CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND
Heart beat rate means the number of heartbeats per unit time, usually expressed as beats per minute (bpm). The human heart pounds to pump oxygen rich blood to the muscles and carry cell waste products away from the tissues. Heartbeat rate can vary according to the demand of the muscles to absorb oxygen and excrete carbon dioxide changes such as during exercise or sleep. It also varies significantly between individuals based on age, fitness and genetics. This means that the heart must beat faster to deliver more oxygen rich blood. During exercise routines, the heartbeat rate gives a strong indication of how effective the exercise is to the body.
The patient monitoring systems is one of the major improvements in the global health care program because of its advanced technology. A patient monitoring system measures the heartbeat and body temperature by using embedded technology. This advancement in technology is highly needed because many sick patients at the hospitals die because of high fever and heart attacks. The trend of cardiovascular disease has shown that heart beat rate plays a key role in determining the possibility of a heart attack while an increase in the body temperature can induce fever on a patient. Heart diseases such as heart attack, coronary heart disease, congestive heart failure, and congenital heart disease are the leading causes of death for men and women in many countries. Most of the time, the aged people of the society are more prone to heart disease problems than the younger ones. For people who live alone with no one to monitor their health condition, this device offers an opportunity to them for a constant monitoring of their health status, it is developed to monitor and alert the doctors about the heartbeat and temperature condition of a patient. It is developed to give patients a timely and proper heath care.
These days it is not easy for doctors and the nurses to remain close to a patients bed side to monitor their heath condition. In the past, a huge and fixed monitoring device was used (only in the hospitals) to know the health status of a patient when on a bed. These monitoring devices are only available in the hospitals and are constantly on the patient’s body. Many of them are not user friendly so it is important that the doctors and family members will have a handy device that can always monitor their patients when they are not around. One of the vital things to monitor on a patient is the body temperature. This has to do with the measurement of the body's ability to generate and get rid of heat. Temperature monitoring is one of chief indicators of the normal functioning of health. The nature of the human body
is to keep its temperature within a narrow, safe range in spite of large variations in temperatures outside the body. Normal human body temperature depends upon the place in the body, from which the measurement is made, and the time and level of activity of the person. The typical body temperature is 37.0 °C ± 0.4°C (98.6 ° F ± 0.7°F). When the body temperature is high, the blood vessels within the skin expand (dilate) to carry the excess heat to the patients skin surface. One may begin to sweat, and as the sweat evaporates, it helps to cool his/her body. When one is too cold, the blood vessels narrows (contracts) so that blood flow to the skin is reduced to conserve body heat. This may cause an involuntary shivering in some people due to cold which is a rapid contraction of the muscles. This extra muscle activity helps to generate more heat. Under normal condition, thus keeping one's body temperature within a narrow, safe range. Body temperature is regulated by neural feedback mechanism which operate primarily through the hypothalamus. The hypothalamus contains not only the control mechanisms, but also the key temperature sensors. Under control of these mechanisms, sweating begins almost precisely at a skin temperature of 37°C and increases rapidly as the skin temperature rises above this value. The heat production of the body under these conditions remains almost constant as the skin temperature rises. If the skin temperature drops below 37°C a variety of
responses are initiated to conserve the heat in the body and to increase heat production. These includes: Vasoconstriction to decrease the flow of heat to the skin, Cessation of sweating, shivering to increase heat production in the muscles, Secretion of nor epinephrine, epinephrine, and thyroxin to increase heat production.
Another vital thing to monitor in a patient is the heartbeat rate. It is very important that the heartbeat is to be normal. That is 72 BPM. If there is any abnormality, then the patient is in distress. Heartbeat rate means the number of heartbeats per unit of time. The normal heartbeat rate of a resting person is about 70 bpm for adult males and 75 bpm for adult females. The average heartbeat per minute for 25-year old ranges between 140-170 beats per minute while for a 60-year old it is typically between 115-140 beats per minute and body temperature is 37 degree Celsius or 98.6 Fahrenheit. . Normally it is difficult to keep track of the abnormalities in the heartbeat count of by manual means. Patients are not well versed with the manual treatments, which the doctors normally use for tracking the count of the heartbeat. Thus, there must be some kind of device which would help patients and their family member to keep track of their health by themselves. This sole reason is why this project presents a heartbeat and temperature monitoring device using radio frequency (RF.). The concept of developing an RF. based patient monitoring device is to have a simple home and hospital based pulse and body temperature monitoring device for sick person’s that are in critical condition and needs to be constantly or periodically monitored by clinician or family.