Applied science facilitates the large-scale expansion of protected areas in an Amazonian hot spot.

Meeting international commitments to protect 17% of terrestrial ecosystems worldwide will require >3 million square kilometers of new protected areas and strategies to create those areas in a way that respects local communities and land use. In 2000-2016, biological and social scientists worked to increase the protected proportion of Peru's largest department via 14 interdisciplinary inventories covering >9 million hectares of this megadiverse corner of the Amazon basin. In each landscape, the strategy was the same: convene diverse partners, identify biological and sociocultural assets, document residents' use of natural resources, and tailor the findings to the needs of decision-makers. Nine of the 14 landscapes have since been protected (5.7 million hectares of new protected areas), contributing to a quadrupling of conservation coverage in Loreto (from 6 to 23%). We outline the methods and enabling conditions most crucial for successfully applying similar campaigns elsewhere on Earth.

A Model Inversion Procedure for Control of Nonlinear Series Elastic Actuators.

This paper presents a model inversion procedure for a viscoelastic compliant element contained within a rotary series elastic actuator (SEA). Model inversion plays an important role in enabling accurate model-based control of physical human-robot interaction (HRI) with SEAs. If the compliant element of the SEA is elastomeric, analytically inverting its model is non-trivial due to the presence of complex non-linear terms. This paper applies an alternative inversion procedure, by coupling a partially analytical inverse model with a disturbance observer (DOB). Results of inverting without a DOB are given as a baseline and compared to the analytical inversion + DOB with two different types of filter. To quantify the accuracy of the inversion, the output of the inversion procedure is passed back through the forward model to identify the 'actual setpoint', the signal that would be generated if the output of the inversion procedure was tracked accurately. The inversions for five desired torque signals are presented; in all cases, the root-mean square (RMS) error between the desired setpoint and actual setpoint is lower when the DOB inversion procedure is used, compared to the RMS error incurred when the DOB is omitted. The results suggest that the proposed inversion procedure provides an accurate and mathematically tractable inverse of the complex viscoelastic elastomer model.

A framework for closing the loop between human experts and computational algorithms for the assessment of movement disorders.

Clinical assessment of abnormal neuromechanics is typically performed by manipulation of the affected limbs; a process with low inter- and intra-rater reliability. This paper aims at formalizing a framework that closes the loop between a clinician's expertise and computational algorithms, to enhance the clinician's diagnostic capabilities during physical manipulation. The framework's premise is that the dynamics that can be measured by manipulation of a limb are distinct between movement disorders. An a priori database contains measurements encoded in a space called the information map. Based on this map, a computational algorithm identifies which probing motions are more likely to yield distinguishing information about a patient's movement disorder. The clinician executes this movement and the resulting dynamics, combined with clinician input, is used by the algorithm to estimate which of the movement disorders in the database are most probable. This is recursively repeated until a diagnosis can be confidently made. The main contributions of this paper are the formalization of the framework and the addition of the information map to select informative movements. The establishment of the framework provides a foundation for a standardized assessment of movement disorders and future work will aim at testing the framework's efficacy.

Comparing Physical Human-Robot Interaction with Spring-and Elastomer-Based Series Elastic Actuators.

Physical human-robot interaction (pHRI) is an important consideration in the design of rehabilitation exoskeletons. Series Elastic Actuators (SEAs) are seen as a promising method of introducing compliance and comfort to robotic exoskeletons. Recently, authors have proposed the use of elastomers in SEAs, rather than springs, but there is a dearth of literature comparing how the two compliant elements are perceived by humans. In this paper, we quantitatively and qualitatively compare human interaction with an elastomer and a spring in terms of comfort and motion smoothness, with the aim of informing future SEA design. Two mechanisms were designed to compare human interaction with a spring and elastomer, and a cross-over experimental design was used to help eliminate any learning effects. Overall, the elastomer appeared to be slightly more comfortable and allow slightly smoother motion than the spring, holding promise for the use of elastomers as a means of improving pHRI in exoskeletons actuated by SEAs.

Virtual Normalization of Physical Impairment: A Pilot Study to Evaluate Motor Learning in Presence of Physical Impairment.

Motor learning is a critical component of the rehabilitation process; however, it can be difficult to separate the fundamental causes of a learning deficit when physical impairment is a confounding factor. In this paper, a new technique is proposed to augment the residual ability of physically impaired patients with a robotic rehabilitation exoskeleton, such that motor learning can be studied independently of physical impairment. The proposed technique augments the velocity of an on-screen cursor relative to the restricted physical motion. Radial Basis Functions (RBFs) are used to both model velocity and derive a function to scale velocity as a function of workspace position. Two variations of the algorithm are presented for comparison. In a cross-over pilot study, healthy participants were recruited and subjected to a simulated impairment to constrain their motion, imposed by the cable-driven wrist exoskeleton. Participants then completed a sinusoidal tracking task, in which the algorithms were statistically shown to augment the cursor velocity in the constrained state such that it matched position-dependent velocities recorded in the healthy state. A kinematic task was then designed as a motor-learning case study where the algorithms were statistically shown to allow participants to achieve the same performance when their motion was constrained as when unconstrained. The results of the pilot study provide motivation for further research into the use of this technique, thus providing a tool with which motor-learning can be studied in neurologically impaired populations. This could be used to give physiotherapists greater insight into underlying causes of motor learning deficits, consequently facilitating and enhancing subject-specific therapy regimes.

Detection of a novel mechanism of acousto-optic modulation of incoherent light.

A novel form of acoustic modulation of light from an incoherent source has been detected in water as well as in turbid media. We demonstrate that patterns of modulated light intensity appear to propagate as the optical shadow of the density variations caused by ultrasound within an illuminated ultrasonic focal zone. This pattern differs from previous reports of acousto-optical interactions that produce diffraction effects that rely on phase shifts and changes in light directions caused by the acoustic modulation. Moreover, previous studies of acousto-optic interactions have mainly reported the effects of sound on coherent light sources via photon tagging, and/or the production of diffraction phenomena from phase effects that give rise to discrete sidebands. We aimed to assess whether the effects of ultrasound modulation of the intensity of light from an incoherent light source could be detected directly, and how the acoustically modulated (AOM) light signal depended on experimental parameters. Our observations suggest that ultrasound at moderate intensities can induce sufficiently large density variations within a uniform medium to cause measurable modulation of the intensity of an incoherent light source by absorption. Light passing through a region of high intensity ultrasound then produces a pattern that is the projection of the density variations within the region of their interaction. The patterns exhibit distinct maxima and minima that are observed at locations much different from those predicted by Raman-Nath, Bragg, or other diffraction theory. The observed patterns scaled appropriately with the geometrical magnification and sound wavelength. We conclude that these observed patterns are simple projections of the ultrasound induced density changes which cause spatial and temporal variations of the optical absorption within the illuminated sound field. These effects potentially provide a novel method for visualizing sound fields and may assist the interpretation of other hybrid imaging methods.

The squeaking hip: a phenomenon of ceramic-on-ceramic total hip arthroplasty.

BACKGROUND: Early reports on modern ceramic-on-ceramic total hip replacements have demonstrated excellent clinical and radiographic results with few cases of catastrophic failure, which, in the case of earlier designs, often had been caused by implant fracture. Several reports, however, have noted the presence of audible squeaking. The purpose of the present study was to determine the incidence of squeaking in association with the use of this bearing couple. METHODS: During the period from March 2003 to May 2005, three surgeons performed 159 total hip arthroplasties in 143 patients with use of a ceramic-on-ceramic bearing. One hundred and forty-nine hips (131 patients) were available for review after at least one year of follow-up. These patients were followed prospectively with use of the modified Hospital for Special Surgery hip score and a patient-administered questionnaire. Additionally, a control group of sixty hips (forty-eight patients) with a metal-on-polyethylene bearing was matched to the ceramic group on the basis of age, sex, and body mass index to compare the incidence of squeaking and other noises. Radiographic evaluations were performed according to previously established criteria. RESULTS: Fourteen (10.7%) of 131 patients described an audible squeak during normal activities. However, squeaking was reproducible clinically in only four patients, and only one patient complained of squeaking before being presented with the questionnaire. The average Hospital for Special Surgery score improved from 19.8 preoperatively to 38.4 at the time of the latest follow-up, indicating excellent clinical results. Ninety-five percent of the patients had a satisfaction score of > or =8 of 10. Three hips dislocated. One of those three hips squeaked and was revised because of recurrent dislocations. One patient was considering revision because of squeaking. In the matched metal-on-polyethylene cohort, there were no cases of squeaking. CONCLUSIONS: The squeaking hip is a phenomenon that is unique to total hip replacements with hard-on-hard bearings. The incidence of squeaking in association with ceramic-on-ceramic bearings may be higher than previously reported as <1% of the patients in the present study reported this finding before being queried. The causes and implications of squeaking are yet to be determined. The use of hard-on-hard bearings offers many advantages in terms of wear reduction, especially for young and active patients. Nonetheless, patients considering ceramic-on-ceramic bearings should be counseled with regard to this phenomenon.

Management of distal humerus fractures with minifragment fixation.

Minifragment implants provide several advantages for the stabilization of distal humerus fractures. Compared with small fragment implants, minifragment implants may provide enhanced fracture fixation because a greater number of screws can be placed into the distal fragments. In addition, minifragment plates are easier to contour and less prominent. We describe the surgical technique of minifragment fixation.

A salvage procedure for refractory shoulder instability.

We present the case of a patient with symptomatic refractory multidirectional shoulder instability who was treated with staged bilateral anterior and posterior glenoid bone augmentation after previous failed arthroscopic and open procedures. The patient was pain free postoperatively and has not had symptoms of instability in either shoulder. At her most recent followup, 24 months after surgery, she had nearly full symmetric shoulder range of motion without anterior or posterior apprehension signs. Her Constant-Murley scores were 77 and 79 on the right and left, respectively, with UCLA scores of 29 on the right and the left shoulders. Her Short Form-36 overall score was 105, indicating overall satisfaction. Currently, the patient states that she can do all daily activities without restrictions. In carefully selected patients, the use of anterior and posterior glenoid bone augmentation may be effective as a salvage procedure in rare cases of refractory multidirectional shoulder instability.

Metacarpal fractures in athletes: treatment, rehabilitation, and safe early return to play.

Specialty gloves and buddy taping of adjacent fingers may cushion impact and dissipate twisting forces so that hands, thumbs, and fingers are protected during play. When fractures occur, athletes must be protected from contact until healing has progressed to a point where reinjury or complications are unlikely and performance standards and expectations can be met. This article outlines a program of fracture management principles and progressive graduated rehabilitation that phase the hand-injured athlete first into general conditioning and non-ball-handling drills, then into return to hand impact activities, body contact, ball handling, and catching with the use of protective hand gear. At this point, specialized playing orthoses, gloves, or taping may be added to the treatment regimen. Batting, the use of golf clubs, and racquet handling occur later, and finally throwing with precision, distance, velocity, and frequency is initiated. The importance of the particular sport, the position played, and hand dominance are factored into the decision-making processes. Safety of the patient and opponents is paramount. Extra-articular metacarpal fractures are discussed as a prototype for treatment, rehabilitation, and early safe return to play because of their frequent occurrence in athletes.

Complicated femoral shaft fractures.

The treatment of femoral shaft fractures has become safe and reproducible since the advent of popularization of intramedullary nailing, however, many femoral shaft fractures are complicated by associated fractures, extensive comminution, extensive contamination, and arterial injury compartmental syndrome. Other conditions associated with the use of femoral nailing include femora nonunions, broken hardware, acute fractures with prior implants, and infections. The management of these complex femoral shaft fractures demands special techniques for successful outcome.