Robert B. Trelease

Patterns of beat-to-beat heart rate variability in advanced heart failure

Diminished heart rate variability is associated with high sympathetic tone and an increased mortality rate in heart failure cases. We constructed Poincaré plots of each sinus R-R interval plotted against the subsequent R-R interval from 24-hour Holter recordings of 24 healthy subjects (control group) and 24 patients with heart failure. Every subject in the control group had a comet-shaped Poincaré plot resulting from an increase in beat-to-beat dispersion as heart rate slowed. No patient with heart failure had this comet-shaped pattern. Instead, three distinctive patterns were identified: (1) a torpedo-shaped pattern resulting from low R-R interval dispersion over the entire range of heart rates, (2) a fanshaped pattern resulting from restriction of overall R-R interval ranges with enhanced dispersion, and (3) complex patterns with clusters of points characteristic of stepwise changes in R-R intervals. Poincaré pattern could not be predicted from standard deviations of R-R intervals. This first use of Poincaré plots in heart rate variability analysis reveals a complexity not readily perceived from standard deviation information. Further study is warranted to determine if this method will allow refined assessment of cardiac-autonomic integrity in heart failure, which could help identify patients at highest risk for sudden death.

Diffusion of innovations: smartphones and wireless anatomy learning resources.

The author has previously reported on principles of diffusion of innovations, the processes by which new technologies become popularly adopted, specifically in relation to anatomy and education. In presentations on adopting handheld computers [personal digital assistants (PDAs)] and personal media players for health sciences education, particular attention has been directed to the anticipated integration of PDA functions into popular cellular telephones. However, limited distribution of early “smartphones” (e.g., Palm Treo and Blackberry) has provided few potential users for anatomical learning resources. In contrast, iPod media players have been self‐adopted by millions of students, and “podcasting” has become a popular medium for distributing educational media content. The recently introduced Apple iPhone has combined smartphone and higher resolution media player capabilities. The author successfully tested the iPhone and the “work alike” iPod touch wireless media player with text‐based “flashcard” resources, existing PDF educational documents, 3D clinical imaging data, lecture “podcasts,” and clinical procedure video. These touch‐interfaced, mobile computing devices represent just the first of a new generation providing practical, scalable wireless Web access with enhanced multimedia capabilities. With widespread student self‐adoption of such new personal technology, educators can look forward to increasing portability of well‐designed, multiplatform “learn anywhere” resources. Anat Sci Ed 1:233–239, 2008.

Anatomical informatics: Millennial perspectives on a newer frontier

One of the most ancient of sciences, anatomy has evolved over many centuries. Its methods have progressively encompassed dissection instruments, manual illustration, stains, microscopes, cameras and photography, and digital imaging systems. Like many other more modern scientific disciplines in the late 20th century, anatomy has also benefited from the revolutionary development of digital computers and their automated information management and analytical capabilities. By using newer methods of computer and information sciences, anatomists have made outstanding contributions to science, medicine, and education. In that regard, there is a strong rationale for recognizing anatomical informatics as a proper subdiscipline of anatomy. A high‐level survey of the field reveals important anatomical applications of computer sciences methods in imaging, image processing and visualization, virtual reality, modeling and simulation, structural database processing, networking, and artificial intelligence. Within this framework, computational anatomy is a developing field focusing on data‐driven mathematical models of bodily structures. Mastering such computer sciences and informatics methods is crucial for new anatomists, who will shape the future in research, clinical knowledge, and teaching. Anat Rec (New Anat) 269:224–235, 2002.

Going Virtual with QuickTime VR: New Methods and Standardized Tools for Interactive Dynamic Visualization of Anatomical Structures

Continuing evolution of computer‐based multimedia technologies has produced QuickTime®, a multiplatform digital media standard that is supported by stand‐alone commercial programs and World Wide Web browsers. While its core functions might be most commonly employed for production and delivery of conventional video programs (e.g., lecture videos), additional QuickTime VR “virtual reality” features can be used to produce photorealistic, interactive “non‐linear movies” of anatomical structures ranging in size from microscopic through gross anatomic. But what is really included in QuickTime VR and how can it be easily used to produce novel and innovative visualizations for education and research? This tutorial introduces the QuickTime multimedia environment, its QuickTime VR extensions, basic linear and non‐linear digital video technologies, image acquisition, and other specialized QuickTime VR production methods. Four separate practical applications are presented for light and electron microscopy, dissectable preserved specimens, and explorable functional anatomy in magnetic resonance cinegrams. Anat Rec (New Anat) 261:64–77, 2000.

A new technique for acute and chronic recording of crural diaphragm EMG in cats.

We have developed a percutaneous technique for placement of electromyogram electrodes in cat diaphragmatic crura. The technique is convenient and relatively atraumatic. Guided by external landmarks, small gauge hypodermic needles are used to advance electrodes through implant sites within or in contact with the crural portions of the diaphragm. Satisfactory EMG is reliably obtained from both acute and chronic preparations.

Respiratory inhibition induced by transient hypertension during sleep in unrestrained cats

The effects of transient blood pressure elevation, induced by intravenous injection of phenylephrine, were studied in drug-free, unrestrained cats during sleep and waking. Transient hypertension evoked an increase in respiratory cycle duration (Ttot), an effect which was most prominent during quiet sleep. Transient hypertension evoked no overall change in inspiratory duration (Tdi) during any sleep-waking state, although reduction of diaphragmatic EMG amplitude was observed. Thus, the ratio of diaphragmatic activity time to total respiratory cycle duration (Tdi/Ttot) was decreased following blood pressure elevation. Apneic episodes occasionally occurred, and these occurrences were more frequent during sleep states. Apneas induced during quiet sleep were often associated with transient or sustained arousal.

Transforming Clinical Imaging Data for Virtual Reality Learning Objects.

Advances in anatomical informatics, three‐dimensional (3D) modeling, and virtual reality (VR) methods have made computer‐based structural visualization a practical tool for education. In this article, the authors describe streamlined methods for producing VR “learning objects,” standardized interactive software modules for anatomical sciences education, from newer high‐resolution clinical imaging systems data. The key program is OsiriX, a free radiological image processing workstation software capable of directly reformatting and rendering volumetric 3D images. The transformed image arrays are then directly loaded into a commercial VR program to produce a variety of learning objects. Multiple types or “dimensions” of anatomical information can be embedded in these objects to provide different kinds of functions, including interactive atlases, examination questions, and complex, multistructure presentations. The use of clinical imaging data and workstation software speeds up the production of VR simulations, compared with reconstruction‐based modeling from segmented cadaver cross‐sections, while providing useful examples of normal structural variation and pathological anatomy. Anat Sci Ed 1:50–55, 2008.

From chalkboard, slides, and paper to e‐learning: How computing technologies have transformed anatomical sciences education

Until the late‐twentieth century, primary anatomical sciences education was relatively unenhanced by advanced technology and dependent on the mainstays of printed textbooks, chalkboard‐ and photographic projection‐based classroom lectures, and cadaver dissection laboratories. But over the past three decades, diffusion of innovations in computer technology transformed the practices of anatomical education and research, along with other aspects of work and daily life. Increasing adoption of first‐generation personal computers (PCs) in the 1980s paved the way for the first practical educational applications, and visionary anatomists foresaw the usefulness of computers for teaching. While early computers lacked high‐resolution graphics capabilities and interactive user interfaces, applications with video discs demonstrated the practicality of programming digital multimedia linking descriptive text with anatomical imaging. Desktop publishing established that computers could be used for producing enhanced lecture notes, and commercial presentation software made it possible to give lectures using anatomical and medical imaging, as well as animations. Concurrently, computer processing supported the deployment of medical imaging modalities, including computed tomography, magnetic resonance imaging, and ultrasound, that were subsequently integrated into anatomy instruction. Following its public birth in the mid‐1990s, the World Wide Web became the ubiquitous multimedia networking technology underlying the conduct of contemporary education and research. Digital video, structural simulations, and mobile devices have been more recently applied to education. Progressive implementation of computer‐based learning methods interacted with waves of ongoing curricular change, and such technologies have been deemed crucial for continuing medical education reforms, providing new challenges and opportunities for anatomical sciences educators. Anat Sci Educ 9: 583–602.

The virtual anatomy practical: A stereoscopic 3D interactive multimedia computer examination program

Continuing advances in computer visualization and interface technologies have enabled development of “virtual reality” programs that allow users to perceive and to interact with objects in artificial three‐dimensional environments. Such technologies were used to create an image database and program for administering a practical examination in human gross anatomy. Stereoscopic image pairs of prepared laboratory dissections were digitized from multiple views of the thorax, abdomen, pelvic region, and upper and lower extremities. For each view, the stereo pairs were interlaced into a single, field‐sequential stereoscopic picture using an image processing program. The resulting color‐corrected, interlaced image files were organized in a database stored on a large‐capacity hard disk. Selected views were provided with structural identification pointers and letters (A and B). For each view, appropriate two‐part examination questions were spoken by a human narrator, digitally recorded, and saved as universal audio format files on the archival hard disk. Images and digital narration were organized in an interactive multimedia program created with a high‐level multimedia authoring system. At run‐time, 24‐bit color 3D images were displayed on a large‐screen computer monitor and observed through liquid crystal shutter goggles. A 90‐second interval timer and tone were provided to give student users a time limit for each question comparable to that of a conventional practical examination. Users could control the program and select regional “subexams” using a mouse and cursor to point‐and‐click on screen‐level control words (“buttons”). Clin. Anat. 11:89–94, 1998.

Transforming clinical imaging and 3D data for virtual reality learning objects: HTML5 and mobile devices implementation

Web deployable anatomical simulations or “virtual reality learning objects” can easily be produced with QuickTime VR software, but their use for online and mobile learning is being limited by the declining support for web browser plug‐ins for personal computers and unavailability on popular mobile devices like Apple iPad and Android tablets. This article describes complementary methods for creating comparable, multiplatform VR learning objects in the new HTML5 standard format, circumventing platform‐specific limitations imposed by the QuickTime VR multimedia file format. Multiple types or “dimensions” of anatomical information can be embedded in such learning objects, supporting different kinds of online learning applications, including interactive atlases, examination questions, and complex, multi‐structure presentations. Such HTML5 VR learning objects are usable on new mobile devices that do not support QuickTime VR, as well as on personal computers. Furthermore, HTML5 VR learning objects can be embedded in “ebook” document files, supporting the development of new types of electronic textbooks on mobile devices that are increasingly popular and self‐adopted for mobile learning. Anat Sci Educ 6: 263–270.