**4. Conclusions**

The paper describes reasons and a series of works which have led to the development of a new treadmill type adapted to the performance of the 6MWT in patient with heart failure, chronic obstructive pulmonary disease or arterial circulation failure in lower limbs.

The common treadmill forces patients to adjust their walking speed to its belt speed. The new treadmill changes its belt speed while the patient changes walking speed. The preparation of such a treadmill needed to combine the speed of the belt with the patient's position on the treadmill. While the patient increasing the walking speed, the patient moves toward the front of the treadmill and the belt speed increases, when he slows down, the belt moves him backwards and the belt speed adjusts again. In order to realize such an algorithm, precise measurements of the patient's position on the treadmill are necessary. The idea of the patient's position measurement was based on using a mixed ultrasound/infrared method.

According to the new method, the patient was carrying a transmitter which produced simultaneously a short impulse of ultrasound wave and infrared beam (about 100 milliseconds long). Both signals were received by the receiver at the front of the treadmill and the distance between the transmitter and receiver was calculated from the time delay between the received signals. Distance measurements turned out to be accurate (error less than 10 mm) and due to the shortest direct way of the ultrasound signal, parasitical echoes

heart failure in NYHA functional class II-III. Twenty people with diagnosed heart failure and tolerance of physical exercise in NYHA functional class II-III took part in the tests.

The analysis of the performance and results of the test indicates that during the six-minute walk test on a modified treadmill, HF patients in NYHA class II-III may slow the treadmill down safely or stop, depending on their exertion level. Our research has demonstrated that a walk test performed on a treadmill, controlled by means of the pace of the patient's walk, is equally well tolerated and generates exertion (Borg Scale 11,87 ± 2,90) that is similar as in

The fact that we have proved that there are no statistical differences in the distance covered (treadmill 317,36 ± 133,92, hallway 312,43 ± 117,76) and in the hemodynamic effects of the test performed on a treadmill compared to a hallway test, enables us to use a modified treadmill to replace the hallway test and vice versa, in order to evaluate patients with HF or chronic obstructive pulmonary disease. The fact that a similar distance was covered in both tests demonstrates that the technological barrier preventing us from obtaining credible results of the six-minute walk test on the treadmill, has been overcome. The availability of a treadmill adapting its pace to the patient's capacity, makes it possible to start treatment assessment or rehabilitation in patients with HF or COPD both inside and outside the hospital. If the results of our work are confirmed by other authors, the centres specializing in exercise tests will certainly be able to perform six-minute walk tests, while the hallways in hospitals and medical centres will be used for internal circulation purposes, as designed.

The modified treadmill providing solutions that are not offered by any other companies, may be additionally recommended for fitness purposes because the person using the

The paper describes reasons and a series of works which have led to the development of a new treadmill type adapted to the performance of the 6MWT in patient with heart failure,

The common treadmill forces patients to adjust their walking speed to its belt speed. The new treadmill changes its belt speed while the patient changes walking speed. The preparation of such a treadmill needed to combine the speed of the belt with the patient's position on the treadmill. While the patient increasing the walking speed, the patient moves toward the front of the treadmill and the belt speed increases, when he slows down, the belt moves him backwards and the belt speed adjusts again. In order to realize such an algorithm, precise measurements of the patient's position on the treadmill are necessary. The idea of the patient's position measurement was based on using a mixed

According to the new method, the patient was carrying a transmitter which produced simultaneously a short impulse of ultrasound wave and infrared beam (about 100 milliseconds long). Both signals were received by the receiver at the front of the treadmill and the distance between the transmitter and receiver was calculated from the time delay between the received signals. Distance measurements turned out to be accurate (error less than 10 mm) and due to the shortest direct way of the ultrasound signal, parasitical echoes

chronic obstructive pulmonary disease or arterial circulation failure in lower limbs.

treadmill may avoid dyspnoea by adjusting his or her walking speed.

**4. Conclusions** 

ultrasound/infrared method.

case of the classic hallway test (Borg Scale 11,87 ± 2,90).

did not interfere with the measurements. As a result, we have developed an algorithm that makes the 6-minute walk test on the treadmill much safer than at the beginning and very similar to a classic hallway test. It has allowed us to prepare a commercial version of the ERT-100 treadmill equipped with a transmitter and receiver. The treadmill has passed the CE certification procedure.

The second part of the chapter contains the evaluation of adjustment of the new treadmill to the walking pace of healthy volunteers, as well as a comparison of the distance covered during the 6-minute walk on the treadmill and in the hallway. A better comfort of the 6MWT and a longer distance covered on the treadmill compared with the distance covered in the hallway may indicate that the algorithm of adjusting the speed of the treadmill to the walking capacity of the tested individual has been properly selected.

The obtained results demonstrating the advantages of the treadmill in healthy volunteers have encouraged us to perform a 6MWT for patients with heart failure in the II-III NYHA classes. In yet not published material it has been shown that the treadmill test was tolerated equally well by the patients as the hallway test. The fact that a similar distance was covered in both tests demonstrates that the technological barrier preventing us from obtaining credible results of the six-minute walk test on the treadmill, has been overcome.

The availability of a treadmill adapting its pace to the patient's capacity, makes it possible to start treatment assessment or rehabilitation in patients with HF or COPD both inside and outside the hospital.

#### **5. Acknowledgements**

The authors would like to thanks all the volunteers from the Academy of Physical Education in Katowice for their participation in the tests.

#### **6. References**


**11** 

*Iran* 

**COPD Due to Sulfur Mustard (Mustard Lung)** 

Sulfur Mustard (SM) is a potent toxic alkylating agent that has been used as a chemical warfare gas during the World War I and in the Iran-Iraq conflict between 1983 and 1988(1). SM can cause serious organ damages especially ocular, neurologic, cutaneous, bone marrow, and pulmonary complications (1). The previous studies have shown that the respiratory complications are the most common late complications of SM toxic exposure including chronic obstructive pulmonary disease (COPD), chronic bronchitis, bronchiolitis oblitrans, bronchiectasis, airway hyperresponsiveness, and lung fibrosis (2-6).The COPD which occur after SM exposure is known as "Mustard lung" (7 ). Since about 45000 patients are now suffering from long term complications of SM toxic exposure, the evaluation of its pathogenesis and finding the possible ways for treatment is necessary. During the last decade, especial attention to the possible underlying mechanism of COPD due to SM intoxications has been applied. Our previous studies have shown that in COPD patients due to SM exposure inflammatory markers (highly sensitive CRP, interleukin 6) are elevated and these markers have direct association with the severity of disease (8,9). The finding which recommends the role of systemic inflammation in the pathogenesis of COPD due to SM intoxication like the COPD due to other causes. In this chapter the historical points, probable pathogenesis, clinical manifestation, and diagnosis of mustard lung will be discussed.

Mustard gas was possibly developed as early as 1822 by César-Mansuete Desperetez (1798– 1863) (10). SM was used as the late 1880 for treating minor tumors (11). Mustard gas is the most widely – used vesicant chemical war agent in the past century (2).Unfortunately SM was first employed effectively as a weapon in World War by the Germans on the British at Ypres (3, 11). It was then used during the Iran-Iraq war (1983-1988) and more than 100 000 military and civilian people were injured by SM gas (12).Now, over 45000 patients are suffering from the late complications of SM exposure (11, 12) and now SM is included as a

SM or [bis-(2-chloroethyl) sulfate] (Fig.1) is also known as" Yperite" (Ypres was the name of the place which it was first used), "Lost" (the initials of two German chemists), and "yellow

**1. Introduction** 

**2. Historical background** 

**3. Sulfur mustard** 

threat to both military and civilians (13).

Shahrzad M. Lari, Davood Attaran and Mohammad Towhidi *Lung Disease and Tuberculosis Research Center, School of Medicine,* 

*Mashhad University of Medical Sciences, Mashhad* 

patients with chronic heart failure. *Can Med Assoc J*, Vol. 132, No 8, pp. 919-923, ISSN 1488-2329.

