2014 7th Cairo International Biomedical Engineering Conference Cairo, Egypt, December 11-13, 2014
Wireless Communication and RFID Based Handheld Database and Medical Diagnostic System M. K. Shahin
Assistant Professor, Electrical Engineering Department, Faculty of Engineering, Suez Canal University Ismailia, Egypt
[email protected] ,
[email protected] Abstract-In the recent decades, Egypt has witnessed an increase need for portable handheld medical diagnostic systems that connected
remotely
or
wirelessly
to
the
central
healthcare
database systems. The main benefits of these systems are the further onsite disease investigations that were consolidated with the patient medical record history. In this paper, a low-cost, light-weight, handheld, and wirelessly/wirely-connected medical diagnostic system is proposed. The main features of the on-hand system are:
(1)
Fast retrieval of the patient basic information and
medical history using a RFID card that is uniquely assigned to and held by each patient.
(2)
The system is wirelessly connected
via a network module to the hospital information system (HIS) for
patient
data
query
and
updating.
(3)
It
has
a
wired
connection via USB to any computer to retrieve and review the patient data either form the device memory card or from the central database. (4) The system is packed with a high capacity memory card for new data storage in case of lack of wireless or wired network connectivity.
(5)
The station is equipped with
diagnostic ECG acquisition, temperature monitoring, and NIBP measurement
(6)
Smart
modules
for
interactive
the
onsite
graphical
patient
assessment.
touch-screen
for
manipulation and accessing the system whole functions.
(7)
easy Long
lifetime rechargeable battery that can operate the entire system for at least allowing
6
such
hours. The new system has the potential for technology
to be
available
at
low
cost
thus
research and development for complete embedded diagnostic and monitoring solutions on these systems is still limited. The main obstacles toward a fully benefIcial handheld biomedical system are: quality and standard requirements, high development time and cost, and complexity and overhead of the mobile operating systems currently in use [4]. On the run toward implementin the ongoing exciting l medical technology on PDAs, iPads , tablets platforms, and other recent handheld devices, this paper introduces a handheld, low-cost, compact, and battery-operated system for medical diagnosis, monitoring, and patient information retrieval/updating. The introduced device is based on the recent embedded technology. The proposed system is capable to help physician to diagnose via measuring and displaying the patient vital signs. In addition to these valued investigation tools, the system is able to retrieve/store the patient personal data, disease history, and vital signs from/on a 4 GBytes multimedia card. The implemented system can communicate wirelessly at real-time over the HIS via the XBee® WiFi® wireless module [5]. Figure 1 shows the proposed system block diagram. One of the on-hand system merits is that it is based on the low cost on shelf components that make the device very cheap and very easy to upgrade via its Hardware/Software modularity.
providing cost-effective healthcare. Keywords-Patient, Diagnosis, Monitoring, ECG, Temperature, NIBP, RFID, Wireless Network Connection, Database, Hospital Information System (HIS).
I.
INTRODUCTION
For assessing just arrived to hospital severe-case patients, the fIrst medical equipment that is urgently needed for investigating and diagnosing, are the vital signs monitoring systems. These devices inform the medical stuff about the physiological state of the human main organs and systems [1]. However, conventional monitors do not have a remote access capability to the patient past medical records, which necessitates a complete blind fresh onsite investigation, every arrival and for each patient, by medical support personnel. Moreover, patient monitoring systems are generally bulky and heavy to be easily carried and transported by hand [2]. With the recent increase of public popularity for handheld systems such as smart phones, tablets and small notebooks, these devices are increasingly required to be integrated into the healthcare environments [3]. Moreover, portable monitoring systems may help for patient telemetry observation applications inside and outside the hospitals. However, the
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Fig. I. The schematic diagram for the proposed wireless communication and RFID based handheld database and medical diagnostic system.
This paper is organized as follows. Section I introduces this paper objectives and demonstrates the advantages of the proposed system. Section II describes the detailed implementation of the target device by focusing on its hardware implementation. In Section III, we describe the designed prototype fabrication, realization, and results. Section IV discusses the ongoing and the future improvements to the proposed system and concludes this paper.
II.
IMPLEMENTATION METHODOLOGY
A. Introduction
Conventially, patient monitors measure and display the patient vital signs. There is a serious problem that can arise during emergencies and critical cases; if there is no onsite trained medical personnel that can fastly interpret, assess, and decide the proper medical intervention. Further, traditional monitors are hard to be portable, and mostly standalone systems. Some suppliers offer a hard-wired network connected monitors to a local central stations, that doesn't offer the hopeful flexibility. If a minuatirized light-weight monitoring system could be connected wirelessly to the HIS, the patient vital signs could be tracked and accessed regardless of the patient residence place. Thus, expert medical stuff could be updated about a patient's symptoms and signs in real time. Moreover, handheld medical devices can be integrated into the HIS database and used to store/update the patients vital signs into the current records that can be very useful shortly [6, 7]. In this work, a portable embedded biomedical system was develpoed. The designed handheld monitor can check the condition of the patient online and transmits her/his vital signals via wireless communication. The physical dimensions of the miniaturized propsed equipment are small and its weight is less than 250 grams. A diagnostic ECG reader, a thermometer, and a non-invasive blood pressure (NIBP) measurement modules were builtin integrated into the system. The monitoring and communication modules are implemented on a dedicated hardware without OS overhead, which facilitates stable and timely responses to the external events. Using a customly programmed graphical display for the acquired signals, we propose that our system implementation was reliable for the patient continous potable monitoring and many other healthcare issues. B. Implementation Details
The target handheld monitor was implemented via a central cheap 8-bit, 80 MHz frequency controller that integrates all the system peripherals. The user can control the whole system via a single touch screen LCD. As demonstrated in Figure 1, the patient vital signs are feed to the controller analog inputs for either: (a) to be online displayed on the built-in LCD, (b) to be sent wirelessly and saved globally to the center station or HIS, or (c) to be saved locally to the built-in multimedia card. Later, the system is able to fast retrieve all the patient basic info and medical record from the memory card or the wirelessly connected database via the RFID tag that is held by each patient as a proof of identity. In the following subsections we will demonstrate each of these subsystem components.
medical stuff to fast diagnose the patient heart status and operation. (4) 12 bits analog to digital converter (ADC) resolution. (5) lK samples per second sampling rate. (6) High common mode rejection ratio (CMRR) via using AD620 instrumentation amplifier with a minimum of 100 dB CMRR [8]. Figure 2 shows the implemented ECG and temperature acquisition circuit.
Fig. 2. The patient eclectrocardiography (EeG) and the body temperature acquisition circuit.
B.2. Temperature Measurement Circuit
In this work, we implemented a simple temperature acquisition circuit for using it as an internal human body temperature level reader. The linear percentage temperature medical-sensor reading is feed directly to an analog controller input for digitizing and displaying. The sensing accuracy is about ±o.soc at 37°C, its measuring range is +20°C to +49°C, and finally its linear scale factor is +0.1Vrc. B.3. Non-Invasive Blood Pressure Device
Instead of building a complex non-invasive blood pressure module from scratch, we exploited a low-cost hand-wrist prefabricated blood pressure measuring apparatus casing, cuff, and pressure sensor to be connected and linked to the designed system. The NIBP module can be fully controlled from the designed embedded system touch screen (i.e. ON/OFF, start/stop, and insufflation/disinflation operations). In order to measure the patient systolic pressure, diastolic pressure, and pulse; the pressure sensor output, of the prefabricated apparatus, is feed to the microcontroller internal counter/timer. In order to get the NIBP reading, the counter checks if there is a detectable significant wrist blood pulsation or not [1]. As shown in Figure 3, the resultant measures are displayed on the LCD module. B. 4. Multimedia Card, Serial USB Inter/ace, Buzzer Alarm,
B.l. ECG Acquistion Module
A 3-lead digital electrocardiography (ECG) acquisition circuit was adopted [8]. The main benefit of the ECG circuit is: (1) Complete patient optical isolation and safety in complying with AAMI standards for safe current levels [9]. (2) Accurate digital implementation for the ECG bandwidth extraction filters (i.e. 100 Hz LPF, 0.05 Hz HPF, and 50 Hz notch filter). (3) Online ECG diagnostic bandwidth acquisition (i.e. from 0.05 Hz to 100 Hz) and plotting, which enables the
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and Real Time Clock (RTC) Modules
A 4-Giga Bytes flash memory card module was installed to hold the patients data. The stored data includes: basic patient data, doctor's notes and diagnosis, and the online acquired and measured vital signs. For tackling the wireless connectivity absence problem that may arise at some places that are far from the wireless LAN coverage areas, a wired USB-to-PC connection port was added to the module. The USB connection has the power to connect to the HIS for retrieval/updating the
patient stored record. In order for data synchronization and interactivity capabilities, a real time clock (RTC) with dedicated back-up battery and a buzzer alarm modules was added to the system implementation. Figure 6 demonstrates these helpful built-in peripherals.
transfer data [7]. The designed system is able to fast retrieve the patient personal info and the medical record history using a built in RFID tag reader. The future usage and medical implementation of the proposed system at the clinical environments supposes that each patient holds a unique medical tag. The medical stuff uses this tag to let the system rapidly call/query the medical archiving system for the hospital just-arrived patient. The data and the previous medical investigations may be loaded offline in case that it resides on the multimedia memory, or may be transferred online in case of wireless/wire connection to the HIS is established. Figure 4 shows the built-in RFID reader module usage to read a tag (up), while the fields for patient personal data retrieval and medical history information demonstration is displayed (bottom).
Fig. 4. The RFiD tag reader hardware module usage to read a patient unique tag (up),while the patient personal data (bottom-left) and the medical history record fields are displayed (bottom-right). Note: The patient personal info and diagnosis were masked for the privacy issues and concerns.
B. 6. XBee
®
Wireless Communication Module
XBee® is the brand name from "Digi International" company [5] for a family of form factor compatible radio modules that utilizes the IEEE 802.15.4 wireless network protocol standard that implement: media accessing, network addressing, acknowledgements, and retries; these features making it ideal for point-to-point and point-to-multipoint on-air communications. The adopted RF module transmits/receives over-the-air data baud rates of 250 Kbit/sec with coverage distance from 30 meters (indoor) to 120 meters (outdoor). The XBee® modules are the best choices for connecting the microcontroller based embedded systems to cloud or any local area wireless network. Figure 5 shows the used XBee® module.
Fig. 3. The patient ECG acquisition (top), the operation testing of the temperature acquiring module (middle), and the patient noninvasive blood pressure (NIBP) measurement (bottom).
B.5. Radio-Frequency Identification (RFID) Module
Radio-frequency identification (RFID) is the wireless non contact use of radio-frequency electromagnetic fields to
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Fig. 5. XBee® "802.15.4", series I, RF wireless communication module.
III.
RESULTS AND DISCUSSION
Based on a single master MicroChip® 18F45K22 8-bit PIC® microcontroller core with 80MHz external crystal oscillator [10], the modules described above were implemented on 2 printed circuit boards (PCBs), one of them is a single-side and the second is a double-faced board. Firstly, Figure 6 (up) shows the single sided PCB that holds the ECG, temperature, NIBP, RTC, buzzer alarm, 12Volt high-capacity battery connector and charger, high efficiency switched mode power supply (SMPS) DC/DC converter, R232/USB converter modules. Secondly, Figure 6 (bottom) shows the double faced PCB that holds the PIC® microcontroller, the RFID tag reader module, the multimedia card holder, and the wireless XBee® connector on the fIrst side. Further, Figure 7 shows the other side of second PCB that integrates the 240X128 pixels, with built-in touch screen module, graphical color LCD. The simple graphical, icon and menu based, software enables the user to interactively control all the system functions.
The proposed system could be exploited for many applications, like, (1) Fast diagnosis of critical case patients especially whom with cardiac arrhythmias symptoms at hospital emergency department, (2) In hospital telemetry and ambulatory applications, (3) At private sector clinics and medical centers for patient illness follow ups and observation studies of drug effects, and (4) Exploiting its low cost for using it as in-home remote patient monitoring and alarm system. IV.
CONCLUSIONS AND PLANNED FUTURE WORK
In this paper, a successful realization for a handheld medical monitoring and central database accessing system was implemented. The proposed device is able to measure the patient vital signals and to provide the patient medical background to the medical technical stuff. Our future work includes integrating peripheral capillary oxygen saturation (Sp02) module to adding the ability to estimate the oxygen saturation level. Further, linking the device to the global positioning system (GPS) will add the value of the awareness of the patient location and will encourage its usage for in-house monitoring applications. Moreover, we are planning for linking the system to the current evolving handheld technology as a separate external module that linked via USB wired, or Bluetooth® wireless connection. Exploiting the existing smart devices evolution will force our system to compete many market applications and segments. ACKNOWLEDGMENT
Eng. Mayada Yousry, Eng. Aya Yahia, and Eng. Hazem Hussein Ghareeb from Suez Canal University, Faculty of Engineering, Ismailia, Egypt are acknowledged for their assistance in prototype preparation and their helpful comments. REFERENCES [I]
Fig. 6. The first single sided PCB (up),the first-side of the second double-faced PCB (bottom).
Fig. 7. The other side of the second PCB while the system is in-duty.
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E. N. Marieb, and K. Hoehn, "Human Anatomy & Physiology", 9th edition, Pearson,2012. [2] 1. Kang, S. Yoo, and D. Oh, "Development of a Portable Embedded Patient Monitoring System", International Journal of Multimedia and Ubiquitous Engineering,Vol. 8,No.6,pp.141-150,2013. [3] M. S. EI-Bially, M. S. Ahmed, M. H. AbdelGawwad, F. A. Ali, F. S. Botros, Y. M. Kadah, "Hand-Held Computer Aided Diagnosis System with Application in Mammography", Proc. 30th National Radio Science Conference, Cairo,pp. 549-556,2013. [4] R.J. Barendse, T.B. van Dam, and S.P. Nelwan, "Portable Platform Independent Patient Monitoring", Proc. Computing in Cardiology Conference (CinC),Zaragoza,pp. 983-986,2013. [5] XBee: connect devices to the cloud - Digi International. http://www.digi.com/xbee/ [6] B. W. Min, "Improvement of the Personalized Mobile U-Health Service System", International Journal of Multimedia and Ubiquitous Engineering, vol. 7,no. I,pp. 23-44,2012. [7] R. S. Tolentino and S. Park, "A Study on U-Healthcare System for Patient Information Management over Ubiquitous Medical Sensor Networks", International Journal of Advanced Science and Technology, vol. 18,no. l,pp. I-10,2010. [8] "ECG Front-End Design is Simplified with MicroConverter",Analog Devices Application Note [Online]. Available at: http://www.analog.com/library/analogdialogue/archives/37-ll/ecg.html [9] AAMI, American National Standard, Safe Current Limits for Electromedical Apparatus (ANSI/AAMI ESI-1993). Association for the Advancement of Medical Instrumentation,1993. [10] 8-bit PIC® MCUs - Microchip http://www.microchip.com/pic/
