Accomplishing of convergent systems for mobile personalized information monitoring

Eftalea CARPUS1,a, Angela DOROGAN1,a,b, Emilia VISILEANU1,a, Mircea IGNAT2,c, Gelu ONOSE3,d, Dimitrie NANU3, Ioana CARPUS3,

Maria BUZDUGAN4,e, Marcela RADU4,f1The National R&D Institute for Textile and Leather, România, Bucureşti, sector 3, 030508, str.

Lucreţiu Pătrăşcanu 16, 2The National R&D Institute for Electronically Engineering, România, Bucureşti 3“Carol Davila” University of Medicine and Pharmacology, România, Bucureşti

4S.C. MAGNUM S.A. – SME, România, Bucureşti acertex@ns.certex.ro, bangeladorogan@yahoo.com, cmignat@icpe-ca.ro , dgeluonose@rdslink.ro ,

ebuzdugan_maria@yahoo.com , fmagsx@rdslink.ro

Keywords: sensors, performance textiles, monitoring Abstract: There is a critical need of integrating the basic electronics technologies, sensors, computers and communications into textiles, so that these, until now passive, to be able to be changed into interactive, intelligent information infrastructure in order to facilitate the personalized mobile information processing to the end user. A field with a special application potential of the intelligent textiles is the medical field. The paper will present a knitted textile product having an attached resistive sensor meant for monitoring the foetus heart rate during the intrauterine development period. Introduction Change is the only constant in the nowadays dynamic world. A change has appeared in the consumers’ values: instead of wanting the finest natural materials, people are looking at engineered beauty, innovative design and smart product aspect. In this context, there is a critical need of integrating the basic electronics technologies, sensors, computers and communications into textiles, so that these, until now passive, to be able to be changed into interactive, intelligent information infrastructure in order to facilitate the personalized mobile information processing to the end user. The research priorities in this field are the outcome of the social trends and needs, together with the top technology impediments regarding the process technology and applicative research. There have been identified five major social trends (global society, health and wellness concerned society, active society, safety and security society and individual activities), each of them having specific requirements concerning textiles and everyday clothing. A field with a special application potential of the intelligent textiles is the medical field (clinical monitoring, complementary investigations, secondary prophylaxis, and medical treatment). At present, the main trends regarding the research in the field include the following aspects and elements:

• Parameters and characteristics that must be monitored depending on application; • Sensors for emphasizing the parameters and characteristics to be monitored; • Specific technologies of implementing and inserting the sensors into textile structures; • The modelling of the intelligent clothing system; • The designing of the map for positioning on the human body of the sensors of the

physiological signal monitoring sensors which are monitored by e-textiles; • Information processing and sending; • Information reading based on a specific algorithm;

Advances in Science and Technology Vol. 60 (2008) pp 95-100Online available since 2008/Sep/02 at www.scientific.net© (2008) Trans Tech Publications, Switzerlanddoi:10.4028/www.scientific.net/AST.60.95

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• The elaboration of a medical protocol/the structure and reading will be based on the bio-clinical investigations, the study of distribution and determinants of the dysfunctional/pathologic states;

The research activity, based on convergent technologies in the field of the human engineering and medical practice has as a result innovative products, which can:

• Offer new treatment alternatives and/or a faster recovery after medical treatments; • Improve the life quality of the people suffering from chronic diseases; • Facilitate and ensure the eldest life; • Non-invasively monitor the bio-physiologic signals of the human existence structures on

three essential levels: body – structure and functions, individual level activity and social participation.

Experiments The field of material and intelligent structures is interdisciplinary between science and technology and combines the knowledge of physics, mathematics, chemistry, computer science and the material, electric and mechanical engineering. It involves the human creativity and innovative ideas for accomplishing the customised, adaptable, person-synchronized textiles, used in information processing at any moment, in any place and for anybody. From the medical point of view one starts from the basic notion of functional status, frequently associated with the level of the health state, being in direct connection with the wellness; its two aspects – functionality and disability – constitute as two sides of the same coin with valences of “umbrella terms”, which cover two important fields: non-problematic (for example integrity, functionality) and problematic (for example disability, operation limitation, constraint), which on their turn are structures on three essential levels characteristic to the human existence: body – structure and functions – named B (body), an activity on individual level – named A (activity) and social participation, named P (participation). Specifically, each of the three levels can be regarded integratively by summing up of two antagonistic sides:

- for level B integrity (normal structure and function) versus disability (prejudice or high deviation within the organic functions)

- for level A activity (adequate fulfilling of the useful or proposed actions) versus activity limitation (for the persons who have difficulties in accomplishing the daily activities, especially the household ones)

- for level P participation (the involvement with no difficulties in the specific activities from the community or social life) versus the participation restriction (problematic aspects in the aimed domains).

Thus, there is allowed the individualized outlining of either conditions/particular states of the investigated persons, or the specific behaviour in approaching them, facilitating a clear, characteristic working mode. This bio-medical model that constitutes a solid base in the health state analysis, including the wellness state, of the population in general, as well as particularly of the persons having various pathologies, is a very useful instrument, being directly compatible with the non-invasive monitoring needs of physiological signals by specific sensors, incorporated into intelligent textiles. The non-invasively monitored physiological signals will be processed and read according to a specific algorithm, in order to allow permanent discriminative identifying of the two major states mentioned earlier: the non-problematic state or the state of comfort versus the problematic, critical or alarming state, including the possibility of wireless notifying of an emergency medical unit being in a close place. The target population has a wide spectrum, aiming at: the eldest people, patients suffering from cardio-vascular diseases, patients suffering from vertebro-medullary trauma, including the chronic ones, patients with high risk of falling (most of them old), pregnant women.

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The experiments were directed towards the accomplishing of a vestimentary accessory with an attached sensor which should allow the monitoring of the foetal heart beats during the pre- and inter-natal period, with the purpose of identifying the problems which, if there are not timely corrected, can lead to the death of the foetus or may be the cause of a long term morbidity. The normal foetal heart beat characteristic: the normal frequency is: 120-160 beats/minute, steady rhythm, clear tone sonority, the presence of acceleration (during pregnancy- spontaneous, during birth – periodical), the absence of the foetal heart beat diminution and bradycardia. The main causes of the abnormal foetal heart beats: tachycardia (mother’s temperature, medicines, premature foetus, foetal anaemia and hypovolemia, imminent hypoxia and chronic acidosis, birth in pelvic presentation); bradycardia (excessive uterus activity, the rapid labour progressing, advanced pregnancy age, congenital heart block); prolonged decelerations (excessive uterus activity, maternal low blood pressure, maternal origin placenta affecting, the compression and prolapse of the umbilical cord, abruptio placentae regional anaesthesia). The clinical evaluation methods of the foetal heart beats during the prenatal period are: the intermittent listening of the foetal cord which can be carried out by a stethoscope or a portable Doppler monitor. The electronic monitoring of the foetus gives the possibility of obtaining clear and easy-to-read information about the foetal heart beats and the uterus activity. Six factors which influence the thermal comfort and belong to the personal ones, as well as to the environment ones, were identified. These can be independent to each other, but together contribute to the thermal comfort. Environment factors: air temperature; radiant temperature; air speed; humidity. Personal factors: clothing insulation, heat produced by the metabolism. As a strategy of accomplishing the equipment for identifying and monitoring the personalized information, the following textile structure variants were chosen: - structures which are woven and/or knitted from yarns properties specific for ensuring the physiologic comfort, used as a flexible support for the sensor attaching; - structures which are woven and/or knitted from HiTech fibres with conductive properties. The functional characteristics are doubled by the comfort and reliability requirements. For accomplishing the knitted vestimentary product meant for attaching the resistive sensor, choosing the raw material had in view the functional and special comfort requirements. From viscose and elastane yarns there was accomplished a plain structure to which the elastane yarn was laid as supplementary yarn by plating, on a section rotary knitting machine with a large diameter. The use of the elastane yarns (nude, simple or double layered) gives the knitted articles a good elasticity and a good capacity of recovery.

Fig. 1 Knitted textile product

A special attention was given to the product functional area (fig. 1) on which the foetus heart rate monitoring sensor will be attached in the intrauterine developing period. This area has the shape of a doubled sliver and assembled on the rest of the product using specific sewing (elastic-flattened). It must be mentioned the fact that the area constructive architecture was chose under V form and was correlated with the evolutional dimensions imposed by the foetus development.

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ec 1 ei ec 2 el

Fig. 2 The constructive structure of a resistive sensor; ce 1,2 – elastic carbon elements , ie- insulating elements,

ce-connection electrodes. The resistive sensor made of spongious carbon with a good conductivity has a structure formed of elastic carbon elements, insulating elements and connection electrodes (fig. no. 2). Detailed images of the sensor having the overall dimensions 44x22x10 are showed in Fig. 3.

F

Fig. 3 Sensor image where the line and electric contact surface that delimitate the two carbon elements are

highlighted When a micromechanical force F appears due to the physiologic strains, a micro deformation of the carbon element materials is produced, that has as effect an alteration of the sensor electric resistance. In the Fig. 4 there is showed the electric resistance (ohms) characteristic depending on the micro mechanical displacing and in Fig. 5 there is showed the electric resistance characteristic depending on the force.

Fig. 4 The electric resistance characteristic vs. displacing

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Fig. 5 The electric resistance characteristic vs. the applied force

In Fig. 6 there is showed also the measurement micro-stand which includes the COREX (D) dynamometer having a resolution of 1cN and the ULTRAS (M) micro mechanical sensitive element having a resolution of 2 microns.

D

M

microsenzor

Fig. 6 Testing micro-stand for resistive micro sensors

The sensor attaching on the textile structure (fig. 7) is made in the indicated position by “the evolution map” of the foetus development. The monitored signals are taken and processed for the elaboration of the medical protocol. The product is under experiments under real use conditions and represents the starting point in accomplishing the textiles meant for monitoring the personalized information.

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Fig. 7 Sensor positioning

Conclusions

- The fixing of the electronic components into/on the clothing products is a challenge. Each organ of the human body has an evolution which is continuously oscillating under a neuronal and hormonal control, the monitoring of the vital signs clarifies the patient clinical synopsis.

- The identifying and defining of the physiological, biomechanical signals that might be monitored with a view to obtaining information regarding the pregnant health state were made starting from the study of the organic physiopathologic mechanisms.

- The knitted vestimentary product having an attached resistive sensor meant for monitoring the heart rate is the result of applying the convergent technologies, is characterized by functionality and psycho-sensorial comfort and represents a starting point in completing the clinical investigation methods.

References Tatsuy Hongu., Glyn O.Phillips., Machiko Takigami., (2005), New illennium fibers H. Strese., (2005), Technologies for Smart Textiles”,MST-News, 6-9. R. Paradiso., K. Wolter.,(2005), Wealthy-A Wearable Health Care System: New Frontier on E-Textile”, MST-News, 10-11. I. Locher., T. Kirstein., G. Troster., (2005), From Smart Textiles to Wearable Systems, MST-News,12-13. D. Cottet., J. Grzyb., T. Kirstein., G. Troster.,(2002), Electrical Characterization of Textile Transmission, IEEE Transactions on advanced packaging,vol.26, 182-190 M.Catrysse., R. Puers., C. Hertleer., (2004), Towards the integration of textile sensors in a wireless monitoring suit, Sensors and Actuators, 302-311.

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