Kenyatta University Department of Electric and Electronics Department BSc Biomedical Engineering

Table of Contents

Kenyatta University Department of Electric and Electronics Department BSc (Biomedical Engineering) Project Proposal Designing and prototyping a mobile wearable blood pressure monitoring device Presented By: GEORGE OBURU J23/4202/2014 Supervisor: Mr. KORE Declaration I hereby declare that this report is my own original work and has not been previously submitted to any other institution of higher learning including my university Kenyatta University .I further declare that all sources cited or quoted are indicated and acknowledged by means of comprehensive list of references NAME : GEORGE OBURU Registration Number: J23/4202/2013 Sign: _______________________ Date: ___________________________ SUPERVISOR CONFIRMATION: SUPERVISOR NAME: MR LAWRENCE KORE Sign: _______________________ Date: ___________________________ ABSTRACTHigh blood pressure is a serious medical condition that increases the risk of stroke and heart attack and this could lead to the damage of the heart. It is therefore necessary to automatically take blood pressure readings from time to time throughout the day in order to see how often the blood pressure is high. This wearable high blood pressure monitoring device helps in informing a person is likely to have a heart attack. The device does this by detecting the heart beat level and inform the person as soon as the heart beat level does not fall within the allowed limit. This device will use two circuits. One will be the transmitting circuit and the receiver circuit. The high blood pressure will have the transmitting circuit whereas the person supervising the blood pressure will have the transmitting circuit. The transmitting circuit will be with the patient and it will include 12 V transformer that will power the transmitting circuit and a microcontroller interfaced to LCD screen. The receiver circuit will similarly have 12 V transformer, RF receiver, LED light, buzzer and a microcontroller. The LED will turn on as the buzzer will alert the person who will be supervising the heart rate as soon as the heart rate is not within the normal.ContentsCHAPTER 1 Introduction 31.1 Background of the study 41.2 Statement of the Problem 41.3 Objectives 41.3.1 Main Objectives 41.3.2 Specific Objectives 41.4 Scope and limitation of the study 41.5 JUSTIFICATION 5CHAPTER 2 LITERATURE REVIEW 5CHAPTER 3 METHODOLOGY 63.1 MATERIALS USED. 93.1.1 Arduino 93.1.2 Bluetooth model 93.1.3 H-039 Pulse sensor 103.1.4 LM-35 Temperature Sensor 103.1.5 LCD I2C 103.1.6 Passive Buzzer. 103.1.7 LED (RGB) 103.1.8 Phone 11CHAPTER 1 IntroductionThe major risk for mortality in Kenya and Africa as whole and the most significant risk factor and the leading cause of cardiovascular disease is basically high blood pressure. High blood pressure also has an extremely high economic burden on health care system, with an estimated cost of more than $ 370 trillion, representing 10% of the global health care expenditures (Uddin, Morita et al, 2016). It’s because of this impact that controlling high blood pressure has been considered a national and international health priority. The high blood pressure monitoring device will enable the doctors and the relatives monitor the high blood pressure patient outside a hospital, clinics or any health facility without necessarily visiting the patient.1.1 Background of the studyHigh blood pressure is one of the main risk factors for most deaths and is the leading cause of death globally. There has been inadequate medical facilities and inappropriate medical devices for the diagnosis, trea3tment of high blood pressure. Delays in diagnosis and lack of a proper high blood pressure monitoring device that will continuously monitor the high blood pressure, may increase the risk of heart attack, stroke and also make the cost treatment go up.1.2 Statement of the ProblemIn Kenya, due to lack of adequate medical facilities, delay in diagnosis and lack of continuous monitoring, there have been deaths that did arise from hypertension and other diseases associated with high blood pressure. These are as result of most people living away, ignorant or rarely visit the medical facilities available. The devices currently available in the market can’t be monitored remotely by the doctors. Most of them are relatively expensive for low income earners that are largely affected by this menace. Globally, wrist band wearable devices have been developed that detect pulse rate from the high blood pressure patient and save the data for self-management. This real time data does not reach a kin of the patient or caregiver that can analyze the situation at hand for the patient. Therefore there is a need of prototype that will send the timely blood pressure measurement to the next of kin and the caregiver and at the same time alert the patient when the measurement is above 140/90mmHg.1.3 Objectives1.3.1 Main ObjectivesTo design a mobile wearable device that monitors high blood pressure.1.3.2 Specific ObjectivesTransmit Blood Pressure measurement to close relative or doctor.Alert the patient, caregiver and the next of kin when the blood pressure is about to be high. 1.4 Scope and limitation of the studyThe device will be designed as a complete solution to monitor blood pressure from the monitored person to the doctor or relative that understand and process the data. The design concept will involve the creation of a mobile application that will gather data from the wearable sensors and process the data and give instant response to the users and also save the data to a memory.The main limitation of the project was enough time and money. The other limitation is that it will be very difficult to monitor high blood pressure on a wrist that is injured or that is under medical treatment. Moreover, the wearable blood pressure monitor cannot be used during blood transfusion or while on an intravenous drip. Finally, the blood pressure monitor should not be used in areas with high frequency surgical equipment such as the computerized tomography scanners (CT scanners), magnetic resonance imaging equipment (MRI), as these will lead to an incorrect reading as a result of the incorrect operation of the monitor.1.5 JUSTIFICATIONMost heart diseases and conditions for example, hypertension, require constant and regular monitoring of the pulse rate so as to manage the high blood pressure through diet and exercise and intervene when medications are required especially when lifestyle modifications cannot lower or maintain the high blood pressure.CHAPTER 2 LITERATURE REVIEWIt’s clearly known that chronic high blood pressure has an adverse impacts on health and daily lives of people. Heart rate is a very important indicator for both the healthy and the unhealthy people. The past research studies have shown that psychological state changes are reflected in the heart rate variability and can successfully be monitored (Itao et al., 2008). According to the study by the World Health Organization (WHO) in 2015, found out that hypertension, stroke and heart diseases are roughly the major causes of most deaths. Based on these observations, the heart rate do vary according to various conditions such as blood vessels thickness, blood fluidity, etc. ( Lopez et al., 2010 ). There are diseases like the pulmonary diseases which have been shown to affect the autonomic nervous system activities thereby affecting the heart rate of patients (Volterrani, et al., 2014). Developments in technology have enabled the creation of heart rate monitors that can be used on organs on the head such as the eye (Google Patents, 2002) and the ear (Google Patents, 2009).The control of high BP starts with measurements that are accurate which further leads to proper diagnosis, assessments of cardiovascular risks and treatment decisions. BP measurement is very critical, though sometimes it is performed poorly by professionals in health care. Generally, the common sources of errors previously monitored in indirect measurement of BP were bias due to the observer, faulty equipment and finally the professionals in healthcare failed to standardize the measurement techniques. Initial the mercury sphygmomanometer, was widely used because it was not only reliable but also accurate. As a result of environmental awareness, there has been increasing pressure to remove medical devices containing mercury from clinical areas, which is leading to the gradual decline in use of the mercury sphygmomanometer and, as a result, automated BP devices have been adopted by clinicians for their convenience and ease of use ( Mlawanda, et al.., 2014). It for this reason that automated and wearables sensors have been adopted. According to Petrie et al.., 2016, they declared that an observer is aware of the false readings and the factors that causes it when measuring BP, this would lead to wrong diagnosis, improper treatment and follow up.According to a study done by Wongsurin, Saravich and Roubsanthisuk, they showed that the BP measurements taken by the trained nurses were rather overestimated but not underestimated, even though, patients with severe hypertension, it was a common practice to underestimate their systolic BP. McKay et al noticed that due to the white coat effect all the BP measurements done by doctors were consistently high (McKay et al., 2015)The Framingham Heart Study suggested that the eventuality of most individuals that are normotensive at the age of 55 becoming hypertensive is 90 percent. Blood pressure can be monitored daily in our life’s through the use of ambulatory blood pressure monitoring (ABPM) technologies. Clinicians and Doctors should be aware of the multiple stimuli like alcohol, physical stress or emotions, meals body postures that affect the BP of human beings and should not be ignored during measurement of BP. The use of wearable devices that can record biological signals for the purpose of diagnosis can provide early detection of diseases for patients with other additional complications such as old age, cognitive and physical incapability, chronical illness and young age who cannot give appropriate response for available diagnosis tools (Darwish & Hassanien, 2011). These devices have been shown to be accurate and fast when it comes to diagnosis and rehabilitation of patients in the healthcare sector (Appelboom, et al., 2014). Another study carried out on arm-band wearable device for blood pressure in pregnantmother (Suhasini & Sudarshini, 2015) recommended that ongoing researches on patientmonitoring system should focus on ensuring systems are more compact and easily availableat affordable price. New technologies could also enhance the performance the new systems.This indicates that less has been done on wearable device acceptability due to compatibilityand affordability issues. In health sector, remote monitoring to patients incorporates digital mobile applicationsthat involve provision of care to patients in terms of medical conditions that can besupervised, frequency to be supervised and whether they should be supervised real-time orperiodically. Remote supervision is the supervision of a medical task from a remote setting,giving diagnosis to the patient without the patient being present physically. When medicalmonitoring is complete, a guidance on whether the patient requires immediate attention bythe doctor is released through a monitoring device. According to (Hemavathy, Sinthuja, &Manoharan, 2014), remote patient monitoring technologies are safer, more effectivemonitoring of health and safety among older adults, control visits to hospitals with anobjective of addressing cost, decongestion issues, geographic challenges, geriatricconditions and lack of mobility.CHAPTER 3 METHODOLOGYI started this project by visiting various county hospitals in both Kisumu and Nairobi County in order to familiarize myself with the heart diseases and conditions and the technology used to record and monitor the heart rate. I realized that most of the level 5 hospitals use the sphygmomanometer to record and determine the heart rate. The wrist wearable high blood pressure monitoring device is not commonly used in the country and East Africa in general. The major problem with the sphygmomanometer is that it cannot be used to continuously monitor the blood pressure of the patients as this would be very uncomfortable to the patient. In my research the wrist band wearable monitoring device will have two circuits, that is the transmitting circuit and the receiving circuit. The transmitting will include AVR family microcontroller that will be interfaced to a LCD screen and a transformer of 12V will be used to power the transmitting circuit. The receiver circuit on the other hand will similarly have an AVR family controller, RF receiver, a buzzer, LED light and a transformer 12V that will be used to power it.BLOCK DIAGRAM FOR THE TRANSMITER BLOCK DIAGRAM FOR THE RECEIVER The block diagram represents the design system of wearable device for blood pressure monitoring. The designed system will include a mobile phone which will receive the commands in teams of heart rate parameter. It acts as a medium between the output command and the microprocessor, an Arduino Uno which is the microprocessor which controls the device. 3.1 MATERIALS USED.3.1.1 Arduino An Arduino Uno microcontroller will be used, a microcontroller board on the ATmega328p. The Arduino Uno microcontroller will either be connected directly to the computer using an USB cable or through directly powering it to the AC to DC adapter which provide between 6-20Volts. The designed Arduino Uno circuit act as the interface between the software and the hardware part of the project.3.1.2 Bluetooth modelThe Bluetooth model will allow for the data exchange over short distances through a wireless technology. The Bluetooth protocol will enable a serial communication between Arduino board and the computer. The serial port profile supported by Bluetooth model for Arduino will aid in exchange data with other devices. This module run on 3.3V power with 3.3V signal levels specification. This device can be paired to your phone through a Bluetooth application downloaded from Google play store. This application is known as the Ardu Tooth (Bluetooth Terminal). After download you can pair through your phone and get the output information from the Arduino Uno.3.1.3 H-039 Pulse sensorThe heart rate sensor will use bright infrared (IR) LED and a phototransistor. The bright infrared (IR) LED and a phototransistor are used to detect the pulse of the finger. The red LED flashes at the rate of the pulse. The heart rate sensor will achieve this when the LED is positioned in the light side of the finger and phototransistor on the other side of the finger. A phototransistor within the heart rate sensor used to obtain the flux emitted.3.1.4 LM-35 Temperature SensorLM35 is a precision IC temperature sensor with its output proportional to the temperature (in °C).The LM 35 has the following features calibrated Celsius, linear + 10-mV/°C Scale Factor, 0.5°C ensured accuracy, rated for Full −55°C to 150°C Range. This temperature is incorporated within the body to measure body temperature at the ear canal. This qualities makes it easy to take body temperature ranges effectively. The IC within LM-35 measure the temperature. The Arduino Uno is integrated to the LM-35 to measure the temperature and translates it either in Fahrenheit and Celsius. The measured temperature through the HC-05 is the transmitted and read in through the smart phone. The above IC uses about +5V DC power since Arduino Uno power pin supplies +5V power. The LM-35 consist of three pins, one is connected to the ground while the other two are connected to the power supply. 3.1.5 LCD I2CThe LCD display consist of an inbuilt register, to store the data and commands given to the LCD display. It consist of two modes namely: READ mode and the WRITE mode. The write mode commands to control the display, is written to the register like display clear, shift right and the cursor. Moreover, in the write mode the register is equally written with data which is needed to be displayed on the display. The pin called Register select (RS) operates in two conditions; if the pin is made to zero, then it is command register while if it is one, then it is a data register. The READ / WRITE selection is done by an R/W pin. If R/W is equal to zero, then it is write mode while if R/W is equal to one it is read mode.The LCD enables the patient monitor his vital parameters namely temperature and heart rate. This will enable the patient monitor their parameters as they vary throughout even if his/her phone is OFF. 3.1.6 Passive Buzzer.A buzzer is a component that will be used efficiently to produce sound alerts. It consists of two pins namely; positive and negative. A passive buzzer will be powered to produce a continuous Beeeeeeppp…. sound. This continuous sound will be due to internal oscillating circuit inside the passive buzzer.The buzzer will able to sound anytime the heart rate is more than the set threshold. In this case, the heart rate for diastole is set to 100 within the software.3.1.7 LED (RGB)Single LED die can only emit one of the three primary colors – red, green and blue, commonly known as RGB. To obtain more colors, the three LED dies will be used together for RGB color mixing. A maximum number of 7 colors can be produced by controlling the switch of the channel for each of the 3 primary color. To produce more than seven colors, each color channel should be able to change in brightness. The most popular control method is Pulse Width Modulation (PWM), that will be used to control the LED brightness. This results when the cycle duty range determines the available brightness levels. It consists of three pins namely: the common cathode RBG LED, one pin is ground and the other three pins are the anodes of the red, green, and blue LED. 3.1.8 PhoneMost of the current smart phones are Bluetooth enabled. This includes even the cheapest phones within the market. The Bluetooth enabled phone will enable the patient or the kin monitor the temperature and heart rate remotely. Project time scheduling BUDGETQuantity Particular Rate Amount1 Arduino Uno 1200 12001 Bluetooth Module HCO5 600 6001 Heartbeart Sensor Detector 450 4501 Bread board and power supply 250 2501 LCD 1602 yellow 250 2501 LCD serial Adapter 200 2001 LM35 Temperature Sensor 150 1501 Jumper wire m-m dupont 40 pcs 100 1001 Jumper wire m-f dupont 40 pcs 100 1001 Buzzer Piezoelectric Active 60 601 LCD RGB Diffused 5mm Cathode 40 40 TOTAL 3400