Browsing by Author "Ranaweera, P"

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The Dexios hand: towards affordable and functional prosthetics
(Faculty of Graduate Studies, 2024) Bandara, H; Amarasinghe, D; Hettiarachchi, N; De Silva, M; Ranaweera, P; Gopura, R
Individuals who have experienced upper-limb loss often face significant challenges in regaining functional independence. The absence of a fully functional limb impairs their ability to perform daily tasks, diminishing both their physical capability and overall quality of life. According to global estimates, approximately 20 million people live with upper-limb loss related to traumatic events [1]. Functional prosthetic devices currently available in the market are prohibitively ex-pensive, and lack utility outside of basic grasping actions. This presents a considerable demand for affordable prosthetic solutions that are capable of restoring lost hand function. With this in mind, a research group from the Department of Mechanical Engineering at University of Moratuwa have developed an upper-limb prosthetic device capable of adaptive grasping, employing a novel mechanism to improve dexterity. The device thus developed, named the Dexios Hand, is a prototype electric hand prosthesis with motorised actuation, which is a more user-friendly alternative to body-powered and cosmetic prostheses. The key characteristics of this functional prosthetic hand are its dexterity and shape-adaptive grasping ability. Dexterity refers to the prosthetic hand’s ability to perform skilful movements, while shape-adaptive grasping allows the prosthetic hand to conform to the contours of various objects for a more secure grip. These features are favoured for restoring natural hand functionality in prosthetics since they widen the range of grasps that the device is capable of.
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Navigating the uncertainty: financial, technological, and geopolitical risks in deep-sea mining ventures
(Faculty of Graduate Studies, 2024) Droohithya, T; Fernando, T; Ranaweera, P; Kuruppu, G; Dushyantha, N; Dassanayake, S
Deep-sea mining (DSM) involves extracting minerals from ocean depths exceeding 200 meters, focusing on resources like hydrothermal vents, ferromanganese crusts, and polymetallic nodules [1]. These resources are rich in valuable metals like cobalt, nickel, rare earth elements, and man-ganese, which are essential for technologies like electric vehicle batteries and renewable energy systems. For instance, as depicted in Figure 1, the electric vehicle market is expected to expand rapidly, leading to an increased need for essential minerals. While the DSM offers an exceptional opportunity to access the minerals, it also raises significant concerns about marine ecosystem degradation, biodiversity loss, and potential conflicts with other marine resource users [3]. The International Seabed Authority (ISA) is currently developing regulations to manage DSM, aiming to balance resource extraction with environmental protection.
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Passively-powered knee exoskeleton to reduce human effort during manual lifting
(Faculty of Graduate Studies, 2024) Ranaweera, P; Gopura, R; Jayawardena, S; Mann, G
The proposed device consists of a system of helical elastic springs bilaterally located on the shank for capturing/storing waste biomechanical energy at the knee, a cable and pulley system to transmit power from and to the knee, a pulley locking/unlocking mechanism to achieve passive control of the device operation ensures no restrictions are posed by the springs during walking and applies a pre-tension on springs to prevent slacking of the Bowden cable using a return spring. However, when the wearer performs a squatting task, the springs engage/disengage energy springs when the knee flexes over a preset angle (i.e., 60 degrees). The energy dissipated and generated at the knee joint during decent and ascent phases from biomechanical studies were recorded as 45 J and 50 J respectively for an average human [3]. Accordingly, the selected energy springs can collectively capture and return approximately 20% of biomechanical energy at the knee.
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Rehabilitation robot for carpal tunnel syndrome patients
(University of Moratuwa, 2023) Weerasoory, K; Nipun, W; Kumasaru, U; De Silva, M; Ranaweera, P; Gopura, R
Carpal Tunnel Syndrome (CTS) represents a prevalent neurological condition frequently encountered among individuals engaged in repetitive hand movements, particularly those involving the wrist and fingers. Preg- nant women, people employed in the tea and cinnamon industries, in the hospitality sector where chefs en- gage in repetitive cutting tasks, musicians who play and practice musical instruments for extended periods, and employees in the IT sector where repetitive finger movements are used, are all prone to be diagnosed with this ailment.
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Will the new circular external fixator ease the surgeon’s burden?
(2022-09) Widanage, K; De Silva, M; Ranaweera, P; Lalithrathne, T; Dharmaratne, P; Bull, A; Gopura, R
Sri Lanka, like many other low-middle income countries, has been a victim of conflict for a long time. While the country is still recovering from the internal conflict that plagued it for over three decades, the shadows of these dark days still haunt these lands. The Sri Lankan soil is still not completely rid of antipersonnel landmines which were once weaponized against military and civilians alike. A more recent terrorist attack that happened in 2019 rekindled this age-old fear against explosions in the hearts of Sri Lankans. While prevention of such disasters is important, realistically, it is the duty of engineering researchers to equip medical professionals with devices that can aid and expedite the treatments if and when such unfortunate disasters occur.