In spite of the lack of low cost biosignal specific purpose generators, there have been processing strategies to simulate control signals and dynamic states of different pathological diseases. Commercial simulators are not able to reproduce all signal behavior; thereby, we developed a light based emulator able to provide different signal patterns using colorimetry and spectrophotometry. Several parameters are configurable according to customer requirements. Amplitude and frequency are controlled by the usage of a DC motor, a coloured band, a mechanical structure, and, particularly, an oximetry probe. The prototype emulator provides basic signals such as sine, square, triangle, or complex physiological signals, as photoplethysmograms (PPG) and Electrocardiograms (ECG). Other complex patterns include sources of error and chaotic characteristics such as noise or motion artifact, can be simulated. The device may be used to analyze, determine and verify data acquisition platforms, medical instrumentation, training tool interfaces, among others. Preliminary results have contributed to the construction and validation of complex patterns; corroborating practicality, operability and reliability of the proposed product and reducing developing time on representations.