A Didactic Transmitter to Support the Communication and Learning Process of Children with Cerebral Palsy

Nowadays, more than one billion people live with some form of disability (almost 15% of the world population). In this line, the preterm and low weight in neonates constitute important public health pro blems, especially in low and middle income countries. Infants who survive preterm birth are at increased risk of developing neurological problems such as Cerebral Palsy (CP) and impaired cognitive function. The CP comprises a series of disturbances in brain functions, motor, hearing, vision and learning for people who have it . In the same way, this disease does not allow to patients to use ICT tools to express their feelings, ideas, and needs, or in general, improve their learning process. On this basis, in this paper we present a ICT -based tool that relies on an embedded system and a mobile application, able to be used by patients that can perform slight head movements, or hand movements. Likewise, our system can detect these movements to help during the communication or learning tasks. The system was evaluated and adjusted in several tests carried out with 47 children (20 girls, and 27 boys). The achieved results are encouraging, and have shown 89% of acceptance by the patients.


Introduction
The CP is directly related to the central nervous system disorders, motor skills, listening and learning d ifficult ies caused by lesions in the brain that mostly occurs while the baby grows in the wo mb or in the first years of life, when the baby is still developing.Likewise, it is important to mention that in so me cases it is no possible to determine what causes CP [3].
Given that CP produces several problems related with motor ab ilities and the normal learn ing process, we have developed a system able to transmit mes sages (that express the patient' s feelings, needs, or ideas) and support several activities related with special education.Our system can used with smartphones or tablets, and was designed to be used by patients of the Cerebral Palsy Institute of Azuay (Instituto de Parálisis Cerebral del Azuay).This institution is an Ecuadorian non-profit organization that attends children with different kinds of disabilit ies in Cuenca, Ecuador.In the same way, our system as the aim of providing a new alternative to carry out the therapy activities through the use of multimedia resources, remote co mmunicat ion, and patient monitoring.The rest of the paper is organized as fo llo ws.So me important facts related with CP and his treatment/therapy is presented in Section 2. Section 3 describes our system as well as the hardware and software elements.The pilot experiment that we have carried out and the preliminary results are depicted in Section 4. Finally, the Sect ion 5 contains some conclusions and ideas for future work.

Cerebral palsy: a brief overview
The CP is a disease that can be produced due lesions suffered by child during the pregnancy or his/her first months of life.In some particular cases, these lesions are due to low o xygen levels in the brain (hypo xia) [3].Other important causes of this disease are the premature birth and the following conditions: intracranial hemorrhage (bleeding in the brain), trau matic brain in juries, severe jaundice, brain infections (bacterial men ingitis or viral encephalitis), and infections suffered by the mother during the pregnancy (even infections that are not easily detected) [4].
The signs and symptoms of CP are d ifferent according to each case and are included in a wide range (fro m mild to severe) that can affect one side of the body or both, and even legs or arms o r both at the same t ime respectively [3,4].Likewise, in some cases, these symptoms can be detected during the first months of life, when the doctors or specialists can see some of the following clues: delays in the ch ildren's ab ility to ach ieve something, difficu lties to sit, turn, crawl, walk, etc. [4,5].The spastic cerebral palsy is one of the most common types of CP.Th is disease is characterized by the loss of movement in d ifferent muscle groups due to stiff joints and the development of muscle tension with the passage of time.In the same way, as the patient grows, he/her can suffer fro m a co mb ination of paralysis with a muscular contracture, several abnormal movements during the walk and loss of coordination [5,6].This disease is related with other disorders as the following: dysarthria, hearing and visual impairments, learning difficult ies, intellectual d isabilities, etc.However, in some cases the intelligence is not totally affected [6].
Due to the symptoms related with CP, the patients can suffer fro m co mplications of motor skills such tremors, flaccidity, incoordination, thin bones (with risk of suffering hip dislocation or sclerosis), etc.In the other hand, the physiologic complications can include malnutrit ion, intestinal occlusion, and even pneumonia due to suffocation.The central nervous can be affected too by several problems, e.g., appro ximately half o f the patients suffer fro m convulsions and recurrent seizu res, and in several cases they present decrease of the intellectual and communication capacity [6,7].

Treatment/therapy for CP
The main goal of the therapy/treatment for a patient suffering fro m CP is to develop as many skills as is possible for reaching an independent life (in the as far as possible).Therefo re, it is important for team of experts (therapists, doctors, psychologists, and relatives and caregivers) conduct in a proper way the different stages related with this therapy process (diagnostic, assessment, and intervention) based on the symptoms present, and trying to prevent future co mp licat ions (given that this disability not necessary affect the life expectancy of the patient) [7].In the medical side, it is necessary to have the support of specialists in rehabilitation, pulmonology and gastroenterology with the aim of p roviding adequate diagnosis and monitoring services as magnetic resonances, audiometry tests, visual and hearing exams, etc.The results of these exams are important to determine the patient general condition, and they allow doctors prescribing drugs to control the recurrent seizures, relax the muscles, or conducting surgeries of different kinds (e.g.some patients require tubes feeding or the cutting of certain nerves of the spinal cord to reduce the pain and spasticity) [8,9,10].On the other hand, it is fundamental for patients with CP to receive co mp lementary treat ment activities at home that can with her/his healthcare.For example, some patients require good nutrition and intestinal protection with softening of feces, fluids, fiber and laxat ives in addit ion protection against injuries to their joints [9,10].The prenatal care reduces significantly the risk of suffering CP in children.In the most of cases, when a wo man presents complications during pregnancy and is treated in time at a prenatal clinic, is possible to prevent lesions that cause disorders in the brain of the fetus [11,12].

The proposed system
We have developed an embedded system that allows users to perform remote co mmun ication taking advantage of any available mobile device (s martphone or tablet) based on the Android Operat ive System (OS).W ith this aim, the system has a mobile application that provides services to establish the communicat ion with the patient, and contains different educational materials and activit ies.Given that our system is portable, it is possible to use it at home or in any place where the patient goes..Some of the most important features of the developed system are described below (Figure 1): x The system relies on two main modules: an electronic device that detects and registers the head/hand movements made by patient, and a mobile application that supports the communication and learning processes.
x To register the movements made by patient, the system uses two different adjustable elements: a headband and a hand belt. 05004-p.2 x The entire system (both the electronic device as the application) was developed using open source tools and elements (Arduino and Java.).
x The system can easily incorporate new modules to perform new co mmunication o r learn ing activities.
x Each therapist can include h is/her mu ltimed ia materials for the different exercises and activities that are included in the mobile application.
As was mentioned above, the electronic device was designed for two types of patients, according to his degree of disability: the first one is intended for children who have a high degree of disability and its motor activity is limited solely to the head movement, while the second option is for those which are able to use their hands.In this line, the device has two types of sensors: a) An adjustable headband made with velcro that has a soft texture, and contains inside a accelerometer o f 9mm with 3 degrees of freedo m (model: MMA7361L).This element provides a set of 3D coordinates of the position of the head in the space.
b) A bracelet that fits to the back of the palm of the hand that is made with the same materials and works with same principle of the headband.In both cases the data processing it is carried out using an Arduino Nano device that encodes and sends the results of the position head or hand position to the mobile device through Bluetooth (using a JY-M CU HC-06 module).The electronic uses a lithiu m battery that provides a voltage of 3.8V to 0.5A as source of energy.This battery is rechargeable using USB port, and given the low consumption of the device is possible to use it during one week (with 3 years of lifetime).The case of the device is made in acrylic with a cuff with velcro adjustable wheelchair as well as to the arm of the patient (depending on his/her condition and particular needs).The mobile device makes possible that patients can use the transmitter at the institute or school, at home o r in any place where is required.In the same way, this device help to entertain children and does not generate discomfort when using it, given that is easily adjustable to any head or hand sizes.
The Android application provides a graphical user interface that it is easy to understand, given that the options menu consists on pictograms that represent the patient's needs and teaching options.Both functions have mu ltimed ia content of high quality, wh ich responds to the movement of the head or hand that is controlled by the headband or bracelet, respectively.The most important options provided by the mobile applicat ion are the following: x Exp ressing needs: the system contains several options to express the patient's needs as: hungry, toilet, sleep, born, among others.These needs are displayed using graphics (pictograms) and sounds.
x Educational contents to learn the following concepts: animals (domestic and wild), parts of the body, family, colors, shapes, among others.

Operation parameters
The operating parameters consist on the different functionalities that patient is able to run through the different menus of the mobile application (without making contact with the mobile device).To achieve this, the patient only needs to make slight movements with his/her head or hand.The process of interaction with the application is the following: x In the main menu the patient can selected between two options: the transmitter of needs, or educational content.To select one of these options, the patients must to move the head/hand to right or left.For the therapists are provided the t wo options: a connection button (to start connection between the mobile device and the electronic device) and an exit button.x The educational content menu shows the different categories mentioned above, and the patient can select the desired category using a vertical movement (fro m up to down).Once the exercises are finished, the patient can back to the previous menu using another vertical movement (fro m down to up).In summary, only in the main menu the user must make left or right head/hand movements, wh ile in the rest of the application are used vertical movements.In the same way, it is important to mention that these movements can configured according to each patient characteristic as sizes of h is/her body, head or hand speeds, or slower movements due other difficulties.

Preliminary results
The Cerebral Palsy Institute of Azuay (IPCA ) is a nonprofit organization that has been providing attention to children with disabilities since 33 years ago.Cu rrently, the IPCA provides diagnosis and intervention services for people suffering fro m cerebral palsy in Cuenca city (province of Azuay).No wadays, this institution helps more than 93 patients among boys, girls and adolescents who daily co me to the institution to receive free therapy.The attention services are provided by 10 teachers, 6 therapists, and 8 professionals of the admin istrative staff (a team of 24 people in charge of the center).
In order to analyze the real feasibility of the proposed system, we have worked with children with CP that suffer severe motor functions, and are in the 7-12 age range.The evaluation of the system was done in this way: once the therapist has put bands on patients, he/she makes several questions and orders that must be answered/accomplished by each patient using the system.
The system was tested in short sessions of 4 minutes (due to the effort that must be done by each patient to achieve the goals).Likewise, the initial tests allowed us to calib rate the sensors and correct s ome bugs of the system (first week).In the second testing phase (second week) the patients have shown high levels of acceptance to use the device (80%), and the activities were performed in a better way.
Table 1 shows the different age ranges of the patients with CP that have participated in the evaluation of the system.The Figure 2 shows the results achieved after the evaluation (in terms of device functionality and acceptance by patients).As we can see, 89% of patients has felt co mfortable using the device, and has reached the goals established in each therapy activity.However, after conducting pilot experiment we have noticed that it is fundamental personalizing the device according to user profile.In the same way, these results shown that development of the system must to continue, as well as the improvements.

Conclusions
In this paper we have presented a new system to provide support for co mmunicat ion of children suffering fro m CP.In the same way, our proposal can be used to support the learning process of this kind of patients.
It is important to bear in mind that each patient has particular needs, requirements, and a specific p rofile (medical and educational).The system allo ws therapists to reduce the time required during therapies, and provides support to stimu late the patient's motor skills .As lines of future work we propose the following ones: x To develop a notification module able to send SMS for patient's relatives.x To design an intelligent module to automat ically select the exercises and activities given the patient's profile.

Figure 2 .
Figure 2. Preliminary results of the pilot experiment (in acceptance terms).