Figure 5

Flow chart of experimental setup;

(a) Myotronic stimulation unit; (b) force gauge; (c) electrolyte basin with incorporated silver electrodes; (d) musculus rectus abdominis; (e) perfusate reservoir; (f) oxygenation circuit with hollow fiber membrane oxygenator and gas supply; (g) perfusion pump; (h) oxygen partial pressure measurement; (i) perfusion pressure measurement; (j) perfusate sampling; Muscle flap and its suspension to the force gauge as well as the stimulation-unit are located in the bioreactor. The periphery includes measurement devices and the perfusion-system. Perfusate is stored in the reservoir and pumped through a sterile filter and is oxygenated via the hollow fiber membrane perfused with ambient air with a flow rate of 3 l/min to ensure oxygen saturation. Part of the perfusate is brought back into the reservoir and part is diverted into the perfusion circuit connected to the muscles pedicle. On the venous side, the perfusate is extruded and pumped back into the reservoir for reoxygenation. Oxygen partial pressure as well as total perfusion pressure is recorded at the arterial and venous branch of the perfusion circuit. The venous branch also houses a sampling point for perfusate retrieval.