The teaching of anatomy has consistently been the subject of societal controversy, especially in the context of employing cadaveric materials in professional medical and allied health professional training. The reduction in dissection-based teaching in medical and allied health professional training programs has been in part due to the financial considerations involved in maintaining bequest programs, accessing human cadavers and concerns with health and safety considerations for students and staff exposed to formalin-containing embalming fluids. This report details how additive manufacturing or three-dimensional (3D) printing allows the creation of reproductions of prosected human cadaver and other anatomical specimens that obviates many of the above issues. These 3D prints are high resolution, accurate color reproductions of prosections based on data acquired by surface scanning or CT imaging. The application of 3D printing to produce models of negative spaces, contrast CT radiographic data using segmentation software is illustrated. The accuracy of printed specimens is compared with original specimens. This alternative approach to producing anatomically accurate reproductions offers many advantages over plastination as it allows rapid production of multiple copies of any dissected specimen, at any size scale and should be suitable for any teaching facility in any country, thereby avoiding some of the cultural and ethical issues associated with cadaver specimens either in an embalmed or plastinated form. Anat Sci Educ 7: 479–486. © 2014 American Association of Anatomists.

The production of anatomical teaching resources using three-dimensional (3D) printing technology

While use of advanced visualization in radiology is instrumental in diagnosis and communication with referring clinicians, there is an unmet need to render Digital Imaging and Communications in Medicine (DICOM) images as three-dimensional (3D) printed models capable of providing both tactile feedback and tangible depth information about anatomic and pathologic states. Three-dimensional printed models, already entrenched in the nonmedical sciences, are rapidly being embraced in medicine as well as in the lay community. Incorporating 3D printing from images generated and interpreted by radiologists presents particular challenges, including training, materials and equipment, and guidelines. The overall costs of a 3D printing laboratory must be balanced by the clinical benefits. It is expected that the number of 3D-printed models generated from DICOM images for planning interventions and fabricating implants will grow exponentially. Radiologists should at a minimum be familiar with 3D printing as it relates to their field, including types of 3D printing technologies and materials used to create 3D-printed anatomic models, published applications of models to date, and clinical benefits in radiology. Online supplemental material is available for this article.

Medical 3D Printing for the Radiologist

Three-dimensional (3D) printing enables the production of anatomically matched and patient-specific devices and constructs with high tunability and complexity. It also allows on-demand fabrication with high productivity in a cost-effective manner. As a result, 3D printing has become a leading manufacturing technique in healthcare and medicine for a wide range of applications including dentistry, tissue engineering and regenerative medicine, engineered tissue models, medical devices, anatomical models and drug formulation. Today, 3D printing is widely adopted by the healthcare industry and academia. It provides commercially available medical products and a platform for emerging research areas including tissue and organ printing. In this review, our goal is to discuss the current and emerging applications of 3D printing in medicine. A brief summary on additive manufacturing technologies and available printable materials is also given. The technological and regulatory barriers that are slowing down the full implementation of 3D printing in the medical field are also discussed.

https://iopscience.iop.org/article/10.1088/1758-5090/aa7279/pdf

Current and emerging applications of 3D printing in medicine.

This paper discusses design and control of a prismatic series elastic actuator with high mechanical power output in a small and lightweight form factor. A design is introduced that pushes the performance boundary of electric series elastic actuators by using high motor voltage coupled with an efficient drivetrain to enable large continuous actuator force while retaining speed. Compact size is achieved through the use of a novel piston-style ball screw support mechanism and a concentric compliant element. Generic models for two common series elastic actuator configurations are introduced and compared. These models are then used to develop controllers for force and position tracking based on combinations of PID, model-based, and disturbance observer control structures. Finally, our actuator's performance is demonstrated through a series of experiments designed to operate the actuator at the limits of its mechanical and control capability.

/pdf/design-and-control-considerations-for-high-performance-55ade88o5z.pdf

Design and Control Considerations for High-Performance Series Elastic Actuators

Although the cheetah is recognised as the fastest land animal, little is known about other aspects of its notable athleticism, particularly when hunting in the wild. Here we describe and use a new tracking collar of our own design, containing a combination of Global Positioning System (GPS) and inertial measurement units, to capture the locomotor dynamics and outcome of 367 predominantly hunting runs of five wild cheetahs in Botswana. A remarkable top speed of 25.9 m s−1 (58 m.p.h. or 93 km h−1) was recorded, but most cheetah hunts involved only moderate speeds. We recorded some of the highest measured values for lateral and forward acceleration, deceleration and body-mass-specific power for any terrestrial mammal. To our knowledge, this is the first detailed locomotor information on the hunting dynamics of a large cursorial predator in its natural habitat. A novel tracking collar provides highly precise location, speed and acceleration data from 367 runs by five cheetahs in the wild; although a top speed of 58 m.p.h. was reported, few runs were above 45 m.p.h. with the average run around 31 m.p.h., and hunting success depended on grip, manoeuvrability and muscle power rather than outright speed. The cheetah is widely recognized as the fastest animal on land, with a reported top speed of 29 metres per second. However, few precise measurements have been made and only rarely have speeds faster than racing greyhounds (18 m s−1) been recorded. Now a team from the Royal Veterinary College, UK, working with the Botswana Predator Conservation Trust, has used custom-built tracking collars containing GPS and inertial measurement units to capture the locomotor dynamics of cheetahs hunting in the wild. The top speed observed was 25.9 m s−1 (93 kilometres per hour). Most hunts involved only moderate speeds, their success relying on a combination of power, acceleration and agility.

Locomotion dynamics of hunting in wild cheetahs

Here, we present a simple stiff-limbed passive model of quadrupedal walking, compare mechanics predicted from the model with those observed from forceplate measurements of walking dogs and consider the implications of deviation from model predictions, especially with reference to collision mechanics. The model is based on the geometry of a 4-bar linkage consisting of a stiff hindleg, back, foreleg and the ground between the hind and front feet. It uses empirical morphological and kinematic inputs to determine the fluctuations in potential and kinetic energy, vertical and horizontal forces and energy losses associated with inelastic collisions at each foot placement. Using forceplate measurements to calculate centre of mass motions of walking dogs, we find that (1) dogs may, but are not required to, spend periods of double support (one hind- and one forefoot) agreeing with the passive model; (2) legs are somewhat compliant, and mechanical energy fluctuates during triple support, with mechanical energy being lost directly after hindfoot placement and replaced following forefoot placement. Footfall timings and timing of mechanical energy fluctuations are consistent with strategies to reduce collisional forces, analogous to the suggested role of ankle extension as an efficient powering mechanism in human walking.

/pdf/mechanics-of-dog-walking-compared-with-a-passive-stiff-4xmr0iuhqn.pdf

Mechanics of dog walking compared with a passive, stiff-limbed, 4-bar linkage model, and their collisional implications

Areas of difficulty faced by our veterinary medicine students, with respect to their learning in dissection classes, were identified. These challenges were both general adult-learning related and specific to the discipline of anatomy. Our aim was to design, implement, and evaluate a modified reciprocal peer-assisted/team-based learning format--Doing Dissections Differently (DDD)--to complement existing dissection classes, with the intention of enhancing both student learning and the student learning experience. Second year veterinary medicine students (n = 193), in their usual dissection groups, were randomly assigned to one of four roles: anatomist, clinician, radiologist, and learning resources manager. Students attended a preparatory workshop outlining the skills required for effective execution of their role. They were then asked to perform their roles throughout five consecutive musculoskeletal dissection classes. Student attitudes to dissection classes before and after DDD were evaluated by questionnaire (146 respondents). There was a significant (P = 0.0001) improvement after DDD in a number of areas: increased perceived value of dissection classes as an anatomy learning aid; improved appreciation of the clinical relevance of anatomy; increased use of resources before and during dissection classes; and longer preparation time for dissection classes. Before DDD, 45% of students felt that at least one peer did not contribute usefully to the group during dissection classes; no improvement was seen in this measure after DDD. Although the new format highlighted a potential need to improve teamwork, most students actively engaged with DDD, with dissection classes valued more highly and utilized more effectively.

Doing dissections differently: A structured, peer-assisted learning approach to maximizing learning in dissections

To establish the current status of canine hydrotherapy in the UK and to ascertain information regarding the current use of hydrotherapy, a questionnaire was sent to 152 hydrotherapy centres throughout the UK, from which 89 responded. Hydrotherapy was found to be a rapidly growing business. Stand-alone centres were in existence; however, many centres were connected to other businesses, including boarding kennels and general practice veterinary surgeries. The dogs using the facility were mainly pedigree breeds, particularly labrador retrievers (30 per cent), and the most commonly encountered conditions were rupture of the cranial cruciate ligament (25 per cent), hip dysplasia (24 per cent) and osteoarthritis (18 per cent). The proportion of qualified versus unqualified staff varied between centres, highlighting a need for improved regulation of this aspect of the industry. However, all the dogs treated by the hydrotherapy centres surveyed were direct veterinary referrals, suggesting a good degree of professionalism in the field and a high regard for the benefits of hydrotherapy.

Evaluation of the status of canine hydrotherapy in the UK

This study aimed to assess the effect of lateral heel studs on foot–ground interaction in the horse by quantifying foot slip during stance whilst cantering on a grass surface. It was hypothesised that using studs would decrease foot slip distance on the ground conditions tested. Nine horses were ridden with and without a stud placed laterally in the shoe of each of the 4 feet. High speed video-analysis was used to track hoof markers and to provide data quantifying foot slip distance, slip duration and stance duration. Using studs resulted in a significant decrease in foot slip distance in all four limbs (all P values  The results supported the hypothesis that using studs will decrease foot slip distance in horses cantering on a grass surface, and additionally, highlights that stud efficacy may vary between limbs. The decrease in slip distance with studs demonstrated increased traction and a more stable foot–ground interaction, although this may cause a concomitant increase in the required energy dissipation, either within the limb or via surface deformation. The effect of repetitive usage of studs in the aetiology of musculoskeletal conditions should therefore be investigated further.

The effect of lateral heel studs on the kinematics of the equine digit while cantering on grass.

Recognition of anatomical landmarks in live animals (and humans) is key for clinical practice, but students often find it difficult to translate knowledge from dissection-based anatomy onto the live animal and struggle to acquire this vital skill. The purpose of this study was to create and evaluate the use of an equine anatomy rug ("Anato-Rug") depicting topographical anatomy and key areas of lung, heart, and gastrointestinal auscultation, which could be used together with a live horse to aid learning of "live animal" anatomy. Over the course of 2 weeks, 38 third year veterinary students were randomly allocated into an experimental group, revising topographical anatomy from the "Anato-Rug," or a control group, learning topographical anatomy from a textbook. Immediately post activity, both groups underwent a test on live anatomy knowledge and were retested 1 week later. Both groups then completed a questionnaire to ascertain their perceptions of their learning experiences. Results showed that the experimental groups scored significantly higher than the control group at the first testing session, experienced more enjoyment during the activity and gained more confidence in identifying anatomical landmarks than the control group. There was not a significant difference in scores between groups at the second testing session. The findings indicate that the anatomy rug is an effective learning tool that aids understanding, confidence, and enjoyment in learning equine thorax and abdominal anatomy; however it was not better than traditional methods with regards to longer term memory recall.

Sarah B. Williams

Papers

Mechanics of dog walking compared with a passive, stiff-limbed, 4-bar linkage model, and their collisional implications

Doing dissections differently: A structured, peer-assisted learning approach to maximizing learning in dissections

Evaluation of the status of canine hydrotherapy in the UK

The effect of lateral heel studs on the kinematics of the equine digit while cantering on grass.

Design and validation of a novel learning tool, the "Anato-Rug," for teaching equine topographical anatomy.