Space Physiology
Head: Prof. Dr. med. Jörn Rittweger

Test Facilities



Physiology Laboratory

The Physiology Laboratory serves the performance of human physiological experiments. Main components are:

  • A multifunction laboratory
  • A force and power diagnostic system Biodex-System 3
  • A muscle lab that includes an NMR-spectrographic device 
  • A peripheral quantitative computer tomography (pQCT)

 The facility pertains to the Space Physiology branch of the Institute. It consists of an air-conditioned room (240 m2) which can be divided in up to five functional units or examination rooms. Additionally, there is an especially shielded room (Faraday Cage) which makes it possible to record very weak bioelectrical signals such as muscular sympathetic nerve activity (MSNA). Each individual room has a conventional electric current supply and also an IT (isolation-terre) network. The latter is mandatory for the performance of medical examinations and physiological experiments with human subjects. Additionally, each unit has three communication lines (Ethernet, ISDN, Telephone), which are free configurable and independent of public networks, as well as two fibre optic ports. These ports make it possible to acquire experimental data centrally without making supplementary security provisions.

The laboratory is available to in-house researchers and, under circumstances, also to external scientists. A facility manager is in charge of the lab. He is familiar with the lab technology and can provide researchers with advices on its utilisation. The facility is equipped with devices to perform non-invasive examinations, primarily in the field of cardiovascular physiology. Other measurement systems and devices can be provided, if required, by the investigators themselves. A tight co-operation between facility manager and researchers allows to configure the facility according to the requirements of particular experiments and to set up the requisite hardware. The hardware is used according to established, predefined procedures which ensure that handling of medical devices comply with the requirements set forth in pertinent European and German legislation and regulations. A final technical security inspection of the experiment set-ups confirms compliance. Experiments that require medical monitoring are assigned medical doctors who are not themselves scientifically involved with the experiments but exclusively responsible for the test subjects’ safety and well-being.

Biodex-3System: Force- and Power Diagnostics of large Muscle Groups

The Biodex-System3 uses a servo motor for force- and power-diagnostics in all large muscle groups of arms, shoulders, back, hips, and legs.

The instrument is used for meassuring force in isometric (without motion) condition and power (force * speed) in isotonic (meassuring speed at a preset force) and isokinetic (meassuring force at preset speed) conditions. For more details of the Instrument see: www.biodex.com/rehab/system4/system4_feat.htm

In our lab the tests will be optimized for reproducible meassurements in untrained and detrained persons, who are -unlike athletes- not used to give maximum force in single muscle groups. The tests will be used, for example in bedrest studies, to assess the effect of immobilistion and the success of investigated countermeassures.

Using electromyography (EMG) the activity of working and unvoluntarily co-activated muscles is recorded.

The local blood- and oxygen-supply is recorded using near infrared spectroscopy.

The Muscle Lab

 The muscle lab allows the non-invasive and continuous examination of the energy metabolism and the electrical activity of foot dorsi-flexor and plantar-flexor muscles.
The effects of different cardio-vascular reactions on muscle metabolism can be studied using a lower-body-pressure (LBNP) device. Body postures from horizontal lying to upright standing can be simulated. The DLR muscle lab combines a world wide unique assembly of non-invasive examination methods with different form of muscle loading and cardio-vascular stimulation.

 

  1. Magnetic resonance system: Bruker Biospec 47/40, 4.7 Tesla, 40-cm horizontal bore, the magnet is placed in a HF-shielded cabin
  2. Calf holder with integrated 5 cm HF surface coil
  3. Force transducer (Design for static work)
  4. Force display
  5. Cuff for the application of arterial or venous occlusion
  6. Regulated compressed air
  7. Emergency valve
  8. EMG-electrodes
  9. EMG-pre-amplifier and optic-coupling
  10. Glass fibre optodes for NIRS-measurements using the Oxymon-system
  11. Oscillometric blood pressure device
  12. Respiration mask and bottle with a pre-mixed respiratory gas mixture
  13. Pulsoximeter
  14. Measurement of respiratory volume
  15. LBNP sealing at the terminal end of the magnet with tubes connected with the vacuum pumps
  16. Neoprene-sealing for the subject used for LBNP-examinations
  17. Electrodes for the direct or indirect electro stimulation of the muscle

     

pQCT (peripheral quantitative computed tomography) (XCT 3000, Stratec)

A radiologic measurement of changes in bone density, structure and geometry can be measured by an highly precise quantitative computed tomography. Crucial for the choice of this device was its reproducibility, non-invasiveness, minimum radiation dose and its capability to measure precise the changes in bone density, bone mass and bone geometry. At present, peripheral computed tomograpphy is - beneath the quantitative computed tomograpphy - the only non-invasive methode which provides true volumetric measurement of bone density (g/cm3) of separate bone compartments and allows in addition to form an opinion about the geometry of bone and an estimation of bone strength. The measurement takes place at tibia and femur and lasts half an hour. (http://www.stratec-medizintechnik.de)


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