Multi-source Harvesting Systems for Electric Energy Generation on Smart Hip Prostheses - Biomedical Engineering Systems and Technologies - page 72

optimized to supply as much electric energy as demanded by the active mechanics of
smart prostheses, even though they may require different periods to generate the same
amount of energy.

6 Conclusions

A therapeutic methodology to cure failures of hip prostheses following primary artro-
plasty, based on a personalized approach, would be of great importance for the quality of
life of many patients. Multi-source electric energy generation systems for orthopaedic
implants contribute forward the implementation of individualized medicine approaches
in the scope of embedded smart bone implants. This new concept was validated with the
use of three vibrational energy harvesters: two electromagnetic generators and a piezo-
electric. Experimental results confirm the inaccuracy of the generators' linear models
operating on hip prostheses fixtures, which invalidates their use in optimization rou-
tines.
There is ongoing work to:

1. Develop non-linear models of vibrational energy harvesters. The main goal is to
reduce the volume of each generator and maximize their performance;
2. Identify the most appropriate method to generate electrical energy on hip implants;
3. Design a new method to ensure an effective tracking of the frequency of the hip
kinematics. The set of generators must be synchronized with the hip dynamics in
order to ensure all energy requirements demanded by active elements of the smart
prostheses;
4. Design an energy management system for a multitude of power sources;
5. Design of energy harvesting systems which are independent of failures due to con-
tact stresses (for instance, magnetically levitated generators);
6. Design of a redundant multi-source harvester structure. Such a redundant ability,
along with the requirements introduced in the previous number and in section 5.4,
are sufficient to ensure reliability of the electric energy generation system.

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