addition to the ECG (or EKG) and stethoscope, there are other anatomical or functional screening modalities to test and diagnose a heart disease. For example, a continual multichannel ECG system may be used to check the level of stress. This test measures the ability of a person's heart to respond to the body's demand for more blood during stress (exercise or work). Combination of ECG, heart rate, and blood pressure information may be examined as a person's exercise is gradually increased on a treadmill. The information helps to show how well the heart responds to the body's demands and may provide information to help diagnose and treat the defects. It can also be used to monitor the effects of heart treatment.
Many people have intermittent symptoms such as intermittent chest pain or occasional feelings of their heart beating faster or irregularly. In such cases, ECG changes may not be sufficiently useful for monitoring the heart over a long period or outside clinics. Instead, a device called a Holter monitor can be used and worn for a longer time. This device acts similarly to a normal ECG.
As another heart screening modality, an echocardiogram is a real-time moving picture of a functioning heart made by using ultrasound waves and generating meaningful images. It can show how well the heart chambers and heart valves operate (for example, effective or poor pumping action as the blood flows through the valves), before and after treatments, as well as other features.
Calcium build-up (plaque), blood clot, or lipid in coronary arteries, which are indeed life-threatening, can also be detected from three-dimensional (3D) computerised tomography (CT) scan of the heart.
Body muscles, on the other hand, translate thoughts to actions and therefore are considered as the most important movement related component of human body. EMG recordings check the health of both the muscles and the nerves controlling the muscles. The EMG signals can be used to detect the problems with muscles during rest or activity. Disorders or conditions that cause abnormal EMG patterns can be neurological, pathological, or biological. These disorders include [12]:
alcoholic neuropathy: damage to nerves from drinking too much alcohol;
amyotrophic lateral sclerosis (ALS): disease of the nerve cells in the brain and spinal cord that control muscle movement;
axillary nerve dysfunction: damage of the nerve that controls shoulder movement and sensation;
Becker muscular dystrophy: weakness of the legs and pelvis muscles;
brachial plexopathy: problem affecting the set of nerves that leave the neck and enter the arm;
carpal tunnel syndrome: problem affecting the median nerve in the wrist and hand;
cubital tunnel syndrome: problem affecting the ulnar nerve in the elbow;
cervical spondylosis: neck pain from wear on the disks and bones of the neck;
common peroneal nerve dysfunction: damage of the peroneal nerve leading to loss of movement or sensation in the foot and leg;
denervation: reduced nerve stimulation of a muscle;
dermatomyositis: muscle disease that involves inflammation and a skin rash;
distal median nerve dysfunction: problem affecting the median nerve in the arm;
Duchenne muscular dystrophy: inherited disease that involves muscle weakness;
facioscapulohumeral muscular dystrophy (Landouzy–Dejerine): disease of muscle weakness and loss of muscle tissue;
familial periodic paralysis: disorder that causes muscle weakness and sometimes a lower than normal level of potassium in the blood;
femoral nerve dysfunction: loss of movement or sensation in parts of the legs due to damage to the femoral nerve;
Friedreich ataxia: inherited disease that affects areas in the brain and spinal cord that control coordination, muscle movement, and other functions;
Guillain-Barré syndrome: autoimmune disorder of the nerves that leads to muscle weakness or paralysis;
Lambert–Eaton myasthenic syndrome: autoimmune disorder of the nerves that causes muscle weakness;
multiple mononeuropathy: a nervous system disorder that involves damage to at least two separate nerve areas;
mononeuropathy: damage to a single nerve that results in loss of movement, sensation, or other function of that nerve;
myopathy: muscle degeneration caused by a number of disorders, including muscular dystrophy;
myasthenia gravis: autoimmune disorder of the nerves that causes weakness of the voluntary muscles;
peripheral neuropathy: damage of nerves away from the brain and spinal cord;
polymyositis: muscle weakness, swelling, tenderness, and tissue damage of the skeletal muscles;
radial nerve dysfunction: damage of the radial nerve causing loss of movement or sensation in the back of the arm or hand;
sciatic nerve dysfunction: injury to or pressure on the sciatic nerve that causes weakness, numbness, or tingling in the leg;
sensorimotor polyneuropathy: condition that causes a decreased ability to move or feel because of nerve damage;
Shy–Drager syndrome: nervous system disease that causes body-wide symptoms;
thyrotoxic periodic paralysis: muscle weakness from high levels of thyroid hormone;
tibial nerve dysfunction: damage of the tibial nerve causing loss of movement or sensation in the foot.
Surface EMGs are very noisy and often include the effects of heart pulsation, movement, and system noise. Therefore, computerised systems and algorithms for recognition of the abnormalities should be robust against noise. In some cases, however, EMG is taken invasively by inserting a needle electrode into the muscle.
A physical or physiological condition caused by a disease is often called the pathological state. Such a state is also evaluated by examining biochemistry and chemical metabolism of the human body often through sampling and laboratory analysis of human blood, exhale, tissue, urine, or faeces.
2.4 Biological State of Human Body
Biology is a general term which describes various organs of living organisms, including human, and their behaviour starting from biochemical reactions in tissue molecules and tissue cell behaviour in circulatory, respiratory, and nervous systems.
Current techniques in system biology focus on complex interactions within biological systems, using a holistic approach to biological research. One of the aims of systems biology is to model and discover emergent properties of cells, tissues, and organisms, collectively functioning as a system, whose theoretical description is only possible using techniques which fall under the remit of systems biology [13]. These typically involve metabolic or cell signalling networks [14] available in all live human organs.
Biological abnormalities refer to either genetic disorders, which may cause secondary problems, or infectious, bacterial, and immunodeficiency diseases. Tuberculosis, cholera, malaria, and AIDS as one of the deadliest one caused by the human immunodeficiency virus (HIV) are some examples of biological diseases.
Genetic disorders are caused by point mutation or gene damage due to insertion or deletion of a gene bond, deletion of a gene or genes, missing chromosomes, or trinucleotide repeat disorder. There are many types of such disorders, including colour blindness, cystic fibrosis, Down syndrome, haemophilia, neurofibromatosis, polycystic kidney disease, and spinal muscular atrophy.
Monitoring the human body for diseases often starts from noninvasive examinations and data recordings followed by taking and testing blood or urine samples. In the later stages, however, invasive tissue sampling by means of biopsy or various imaging modalities may become necessary. As an example,