Practical guidance and clinical applications of transoesophageal echocardiography. A position paper of the working group of echocardiography of the Hellenic Society of Cardiology.

Transoesophageal echocardiography (TOE) is a well-established imaging modality, providing more accurate and of higher quality information than transthoracic echocardiography (TTE) for a wide spectrum cardiac and extra-cardiac diseases. The present paper represents an effort by the Echocardiography Working Group (WG) of the Hellenic Cardiology Society to state the essential steps of the typical TOE exam performed in echo lab. This is an educational text, describing the minimal requirements and the preparation of a meticulous TOE examination. Most importantly, it gives practical instructions to obtain and optimize TOE views and analyses the implementation of a combined two-and multi-dimensional protocol for the imaging of the most common cardiac structures during a TOE. In the second part of the article a comprehensive review of the contemporary use of TOE in a wide spectrum of valvular and non-valvular cardiac diseases is provided, based on the current guidelines and the experience of the WG members.

Updated knowledge and practical implementations of stress echocardiography in ischemic and non-ischemic cardiac diseases: An expert consensus of the Working Group of Echocardiography of the Hellenic Society of Cardiology.

Stress echocardiography (SE) is a well established and valid technique, widely used for the diagnostic evaluation of patients with ischemic and nonischemic cardiac diseases. This statement of the Echocardiography Working Group of the Hellenic Society of Cardiology summarizes the consensus of the writing group regarding the applications of SE, based on the expertise of their members and on a critical review of present medical literature. The main objectives of the consensus document include a comprehensive review of SE methodology and training-which focus on the preparation, the protocols used, the analysis of the SE images, and updated, evidence-based knowledge about SE applications on ischemic and nonischemic heart diseases, such as in cardiomyopathies, heart failure, and valvular heart disease.

Explicit analytical tuning rules for digital PID controllers via the magnitude optimum criterion.

Analytical tuning rules for digital PID type-I controllers are presented regardless of the process complexity. This explicit solution allows control engineers 1) to make an accurate examination of the effect of the controller's sampling time to the control loop's performance both in the time and frequency domain 2) to decide when the control has to be I, PI and when the derivative, D, term has to be added or omitted 3) apply this control action to a series of stable benchmark processes regardless of their complexity. The former advantages are considered critical in industry applications, since 1) most of the times the choice of the digital controller's sampling time is based on heuristics and past criteria, 2) there is little a-priori knowledge of the controlled process making the choice of the type of the controller a trial and error exercise 3) model parameters change often depending on the control loop's operating point making in this way, the problem of retuning the controller's parameter a much challenging issue. Basis of the proposed control law is the principle of the PID tuning via the Magnitude Optimum criterion. The final control law involves the controller's sampling time Ts within the explicit solution of the controller's parameters. Finally, the potential of the proposed method is justified by comparing its performance with the conventional PID tuning when controlling the same process. Further investigation regarding the choice of the controller's sampling time Ts is also presented and useful conclusions for control engineers are derived.