cloud integrated low cost customizable smart medical · pdf file · 2014-09-17cloud...

International Journal of

Intelligent Engineering & Systems

http://www.inass.org/

Cloud Integrated Low Cost Customizable Smart Medical Chair for Diagnosisand Doctor Assistance

Yokesh Babu Sundaresan1∗ , Kumaresan P2, Arjun Rajshekhar3,Swayamdeepta Sanyal4 and Rohan Puri5

1−5 Third year Computer Science and Engineering and Professors - SCSE, SITE, VIT University,Vellore, TN, India, Pincode 632014

∗ Corresponding author’s Email: [email protected]

Abstract: The application of embedded systems in the field of Biomedical Sciences provides the means to build anaccurate health and vital signs monitor. The usage of superficial and non-superficial sensors allows the extraction ofvarious parameters required for the diagnostics of a patient. Such health monitoring devices are not a viable optionfor the less fortunate who continue to use traditional detection techniques. Furthermore, the systems commerciallyproduced are not open to customization and hence may not be incremented upon to detect new parameters, hencerequiring the purchase of a new system. The proposed system instead grants more customizability and portability tothe user to allow the creation of a general purpose health monitor that is offered at a lower cost. In this project, wemeasure the viability of the proposed system by fabricating sensors of various vital signs such as sweat levels, bodytemperature, pulse rate and blood oxygenation levels using superficial sensors and a tracking system on a smart phonedevice that serves as a back end. An alternate cloud model approach has also been proposed considering the benefitsof cloud computing and to enact the requirement of the ubiquitous nature of the project.

Keywords: Vital Signs Monitor, Medical Frame, Electronic Medical Assistance, Oximeter, Galvanic Skin Response,Pulse Rate Monitor, Electrocardiograph Monitor, Body Temperature Monitoring, Smart Data Acquisition, Cloud Com-puting

1. Introduction

Health and vital signs monitors developed for com-mercial purposes are sold at reasonable prices that caterto the health professionals who wish to asses a pa-tient’s vital signs. But an alternative is required forthose who are less fortunate and those who do nothave the means to access such medical facilities ondemand. Furthermore, the demand of every countryto possess an excellent health care system directly im-plies the necessity in treating patients as quickly andefficiently as possible to prevent a back log of med-ical care. This has been countered through the agesby the increasing number of doctors to treat the in-

creasing number of patients. But for all efforts main-tained, cities and countries with high population den-sities still see delayed doctor appointments. The pro-posed method assumes to counter these issues by theautomation of a part of the diagnostics process. Inaddition, with the revelations achieved thus far in in-ternet related technologies, cloud computing has be-come a common place of application based services.Such services also extend to the domain of medicalservicing, an example of which can be noted in theCloud Sensor Sock [1]. Hence a cloud based modelhas been considered in the proposed method to im-prove the scope of access of information related to di-

International Journal of Intelligent Engineering and Systems, Vol.7, No.3, 2014 10

Figure 1 Illustration of medical frame

agnostics.The prime sector of application of the proposed project

lies within the Health Monitoring domain. While a lotof work has already been carried out in this field in thepast, a new innovation is required to counter the pri-mary challenges that have been identified in the stateddomain, which is listed thusly:

1. Cost effectiveness

2. Portability

3. Ubiquity of information

4. Customizability

A prime example of customizability is the concept ofa medical frame as shown in Figure 1 which recordsthe vital signs of the patients as they walk through it.

2. Related Work

Due to the extensive list of papers that already existin the field of the Application of Biomedical Sciencewith Embedded Systems, five base papers have beenselected as a source of reference of the method pro-posed. The first base paper [1] implements a CloudSensor Sock which relays sensor information to thecloud, namely using the Google App Engine. TheCloud Sensor Sock allows a wearable sensing plat-form by obtaining information from a heartbeat strapwhich is connected to an Arduino Lily Pad and thencommunicated to both an Android device through Blue-tooth and directly to the App Engine via the RESTAPI whenever a direct wireless connection is avail-able. The data stored through the App Engine’s Datastore feature is then visualized through a J2EE webapplication which also allows users to manage data

points from the sensor data. The second [2] paper pro-poses cloud integration into the field of Telemedicine.Remote EEG monitoring, or TeleEEG, surgery throughremotely controlled robotic arms, medical record view-ing, prescription monitoring and appointment schedul-ing are stated to already be in practice by surgeonsand physicians. The paper adds to this by suggest-ing remote patient monitoring and patient admissionthrough cloud services. Relieving the processing loadfrom mobile devices to the server via the cloud is alsoproposed, which no doubt would give an edge overthe necessity of heavy duty functional requirementssuch as signal pattern recognition. The third [3] im-plements a “Health Tracker 2000” which is composedof a temperature sensor, pulse sensor and an oxime-ter. This wearable device uses RFID tags to identifythe patients and then the parameters monitored is thenwirelessly relayed to a computer using the MICA2and MICA2DOT components as the transceivers andreceivers. The advantage of using such a system isits focus on a well-defined network organization thatenables remote monitoring of the patient’s data. Thisgave us the motivation to create our own method ofcommunication between the base monitoring systemand the information recipient and also to add an im-provement to the portability factor by incorporatingsmart phone devices. The fourth [4] base paper uti-lizes ZigBee to communicate the electrocardiograph(ECG) information to two mobile embedded platformsusing the HBE-ZigbeX. The ECG sensor first sendsthe ECG signal to a mobile embedded platform thatclassifies the received signal by the application of auto-associative multilayered perceptron networks after con-verting the raw ECG signal to a histogram of gradientform. The results are then sent to a second mobileembedded platform that acts an ECG state monitoringdevice. The usage of the histogram of gradient as theinput for a multi-layered perceptron network has beenimplemented on the front end android device to detectabnormal signal readings and to alert the user aboutthem. The final base paper [5] focuses on the designof a wearable heart rate, blood pressure and temper-ature sensor. The temperature is sensed by using a10K Ohms thermistor in a Wheatstone Bridge, theheart rate is measured by an ECG circuit and the bloodpressure is calculated from the Pulse Width TransitTime which is the time interval between the peak ofthe ECG graph and the minimum trough of the photo-plethysmograph (PPG) signal obtained by using a redLED. The signals received are conditioned throughband pass filters and amplifiers and then wirelessly


transferred to the user’s phone. It is from this paperthat we obtained the information we needed to designour own circuits for the modules proposed.

3. Proposed Method

The implementation requires several biomedical sig-nal sensors to obtain parameters such as pulse rate,perspiration levels, and body temperature and oxy-genation saturation. These parameters have been mea-sured by implementing sensor circuits in combinationwith a microcontroller. The integration of these cir-cuits to the medical frame would require “sensory arms”that would protrude toward the user at appropriate lo-cations to acquire the necessary signals.

Figure 2 Proposed architecture

Figure 3 Circuit design for galvanic skin response sensor

The medical frame would also require a degree ofcomputer assistance for the patient to understand themethod of utilizing the medical frame. The methodof wirelessly relaying the processed information fromthe medical frame to the doctor has been derived from[3] and [4]. The ability to send patient informationover the cloud also allows a system of in-house treat-

ment of the patient remotely from the doctor’s office.Hence the complete virtualization of the treatment pro-cess is possible in cases where the ailment is one thatis easy to diagnose, i.e. not one that has irregularsymptoms. This also enables an international treat-ment system for countries with poor health care sys-tems that have a deficit of doctors. The proposed ar-chitecture of implementation, shown in Figure 2, de-fines the final acceptor of the monitored parametersas a separate individual responsible for diagnostics,for example a doctor. The option of accessing thediagnostics over the internet has also been depictedto provide visualization and patient data managementfor concerned medical institutions. The method of op-eration via cloud services has been elucidated in thedesign and implementation section. The architecturecan also be modified to make the final informant asa patient in order to allow self-monitoring and self-evaluation for those who wish to have on demand ac-cess to their vital signs status. The smart phone de-vices are equipped with an application that recognizessymptoms to deduce possible diseases and a trackingsystem that provides a visual display and user-friendlyGUI of the parameters monitored.

4. Design and Implementation

The Arduino ATmega1280 has been selected as themicrocontroller for the implementation. The sweatlevels are detected through skin conductance using aGalvanic Skin Response Device. The galvanic metalused in skin contact is an aluminum foil attached toa piece of Velcro intended to be wrapped around thepatient’s finger as seen in Figure 4. The signal fromthe skin contact is passed through a high pass filter,low pass filter and then amplified as shown in Fig-ure 3. The signals fluctuate according to the surfacearea perspiration percentage around the portion of thefinger exposed to the foil. The signal received is thenprocessed to obtain the perspiration percentage, whichis then used to provide an approximation of sweat lev-els in the form of liters per day. The final implementa-tion of the GSR sensor based on the circuit schematiccan be seen in Figure 5. The body temperature ofthe patient is detected using the 10D-9 thermistor asthe temperature sensor. The thermistor’s resistance at25KC is 10 Ohms and decreases according to the in-crease in temperature. The thermistor circuit works onthe principle of voltage dividing as shown in Figure 6and whose implementation can be seen in Figure 7.The formula applied in Equation 1 on the voltage sig-nal received obtains the resistance of the thermistor.


Figure 4 Galvanic skin contact

Figure 5 Implementation of GSR sensor

The voltage source of 5V is used and the potentiome-ter is cranked to 1K Ohms resistance. The resistance isthen applied to Equation 2 to obtain the Celsius read-ing of the thermistor. The Steinhart-Hart coefficientof the 10D-9 NTC thermistor is substituted to obtainEquation 2.

R = (SV ∗PR/SV−V), (1)

where SV is the source voltage, PR is the resistancethe potentiometer is set to, and V is the voltage read-ing obtained from the raw analog input.

Temperature = [(log(R/10)/3000)+(25+273.15)−1]−1−273.15 (2)

The pulse oximeter and pulse rate sensors are basedon a fundamental design from [5] and is intended tobe used a shell that wraps around a thin part of the pa-tient’s body, such as the earlobe or a finger. Each shellencapsulates an LED and a photodiode to measuretwo different readings. The pulse rate is calculated by

Figure 6 Circuit design for body temperature sensor

Figure 7 Implementation of body temperature sensor

using an infra-red LED in the photoplethysmographcircuit as shown in Figure 9, and a red LED is used todetect the ratio of oxygenated blood, which absorbsthe red light, versus de-oxygenated blood, which ab-sorbs infra-red light. The implementation of the cir-cuit design can be seen in Figure 8. The photodiodeused is the BPW34 due to its range of spectral respon-sivitiy which detects wavelengths between 700nm to600nm with excellent sensitivity. The pulse rate iscalculated by obtaining the total time taken obtain 10peaks which is then scaled to obtain the number ofbeats per minute. The oxygen saturation percentageis obtained by tracking the ratio of the peak values.All measurements are automated by a microcontrollerand are transferred to a smart phone device, in thiscase, and Android device, via the Bluetooth moduleHC-05 in order to implement a user friendly trackingsystem. Bluetooth has been selected over ZigBee, assuggested in [4], under the assumption that the user re-ceiving the real time feedback lies within close prox-imity to the system. The HC-05 can be configured ei-ther as a master or a slave and the TX, RX, 3.3V and


Figure 8 Implementation of oximeter

Figure 9 Circuit design for the photoplethysmograph sen-sor

GND pins are the only pins used in the implementa-tion. The TX and RX pins are used for the serial trans-fer of data and commands to perform operations suchas pairing and sending data. Due to the asynchronousmanner of the Bluetooth module, the numerical datasent from the microcontroller is encoded. Cloud inte-gration can be achieved by incrementing on the exist-ing architecture with Figure 11. The figure illustratesthe smart phone device communicating to the cloudby making a web service request. The smart phonemust initially create a snapshot of data points whichis uploaded to the server’s database. The web ser-vice request executes a server side script that preparesthe user’s existing data snapshot to accommodate thesnapshot sent by the smart phone. The request alsoexecutes a server side script that detects abnormal sig-nals. If an abnormal signal is detected, a warning no-tification is pushed to the user’s caregivers via emailor SMS. The proposed cloud service provider is theGoogle App Engine which is a Platform As A Serviceplatform that also has Software As A Service(SaaS)capabilities. The SaaS allows the development of a

Figure 10 Snapshot of the HC-05 bluetooth module

Figure 11 Cloud integration architectural design proposal

visual rendering and data management application ofthe snapshots obtained thus far. The algorithm of thecode executed on the hardware is illustrated in Algo-rithm 1.

4.1 Algorithm 1 signal acquisition and transmit-ting

1. procedure AcquireAndTransmit

2. BluetoothModule b;

3. Number analogR, celsius, analogPulse, analog-Pulse2, bpm, perspiration;

4. analogR←− ReadAnalog(TemperaturePin);

5. celsius←− caculateTemperature(analogR);

6. analogPulse←− ReadAnalog(PulsePin);

7. bpm←− timeFor10Troughs(analogPulse);

8. analogPulse2←−ReadAnalog(RedLEDPulsePin);

9. perspiration←− getOxygenation (analogPulse,analogPulse2);


10. b.encodeAndSend(celsius,bpm,perspiration)

11. end procedure

The n-component-n hardware details are listed as such:

1. Resistors

(a) 100 Ohm× 3

(b) 1M Ohm× 4

(c) 3.3M Ohm× 1

(d) 100K Ohm× 1

(e) 10K Ohm× 2

(f) 220 Ohm× 1

(g) 10K potentiometer× 1

(h) NTC thermistor 10d -9

2. Diodes

(a) IR Led 940mn wavelength× 1

(b) Red Led 620nm wavelength× 1

(c) BPW34 Photodiode× 2

(d) IN4001 Diode× 3

3. Capacitors

(a) 4.7µF× 2

(b) 0.1µF× 1

(c) 10νF× 1

4. LM741 Op Amps× 4

5. Breadboard× 3

6. AA Battery× 16

7. 20 cm Velcro Tape

8. 6 m insulated copper wire

A disease recognition application was developed to al-low a quick lookup of diseases according to the symp-toms determined as seen in Figure 13 and Figure 14.A health tracking application was also developed todisplay the data received from the microcontroller, fromFigure 15, which could also be displayed in the formof a real-time graphical representation [6] as seen inFigure 16-19. The operation of the application de-veloped is illustrated in the control flow diagram inFigure 12. An assumption made is the diagnostic ca-pability of the software portion of the implementationwhich should be well versed with the basic medicalsymptom evaluation techniques. The next assumptionis that the records for all symptom/ailment details areenlisted in the database for the reference of the doctor.

Figure 12 Control flow of the front end application

5. Results

The snapshot of the total system can be seen in Fig-ure 20. One of the challenges faced by the implemen-tation of the Bluetooth module was to ensure an ac-ceptable rate of obtaining correct parameter strings onthe smartphone device, and this was achieved by im-plementing an encoding scheme that contained a cus-tomized parity checking mechanism that allowed dataretrieval through error correction. The performancethroughput of the back-end has been recorded up to200 stable detections per second, while the perfor-

Figure 13 User interface for the disease recognition searchfunction


Figure 14 User interface for viewing the disease informa-tion

Figure 15 User interface for the health tracking system

mance throughput of data between the hardware to thesoftware display has been recorded up to 50 detectionsper second of which 10% of the sent data was left un-parsed since they corrupted data were filtered out inthe decoding process. The testing phase of our projectentailed an accuracy check of the parameters recordedwith some monitoring tools purchased from the localpharmacy. The accuracy of the readings was initiallynot as high as expected and several modifications wereperformed on both the hardware and program ends toimprove the final accuracy of the readings.

6. Conclusion and Future Work

The accuracy of the values received by the sensorsused was high enough to obtain vital information aboutthe state of the user. The back end hardware imple-mentation allowed a continuous analysis of the user’svital signs with minimal processing latency. The scopeof improvement in the implementation lies in the opti-mization of power consumption and a smaller circuitby converting the separate Photoplethysmograph and

Figure 16 Real-time graphical representation of tempera-ture from the health tracking system

Figure 17 Real-time graphical representation of oxygensaturation from the health Tracking system

the Pulse Oximeter circuits into a single power sourcecircuit that switches functionality using a multiplexer.Another improvement is to design an ergonomic shellthat contains the photodiode and the LEDs. To achievea closer simulation to the proposed Medical Frame,an intuitively designed mechanical set-up is requiredthat scans the patients vital signs. The implementa-tion only scans some of the several parameters re-quired by the doctors and hence is open to additionof other scanners to obtain any necessary informationabout the patient. Carrying the project further, the in-tegration of cloud services is yet to be implemented.The goal of this objective would be to successfullycombine the health tracking application with cloud ca-pabilities by uploading snapshot data of a fixed set ofdata points. This would also allow us to integrate pro-cessor intensive functionalities such as signal anomalydetection, which would be beneficial in the cases wherethe user is incapacitated and requires dire medical as-sistance.


Figure 18 Real-time graphical representation of perspira-tion from the health tracking system

Figure 19 Real-time graphical representation of pulse ratefrom the health tracking system

References

[1] Charalampos Doukas, Ilias Maglogiannis, “Manag-ing Wearable Sensor Data through Cloud Comput-ing,” IEEE Third International Conference on CloudComputing Technology and Science, 2011, pp. 440-445

[2] Princy Matlani , Narendra D Londhe, “A Cloud Com-puting Based Telemedicine Service,”IEEE Point-of-Care Healthcare Technologies(PHT), 2013, pp. 326-330

[3] Edward Teaw, Guofeng Hou, Michael Gouzman, K.Wendy Tang, Amy Kesluk, Matthew Kane and Ja-son Farrell, “A Wireless Health Monitoring System,”IEEE International Conference on Information Ac-quisition, 2005.

[4] Hye-Jin Lee, Dong-Oh Kim, Bub-Joo Kang, Sang-Woo Ban, “Mobile Embedded Health-Care SystemWorking on Wireless Sensor Network,”Third Inter-national Conference on Communications and MobileComputing, 2011, pp. 161-164

Figure 20 Snapshot of the final implementation

[5] Dhvani Parekh, “Designing Heart Rate, Blood Pres-sure and Body Temperature Sensors for Mobile On-Call System” (2010),EE 4BI6 Electrical Engineer-ing Biomedical Capstones. Paper 39.

[6] Jonas Gehring, “Android GraphView,” [Online].Available: http://android-graphview.org


cloud integrated low cost customizable smart medical · pdf file · 2014-09-17cloud...

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