detect urine leakage even though when the patient wears a diaper. The functionally allows to develop a real time monitoring system which can help nursing and medical assistants to take care of elderly and disabled people and improve the quality of life of these patients. Keywords—wearable; sensor; humidity; device; smart textile. I. INTRODUCTION Nowadays, the electronic and communication technology can help to improve the quality of life of population. Several wearable devices can be found in the literature and the market to analyze several biological fluids [1], gait analysis based on inertial measurement units [2], evaluation of patient with Parkinson’s disease [3], the protection and monitoring of firefighter’s [4], etc. However, in order to guarantee a full wearability and comfort of these devices a lot effort for integrating this type of sensing functionalities on textile materials has been developed [5]. Some textile sensors can be found in the literature for measuring limb motion [6], spinal extension [7], finger touch and pressure [8], humidity [9], etc. The urine leakage and urinary incontinence is a disorder with high social and economic cost that can affect up to 33% of patients in health centers [10]. Despite of this problem can be solved by means of diapers, in some cases, the patient doesn’t know if the urinary incontinence has been produced. Due to this fact, in hospitals and retirement homes, the nurses should check periodically the patients in order to know if the diaper should be replaced which implies an associate social and economic cost. In order to increase the quality of life of these patients and also to reduce the workload of nursing and medical assistants of retirement homes and hospitals in this paper a wearable system to detect urine leakage and/or urinary incontinence is presented. The system is based on a capacitive textile moisture sensor previously published by the authors [9]. The proposed system is able to detect urine leakage also when the patients wears a diaper. II. MATERIALS AND METHODS Fig. 1 depicts the bloc diagram of the proposed wearable system. The urine leakage system consists of: an embroidered textile capacitive sensor to detect the leaks, a conventional electronic circuit, which is responsible for the acquisition and wireless transmission of the information provided by the sensor and finally, a smart phone to receive the information and notify if a urine leakage has been produced. The urine leakage sensor is embroidered with a commercial Shieldex 117/17 dtex 2-ply conductive yarn with a polyester/cotton support yarn. Shieldex yarn is made by filaments of polyamide coated by pure silver, which provides a good conductivity and fastness to washing [11]. The sensor has been embroidered on a commercial cotton underwear due to both, its hydrophilic behaviour and the comfort that cotton provides to the user. The sensor has been located in the underwear area where higher humidity will be present. Fig. 2 shows the underwear with the embroidered sensor. Fig. 1. Proposed bloc diagram Textile Sensor Hardware