History of TMT Machine

The invention of the treadmill happened in 1875. The very first machines were agriculture machine called “level power” treadmills. They were built in various sizes to accommodate various sized animals. The smaller treadmills were run by dogs and sheep to power attached fanny mills or butter churners. The bigger ones were run by horses to power threshing machines .

·         The first Medical  Treadmill

In 1952 the first medical was invented by cardiologist Robert Bruce, called the father of exercise cardiology, along with staffer Wayne Quinton. Together they developed the standard stress test to diagnose and evaluate heart and lung disease. Quinton later sold his interest to Stairmaster, which was subsequently bought by Nautilus.

·         Tunturi

The Company Tunturi was founded in 1922 as a bicycle repair shop. This company is credited by many people as the starter of the physical fitness equipment business, because of their legendary W1 exercise bike. Based in Finland, today they have the enviable reputation as being one of the leading and best-known manufactures of high class fitness equipment, including exercise bikes, steppers , and rowers.

·         Aerobics, Inc.

In the late 1960’s Bill Staub noticed that treadmills were very expensive and were used mainly as medical testing machines. Staub, a medical engineer, built an affordable home treadmill. He sent Dr. Copper a prototype , and he was so impressed, he sold the first few hundred to people that were his referrals. In 1968, Dr. Coopers’ company, Aerobics, Inc., began full scale production of PaceMaster. Since then, they have grown from making simple treadmills to making machines that feature computerized electronics and automated controls.

·         NASA

The U.S. space program used treadmills onboard Skylab to keep the astronauts in good shape, while they were in gravity free environment. This first treadmill used in outer space was merely a teflon-coated plate that allowed the feet to slide as astronaut ran in place bungee cord tethers.

Method of performing TMT

·   The patient’s heart rate and blood pressure are recorded at rest. Sticky electrodes are attached to the chest and connected to the ECG portion of the Stress test machine.

·   The treadmill is then started at a relatively slow "warm-up" speed. The treadmill speed and its slope or inclination is increased every three minutes according to a preprogrammed protocol (Bruce protocol). The protocol dictates the precise speed and slope. Each three minute interval is known as a Stage (Stage 1, Stage 2, Stage 3, etc. Thus a patient completing Stage 3 has exercised for 3 x 3 = 9 minutes). The patient's blood pressure is usually recorded during the second minute of each Stage. However, it may be recorded more frequently if the readings are too high or too low .

·   The ECG is constantly displayed on the monitor. It is also recorded on paper at one minute intervals. The physician pays particular attention to the heart rate, blood pressure, changes in the ECG pattern, irregular heart rhythm, and the patient's appearance and symptoms.

·   The treadmill is stopped when the patient achieves a target heart rate (this is 85% of the maximal heart rate predicted for the patient's age). However, if the patient is doing extremely well at peak exercise, the treadmill test may be continued further.

·   The test may be stopped prior to achievement of the target heart rate if the patient develops significant chest discomfort, shortness of breath, dizziness, unsteady gait, etc., or if the ECG shows alarming changes or serious irregular heartbeats. It may also be stopped if the blood pressure (BP) rises or falls beyond acceptable limits .

Physiological signals measured by TMT

a. Electrocardiogram (ECG):

The electrocardiogram (ECG or EKG) is a diagnostic tool that measures and records the electrical activity of the heart in exquisite detail. Interpretation of these details allows diagnosis of a wide range of heart conditions. These conditions can vary from minor to life threatening. It is a noninvasive recording produced by an electrocardiographic device .

Electrical impulses in the heart originate in the Sino atrial node and travel through the intimate conducting system to the heart muscle. The impulses stimulate the myocardial muscle fibers to contract and thus induce systole. The electrical waves can be measured at electrodes placed at specific points on the skin. Electrodes on different sides of the heart measure the activity of different parts of the heart muscle. An ECG displays the voltage between pairs of these electrodes, and the muscle activity that they measure, from different directions, can also be understood as vectors. This display indicates the overall rhythm of the heart and weaknesses in different parts of the heart muscle.

b.   Blood pressure (BP):

Blood pressure (BP) is the pressure exerted by circulating blood on the walls of blood vessels, and is one of the vital signs. During each heartbeat, BP varies between a maximum (systolic) and a minimum (diastolic) pressure. The mean BP, due to pumping by the heart and resistance in blood vessels, decreases as the circulating blood moves away from the heart through arteries. It has its greatest decrease in the small arteries and arterioles, and continues to decrease as the blood moves through the capillaries and back to the heart through veins .Gravity, valves in veins, and pumping from contraction of skeletal muscles, are some other influences on BP at various places in the body .

The term blood pressure usually refers to the pressure measured at a person's upper arm. It is measured on the inside of an elbow at the brachial artery, which is the upper arm's major blood vessel that carries blood away from the heart. A person's BP is usually expressed in terms of the systolic pressure and diastolic pressure. BP is sometimes measured at other places and by other methods, for instance at an ankle. Arterial pressure is most commonly measured via a sphygmomanometer, which use the height of a column of mercury to reflect the circulating pressure. Today BP values are still reported in millimeters of mercury (mmHg), though aneroid and electronic devices do not use mercury  .For each heartbeat, BP varies between systolic and diastolic pressures. Systolic pressure is peak pressure in the arteries, which occurs near the end of the cardiac cycle when the ventricles are contracting. Diastolic pressure is minimum pressure in the arteries, which occurs near the beginning of the cardiac cycle when the ventricles are filled with blood.

INTRODUCTION

Background

Treadmill testing is commonly used for assessment of cardiac and respiratory function with a use of treadmill machine. Tests often proceed with increasing work rate to the limit of functional capacity. Treadmills are also used in fitness training with a wide variety of work rate profiles . A regular stress test is considered important for patients with symptoms or signs that are suggestive of Coronary Artery Diseases (CAD) and for patients with significant risk factors for CAD. It is also important in order to evaluate exercise tolerance when patients have unexplained fatigue and shortness of breath and also to evaluate blood pressure response to exercise in patients with borderline hypertension. It is also suggested to the patient to look for exercise-induced serious irregular heartbeats . The TMT utilizes a motorized treadmill based on protocol, ECG component for measurement of ECG for assessment of cardiac function and a sphygmomanometer for time based Blood Pressure (BP) measurement. According to the protocol, the speed and the inclination of the treadmill increase at some time interval.

In the modern world, people constantly experience the influence of many negative factors such as stress, polluted environment, and poor quality of food causing health problems. Many diseases develop very slowly without showing any symptoms for long time. Therefore, proper and systematic health assessment becomes very important regardless to whether or not people have any health problems by using existing technologies. So, it is extremely important to focus on using methods of cardiovascular health assessments. TMT is one of the techniques for proper cardiovascular assessments.

Objectives

The objectives of this project are:

• To develop ECG measurement device for stress testing that uses fewer components than traditional designs while trying to achieve the same performance.
• Assessment of cardiac function.

Treadmill Testing

Treadmill testing (TMT) is commonly used for assessment of cardiac and respiratory function. Tests often proceed with increasing work rate to the limit of functional capacity. Traditional clinical tests include the Bruce Protocol where speed and angle are increased together in seven 3-minutes stages, and the Balke Protocol in which speed is constant and angle is increased every minute. Treadmills are also used in fitness training with a wide variety of work rate profiles. Modern treadmill technology allows speed and angle to be pre-programmed and finely adjusted, thus offering the possibility of precise imposition of arbitrary work rate profiles .

Treadmill testing is also referred to as stress testing. Treadmill testing is heavily dependent upon interpretation of ECG changes produced by exercise. A regular stress test is considered in the following circumstances :

·                     Patients with symptoms or signs that is suggestive of coronary artery diseases (CAD).

·                     Patients with significant risk factors for CAD.

·                     To evaluate exercise tolerance when patients have unexplained fatigue and shortness of       breath.

·                     To evaluate blood pressure response to exercise in patients with borderline hypertension.

·                     To look for exercise-induced serious irregular heartbeats.

Normally, Patients with coronary artery blockages may have minimal symptoms and an unremarkable or unchanged ECG while at rest. However, symptoms and signs of heart disease may become unmasked by exposing the heart to the stress of exercise.

Treadmill Testing

Treadmill testing (TMT) is commonly used for assessment of cardiac and respiratory function. Tests often proceed with increasing work rate to the limit of functional capacity. Traditional clinical tests include the Bruce Protocol where speed and angle are increased together in seven 3-minutes stages, and the Balke Protocol in which speed is constant and angle is increased every minute. Treadmills are also used in fitness training with a wide variety of work rate profiles. Modern treadmill technology allows speed and angle to be pre-programmed and finely adjusted, thus offering the possibility of precise imposition of arbitrary work rate profiles .

Treadmill testing is also referred to as stress testing. Treadmill testing is heavily dependent upon interpretation of ECG changes produced by exercise. A regular stress test is considered in the following circumstances :

·                     Patients with symptoms or signs that is suggestive of coronary artery diseases (CAD).

·                     Patients with significant risk factors for CAD.

·                     To evaluate exercise tolerance when patients have unexplained fatigue and shortness of       breath.

·                     To evaluate blood pressure response to exercise in patients with borderline hypertension.

·                     To look for exercise-induced serious irregular heartbeats.

Normally, Patients with coronary artery blockages may have minimal symptoms and an unremarkable or unchanged ECG while at rest. However, symptoms and signs of heart disease may become unmasked by exposing the heart to the stress of exercise.