Perspectivas para la Evaluación de Tecnologías en Salud: Perspectives for health technology assessment

An unplanned health care system is like a paper boat carried by a slowly sinking current. In times of disinformation and excessive distraction, investing in better facts on health technology assessment (HTA) will enable more active actions rather than reactive to the market dynamics. This paper aims to raise some reflections on HTA in terms of political context, health technologies and epidemiological priorities. The perspective of HTA is context dependent, intrinsic to its political and institutional articulation. At the moment, the paradox is to maintain a specialized structure in the face of economic austerity policies that reduce health resources, and a scenario of greater interest in raising public funds by the private sector. Particularly in Brazil, HTA will also have to deal with the gradual shift from a universal health system to a minimum portfolio of services offered by the private sector. The public sector will be requested for very expensive technologies, usually by judicial measures. The precariousness of work relationships will influence HTA workers because they will not have a link and identity with the health system. Thus, there will be more productive and less reflective HTA processes. The context of greater dependence on the private market will allow new problems with medical technologies to emerge, such as the opioid crisis in the United States.Un sistema de atención médica no planificado es como un barco de papel transportado por una corriente que se hunde lentamente. En tiempos de desinformación y distracción excesiva, invertir en mejores hechos sobre evaluación de tecnología de salud (HTA) permitirá acciones más activas en lugar de reaccionar a la dinámica del mercado. Este documento tiene como objetivo plantear algunas reflexiones sobre la ETS en términos de contexto político, tecnologías sanitarias y prioridades epidemiológicas. La perspectiva de la HTA depende del contexto, intrínseca a su articulación política e institucional. Por el momento, la paradoja es mantener una estructura especializada frente a las políticas de austeridad económica que reducen los recursos de salud, y un escenario de mayor interés en recaudar fondos públicos por parte del sector privado. Particularmente en Brasil, HTA también tendrá que lidiar con el cambio gradual de un sistema de salud universal a una cartera mínima de servicios ofrecidos por el sector privado. Se solicitará al sector público tecnologías muy caras, generalmente mediante medidas judiciales. La precariedad de las relaciones laborales influirá en los trabajadores de HTA porque no tendrán un vínculo e identidad con el sistema de salud. Por lo tanto, habrá procesos de HTA más productivos y menos reflexivos. El contexto de una mayor dependencia del mercado privado permitirá que surjan nuevos problemas con las tecnologías médicas, como la crisis de los opioides en los Estados Unidos

Practical characterization of quantum devices without tomography

Quantum tomography is the main method used to assess the quality of quantum information processing devices, but its complexity presents a major obstacle for the characterization of even moderately large systems. The number of experimental settings required to extract complete information about a device grows exponentially with its size, and so does the running time for processing the data generated by these experiments. Part of the problem is that tomography generates much more information than is usually sought. Taking a more targeted approach, we develop schemes that enable (i) estimating the fidelity of an experiment to a theoretical ideal description, (ii) learning which description within a reduced subset best matches the experimental data. Both these approaches yield a significant reduction in resources compared to tomography. In particular, we demonstrate that fidelity can be estimated from a number of simple experimental settings that is independent of the system size, removing an important roadblock for the experimental study of larger quantum information processing units.Comment: (v1) 11 pages, 1 table, 4 figures. (v2) See also the closely related work: arXiv:1104.4695 (v3) method extended to continuous variable systems (v4) updated to published versio

Entanglement enhances cooling in microscopic quantum fridges

Small self-contained quantum thermal machines function without external source of work or control, but using only incoherent interactions with thermal baths. Here we investigate the role of entanglement in a small self-contained quantum refrigerator. We first show that entanglement is detrimental as far as efficiency is concerned---fridges operating at efficiencies close to the Carnot limit do not feature any entanglement. Moving away from the Carnot regime, we show that entanglement can enhance cooling and energy transport. Hence a truly quantum refrigerator can outperform a classical one. Furthermore, the amount of entanglement alone quantifies the enhancement in cooling.Comment: 7 pages, 3 figure

Unifying paradigms of quantum refrigeration: fundamental limits of cooling and associated work costs

In classical thermodynamics the work cost of control can typically be neglected. On the contrary, in quantum thermodynamics the cost of control constitutes a fundamental contribution to the total work cost. Here, focusing on quantum refrigeration, we investigate how the level of control determines the fundamental limits to cooling and how much work is expended in the corresponding process. \jona{We compare two extremal levels of control. First coherent operations, where the entropy of the resource is left unchanged, and second incoherent operations, where only energy at maximum entropy (i.e. heat) is extracted from the resource. For minimal machines, we find that the lowest achievable temperature and associated work cost depend strongly on the type of control, in both single-cycle and asymptotic regimes. We also extend our analysis to general machines.} Our work provides a unified picture of the different approaches to quantum refrigeration developed in the literature, including algorithmic cooling, autonomous quantum refrigerators, and the resource theory of quantum thermodynamics.Comment: 17 + 28 pages, 10 figure