## 4 Conclusions  
In this study, a pulse simulator system with a universal or 3D cam has been developed. The cam offers a cost-effective and simple (yet versatile) way to produce a wide range of radial pulse pressure (RAPP) waveforms. Unlike conventional thin disk-type cams, the newly devised 3D cam allows the pulse simulator to generate a specific pulse in a range of pulse waveforms without having to make multiple cams and replace them. In designing the 3D cam, this study used in vivo pulse waveform data for four age groups (15, 35, 65, and 85 years old) obtained from tonometric measurements. After a coordinate transformation of the average pulse waveforms, the cam profile (a two-dimensional cam  
Figure 6: Comparison of human pulse pressure waveforms and artificial waveforms generated by 3D cam simulator: (**a**) 15-year-old waveforms in human and the simulator; (**b**) 25-year-old waveforms; (**c**) 35-year-old waveforms; (**d**) 45-year-old waveforms; (**e**) 55-year-old waveforms; (**f**) 65-year-old waveforms; (**g**) 75-year-old waveforms; (**h**) 85-year-old waveforms. shape) was created for each of the four age groups. These four cam profiles were then used to create the profile of the 3D cam by the linear regression method. A 3D cam was fabricated using precision machining technology, and it was incorporated into the prototype pulse simulator. The prototype simulator utilizes stepping motors to control the rotational speed of the cam and the position of the cam follower assembly at a specific location of the 3D cam in order to produce the desired pulse waveform. The prototype simulator generated age-dependent pulse waveforms from 15 years old to 85 years old with an increment of 10 years. These waveforms were compared with approximate human RAPP waveforms to evaluate the performance of the prototype system. The results show that the simulator-generated pulse waveforms capture the age-related physiological characteristics of the human RAPP well. Furthermore, the augmentation index (AI) and the L\({}^{2}\) errors between the pulse waveforms by the simulator and those of approximate human data were analyzed. The results show that the errors are less than 10% for all ages, indicating that the 3D cam-based pulse simulator is capable of generating virtually all age-specific radial pulse pressure waveforms that are equivalent to human RAPPs. The simulator is also capable of producing pulse waveforms consistently and repeatedly and altering pulse parameters conveniently to reproduce variant pule waveforms. This is a significant benefit of the current simulator, as existing pulse simulators cannot guarantee repeatability or consistent accuracy. For example, pulse simulators that use working fluids are prone to inconsistent measurements caused by unwanted vortexes in the fluid due to the reflection of pulse waves. Moreover, commercially available pulse simulators are significantly more complex and bulky as compared to the pulse simulator developed in this study. Hence, this pulse simulator would be an excellent system for health professionals to train RAPP palpations because it can reproduce known pulses consistently. The pulse simulator could be integrated into a medical Mixed Reality (MR) system as well. Great portability due to its compact design and ease of operation are additional benefits of the system. In order to complete the medical palpation system, we are planning research on the development of an artificial wrist, including an artificial blood vessel and skin that transmits the generated pulse pressure waveform. If an artificial wrist is installed, this simulator is expected to be used for wearable pressure sensor evaluation, transmission function or relationship research between radial and central pulse pressure, and Oriental medicine pulse diagnosis training. Conceptualization, D.-J.K., T.-H.Y., Y.-M.K. and J.-H.K. ; methodology, T.-H.Y. and J.-H.K. ; validation, D.-J.K., G.J., T.-H.Y., J.-H.K. and Y.-M.K.