Recently, during the Christmas season, a friend of mine visited me and, sneaking a look at my bookshelves, found two rather old Nikola Tesla biographies, which I had used to prepare a "Retrospectroscope" column for the then-named IEEE Engineering in Medicine and Biology Magazine when our dear friend Alvin Wald was its editor-inchief [2]. Eighteen years have elapsed since then; soon, the idea came up of revamping the article. Cynthia Weber, the magazine's current associate editor, considered it acceptable, and here is the new note divided in two parts: that is, a slightly revised version of the original article followed by new material, including some quite interesting information regarding Tesla's homes and laboratories. On top of this, Tesla is not devoid of a science fiction touch, as mentioned at the end.

A novel electrocardiographic (ECG) and vectorcardiographic (VCG) signal processing technique is proposed for identification of patients with Acute Myocardial Infarction (AMI). To this end, we propose a method based on two QRS-loops features: a) Volume, and b) Planar Area; along with five orthogonal ECG indexes: c) ST-T vector difference, d) T vector difference, and e-g) the area under the T-wave in X, Y and Z leads. Our method was tested using ECG recordings of 97 AMIs and 52 healthy subject from the PhysioNet PTB database. The results indicate that these indexes show significant statistical differences (p-values < 0.05) between the two populations (Healthy versus AMI population, with the exception of c). To validate the suggested index a 70/30 cross validation technique was used. Moreover, combining all parameters (with the exception of the T-wave area in Y and Z leads), it was possible to classify the AMI and healthy subjects with a sensitivity = 93.90%, a specificity = 93.44% and an accuracy = 93.73%, applying a linear discriminant classifier method. We conclude that the proposed technique could be used as an alternative diagnostic technique in the emergency room.

Most common electrocardiographic diagnostic criteria for left ventricular hypertrophy (LVH) are based on depolarization information. However, reports support that LVH also alters repolarization. Two measures relate depolarization/repolarization: the angle between the QRS-complex and the T-wave in a plane; the planar QRST (QRST(P)) and the vector obtained from the cross sum of the depolarization and repolarization vectors (RT alpha and RTm). We compared the performance of these measures as hypertrophy markers in two sets of planes: the ECG frontal plane (FP) versus the VCG frontal plane (XYP) and the ECG horizontal plane (HP) versus the VCG horizontal plane (XZP). The horizontal views picked up a significant increase of the QRSTP (HP controls vs LVH: 40.18 +/- 41.20 degrees vs 66.50 +/- 51.65 degrees, p< 0.05; XZP controls vs LVH: 43.87 +/- 39.76 vs 66.35 +/- 38.30 degrees, p< 0.05) and a consistent behaviour in the frontal views (XYP controls vs LVH: 17.71 +/- 37.23 vs 35.60 +/- 47.98 degrees, p< 0.005). On the other hand, the angle of the equivalent RT vector significantly increased in the HP (HP controls vs LVH: 24.28 +/- 26.50 degrees vs 33.53 +/- 22.42 degrees, p< 0.05). In conclusion, the angular information in their two forms (QRSTP and RTa) relating depolarization and repolarization was the most informative parameter and should be regarded for the construction of more sensitive electrocardiographic LVH indexes.

Cardiac fibrillation-defibrillation : , Cardiac fibrillation-defibrillation : , کتابخانه دیجیتال جندی شاپور اهواز

In the morning and afternoon of the 19th October 1973, the 52nd scientific meeting of the BES was held at the Royal College of Surgeons of England with Professor J. P. Payne of the College's Research Dept. of Anaesthetics in the Chair. Eight papers were presented and these were followed with demonstrations of work in progress in various departments of the College. At the end of the afternoon, the Annual General Meeting of the BES took place, and Prof. David Simpson was elected President. David has been a staunch supporter of the BES for many years and has built up an international reputation for his work Oil the development of artificial limbs for thalidomide children. The, 11 th Woolmer Memorial Lecture of the Society' was given by Sir Peter Medawar on the theme 'All engineering is bioengineering'.

A new method to measure hematocrit (HTC) in extracorporeal blood systems is presented based on permittivity changes. Human blood samples were tested at different hematocrit levels pairing the values of permittivity (obtained with a commercial impedance analyzer) with the traditional centrifugation results. The comparison yielded a high correlation (R=0.98) while theoretical simplifications suggest that the method is independent of possible changes in the conductivities of the intra- and extra-cellular compartments.

A distributed parameter non-linear circuit is presented as fractal model of an electrode–electrolyte interface. It includes the charge transfer resistance and the double layer capacitance at each fractal level. The circuit explains the linear behavior of its series equivalent resistance Req with signals of amplitudes <20mV and constant frequency; however, for amplitudes beyond that limit, non-linearitiy is manifested in the dc component of the Req Fourier spectrum. As a consequence, both the equivalent resistance and reactance drop with voltage, facts reported experimentally by other authors.

Pacing and Clinical ElectrophysiologyVolume 28, Issue 3 p. 241-242 Horses Also Deserve Our Respect and Love MAX E. VALENTINUZZI, MAX E. VALENTINUZZI Department of Bioengineering Universidad Nacional de Tucumán, ArgentinaSearch for more papers by this author MAX E. VALENTINUZZI, MAX E. VALENTINUZZI Department of Bioengineering Universidad Nacional de Tucumán, ArgentinaSearch for more papers by this author First published: 25 February 2005 https://doi.org/10.1111/j.1540-8159.2005.08152.xCitations: 1 Address for reprints: Max E. Valentinuzzi, Ph.D., Universidad Nacional de Tucumán, Argentina. Fax: +(54)381-436-4120; e-mail: mvalentinuzzi@herrera.unt.edu.ar Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume28, Issue3March 2005Pages 241-242 RelatedInformation

In a previous paper, a new dielectric technique was used to estimate hematocrit (HTC) in extracorporeal blood circulation systems, independently of plasma conductivity or osmolarity. Although many impedance techniques have been formerly proposed in the literature, none has been evaluated against plasma conductivity and osmolarity. Herein, we estimate HTC based on permittivity changes and also with other four techniques found in the literature. Besides, the error incurred in each is also studied when plasma conductivity and osmolarity changed as much as 1 mS/cm and 50 mOsm/kg, respectively. The dielectric (permittivity) technique has an error close to 5.4%, while the others showed both tendencies, i.e., lower error (2.5%, two of them) and higher error (8.6% and 16.3%, the other two). The dielectric technique, even though did not produce the lowest error, provides a well-described physical model along with simple instrumentation.

Pacing and Clinical ElectrophysiologyVolume 27, Issue 5 p. 667-667 Honor Thy Dog Max E. Valentinuzzi PhD, Max E. Valentinuzzi PhD Universidad Nacional de Tucumán Tucumán, ArgentinaSearch for more papers by this author Max E. Valentinuzzi PhD, Max E. Valentinuzzi PhD Universidad Nacional de Tucumán Tucumán, ArgentinaSearch for more papers by this author First published: 04 May 2004 https://doi.org/10.1111/j.1540-8159.2004.00504.xCitations: 2Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume27, Issue5May 2004Pages 667-667 RelatedInformation

Electromyography of the scapular waist muscles-in particular, the deltoid medium-showed a behavior resembling a hysteresis loop when the signal amplitude was plotted as a function of the arm position. Such loop was repeated in all the candidates who performed the test. It probably manifests the contribution of other regional muscles, as they enter into action or cease to contract, during the abduction-adduction maneuver. The phenomenon deserves further analysis