How the Project Began
By Robert Acland
A helpful suggestion.
Many things led up to my decision to make the Video Atlas, but the immediate cause was a conversation that happened in the fall of 1993. I had just given a clinical correlation lecture to our medical students about the importance of anatomy to me in my career as a surgeon.
One student, Suzanne l'Ecuyer, said, "You can't imagine how helpful it would be if you could make videos as beautiful as the slides you just showed us." Overhearing her, one of our senior anatomists said "Bob, you've been talking about doing that for years, it's time you did it." Within two weeks I had committed myself to making a major series of anatomical videos for students.
At that time I was moving from my first career as a reconstructive microsurgeon to my second as a clinical anatomist. For many years before that I had run the University of Louisville Medical School's microsurgery teaching laboratory, where I had learned how to make effective instructional videos. My deepening interest in anatomy had led me to become director of our school's unique Fresh Tissue Dissection Laboratory, and it was in that setting that a chance event had shown me a way of presenting anatomy in three dimensions.
Lights, Camera, Action!
In the lab there was an overhead surgical light fixture that had been converted to hold a TV camera. The camera was on the end of a swinging arm that hung from the ceiling. The pivot it hung from was supposed to be vertical, but it was off by a degree, so the whole fixture had an urge to swing around till it reached its low point. Whenever we used it, someone had to hold the camera still. One day in 1984 we were making a shot of a specimen that was placed directly below the pivot. The person holding the camera let go by mistake, and it swung round in an arc while the shot was being recorded. To our amazement, we found we had made a video shot of an object that appeared to be rotating. It looked perfectly three dimensional.
It was clear that video of a rotating object could be used as a powerful teaching tool, but I put the idea on the back burner for nearly ten years. During that time the prospects for a high quality anatomy video project brightened. TV cameras became lighter and better, VCRs in the home became universal, and computer-driven anatomy projects, once considered the way of the future, began to fall short of their early promise. By 1993 I was ready to put the rotating video idea to good use.
Suzanne L'Ecuyer not only launched the Video Atlas project with her initial suggestion, she also became my main adviser as the project took shape. Many of the features of the Video Atlas that students now value were shaped by her keen perception.
Seeing and Learning in Three Dimensions
The hardest challenge for anyone studying anatomy is trying to understand a complex three-dimensional structure without having three-dimensional learning tools. Few people can form a mental image that's three dimensional by looking at pictures in books or static images on a monitor.
The best three-dimensional learning experience comes from dissecting the human body itself, but we don't all have access to that, and when we do it's not always at the best time in our learning careers. For those who must learn or re-learn human anatomy without access to cadaver dissection, there's a critical need for a learning aid that presents images of the real human body in three dimensions. The Video Atlas of Human Anatomy is designed to meet that need in a form that can be used by anyone with a mid-speed internet connection.
When we look at something we haven't seen before, our visual sense provides us with two different ways to perceive it in three dimensions. One way is to use our stereoscopic vision, the other is to make it rotate. With stereoscopic vision, we put together the two images from our right and left eye, with their slightly different viewpoints, to get information about shape and depth. With object rotation we put together many images from a sequence of viewpoints to get a far greater amount of useable information.
Stereoscopic vision is what we use for much of our everyday depth perception, and it's the basis for 3D visual aids we've all experienced. These include stereoscopes and Viewmaster® slides from long ago, and 3D movies in the present day. These visual aids all call for special equipment that's not useful for much else. They all suffer from the disadvantage that stereoscopic vision is not our most effective way of seeing things in three dimensions. Our most effective way is rotation of the object.
Object rotation is what we do without thinking every time we're curious to learn about a solid object we haven't seen before. If it's small, we turn it around. If it's big, we walk around it. By doing this, we give our seeing brain a succession of images that we put together to create a three-dimensional mental image. Once we gain that image, we know about the object in a way we never could by looking at two-dimensional pictures or by looking at it from a single viewpoint. What's more, once we have that 3D understanding of the object, any 2D image of it that we see later makes three-dimensional sense to us.
We take object rotation for granted as a constantly active part of our visual sense, but you may find it hard to envision its power as a way to transmit a three-dimensional image. For a demonstration, view one of the sample videos.
You don't need any special 3D glasses or make any visual adjustment to make it work. You don't even need to use both eyes: one is enough.
How the Atlas Was Made
The bodies used for the Video Atlas dissections were those of individuals who in life had bequeathed their bodies to the University of Louisville's Body Bequeathal Program. We appreciate the selfless spirit in which our donors acted, and we respect their desire for anonymity. No individual is depicted in the Atlas in a way that reveals his or her identity.
Specimen preservation and dissection.
We did not use traditional embalming on the bodies for the Video Atlas, as it discolors and stiffens the tissues producing an unnatural appearance. Instead we used either no embalming, or a mild preservation technique that leaves the color and texture of the tissues almost exactly as they are in the living body.
To keep the specimen in good condition, the dissection and Video recording were done in a laboratory refrigerated to 8°C (46°F). The dissections were done using fine surgical instruments, magnifying eyeglasses, and our best surgical and microsurgical skills. Sometimes two individuals worked on a dissection, sometimes only one. The initial stages of a large dissection might take 6-8 hours. The dissected specimen was placed on a table that had a rotating top, and was held in place by wires that connected it to an unseen support device. The images were made using a broadcast-quality, 3-chip analog video camera mounted on a rotating arm. The images were recorded on SP-beta analog tape. Cool fluorescent studio lighting was used to create the best definition and modeling. The shots were recorded against a background of black velvet. The same material was used to cover the table and support devices so that they are not seen.
The dissection was done in planned stages. The order in which shots appear in the edited video is often the reverse of the order in which they were made. We embarked on a dissection with a script in hand that told us not only what we were going to show, but the exact words, actions, and shot sequence we would use.
Production and narration.
We are often asked what computer program we used to create the rotation effects that give the Video Atlas images their striking three-dimensional quality. We didn't use any computer program. When you see rotation about a vertical axis, it was produced by rotating the table top by hand while the shot was being recorded. Rotation around a horizontal axis was produced by rotating the camera arm, again by hand.
For each shot, we read the words of the prepared script into an audio recorder. The words gave exact timing cues for all the actions that happened in the course of the shot. When we were ready to record the shot, we played back the audio recording while the video recorder was running and the actions were being performed. The words from the audio recorder were re-recorded onto the first of the videotape's two sound tracks, giving an accurately timed "scratch" audio track. Later, the words were re-spoken onto the second sound track to create the finished narrative.
The program was edited at the University of Louisville Medical School's IT Television Service using SP-Beta analog equipment. The Atlas was originally released as a series of VHS tapes, published individually between 1995 and 2003 as Acland's Video Atlas of Human Anatomy. Because of the limitations of the VHS format, these tapes showed a distinct loss of image quality compared to the SP-Beta masters.
By the time the series was completed, the DVD format was overtaking tape as the dominant video medium. The DVD version of the Atlas was released in 2003. It displayed the video images for the first time in their full original quality.
This high-quality streaming video website brings the Video Atlas to a new level of access, navigability, and ease of use. Instead of six volumes there are now five: the two that show the Head and Neck, which were Vol. 4 and 5, now form an extended Vol. 4. The previous Vol. 6, the Internal Organs and Reproductive System, is now Vol. 5.
Each minute of the finished product took twelve hours to produce: five in creating the script, five in making the shots, and two in post-production.
A combination of unique features make the Video Atlas different from all other anatomical teaching tools.
A truly three-dimensional look at anatomy.
As you watch, the fact that the specimen rotates lets you to see it as a fully three-dimensional object. View a sample video clip to experience the impact of this powerful imaging technique.
Fresh human specimens in their natural colors.
The Video Atlas images are direct video recordings of real human anatomic specimens. The cadavers used were not stiffened or discolored by embalming. Their tissues retain the color, texture, and mobility of the living body.
Besides showing the structure of the human body in its natural beauty, the Video Atlas shows moving structures - muscles, tendons and joints - making the same movements that they make in life.
The dissections were done by skilled clinical anatomists, using the finest surgical techniques. Studio lighting accentuates the shape and definition of the structures. A black background enhances their outline.
Clear narration and labeled structures.
A concise narration runs throughout the program, using the simplest possible language. The words you hear correspond exactly with what you see in the video. The names of structures, when seen for the first time, appear on screen as a learning reinforcement.
Building complex stuctures step-by-step.
In each part of the body, the Video Atlas starts with structures that give you the foundation for your understanding. The bones are shown first, then joints and their movements, then the muscles, and then the blood vessels and nerves. This is the reverse of the order that is seen in dissection, where the foundation is not understood until the end.
Throughout each program there are brief review sections that let you test yourself on what you have seen in the preceding 10-15 minutes.
The content can be searched by anatomical regions and parts, as well as by the A-Z index. Run times are listed for each part. You can start, stop, and pause at any time while viewing a video.
Volume 1: The Upper Extremity
Volume 1 has three sections: 1) the shoulder, 2) the arm and forearm, and 3) the hand. Each section shows first the bones and the movements they can make, then the joints and the ligaments that limit their movements, and then the muscles and the movements they produce. Once these major structures are understood, the blood vessels and nerves are added to the picture.
The section on the shoulder includes structures that are essential to the upper extremity, but that are often taught as parts of either the trunk or the neck. These include the muscles that move the scapula, the brachial plexus, and the subclavian blood vessels.
Volume 2: The Lower Extremity
Volume 2 has four sections: 1) the hip, 2) the knee, 3) the ankle, and 4) the foot. Each section shows first the bones and the movements they can make, then the joints and the ligaments that limit their movements, and then the muscles and the movements they produce. Once these major structures are understood, the blood vessels and nerves are added to the picture.
The section on the hip includes a full account of the bony pelvis. The first three sections are focused on a joint and the muscles that move it. Muscles that produce movements at two joints are shown in both sections. The effect of any muscle action is shown both when the extremity is bearing weight and when it is free to move.
Volume 3: The Trunk (Musculoskeletal System)
Volume 3 has four sections: 1) the spine, 2) the thorax, 3) the abdomen, and 4) the pelvis.
Section 1 shows the vertebral column, the paraspinous muscles, and the spinal cord. Section 2 shows the thorax as the structure that contains the heart and lungs, including the dynamic anatomy of respiratory movement. Sections 3 and 4 show the musculoskeletal anatomy of the abdomen and pelvis, as the upper and lower parts of the "container" for the abdominal and pelvic viscera. Sections 2, 3, and 4 also show the major blood vessels and nerves of their respective regions.
Note: The internal organs of the thorax, abdomen, and pelvis are shown in Volume 5.
Volume 4: The Head and Neck
Volume 4 has 11 sections: 1) support and movement of the head, 2) the skull and facial skeleton, 3) the nasal cavity and associated structures, 4) the oral cavity and associated structures, 5) the larynx and associated structures, 6) the facial muscles and the scalp, 7) the brain and its surroundings, 8) the nerves of the head and neck, 9) the blood vessels of the head and neck, 10) the eye and its surroundings, and 11) the ear.
Section 1 shows the cervical spine and the musculoskeletal structures that connect the head to the body. Section 2 gives a highly three-dimensional display of the challenging bony anatomy of the skull and facial skeleton. Sections 3, 4, and 5 focus on the major "visceral" parts of the head and neck that are associated with breathing, eating, and speaking.
Section 6 shows the muscles involved in facial movement. Section 7 covers the external features of the brain and its relation to the cranial cavity. Section 8 shows the intracranial and extracranial course of the twelve cranial nerves. Section 9 shows both the intracranial and extracranial arteries and veins, including the venous sinuses. Section 10 shows the structures of the orbital cavity, the eyelids, and the external features of the eye. Section 11 shows the external and middle ear, including the dynamic anatomy of the ear drum and auditory ossicles.
Volume 5: The Internal Organs and Reproductive System
Volume 5 has three sections: 1) the thoracic organs, 2 the abdominal organs, and 3) the reproductive system.
Section 1 includes a highly three-dimensional display of the heart, including internal views of the four chambers of the heart, and action shots of the valves in motion. Section 2 shows the stomach and intestines (with developmental animations explaining the rotation of the midgut), the liver and pancreas, and the kidneys and urinary system. Section 3 shows the internal and external features of the male and female reproductive organs.
Note: The musculoskeletal anatomy of the thorax, abdomen and pelvis is shown in Volume 3.
Dr. Robert Acland is a professor emeritus in the Department of Anatomical Sciences at the University of Louisville School of Medicine. He gained his expertise in instructional video during his first career, as a pioneer and teacher of microsurgical techniques. In his second career as a clinical anatomist, Dr. Acland directs his school's renowned Fresh Tissue Dissection Laboratory, where he teaches anatomy to students and surgeons, and pursues anatomical research. Working with fresh, unembalmed cadavers, Dr. Acland has pioneered new and highly effective techniques of anatomical videography that give the viewer a clear three-dimensional understanding of spatial relationships.