Carbon dioxide (CO${}_2$) monitoring in human subjects is of crucial importance in medical practice. Transcutaneous monitors based on the Stow-Severinghaus electrode make a good alternative to the painful and risky arterial “blood gases” sampling. Yet, such monitors are not only expensive, but also bulky and continuously drifting, requiring frequent recalibrations by trained medical staff. Aiming at finding alternatives, the full panel of CO${}_2$ measurement techniques is thoroughly reviewed. The physicochemical working principle of each sensing technique is given, as well as some typical merit criteria, advantages, and drawbacks. An overview of the main CO${}_2$ monitoring methods and sites routinely used in clinical practice is also provided, revealing their constraints and specificities. The reviewed CO${}_2$ sensing techniques are then evaluated in view of the latter clinical constraints and transcutaneous sensing coupled to a dye-based fluorescence CO${}_2$ sensing seems to offer the best potential for the development of a future non-invasive clinical CO${}_2$ monitor.

Nowadays, electric vehicles are one of the main topics in the new industrial revolution, called Industry 4.0. The transport and logistic solutions based on E-mobility, such as handling machines, are increasing in factories. Thus, electric forklifts are mostly used because no greenhouse gas is emitted when operating. However, they are usually equipped with lead-acid batteries which present bad performances and long charging time. Therefore, combining high-energy density lithium-ion batteries and high-power density supercapacitors as a hybrid energy storage system results in almost optimal performances and improves battery lifespan. The suggested solution is well suited for forklifts which continuously start, stop, lift up and lower down heavy loads. This paper presents the sizing of a lithium-ion battery/supercapacitor hybrid energy storage system for a forklift vehicle, using the normalized Verein Deutscher Ingenieure (VDI) drive cycle. To evaluate the performance of the lithium-ion battery/supercapacitor hybrid energy storage system, different sizing simulations are carried out. The suggested solution allows us to successfully optimize the system in terms of efficiency, volume and mass, in regard to the battery, supercapacitors technology and the energy management strategy chosen.

We demonstrate time-correlated single photon counting (TCSPC) in microfluidic droplets under high-throughput conditions. We discuss the fundamental limitations in the photon acquisition rate imposed by the single photon detection technique and show that it does not preclude accurate fluorescence lifetime (FLT) measurements at a droplet throughput exceeding 1 kHz with remarkable sensitivity. This work paves the way for the implementation of innovative biomolecular interaction assays relying on the FLT detection of nanosecond-lived fluorophores for high-throughput biotechnological applications, including high-throughput screening or cell sorting potentially allowed by droplet microfluidics or other fast sample handling facilities.

In this paper, we describe a low cost pulse generator based on bipolar transistors designed to emit very short light pulses with a simple laser diode. Its main characteristics are laser pulses as short as 60 ps Full Width at Half Maximum (FWHM) and a repetition rate from DC up to 100 MHz. The circuit is based on three standard RF bipolar transistors which emit a short electrical pulse of 1.2 ns FWHM with 5 Volt amplitude peak-peak into 50 Ω. This unit can directly drive a classical laser diode to emit short laser pulses. A DC current generator is added in order to polarize the laser diode near its emission point and reduce the power delivered by the pulse generator and enhance its life time. This generator allows the adjustment of the emitted power of the laser diode. If the power emitted is too high, secondary pulses are observed. There is an optimal power where there is a single short pulse with duration down to 60 ps FWHM. The system is simply triggered by a TTL signal and its structure allows the generation of a single shoot, or a complex pattern generation and repetitive generation. The unique limitation is the delay between pulse emissions which must be greater than 10 ns. The typical optical power with a standard laser diode at 660 nm (45 mW continuous) is 1.7 mW with a repetition rate of 80 MHz and a pulse width down to 60 ps measured with a synchroscan streak camera. The peak power is about 350 mW. The pulse to pulse jitter is less than 10 ps rms. This system can be a competitive alternative to expensive commercial products.

Optical imaging methods capable of providing real-time information related to functional and structural conditions of living tissues are becoming increasingly popular.1–6 Some medical fields in particular, such as surgery, are driving this need for real-time interpretable information content to aid decision-making in a time-constrained environment.7–12 Several solutions have been investigated to fulfill this need, each with their pros and cons, ranging from raster scanning of microscopic information to wide-field acquisitions of diffused information.13,14 For instance, fluorescence imaging to help surgeons visualizing structures of interest, such as lymph nodes, ureters, or micrometastasis, stands as an example where providing tissue-related information in real time plays a key role in clinical adoption.15–18

The accurate determination of blood gases—namely dioxygen (${\mathrm{O}}_2$) and carbon dioxide (${\mathrm{CO}}_2$)—is of crucial importance in medical care since it gives circulatory as well as ventilatory clues on the state of a patient.¹ In particular, in case of acute respiratory failure, chronic obstructive pulmonary disease or cystic fibrosis, the monitoring of parameters such as the arterial blood dioxygen saturation (${\mathrm{SatO}}_2$) and ${\mathrm{CO}}_2$ arterial pressure (${\mathrm{Pa}}_{{\mathrm{CO}}_2}$) can strongly affect patient handling and outcome.^{2 – 4}