Exercise Physiology Laboratories

The Institute for Sports Sciences at the University of Göttingen has two different laboratories where evaluations took place. The first is equipped with a high performance treadmill-ergometer and the second with an electric bicycle ergometer. Both laboratories provide excellent facilities for the purpose of cardiopulmonary testing and analysis involving oxygen uptake for disabled people.

The first laboratory is a room (dimension 5.30m x 6.50m x 2.50m height) with natural lighting provided from windows at the top and has a radiator heating system. Entry is gained via a main entrance door to the laboratory and in addition there is an emergency door allowing a quick exit from the building and a speedier access to medical services, if necessary. Other features of the room include: a main power control panel complete with emergency shut off key for immediate interruption of the testing procedure; a wash basin for cleansing, mirror, waste bin; a small mobile table and a desk area for the computer operator; a desktop computer and telephone.

Fig. 11(a,b): View from the emergency exit of the Laboratory showing tripod and electrocardiograph; View from right side of the Laboratory showing treadmill and safety harness, power unit, desktop computer and interface.

Fig. 12 (a, b): View showing the wash area with basin for cleansing, mirror and waste bin, and pulley system;

View from left side of the Laboratory.

The second exercise physiology laboratory is oversized for the cycle ergometer, however, it can be considered a multifunctional area as it has other test and evaluation equipment that can be arranged in the same space. It consists of three interconnected rooms, each of which can be isolated if necessary. For the purposes of this research, the bicycle ergometer was positioned in the centre of the main laboratory area. One wall of this room is of glass construction, allowing in plentiful natural light and providing a contemplative setting for the volunteers performing the test. This space also has radiator heating, opening windows to a second attached room allowing for ventilation, a wash basin, waste bin, and cabinets to store emergency equipment.

Fig. 13 (a, b, c): Centre section of the laboratory with the cycle ergometer; Head-on view of the laboratory; View from the right side of the lab.

5.2.2 Test Equipment Treadmill-Ergometer

The principal piece of equipment provided in the first laboratory is the treadmill-ergometer (SATURN 300-125R hp cosmos sports & medical GmbH, Nussdorf-Traunstein, Germany). The device is located in a central position of the room and is set at ground level, therefore having the advantage of being very accessible for the tests conducted with the wheelchair athletes. The treadmill is mounted in such a way that the operating systems (mechanical and hydraulic) are located below floor level. The visible part of the treadmill consists of an embedded structure that also reinforces the surrounding framework, responsible for giving support to the subject under evaluation and ensuring their safety. The frame surrounding the treadmill/test site is 4.0m in length by 2.10m wide, with the area of the treadmill itself being 3.20m long by 1.25m wide.

Pulley System

The pulley system is a device external to the treadmill that must be connected to the wheel chair via a rope, making it possible to measure forces from 10W to 300W (Niklas, 1980/1987/1988/1989/1994/1997). A rail is fixed to the wall behind the wheelchair and the pulleys are mounted on this rail in two different axes. The rope that is attached to the wheelchair is guided by two pulleys. The load at the rope end can be increased (i.e. 20W each 3 minutes) during the course of the exercise.

Fig. 15: Pulley System, auxiliary force admission.

Electric Bicycle-Ergometer

One of the pieces of equipment available in the second laboratory and used for this study is the electric bicycle ergometer (Ergoselect 200, Ergoline GmbH, Bitz, Germany). The brake system for the cycle is a microprocessor controlled eddy current brake with torque measurement: speed independent according to DIN VDE 0750-0238. The seat height is fully adjustable to suit the person under evaluation, ensuring a comfortable position for the task, and the graphic display unit is turned toward the person supervising the test. More characteristics of the equipment are detailed in Table 3.

Table 3: Characteristics of the Ergoselect 200 Electric Bicycle Ergometer (Annex 4).

Load range: 20-999 Watts, speed independent Speed range: 30 - 130 n/min^-1

Workload accuracy: max. +/- 3% between 100 and 999 W max. +/- 3 W between 20 and 100 W Load grades: 5 W or multiple over program

Physical Specifications:

Weight – approximately 68 kg Max. Patient Weight – 150 kg

Display –115 x 88 mm or 320 x 240 Pixel

Fig. 16 (a, b): Ergoselect 200 electric bicycle ergometer; bicycle graphic display unit.

5.2.3 Measurement Equipment Spirometer

As can be seen in Figure 18b, the spirometer used in this study is the Metamax 3B (Cortex, 2000), which is a robust and portable cardiopulmonary exercise testing device for outdoor and indoor application assessment, weighing just 650 grams complete with batteries. It measures breath-by-breath the oxygen and carbon dioxide content of the air inspired and expired, as well as heart rate, temperature and air pressure under both laboratory and field conditions. The device is formed of two modules. The central computer unit used runs at 20 MHz with a 16-bit processor. The flow meter employed is the Ultra model (Triple-V turbine from 0.05 to 20 l/s) and has a resolution of 7 ml and an accuracy of 2%. The type of oxygen analyzer used is an electrochemical cell with a measuring range of 0-35%, an accuracy of 0.1% and a 90% strength mixing of the gas mixture of 100ms. The carbon dioxide analyzer works with infrared absorption and has a specified range of 0-13%. The temperature sensor is an NTC thermistor and has a measuring range of -55ºC to 155ºC with an accuracy of 1ºC.

Table 4: Main Characteristics of the Spirometer Metamax 3B (complete table by Annex 5)

Sensors: Physical Specifications:

Flow/ Volume Type – Turbine digital Dimension (LxWxH) – 2x(120 x 110 x 45 mm) Range – 0.05 – 20L/s Weight – 570 g (without battery)

Resolution – 7 mL Electrical Specifications:

Accuracy – 2% PC Interface – Serial (RS232)

O2 Type – Electro-Chemical Cell Power Supply – Battery, Internal 7.2 V nominal; 2200 mA

Range – 0 – 60 Vol. % Operating Conditions:

0 – 100 Vol. % (optional) Warm-up Time – approx. 30 min.

T90 Time <100ms Temperature - 10º to max. +40 º C Accuracy – +- 0.1 Vol. % Ambient Pressure – 500 – 1050 mbar

CO2 Type – ND Infrared Relative Humidity – 0 – 99 % (non-condensing)

Range – 0 – 13 Vol. % Minimal Computer Requirements:

T90 Time <100ms Processor – min. 2000MHz

Accuracy – +- 0.1 Vol. % Hard Disc Drive – >40 GB

Heart Rate Polar^® HR Set RAM – min. 512 MB

3 Channel ECG (optional) Disc Drive – CD-ROM

12 Channel ECG (optional) Operating System – MS-Windows XP (SP2),

Telemetry: MS-Windows Vista (32 Bit)

Type – Bidirectional 19200 Baud Monitor – 17” TFT, min. 1024 x 768 Pixel

Frequency – 433 – 424 MHz Interfaces – LAN, min. 2 x USB, serial (COM)

Range – 1000 m Optional – Sound Card, CD/ DVD Writter

The silicone type pressure sensor works at a range of 200 mbar to 1050 mbar with an accuracy of 1.8%. The heart rate monitor is a Polar diameter determined by default. The Metamax 3B can be used for a variety of functions as detailed below:

 Smoothing of the values (pointwise breath-based or time-related) by a moving average.

 Calculation of the anaerobic threshold by V-slope method and minimum method (based on O2

and CO2 equivalent).

 Calculation of the oxygen debt and the maximum oxygen uptake.

 Print a report as a 9-box graphics for Wassermann, as ergometry/ calorimetry standard report or custom.

The laboratory has a computerized system of control along with computing hardware support and data-processing software aimed at maximising the use of the equipment and facility. The Metamax 3B is preloaded with its own specific Metasoft CPX software, which is modular and incorporates a database to include subject data, a measurement module and an evaluation and calibration module.

After the measurements take place, the values are considered and processed using the evaluation mode. More characteristics for this equipment are detailed in Table 4.

Equipment used during Spiroergometry

The wheelchair dependent athletes used their personal wheelchairs whilst taking part on the treadmill and the stand-ski athletes were seated on the bicycle. All athletes were dressed appropriately for the test. The heart rate monitor used was the Polar^® HR set (Polar Electro Oy HQ, Kempele, Finland) and was adjusted to each of the athletes. In addition, the wheelchair athletes were fitted with a shoulder harness which was attached to the framework surrounding the treadmill in order to reduce the risk of accident.

Fig. 17: Portable Electrocardiograph.

The cardiopulmonary exercise testing equipment used was a Metamax 3B (Cortex Biophysik GmbH, Leipzig, Germany) spirometer, a portable 3-channel electrocardiograph model AT-4 EKG (Schiller AG, Switzerland, fig. 17), and a SCOUT (SensLab GmbH, Leipzig, Germany) lactate

analyser. Two computers were also used during the experiments with a desktop computer and interface controlling the treadmill, and a laptop computer for monitoring the spiroergometry. Both computers were equipped with specific software for their individual tasks.

Fig. 18 (a, b): View from right side of the Laboratory, including desktop computer, interface and lap top;

Spirometer (Metamax 3B).

5.3 Wind Tunnel