Investigation of a Deep Brain Stimulator (DBS) System

Figures

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  Figure 1. A pie chart showing the percentage of those affected by Parkinson’s disease, epilepsy, OCD, dystonia, essential tremor, and others that utilize DBS for treatment of movement symptoms [5].

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  Figure 2. The deep brain stimulator (DBS) system comprises the implantable pulse generator (IPG), the extensions that connect the IPG to the leads, and the electrode leads that are implanted into the brain.

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  Figure 3. The figure shows adverse product performance events, clearly demonstrating that extensions and leads constitute greater than 50% of potential problems with a DBS system [5].

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  Figure 4. The digital microscope captured evidence of damage to the DBS system including scratches, abrasions, pitting, separation of components, eruption and loss of insulation, and evidence of biomaterials.

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  Figure 5. The digital microscope captured evidence of damage to the IPG case, such as scratches which had an average of ~10 mm in length and 0.58 mm in width. (a) is an image of the DBS device that was evaluated, and the red circles indicate the location of the scratches. (b) is an image of the scratches that are possibly a result of instruments used to posthumously extract the device.

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  Figure 6. The digital microscope captured evidence of damage to the leads including corrosion, cracks, pitting, eruptions, and tears.

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  Figure 7. Distance measurements between coils using the inverted compound microscope. The distances between coils were made by measuring from the left edge of the coil to the neighboring left edge of the coil (sample 1); from the middle of the coil to the middle of the neighboring coil (sample 2); and from the right edge of the coil to the neighboring right edge of the coil (sample 3).

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  Figure 8. Measurement of the thickness of coils using the inverted compound microscope at two different locations.

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  Figure 9. Testing tensile strength of the silicone insulation of the Medtronic extension.

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  Figure 10. Load vs. displacement results of the extension wire protected by silicone.

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  Figure 11. Multiple regression results of predicting duration given load to failure, maximum elongation, 5 N elongation, UTS, and modulus of elasticity.

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  Figure 12. Stretching of the coils can lead to a lower resistance and, potentially, a higher current.