scholarly journals Stakeholder and Constraint-Driven Innovation of a Novel, Lever-Propelled, All-Terrain Wheelchair

Author(s):  
Amos G. Winter

The Leveraged Freedom Chair (LFC) is a low-cost, all-terrain, lever-propelled wheelchair designed primarily for use in developing countries. LFC technology was conceived because 70 percent of wheelchair users in these markets live in rural areas and no currently available mobility aid enables them to travel long distances on rough terrain and maneuver in tight, indoor confines. Because developing world markets impose constraints on cost, durability, and performance, a novel solution was required to satisfy stakeholder requirements. The key innovation behind the LFC is its single speed, variable mechanical advantage lever drivetrain. The user effectively changes gear by shifting his hands along the levers; grasping near the ends increases torque, while grasping near the pivots enables a larger angular displacement with every stroke, which increases speed. The drivetrain is made from low-cost bicycle parts found throughout the developing world, which enables the LFC to be sold for $200 and be repairable anywhere. During three user trials in East Africa, Guatemala, and India, stakeholder feedback was used to refine the chair between trials, resulting in a device 9.1 kg (20 lbs) lighter, 8.9 cm (3.5 in) narrower, and with a center of gravity 12.7 cm (5 in) lower than the first iteration. Survey data substantiated increases in performance after successive iterations. Quantitative biomechanical performance data were also measured during the Guatemala and India trials, which showed the LFC to be 76 percent faster and 41 percent more efficient during a common daily commute, and able to produce 53 percent higher peak propulsion force compared to conventional, pushrim-propelled wheelchairs. The LFC offers comparable performance at less than one-twentieth the cost of off road wheelchairs available in the rich world. Stakeholder feedback and the highly-constrained environment for which the LFC was created drove the technology towards a novel, innovative solution that offers a competitive advantage in both developing and developed markets. The paper concludes with a description of how the LFC is a “constraint-driven innovation.” This idea ties together the theories of “disruptive innovation” and “reverse innovation,” and may be used as a design tool for engineers striving to create technologies that have global impact.

Author(s):  
Amos G. Winter ◽  
Mario A. Bollini ◽  
Benjamin M. Judge ◽  
Natasha K. Scolnik ◽  
Harrison F. O’Hanley ◽  
...  

The Leveraged Freedom Chair (LFC) is a low-cost, all-terrain, variable mechanical advantage, lever-propelled wheelchair designed for use in developing countries. The user effectively changes gear by shifting his hands along the levers; grasping near the ends increases torque delivered to the drive-train, while grasping near the pivots enables a larger angular displacement with every stroke, which increases angular velocity in the drivetrain and makes the chair go faster. This paper chronicles the design evolution of the LFC through three user trials in East Africa, Guatemala, and India. Feedback from test subjects was used to refine the chair between trials, resulting in a device 9.1 kg (20 lbs) lighter, 8.9 cm (3.5 in) narrower, and with a center of gravity 12.7 cm (5 in) lower than the first iteration. Survey data substantiated increases in performance after successive iterations. Quantitative biomechanical performance data were also measured during the Guatemala and India trials, which showed the LFC to be 76 percent faster and 41 percent more efficient during a common daily commute and able to produce 51 percent higher peak propulsion force compared to conventional, pushrim-propelled wheelchairs.


Inventions ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 68
Author(s):  
Juan D. Borrero

Climate and social changes are deeply affecting current agro-food systems. Unsustainable agricultural practices and the low profitability of small farmers are challenging the agricultural development of rural areas. This study aims to develop a novel, modular and low-cost vertical hydroponic farm system through reviews of the patented literature, research literature and variants of commercial products. After a detailed conceptualization process, a prototype was fabricated and tested at my university to validate its technology readiness level (TRL). The outcomes supported the usability and performance of the present utility model but highlighted several changes that are necessary before it can pass to the next TRL. This study shows that the prototype has the potential to not only solve food sovereignty but also to benefit society by advancing the innovations in food production and improving quality of life.


Author(s):  
Pablo S. Santaeufemia ◽  
Nathan G. Johnson ◽  
Christopher McComb ◽  
Kenji Shimada

Water-lifting technologies in rural areas of the developing world have enormous potential to stimulate agricultural and economic growth. The treadle pump, a human-powered low-cost pump designed for irrigation in developing countries, can help farmers maximize financial return on small plots of land by ending their dependency on rain-fed irrigation systems. The treadle pump uses a suction piston to draw groundwater to the surface by way of a foot-powered treadle attached to each suction piston. Current treadle pump designs lift water from depths up to 7 meters at a flow-rate of 1–5 liters per second. This work seeks to optimize the design of the Dekhi style treadle pump, which has gained significant popularity due to its simplicity. A mathematical model of the working fluid and treadle pump structure has been developed in this study. Deterministic optimization methods are then employed to maximize the flow rate of the groundwater pumped, maximize the lift height, and minimize the volume of material used for manufacturing. Design variables for the optimization included the dimensions of the pump, well depth, and speed of various parts of the system. The solutions are subject to constraints on the geometry of the system, the bending stress in the treadles, and ergonomic factors. Findings indicate that significant technical improvements can be made on the standard Dekhi design, such as increasing the size of the pump cylinders and hose, while maintaining a standard total treadle length. These improvements could allow the Dekhi pump to be implemented in new regions and benefit additional rural farmers in the developing world.


2019 ◽  
Vol 8 (2) ◽  
pp. 3078-3081

Rural aquaculture is mostly based on open pond system. People in rural areas depend on aquaculture not only for food but also for livelihood. These are unmanaged fish ponds and deprived of any technological touches. To increase the livelihood, establishment of managed ponds and use of low cost IoT technology for monitoring fishponds is an important issue. By monitoring water parameters like PH, temperature, Turbidity fish growth can be increased. In this paper we have proposed a multiple fish pond design controlled by single center and wire and wireless mode of data collection. The proposed model is simulated using NetSim to generate network performance matrices. To achieve a prolonged battery life, concept of energy harvesting at sensor node level is introduced in the simulation study


2018 ◽  
Author(s):  
Christopher McComb ◽  
Pablo S Santaeufemia ◽  
Nathan G Johnson ◽  
Kenji Shimada

Water-lifting technologies in rural areas of the developing world have enormous potential to stimulate agricultural and economic growth. The treadle pump, a human-powered low-cost pump designed for irrigation in developing countries, can help farmers maximize financial return on small plots of land by ending their dependency on rain-fed irrigation systems. The treadle pump uses a suction piston to draw groundwater to the surface by way of a foot-powered treadle attached to each suction piston. Current treadle pump designs lift water from depths up to 7 meters at a flow-rate of 1–5 liters per second. This work seeks to optimize the design of the Dekhi style treadle pump, which has gained significant popularity due to its simplicity. A mathematical model of the working fluid and treadle pump structure has been developed in this study. Deterministic optimization methods are then employed to maximize the flow rate of the groundwater pumped, maximize the lift height, and minimize the volume of material used for manufacturing. Design variables for the optimization included the dimensions of the pump, well depth, and speed of various parts of the system. The solutions are subject to constraints on the geometry of the system, the bending stress in the treadles, and ergonomic factors. Findings indicate that significant technical improvements can be made on the standard Dekhi design, such as increasing the size of the pump cylinders and hose, while maintaining a standard total treadle length. These improvements could allow the Dekhi pump to be implemented in new regions and benefit additional rural farmers in the developing world.


2016 ◽  
Vol 10 (1) ◽  
pp. 70-77
Author(s):  
Jantri Sirait ◽  
Sulharman Sulharman

Has done design tool is a tool of refined coconut oil coconut grater, squeezer coconut milk and coconut oil heating, with the aim to streamline the time of making coconut oil and coconut oil increase production capacity. The research method consists of several stages, among others; image creation tool, procurement of materials research, cutting the material - the material framework of tools and performance test tools. The parameters observed during the performance test tools is time grated coconut, coconut milk bleeder capacity, the capacity of the boiler and the heating time of coconut oil. The design tool consists of three parts, namely a tool shaved coconut, coconut milk wringer and coconut milk heating devices. Materials used for the framework of such tools include iron UNP 6 meters long, 7.5 cm wide, 4 mm thick, while the motor uses an electric motor 0.25 HP 1430 rpm and to dampen the rotation electric motor rotation used gearbox with a ratio of round 1 : 60. the results of the design ie the time required for coconut menyerut average of 297 seconds, coconut milk wringer capacity of 5 kg of processes and using gauze pads to filter coconut pulp, as well as the heating process takes ± 2 hours with a capacity of 80 kg , The benefits of coconut oil refined tools are stripping time or split brief coconut average - average 7 seconds and coconut shell can be used as craft materials, processes extortion coconut milk quickly so the production capacity increased and the stirring process coconut oil mechanically.ABSTRAKTelah dilakukan rancang bangun alat olahan minyak kelapa yaitu alat pemarut kelapa, pemeras santan kelapa dan pemanas minyak kelapa, dengan tujuan untuk mengefisiensikan waktu pembuatan minyak kelapa serta meningkatkan kapasitas produksi minyak kelapa. Metode penelitian terdiri dari beberapa tahapan antara lain; pembuatan gambar alat, pengadaan bahan-bahan penelitian, pemotongan bahan - bahan rangka alat dan uji unjuk kerja alat. Parameter yang diamati pada saat uji unjuk kerja alat adalah waktu parut kelapa, kapasitas pemeras santan kelapa, kapasitas tungku pemanas serta waktu pemanasan minyak kelapa. Rancangan alat terdiri dari tiga bagian yaitu alat penyerut kelapa, alat pemeras santan kelapa dan alat pemanas santan kelapa. Bahan yang dipergunakan untuk rangka alat tersebut  yaitu besi UNP panjang 6 meter, lebar 7,5 cm, tebal 4 mm, sedangkan untuk motor penggerak menggunakan motor listrik 0,25 HP 1430 rpm dan untuk meredam putaran putaran motor listrik dipergunakan gearbox  dengan perbandingan putaran 1 : 60. Hasil dari rancangan tersebut yaitu waktu yang dibutuhkan untuk menyerut kelapa rata-rata 297 detik, kapasitas alat pemeras santan kelapa 5 kg sekali proses dan menggunakan kain kassa untuk menyaring ampas kelapa, serta Proses pemanasan membutuhkan waktu ± 2 jam dengan kapasitas 80 kg. Adapun keunggulan alat olahan minyak kelapa ini adalah waktu pengupasan atau belah kelapa singkat rata – rata 7 detik dan tempurung kelapa dapat digunakan sebagai bahan kerajinan, proses pemerasan santan kelapa cepat sehingga kapasitas produksi meningkat dan proses pengadukan minyak kelapa secara mekanis. Kata kunci : penyerut, pemeras, pemanas,minyak kelapa,olahan minyak kelapa.


Author(s):  
José Capmany ◽  
Daniel Pérez

Programmable Integrated Photonics (PIP) is a new paradigm that aims at designing common integrated optical hardware configurations, which by suitable programming can implement a variety of functionalities that, in turn, can be exploited as basic operations in many application fields. Programmability enables by means of external control signals both chip reconfiguration for multifunction operation as well as chip stabilization against non-ideal operation due to fluctuations in environmental conditions and fabrication errors. Programming also allows activating parts of the chip, which are not essential for the implementation of a given functionality but can be of help in reducing noise levels through the diversion of undesired reflections. After some years where the Application Specific Photonic Integrated Circuit (ASPIC) paradigm has completely dominated the field of integrated optics, there is an increasing interest in PIP justified by the surge of a number of emerging applications that are and will be calling for true flexibility, reconfigurability as well as low-cost, compact and low-power consuming devices. This book aims to provide a comprehensive introduction to this emergent field covering aspects that range from the basic aspects of technologies and building photonic component blocks to the design alternatives and principles of complex programmable photonics circuits, their limiting factors, techniques for characterization and performance monitoring/control and their salient applications both in the classical as well as in the quantum information fields. The book concentrates and focuses mainly on the distinctive features of programmable photonics as compared to more traditional ASPIC approaches.


1987 ◽  
Vol 14 (3) ◽  
pp. 134-140 ◽  
Author(s):  
K.A. Clarke

Practical classes in neurophysiology reinforce and complement the theoretical background in a number of ways, including demonstration of concepts, practice in planning and performance of experiments, and the production and maintenance of viable neural preparations. The balance of teaching objectives will depend upon the particular group of students involved. A technique is described which allows the embedding of real compound action potentials from one of the most basic introductory neurophysiology experiments—frog sciatic nerve, into interactive programs for student use. These retain all the elements of the “real experiment” in terms of appearance, presentation, experimental management and measurement by the student. Laboratory reports by the students show that the experiments are carefully and enthusiastically performed and the material is well absorbed. Three groups of student derive most benefit from their use. First, students whose future careers will not involve animal experiments do not spend time developing dissecting skills they will not use, but more time fulfilling the other teaching objectives. Second, relatively inexperienced students, struggling to produce viable neural material and master complicated laboratory equipment, who are often left with little time or motivation to take accurate readings or ponder upon neurophysiological concepts. Third, students in institutions where neurophysiology is taught with difficulty because of the high cost of equipment and lack of specific expertise, may well have access to a low cost general purpose microcomputer system.


2021 ◽  
Vol 11 (6) ◽  
pp. 2535
Author(s):  
Bruno E. Silva ◽  
Ramiro S. Barbosa

In this article, we designed and implemented neural controllers to control a nonlinear and unstable magnetic levitation system composed of an electromagnet and a magnetic disk. The objective was to evaluate the implementation and performance of neural control algorithms in a low-cost hardware. In a first phase, we designed two classical controllers with the objective to provide the training data for the neural controllers. After, we identified several neural models of the levitation system using Nonlinear AutoRegressive eXogenous (NARX)-type neural networks that were used to emulate the forward dynamics of the system. Finally, we designed and implemented three neural control structures: the inverse controller, the internal model controller, and the model reference controller for the control of the levitation system. The neural controllers were tested on a low-cost Arduino control platform through MATLAB/Simulink. The experimental results proved the good performance of the neural controllers.


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