Tutorials

In this tutorial we show how optical sensors can be exploited in order to manufacture a conformable system able to monitor the arterial stiffness by means of a fully optical technique, which is the photopletysmography PPG. We show how a PPG signal can be usefully monitored by exploiting also the ECG signals. In the tutorial, after an introduction on the PPG/ECG combined system, developed within the ASTON!SH ECSEL JU EU project, we proceed with a demo-live of a PPG/ECG portable system.  

In details, we present a portable PPG/ECG combo system (Fig. 1) developed by the LOOX (Laboratory of Optics and OptoelectroniX) of the University of Palermo, Italy. The system supports the synchronous acquisition of 8 channels (5 PPG + 3 ECG leads) with 24-bit resolution, a sampling rate of 1 kSPS and is capable to visualize, in real-time, the following physiological parameters: heart rate, ECG R-R intervals or PPG pulse-pulse interval, Pulse Arrival Time, Pulse Transit Time, Pulse Wave velocity and breathing rate. The visualization is achieved through an appositely developed Graphical User Interface (Fig. 2). The physiological parameters can be plotted in real time and saved for offline post-processing.

Each PPG probe includes a Silicon Photomultiplier (SiPM) detector, provided by STMicroelectronics, and a 735/850 nm Bi-Color LED. The functional parts of the system are: the Analog Front-End (Texas Instruments ADS1298, designed for Biopotential Measurements), the circuitry to drive the LEDs of the probes (employing an I2C interface), an STM32 microcontroller and the power supply circuitry. The system also includes USB and Bluetooth interfaces to transmit (both wired and wirelessly) the acquired data to the PC and is battery operated using standard AA batteries.

Fig. 1 The portable PPG/ECG combo system with the standard ECG probes and a custom PPG probe.

Fig. 2: Our Graphical User Interface for the PPG/ECG system.

During the last several years, 3D printing has been receiving significant attention in the scientific literature and the popular press.  It has also generated exciting business interests and prospects.  To many, 3D printing (in many cases using polymeric materials) is a transformative technology capable of impacting many areas of experimental Science, of Engineering, of Medicine (including dentistry), and of fabrication and manufacturing technology (to name but a few).  In addition, 3D printing has often been described as a technology that has the potential to alter rapid prototyping (an early publication in reference [1]) and to influence (if not disrupt) traditional methods of manufacturing.  In fact, the capability of 3D printing to make personalized (i.e., one-of-a-kind) items on-demand may offer the necessary stepping stones for the implementation of the emerging Industry 4.0, and of the over the horizon Industry 5.0 and of Society 5.0.

The aim of this tutorial is to provide an introduction to 3D-printing and to highlight potential future directions.

The content of this tutorial is (roughly) divided into five parts:

1. 3D printing technologies.
2. Materials for 3D-printing.
3. Comparison of technologies, capabilities and materials used for 3D printing.
4. Selected applications of 3D printing, with examples drawn from the Engineering and the Scientific literature (with many) from the author's laboratory.
5. Future directions of 3D printing technology, the potential impacts of this technology on IoT, on Industry 4.0 and (potentially) on Industry 5.0 and of its capability to influence (if not enable) Society 5.0 approaches will be discussed.  General comments on future societal and economic impacts of 3D printing will be made.

[1]    S. Weagent, L. Li and V. Karanassios, “Rapid prototyping of hybrid, plastic-quartz 3D-chips for battery-operated microplasmas”, Open-access book chapter, Chapter 10, Pages 209-226, InTech publishing (2011), DOI: 10.5772/24994