**3. Intra-thoracic implantation**

**Figure 2.** Topography of the latissimus dorsi muscle (LDM) in a big animal (goat) and a human. LDM consists of three parts: Pars transversalis (1), Pars obliqua (2) and Pars lateralis (3), LDMs weight is 300 to 450g in Boer bocks and about 600g in hu‐

**Figure 1.** Boer goats with a weight between 60 and 100 kg and a latissimus dorsi muscle of 300 to 450 g.

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mans.

Experiments were carried out in adult Boer goats (Figure 1), with a weight of 70±11 kg. They were castrated 4 weeks before the operation to keep them together and avoid injuries between them. The experiments were performed in accordance with the Guide for the Care and Use of Laboratory Animals published by the National Institutes of Health. They were supervised by a representative of the District President of the local society for Prevention of Cruelty to Animals.

The operation was performed under general anaesthesia. Left LDM was dissected free, folded to a double layer, and wrapped around the central chamber of the training device. The SMV was transferred into the thorax and fixed at the thoracic wall.

Commercially available myostimulators were used (Medtronic model 7420/7424 and Tele‐ ctronics model 7220). An epi-mysial electrode 30mm long (custom-made, Medtronics, Bakken Research Center) was attached to the muscle close to the branches of the nervus thoracodor‐ salis. On the opposite side of the muscle, an electrode 60mm long (Medtronics SP 5591 – 500-60- NMS) was placed sub-fascially.

**Figure 4.** An intra-thoracic skeletal muscle ventricle is wrapped around the Frog: A myostimulator induces muscle contractions via 2 electrodes. Contractions of LDM cause a volume shift from the central chamber into the expanding bladders, with a corresponding pressure increase. This pressure is measured by piercing a subcutaneous vascular ac‐ cess port (PaC).

Skeletal Muscle Ventricles (SMVs) and Biomechanical Hearts (BMHs) with a Self Endothelializing Titanized… http://dx.doi.org/10.5772/55993 345

The operation was performed under general anaesthesia. Left LDM was dissected free, folded to a double layer, and wrapped around the central chamber of the training device. The SMV

Commercially available myostimulators were used (Medtronic model 7420/7424 and Tele‐ ctronics model 7220). An epi-mysial electrode 30mm long (custom-made, Medtronics, Bakken Research Center) was attached to the muscle close to the branches of the nervus thoracodor‐ salis. On the opposite side of the muscle, an electrode 60mm long (Medtronics SP 5591 – 500-60-

**Figure 4.** An intra-thoracic skeletal muscle ventricle is wrapped around the Frog: A myostimulator induces muscle contractions via 2 electrodes. Contractions of LDM cause a volume shift from the central chamber into the expanding bladders, with a corresponding pressure increase. This pressure is measured by piercing a subcutaneous vascular ac‐

was transferred into the thorax and fixed at the thoracic wall.

NMS) was placed sub-fascially.

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cess port (PaC).

**Figure 5.** Method of stroke volume and stroke energy determination, relating pressure increase of a ventricle contrac‐ tion (left) to the compliance curve of the bladders of the Frog, stroke volume is received (right). The area of the stroke volume below the compliance curve represents the stroke work or stroke energy [7].

Stroke volume evaluation is performed relating maximal pressure Pmax from the pressure curve during muscle contraction to the compliance curve of the Frog's elastic side bladders (Figure 5). Stroke volume multiplied with Pmax results in stroke work W. Daily energy in KJ/d is to calculate by stroke work W multiplied with the number of SMV contractions per day.
