Posts Tagged Hand

[BLOG POST] SaeboFlex Helps Client Regain Hand Function 23 Years After Stroke

SaeboFlexStroke survivor exhibits remarkable improvement in hand function more than two decades after stroke, disproving theories that recovery window is limited to 6 months. 

Charlotte, N.C. – Tuesday, July 25, 2017 – Until recently, researchers believed that if a stroke survivor exhibited no improvement within the first 6 months, then he or she would have little to no chance of regaining motor function in the future. This assumed end of recovery is called a plateau. However, a groundbreaking new article published in the Journal of Neurophysiology discusses a stroke patient’s remarkable improvement decades after suffering a stroke at the age of 15. Doctors Peter Sörös, Robert Teasell, Daniel F. Hanley, and J. David Spence formally dismiss previous theories that stroke recovery occurs within 6 months, reporting that the patient experienced “recovery of hand function that began 23 years after the stroke.”

The patient’s stroke resulted in paralysis on the left side of his body, rendering his left hand completely nonfunctional, despite regular physical therapy. More than twenty years after his stroke, the patient took up swimming when his doctor recommended he lose weight. A year later, he began to show signs of movement on his affected side and returned to physical therapy. Therapists fitted the patient with the SaeboFlex, a mechanical device shown to improve hand function and speed up recoveryand, after only a few months of therapy, he began picking up coins with his previously nonfunctional hand. He also saw notable improvement in hand strength and control with the SaeboGlove, a low-profile hand device recently patented by Saebo.

Functional MRI studies showed the reorganization of sensorimotor neurons in both sides of the patient’s brain more than two decades after his stroke, resulting in a noticeable recovery in both hemispheres and improved motor function. “The marked delayed recovery in our patient and the widespread recruitment of bilateral areas of the brain indicate the potential for much greater stroke recovery than is generally assumed,” the doctors reported. “Physiotherapy and new modalities in development might be indicated long after a stroke.”

“This article highlights what we have seen for the last 15 years with many of our clients,” states Saebo co-founder, Henry Hoffman. “Oftentimes, stroke survivors are told that they have plateaued and no further progress is possible. We believe it is not the client that has plateaued but failed treatment options have plateaued them. In other words, traditional therapy interventions that lack scientific evidence can be ineffective and can actually facilitate the plateau.”

“The SaeboFlex device is a life-changing treatment designed for clients that lack motor recovery and function,” Hoffman continues. “Whether the client recently suffered a stroke or decades later, they can immediately begin using their hand with this device and potentially make significant progress over time. I agree with the authors that the neurorehabilitation community needs to take a hard look at traditional beliefs with respect to the window of recovery following stroke. It is my hope that this article will spark more interest by researchers to investigate upper limb function with clients at the chronic stage using Saebo’s hand technology.”

The abstract and article in its entirety can be viewed at the Journal of Neurophysiology’s website, jn.physiology.org.

If you are suffering from limited hand function or have been told you have plateaued, then schedule a call with a Saebo Specialist or click here to get started on the road to recovery.

via SaeboFlex Helps Client Regain Hand Function 23 Years After Stroke | Saebo

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[Abstract] Combined Brain and Peripheral Nerve Stimulation in Chronic Stroke Patients With Moderate to Severe Motor Impairment

First published: 

Abstract

Objectives

To evaluate effects of somatosensory stimulation in the form of repetitive peripheral nerve sensory stimulation (RPSS) in combination with transcranial direct current stimulation (tDCS), tDCS alone, RPSS alone, or sham RPSS + tDCS as add-on interventions to training of wrist extension with functional electrical stimulation (FES), in chronic stroke patients with moderate to severe upper limb impairments in a crossover design. We hypothesized that the combination of RPSS and tDCS would enhance the effects of FES on active range of movement (ROM) of the paretic wrist to a greater extent than RPSS alone, tDCS alone or sham RPSS + tDCS.

Materials and Methods

The primary outcome was the active ROM of extension of the paretic wrist. Secondary outcomes were ROM of wrist flexion, grasp, and pinch strength of the paretic and nonparetic upper limbs, and ROM of wrist extension of the nonparetic wrist. Outcomes were blindly evaluated before and after each intervention. Analysis of variance with repeated measures with factors “session” and “time” was performed.

Results

After screening 2499 subjects, 22 were included. Data from 20 subjects were analyzed. There were significant effects of “time” for grasp force of the paretic limb and for ROM of wrist extension of the nonparetic limb, but no effects of “session” or interaction “session x time.” There were no significant effects of “session,” “time,” or interaction “session x time” regarding other outcomes.

Conclusions

Single sessions of PSS + tDCS, tDCS alone, or RPSS alone did not improve training effects in chronic stroke patients with moderate to severe impairment.

Source: Combined Brain and Peripheral Nerve Stimulation in Chronic Stroke Patients With Moderate to Severe Motor Impairment – Menezes – 2017 – Neuromodulation: Technology at the Neural Interface – Wiley Online Library

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[ARTICLE] On neuromechanical approaches for the study of biological and robotic grasp and manipulation – Full Text

Abstract

Biological and robotic grasp and manipulation are undeniably similar at the level of mechanical task performance. However, their underlying fundamental biological vs. engineering mechanisms are, by definition, dramatically different and can even be antithetical. Even our approach to each is diametrically opposite: inductive science for the study of biological systems vs. engineering synthesis for the design and construction of robotic systems. The past 20 years have seen several conceptual advances in both fields and the quest to unify them. Chief among them is the reluctant recognition that their underlying fundamental mechanisms may actually share limited common ground, while exhibiting many fundamental differences. This recognition is particularly liberating because it allows us to resolve and move beyond multiple paradoxes and contradictions that arose from the initial reasonable assumption of a large common ground. Here, we begin by introducing the perspective of neuromechanics, which emphasizes that real-world behavior emerges from the intimate interactions among the physical structure of the system, the mechanical requirements of a task, the feasible neural control actions to produce it, and the ability of the neuromuscular system to adapt through interactions with the environment. This allows us to articulate a succinct overview of a few salient conceptual paradoxes and contradictions regarding under-determined vs. over-determined mechanics, under- vs. over-actuated control, prescribed vs. emergent function, learning vs. implementation vs. adaptation, prescriptive vs. descriptive synergies, and optimal vs. habitual performance. We conclude by presenting open questions and suggesting directions for future research. We hope this frank and open-minded assessment of the state-of-the-art will encourage and guide these communities to continue to interact and make progress in these important areas at the interface of neuromechanics, neuroscience, rehabilitation and robotics.

Introduction

Grasp and manipulation have captivated the imagination and interest of thinkers of all stripes over the millennia; and with enough reverence to even attribute the intellectual evolution of humans to the capabilities of the hand [123]. Simply put, manipulation function is one of the key elements of our identity as a species (for an overview, see [4]). This is a natural response to the fact that much of our physical and cognitive ability and well-being is intimately tied to the use of our hands. Importantly, we have shaped our tools and environment to match its capabilities (straightforward examples include lever handles, frets in string instruments, and touch-screens). This co-evolution between hand-and-world reinforces the notion that our hands are truly amazing and robust manipulators, as well as rich sensory, perceptual and even social information.

It then comes as no surprise that engineers and physicians have long sought to replicate and restore this functionality in machines—both as appendages to robots and prostheses attached to humans with missing upper limbs [5]. Robotic hands and prostheses have a long and illustrious history, with records of sophisticated articulated hands as early as Gottfried ‘Götz’ von Berlichingen’s iron hand in 1504 [6]. Other efforts [7891011] were often fueled by the injuries of war [12131415] and the Industrial Revolution [16]. The higher survival rate in soldiers who lose upper limbs [1718] and the continual emergence of artificial intelligence [1920] are but the latest impetus. Thus, the past 20 years have seen an explosion in designs, fueled by large scale governmental funding (e.g., DARPA’s Revolutionizing Prosthetics and HAPTIX projects, EU’s INPUT and SOFTPRO projects) and private efforts such as DeepMind. A new player in this space is the potentially revolutionary social network of high-quality amateur scientists as exemplified by the FABLAB movement [21]. They are enabled by ubiquitously accessible and inexpensive 3D printing and additive manufacturing tools [22], collaborative design databases (http://www.eng.yale.edu/grablab/openhand/ and others), and communities with formal journals (http://www.liebertpub.com/overview/3d-printing-and-additive-manufacturing/621/ and http://www.journals.elsevier.com/additive-manufacturing/). Grassroots communities have also emerged that can, for example, compare and contrast the functionality of prosthetic hands whose price differs by three orders of magnitude (http://www.3dprint.com/2438/50-prosthetic-3d-printed-hand).

For all the progress that we have seen, however, (i) robotic platforms remain best at pre-sorted, pick-and-place assembly tasks [23]; and (ii) many prosthetic users still prefer simple designs like the revered whole- or split-hook designs originally developed centuries ago [2425].

Why have robotic and prosthetic hands not come of age? This short review provides a current attempt to tackle this long-standing question in response to the current technological boom in robotic and prosthetic limbs. Similar booms occurred in response to upper limb injuries [25] after the Napoleonic [26], First [12] and Second World Wars [8], and—with the advent of powerful inexpensive computers—in response to industrial and space exploration needs in the 1960’s, 1970’s and 1980’s [272829303132]. We argue that a truly bio-inspired approach suffers, by definition, from both gaps in our understanding of the biology, and technical challenges in mimicking (what we understand of) biological sensors, motors and controllers. Although biomimicry is often not the ultimate goal in robotics in general, it is relevant for humanoids and prostheses. Thus, our approach is to clarify when and why a better understanding of the biology of grasp and manipulation would benefit robotic grasping and manipulation.

Similarly, why is our understanding of the nature, function and rehabilitation of biological arms and hands incomplete? Jacob Benignus Winsløw Jacques-Bénigne Winslow, (1669—1760) noted in his Exposition anatomique de la structure du corps humain (1732) that ‘The coordination of the muscles of the live hand will never be understood’ [33]. Interestingly, he is still mostly correct. As commented in detail before [4], there has been much work devoted to inferring the anatomical, physiological, neural and cognitive processes that produce the upper limb function we so dearly appreciate and passionately work to restore following trauma or pathology. We argue, as Galileo Galilei did, that mathematics and engineering have much to contribute to the understanding of biological systems. Without such a ‘mathematical language’ we run the risk, as Galileo put it, of ‘wandering in vain through a dark labyrinth’ [34]. Thus, this short review also attempts to point out important mathematical and engineering developments and advances that have helped our understanding of our hands.

This review first contrasts the fundamental differences between engineering and neuroscience approaches to biological robotic systems. Whereas the former applies engineering principles, the latter relies on scientific inference. We then discuss how the physics of the world provides a common ground between them because both types of systems have similar functional goals, and must abide by the same physical laws. We go on to evaluate how biological and robotic systems implement the necessary sensory and motor functions using the dramatically different anatomy, morphology and mechanisms available to each. This inevitably raises questions about differences in their sensorimotor control strategies. Whereas engineering system can be designed and manufactured to optimize well-defined functional features, biological systems evolve without such strict tautology. Biological systems likely evolve by implementing ecologically and temporally good-enough, sub-optimal or habitual control strategies in response to the current multi-dimensional functional constraints and goals in the presence of competition, variability, uncertainty, and noise. We conclude by exploring the notion that the functional versatility of biological systems that roboticists admire is, in fact, enabled by the very nonlinearities and complexities in anatomy, sensorimotor physiology, and neural function that engineering approaches often seek to avoid. […]

Continue —> On neuromechanical approaches for the study of biological and robotic grasp and manipulation | Journal of NeuroEngineering and Rehabilitation | Full Text

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[Abstract] The Combined Effects of Adaptive Control and Virtual Reality on Robot-Assisted Fine Hand Motion Rehabilitation in Chronic Stroke Patients: A Case Study

Robot-assisted therapy is regarded as an effective and reliable method for the delivery of highly repetitive training that is needed to trigger neuroplasticity following a stroke. However, the lack of fully adaptive assist-as-needed control of the robotic devices and an inadequate immersive virtual environment that can promote active participation during training are obstacles hindering the achievement of better training results with fewer training sessions required. This study thus focuses on these research gaps by combining these 2 key components into a rehabilitation system, with special attention on the rehabilitation of fine hand motion skills. The effectiveness of the proposed system is tested by conducting clinical trials on a chronic stroke patient and verified through clinical evaluation methods by measuring the key kinematic features such as active range of motion (ROM), finger strength, and velocity. By comparing the pretraining and post-training results, the study demonstrates that the proposed method can further enhance the effectiveness of fine hand motion rehabilitation training by improving finger ROM, strength, and coordination.

Source: The Combined Effects of Adaptive Control and Virtual Reality on Robot-Assisted Fine Hand Motion Rehabilitation in Chronic Stroke Patients: A Case Study

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[ARTICLE] Reorganization of finger coordination patterns through motor exploration in individuals after stroke – Full Text

 

Abstract

Background

Impairment of hand and finger function after stroke is common and affects the ability to perform activities of daily living. Even though many of these coordination deficits such as finger individuation have been well characterized, it is critical to understand how stroke survivors learn to explore and reorganize their finger coordination patterns for optimizing rehabilitation. In this study, I examine the use of a body-machine interface to assess how participants explore their movement repertoire, and how this changes with continued practice.

Methods

Ten participants with chronic stroke wore a data glove and the finger joint angles were mapped on to the position of a cursor on a screen. The task of the participants was to move the cursor back and forth between two specified targets on a screen. Critically, the map between the finger movements and cursor motion was altered so that participants sometimes had to generate coordination patterns that required finger individuation. There were two phases to the experiment – an initial assessment phase on day 1, followed by a learning phase (days 2–5) where participants trained to reorganize their coordination patterns.

Results

Participants showed difficulty in performing tasks which had maps that required finger individuation, and the degree to which they explored their movement repertoire was directly related to clinical tests of hand function. However, over four sessions of practice, participants were able to learn to reorganize their finger movement coordination pattern and improve their performance. Moreover, training also resulted in improvements in movement repertoire outside of the context of the specific task during free exploration.

Conclusions

Stroke survivors show deficits in movement repertoire in their paretic hand, but facilitating movement exploration during training can increase the movement repertoire. This suggests that exploration may be an important element of rehabilitation to regain optimal function.

Background

Stroke often results in impairments of upper extremity, including hand and finger function, with 75% of stroke survivors facing difficulties performing activities of daily living [12]. Critically, impairments after stroke not only include muscle- and joint-specific deficits such as weakness, and changes in the kinetic and kinematic workspace of the fingers [34], but also coordination deficits such as reduced independent joint control [5] and impairments in finger individuation and enslaving [6789]. Therefore, understanding how to address these coordination deficits is critical for improving hand rehabilitation.

Typical approaches to hand rehabilitation emphasize repetition [10] and functional practice based on evidence that such experience can cause reorganization in the brain [11]. Although this has proven to be reasonably successful, functional practice (such as repetitive grasping of objects) does not specify the coordination pattern to be used when performing the tasks. As a result, because of the redundancy in the human body, there is a risk that stroke survivors may adopt atypical compensatory movements to perform tasks [12]. These compensatory movements have been mainly identified during reaching [1314], but there is evidence that they are also present in finger coordination patterns during grasping [15]. Although there is still debate over the role of compensatory movements in rehabilitation [16], there is at least some evidence both in animal and humans that continued use of these compensatory patterns may be detrimental to true recovery [171819].

To address this issue, there has been a greater focus on directly facilitating the learning of new coordination patterns. Specifically, in hand rehabilitation, virtual tasks (such as playing a virtual piano) have been examined as a way to train finger individuation [2021]. In these protocols, individuation is encouraged by asking participants to press a particular key with a finger, while keeping other fingers stationary. A similar approach to improve hand dexterity was also adopted by developing a glove that could be used as a controller for a popular guitar-playing video game [22]. However, directly instructing desired coordination patterns to be produced becomes challenging as the number of degrees of freedom involved in the coordination pattern increase. For example, the hand has approximately 20 kinematic degrees of freedom, and providing verbal, visual or auditory feedback for simultaneously controlling all these degrees of freedom would be a major challenge. A potential solution that has been suggested is not to directly instruct the coordination pattern itself, but rather let participants explore different coordination patterns [23]. This idea of motor exploration is based on dynamical systems theory that suggests that variability and exploration may help participants escape sub-optimal pre-existing coordination patterns and potentially settle in more optimal coordination patterns [24252627]. Such exploration has been shown to be important in adapting existing movement repertoire [28], and has also been shown to be associated with faster rates of learning [29].

In order to test the hypothesis that exploration of novel coordination patterns can improve overall movement repertoire, I used a body-machine interface [3031] to examine how stroke survivors explore and reorganize finger coordination patterns with practice. A body-machine interface maps body movements (in this case finger movements) to the control of a real or virtual object (in this case a screen cursor), which can provide a way to elicit different coordination patterns in the context of an intuitive task. Specifically I examined: (i) how stroke survivors reorganize their finger coordination patterns, (ii) how training to explore novel coordination patterns affects their ability to reorganize their coordination pattern, and (iii) if training to explore novel coordination patterns has an effect on their overall movement repertoire. In this context, I use the term “novel” to indicate coordination patterns that require finger individuation. This assumption is motivated by the finding that stroke survivors have difficulty producing finger individuation even under explicit instruction [69], and therefore it is highly likely that they would not use coordination patterns requiring finger individuation frequently in activities of daily living.[…]

Continue —>  Reorganization of finger coordination patterns through motor exploration in individuals after stroke | Journal of NeuroEngineering and Rehabilitation | Full Text

Fig. 1 a Experimental setup – participants wore a data glove and moved their fingers to control a screen cursor b Schematic of task – participants moved a cursor between two targets using movements of four fingers (thumb excluded). c Experimental protocol. Participants came in for 5 total sessions – an initial assessment phase, followed by a learning phase. d Weighting coefficients of the index and middle (blue), and ring and little (red) fingers during the initial assessment phase, and e weighting coefficients during the learning phase

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[VIDEO] Pablo Product Film – YouTube

 

Δημοσιεύτηκε στις 18 Ιουλ 2017

The PABLO is the latest in a long row of clinically tried and tested robotic- and computer-assisted therapy devices for arms and hands. The new design and the specially developed tyroS software make the PABLO more flexible and offer an expanded spectrum of therapy options.

 

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[ARTICLE] A novel generation of wearable supernumerary robotic fingers to compensate the missing grasping abilities in hemiparetic upper limb – Full Text PDF

Abstract

This contribution will focus on the design, analysis, fabrication, experimental characterization and evaluation of a family of prototypes of robotic extra fingers that can be used as grasp compensatory devices for hemiparetic upper limb.

The devices are the results of experimental sessions with chronic stroke patients and consultations with clinical experts. All the devices share a common principle of work which consists in opposing to the paretic hand/wrist so to restrain the motion of an object.

Robotic supernumerary fingers can be used by chronic stroke patients to compensate for grasping in several Activities of Daily Living (ADL) with a particular focus on bimanual tasks.

The devices are designed to be extremely portable and wearable. They can be wrapped as bracelets when not being used, to further reduce the encumbrance. The motion of the robotic devices can be controlled using an Electromyography (EMG) based interface embedded in a cap. The interface allows the user to control the device motion by contracting the frontalis muscle. The performance characteristics of the devices have been measured through experimental set up and the shape adaptability has been confirmed by grasping various objects with different shapes. We tested the devices through qualitative experiments based on ADL involving a group of chronic stroke patients in collaboration with by the Rehabilitation Center of the Azienda Ospedaliera Universitaria Senese.

The prototypes successfully enabled the patients to complete various bi-manual tasks. Results show that the proposed robotic devices improve the autonomy of patients in ADL and allow them to complete tasks which were previously impossible to perform.

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[Abstract] Design and Test of a Closed-Loop FES System for Supporting Function of the Hemiparetic Hand Based on Automatic Detection Using the Microsoft Kinect Sensor

Abstract
This paper describes the design of a FES system automatically controlled in a closed loop using a Microsoft Kinect sensor, for assisting both cylindrical grasping and hand opening. The feasibility of the system was evaluated in real-time in stroke patients with hand function deficits. A hand function exercise was designed in which the subjects performed an arm and hand exercise in sitting position. The subject had to grasp one of two differently sized cylindrical objects and move it forward or backwards in the sagittal plane. This exercise was performed with each cylinder with and without FES support. Results showed that the stroke patients were able to perform up to 29% more successful grasps when they were assisted by FES. Moreover, the hand grasp-and-hold and hold-and-release durations were shorter for the smaller of the two cylinders. FES was appropriately timed in more than 95% of all trials indicating successful closed loop FES control. Future studies should incorporate options for assisting forward reaching in order to target a larger group of stroke patients.

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[Thesis] The Effects of Limb Dominance on Cross-Education in a Four Week Resistance Training Program – Full Text PDF

ABSTRACT

Cross-education is known as the phenomenon of strength transfer from the trained side of the body to the untrained side of the body by unilateral resistance training. Research has shown that limb dominance has an effect on the amount of strength that is gained on the untrained side. Studies have found that there is a greater cross over effect in strength from the dominant side of the body to the non-dominant side of the body than vice versa. The present study examined this effect by taking 12 college females and splitting them into three groups: dominant training, nondominant training, and control group. The hypothesis was that the dominant training group would have a greater increase in peak grip strength in the untrained, non-dominant arm than the arm of the untrained, dominant group of the non-dominant training group. The dominant training group only trained their dominant arm with a hand dynamometer, while the non-dominant training group only trained their non-dominant arm with the same hand dynamometer. Both groups went through a 4-week, 13 sessions of grip strength training on the handy dynamometer.
They performed 3 sets of 6 maximal squeezes with a 2-minute rest in between sets. Pre-and post tests were taken of maximum grip strength squeeze. There was no significance difference in peak grip strength between the untrained arms of both groups. Also, there was no significance  difference in peak grip strength between the trained arms of both groups however there was a
trend in data in the untrained arm of the dominant training group showing a slight increase in  strength from baseline measurements. These findings do not directly support the hypothesis however, if the number of subjects’ value was greater, the trend in data in the dominant training group might have found significant effect from limb dominance.

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[Abstract] Case Report on the Use of a Custom Myoelectric Elbow–Wrist–Hand Orthosis for the Remediation of Upper Extremity Paresis and Loss of Function in Chronic Stroke.

Abstract:

Introduction: This case study describes the application of a commercially available, custom myoelectric elbow–wrist–hand orthosis (MEWHO), on a veteran diagnosed with chronic stroke with residual left hemiparesis. The MEWHO provides powered active assistance for elbow flexion/extension and 3 jaw chuck grip. It is a noninvasive orthosis that is driven by the user’s electromyographic signal. Experience with the MEWHO and associated outcomes are reported.

Materials and Methods: The participant completed 21 outpatient occupational therapy sessions that incorporated the use of a custom MEWHO without grasp capability into traditional occupational therapy interventions. He then upgraded to an advanced version of that MEWHO that incorporated grasp capability and completed an additional 14 sessions. Range of motion, strength, spasticity (Modified Ashworth Scale [MAS]), the Box and Blocks test, the Fugl–Meyer assessment and observation of functional tasks were used to track progress. The participant also completed a home log and a manufacturers’ survey to track usage and user satisfaction over a 6-month period.

Results: Active left upper extremity range of motion and strength increased significantly (both with and without the MEWHO) and tone decreased, demonstrating both a training and an assistive effect. The participant also demonstrated an improved ability to incorporate his affected extremity (with the MEWHO) into a wide variety of bilateral, gross motor activities of daily living such as carrying a laundry basket, lifting heavy objects (e.g. a chair), using a tape measure, meal preparation, and opening doors.

Conclusion: Custom myoelectric orthoses offer an exciting opportunity for individuals diagnosed with a variety of neurological conditions to make advancements toward their recovery and independence, and warrant further research into their training effects as well as their use as assistive devices.

Source: EBSCOhost | 123998452 | Case Report on the Use of a Custom Myoelectric Elbow–Wrist–Hand Orthosis for the Remediation of Upper Extremity Paresis and Loss of Function in Chronic Stroke.

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