Wireless Control Smart Stretcher Using ZIGBEE

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 3, Issue 4, April 2013)

606

Wireless Control Smart Stretcher Using ZIGBEE

Safwaan Companywala

1

, Tauseef Companywala

2

, Syed Amjed Ali

3 1_{Electronics & Telecommunication Department, Theem College of Engineering}

2_{Electronics Department, M.H. Saboo Siddik College of Engineering} 3

Assistant Professor,Electronics & Telecommunication Department, Theem College of Engineering

Abstract— Till date, wireless technology was a patchwork of incompatible system from a variety of vendors. The technology was slow, expensive and reserved for mobile situation or hostile environments where cabling was impractical or impossible. In recent years, Zigbee has becoming one of the most promising protocols for wireless networking. Consequently, interoperation with Zigbee-enabled home network devices such as wireless sensor and appliances is an essential functionality in gateway systems. With maturity of industry standards and the deployment of lightweight wireless networking hardware across a broad market section, wireless technology has come of age and Zigbee is a new player in the field. This paper gives an overview of Zigbee’s technical attributes, applications, products and its future and its application network in detail.

Keywords— Zigbee, Heartbeat, LM-35, Load Cell,

PIC, Sensors

I. INTRODUCTION

Advances in ubiquitous communication

technologies, such as radio frequency identification (RFID) and small sensor and Zigbee networks, are giving rise to new applications in the various fields. In the medical field, especially in hospitals, these ubiquitous communication technologies can improve the safety of medical treat mention order to prevent malpractice and improve the quality of medical care. Various measures to prevent medical errors by using checklist or repetition of the orders have been put in place already, but medical errors cannot be eliminated by human effort alone. The utilization of ubiquitous communication technology is expected to cover “non-computerized gaps” in medical practice where conventional hospital information systems have not been sufficiently effective. The application of ubiquitous communication technologies in medicine ultimately aims to realize an “intelligent environment” within the hospital, in which the physiological status and behaviour of patients are continuously monitored in order to provide the best medical care at any time and at any location within the hospital, with security and safety.

Wireless Control Smart Stretcher is a medical device used for carrying of patients who require medical care identification which can determine and display certain important parameters of patient such as body temperature, body weight, blood pressure and heartbeat. It can display all the mentioned parameters wirelessly. This can however save time and could prove more beneficial for patients who need to be hospitalized immediately. The main use of the smart stretcher is that at the time of emergency the stretcher automatically fetches the important parameter of the patient body will on the departure towards hospital ward rather that calculating it after reaching the ward which will reduce the time and human efforts.

II. GENERAL DESCRIPTION

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A driver circuit along with the buzzer is used to warn the exceeding value of reading. Zigbee TX/RX. Zigbee TX/RX is used to remotely display emergency condition of patient using Zigbee module. Zigbee TX/RX also has an antenna which will communicate to Zigbee via remote. Zigbee RX in the remote will receive signal and will notify the user about same.

Basic block diagram of Smart Stretcher Transmitter

Basic block diagram of Smart Stretcher Receiver

RF remotes provide new levels of interactivity and convenience for today’s digital world when compared to IR remotes. As more devices add internet connectivity and other features, the need for two -way communication grows. RF remotes are also faster. More reliable and have greater range than IR remotes. Plus they do not require line-of-sight operation like IR remotes. Other benefits includes low power consumption, avoidance of using manufacture-specific IR codes, reduced interference from LCD and plasma TVs, and connectivity with home automation systems. RF technology has gradually been replacing IR technology in the high-end remote control products. New network protocols, such as Zigbee RF4CE, are helping to make this technology accessible to rest of us. Zigbee receiver will capture the data transmitted via a Zigbee transmitter and will remotely display it on LCD display as shown. This will help us to remotely view the status of patient which can be very helpful when it is not feasible to go to nearer place. Main control unit of stretcher has Zigbee receiver which will receive the signals transmitted from main circuitry kept at stretcher. Here also pic controller is used. It also has an LCD display to display the warning messages or security messages. A driver circuit along with buzzer is used to indicate that some problem has occurred. The elements discussed above will work in synchronization to achieve careful monitoring of patient.

The display at the receiver side will continuously display the values of temperature of patient at the stretcher at degree Celsius. The human tendency is that when a human breathe it produces some amount of heat and this can be captured by the temperature sensor and can be displayed whether a person is dead or alive. Heart beat sensor is designed to give digital output of heat beat when a finger is placed on it. When the heart beat detector is working, the beat LED flashes in unison with each heartbeat. A load cell is a transducer that is used to convert a force into electrical signal. The most common use of this sensor is in weighing machine. Every weighing machine which shows weight has a load cell as sensing element. This conversion is indirect and happens in two stages. Through a mechanical arrangement, the force being sensed deforms a strain gauge. The strain gauge measures the deformation (strain) as an electrical signal, because the strain changes the effective electrical resistance of the wire. A load cell usually consists of four strain gauges in a Wheatstone bridge configuration. Load cells of one strain gauge (Quarter Bridge) or two strain gauges (half bridge) are also available. Similar to other sensors can be used in multipurpose applications making the system more flexible. Along with Zigbee networks using mesh technique the user can be secured that no unauthorized hacking can take place in the system as Zigbee security standards prohibits the same.

III. ZIGBEE

RF remotes provide new levels of interactivity and convenience for today’s digital home when compared to IR remotes. As more devices add Internet connectivity and other features, the need for two-way communication grows. RF remotes are also faster, more reliable and have greater range than IR remotes. Plus they do not require line-of-sight operation like IR remotes. Other benefits include low

power consumption, avoidance of using

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It is also important that systems inter-operate with the primary emerging wireless sensor protocols, such as IEEE 802.15.4(sold under the commercial name Zigbee). A low-data rate, low-power, low-cost wireless networking protocol, Zigbee is targeted toward automation and remote sensor I/O control applications. It is expected to provide low-cost and low-power connectivity for equipment that needs battery of life for as long as several years, but does not require data transfer rates as high as those enabled by Bluetooth. The industry- leading CC2420 from Texas Instruments(TI) was the first 2.4 GHz single chip RF transceiver compliant with IEEE 802.15.4/Zigbee; The CC2520 is TI’s second generation 2.4GHz IEEE 802.15.4/Zigbee RF transceiver; The CC2430 is the first true System-on- Chip Zigbee solution while CC2430 is the first system-on-chip(SoC) with a hardware location engine. And now Zigbee is easier than ever with the CC2480- the first product from TI’s new Z-Accel family of Zigbee-certified network processors that simplifies design and reduces time- to- market. Our latest addition to our family of Zigbee products is the second generation 2.4GHz CC2530 System-on-Chip suitable for RF4CE and Smart Energy application with up to 256KB flash memory. The Z-Stack has been awarded the Zigbee Alliance golden unit status by the Zigbee test house TUV Rheinland and is used by thousands of Zigbee developers worldwide while Remo TI(tm) is the first complete network protocol, including both hardware and software, for the new standardized Zigbee RF4CE specification for radio frequency (RF)- based remote controls.

IV. SENSORS A Heart beat sensor:

Heart beat sensor is designed to give digital output of heat beat when a finger is placed on it. When the heart beat detector is working, the beat LED flashes in unison with each heartbeat. This digital output can be connected to microcontroller directly to measure the Beats per Minute (BPM) rate. It works on the principle of light modulation by blood flow through Finger at each pulse.TSL230 light to frequency converter. Blood passes through the heart in two phases that alternate continuously: Diastole & Systole.

During the systolic phase, the heart contracts, pushing the blood into arteries, capillaries, and veins. Blood flows back to the heart from the veins during the diastolic phase.

Pulse rate is a direct measure of number of heart cycles in a minute. A heart rate of 70 bpm is considered normal for an adult

A new-born’s heart rate is typically around 120bpm. Heart rate slows to approx. 50bpm as you enter your golden years. When exercising, your heart rate may be double.

Heartbeat Sensor

B Weight Sensor:

A load cell is a transducer that is used to convert a force into electrical signal. The most common use of this sensor is in weighing machine. Every weighing machine which shows weight has a load cell as sensing element.

This conversion is indirect and happens in two stages. Through a mechanical arrangement, the force being sensed deforms a strain gauge. The strain gauge measures the deformation (strain) as an electrical signal, because the strain changes the effective electrical resistance of the wire. A load cell usually consists of four strain gauges in a Wheatstone bridge configuration. Load cells of one strain gauge (Quarter Bridge) or two strain gauges (half bridge) are also available. The electrical signal output is typically in the order of a few millivolts and requires amplification by an instrumentation amplifier before it can be used. The output of the transducer is plugged into an algorithm to calculate the force applied to the transducer.

Load cells are used in several types of measuring instruments such as weighing scales, universal testing machines.

The output of the transducer can be scaled to calculate the force applied to the transducer.

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C Body TEMPERATURE SENSOR:

Number of sensor is available in market, selection criteria of sensor is depend on system, operating temperature, power supply, sensitivity, need of amplifier & A/D converter according to the system requirement. We use LM35 temperature sensor. Because PIC controllers are having A/D converter & LM35 not required amplifier circuit & it suitable for wireless operation. Calibrated directly in Celsius accuracy of sensor is high. Operating voltage range is suitable for system. The LM35 series are precision integrated-circuit temperature sensors, whose output voltage is linearly proportional to the Celsius (Centigrade) temperature.

The LM35 series are precision integrated temperature sensors, whose output voltages are linearly proportional to the Celsius (Centigrade) temperature. The LM35 thus has advantages over linear temperature sensors calibrated in Kelvin, as the user is not required to subtract a large constant voltage from its output to obtain convenient Centigrade scaling. The LM35 does not require any external calibration or trimming to provide typical accuracies of ¼ degree centigrade at room temperature and ¼ degree centigrade over a full b55 to a150degree centigrade temperature range. Low cost is assured by trimming and calibration at water level. The LM35’s low output impedance, linear output, and precise inherent calibration make interfacing to readout or control circuitry especially easy. It can be used with single power supplies, or with plus and minus supplies. Ass it draws only 60 mA from its supply, it has very low self-heating, less 0.1 degree centigrade in still air. The LM35 is rated to operate over a b55 to a150 degree centigrade temperature range, while the LM35C is rated for a b40 to a110 degree centigrade range. The LM35 series is availed packaged in hermetic TO-46 transistor packages, while the LM35C, LM35CA, and LM35D are also available in the plastic TO-92 transistor package. The LM35D is also available in an surface mount small outline package and a plastic TO-202 package.

LM-35 Sensor

V. RESULT

1. The data communication between the main unit

and the remote unit using Zigbee has been achieved successfully. The system was tested in a closed space and the distance between transmitter and receiver was 10-15 meters. The data transmission and reception was successful with a delay of less than 1 sec.

2. Four different sensors are used in the system to sense various physical parameters that can go off limit due to some accident and human mistakes. The result for various sensors are as follows:

3. Body Temperature Sensor: The body temperature output is from LM-35 it is set at a particular value up to 55 degree Celsius in our case we are shown it with heat of an iron or heat sink transistor.

4. Heartbeat Sensor: The Heart Beat sensor is designed to give the output of various heart rates. Since it is an entry level project we are getting a quite variation in heart rates.

5. Respiratory Sensor: The body temperature output is from LM-35 it is set at a particular value up to 55 degree Celsius in our case its value is depending upon corresponding change in body temperature.

6. Body Weight Sensor: The body weight sensor consist of a load cell which is 40kg since we cannot measure the weight directly we are using the load cell and corresponding weight is measured

7. The remote unit consist of 16x2 LCD display along with a Zigbee transreceiver. The main stretcher unit sends the information to be displayed at the remote side via Zigbee devices. The information is displayed on the display.

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Parameters at Receiver Side

Status of Patient

Change in Parameter Value

VI. CONCLUSION

A small wireless stretcher consisting of four sensors has been implemented successfully using Zigbee. It is more secure than the systems that use the regular RF modules.

The IEEE 802.15.4 standard provides low cost, low power and reliable wireless network. The four sensors have been used to sense body weight, body temperature, respiratory and heartbeat. The system is very flexible and the number of sensors can be added are subtracted easily. Due to the use of Zigbee the network size is also flexible and can be increased by adding more nodes.

PIC 16F877A microcontroller has been used to provide interfacing and processing. It one of the best microcontroller for the development of midrange embedded systems. A 16x2 LCD display has been used to display the variations in various parameters of the sensor in real time.

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