Natural Frequency Transmissibility for Detection of Cracks in Horizontal Axis Wind Turbine Blades.

Defects on horizontal axis wind turbine blades are difficult to identify and monitor with conventional forms of non-destructive examination due to the blade's large size and limited accessibility during continuous operation. This article examines both strain and acceleration transmissibility as methods of continuous damage detection on wind turbine blades. A scaled 117 cm offshore wind turbine blade was first designed, 3D printed, and modelled numerically in ANSYS. Transverse cracks were deliberately introduced to the blade at 10 cm intervals along its leading edge. Subsequent changes in the transmissibility, relative to an undamaged baseline model, were measured using different variable combinations at the blade's first three natural frequencies. Experimental results indicated that strain transmissibility was able to locate a 1.0 cm defect at a range of 70-110 cm from the blade hub using the amplitudes of the first natural frequency of vibration. The numerical model was able to simulate the strain experimental results and was determined to be valid for future defect characterization. Acceleration transmissibility was unable to experimentally identify defects sized at 1.0 cm and below but was able to identify 1.0 cm sized defects numerically. It was concluded that transmissibility is viable for continuous damage detection on blades but that further research into other defect types and locations is required prior to conducting full-scale testing.

Filament-arrayed Bragg gratings for azimuthally resolved displacement sensing in single-mode fibers.

Filament arrays were inscribed off-axis in the core of standard single-mode telecommunication fiber, using femtosecond laser pulses. The flexible line-by-line writing formed uniform, parallel filaments, permitting Bragg grating sensing of the photoelastic response from inside of the narrow grating plane. Active monitoring of the Bragg resonance wavelength while driving a lateral fiber tip displacement directly informed on the fiber mechanics when coupled with opto-mechanical modelling. Overlaying of parallel and orthogonal gratings further provided a strongly contrasting azimuthal sensitivity, which paves the way for multi-dimensional displacement sensing with improved precision.

Resources, relationships, and resilience: The psychosocial experiences of women with lower limb absence during pregnancy and postpartum.

BACKGROUND: There is limited research on the unique needs of women with lower limb absence (LLA) during pregnancy and postpartum. The lack of information can negatively impact women's physical and emotional experiences. OBJECTIVE: The purpose of this study is to explore the psychosocial experiences of individuals with LLA through the pregnancy and postpartum periods, and to provide information to women and health care providers (HCPs) on what they can expect. METHODS: Semi-structured interviews were conducted with 19 women with LLA who had been pregnant in the previous 10 years. Interviews were analyzed using thematic analysis. RESULTS: Participants experienced uncertainty due to a lack of information and limited resources related to pregnancy and LLA. While most women had strong support networks including family, other mothers with LLA and HCPs, some women faced stigma or judgement from HCPs and people in their social networks. Some women had periods where they struggled mentally due to a temporary loss of independence. Despite these challenges, they demonstrated tremendous resilience and noted that their ability to adapt helped them to navigate the difficulties they experienced in the perinatal period (PNP). CONCLUSION: There is an immediate need to fill the 'information gap' about pregnancy and LLA. We recommend the development of support networks, informational guidelines, and further education for HCPs to better support women with LLA through the PNP. Further research is warranted to gain a better understanding of the mental health experiences of women with LLA in the PNP.

The physical experiences of women with lower limb absence during pregnancy and postpartum: symptoms, prosthesis management & mobility.

PURPOSE: Little information is available to women with lower limb absence (LLA) and their health care providers regarding the impacts they may experience during the perinatal period. This study explores the physical impacts of pregnancy on women with LLA, including mobility, prosthesis fit and prosthesis use. METHODS: We conducted semi-structured interviews with 19 women with LLA who had experienced pregnancy in the last 10 years. Interviews were analyzed using thematic analysis. RESULTS: Substantial variation exists in the experience of women's physical symptoms, prosthesis management and mobility. Physical symptoms were similar to any pregnant individual, but the impacts were more substantial. As volume change in the residual limb can impact prosthesis fit, self-management techniques and prosthetist adjustments were used to manage it. Pregnancy impacted the way in which women were mobile and the activities they chose to participate in. A wide variety of creative mobility solutions were utilized to complete activities including prosthesis use, assistive equipment and adaptive movement. CONCLUSIONS: Women with LLA and their health care providers must be aware of the wide range of experiences women face during pregnancy and treat each pregnancy uniquely. Planning ahead and working with a health care team can mitigate many of these challenges.

A case study on the value of in-socket force measurements in gait monitoring of lower-limb prosthesis users.

Wearable sensors have the potential to drastically improve gait rehabilitation and assessments. This is especially the case for lower limb prosthesis users as small wearables can provide useful information about in-socket conditions. Through a simple case study, we investigated the value of measuring in-socket forces in addition to gait parameters in gauging the effectiveness of a training intervention. The results showed that the additional objective information obtained through in-socket measurements can enhance our understanding of how a particular intervention affects both gait and socket comfort.

Identifying priorities and developing strategies for building capacity in amputation research in Canada.

BACKGROUND: Compared to other patient population groups, the field of amputation research in Canada lacks cohesion largely due to limited funding sources, lack of connection among research scientists, and loose ties among geographically dispersed healthcare centres, research institutes and advocacy groups. As a result, advances in clinical care are hampered and ultimately negatively influence outcomes of persons living with limb loss. OBJECTIVE: To stimulate a national strategy on advancing amputation research in Canada, a consensus-workshop was organized with an expert panel of stakeholders to identify key research priorities and potential strategies to build researcher and funding capacity in the field. METHODS: A modified Delphi approach was used to gain consensus on identifying and selecting an initial set of priorities for building research capacity in the field of amputation. This included an anonymous pre-meeting survey (N = 31 respondents) followed by an in-person consensus-workshop meeting that hosted 38 stakeholders (researchers, physiatrists, surgeons, prosthetists, occupational and physical therapists, community advocates, and people with limb loss). RESULTS: The top three identified research priorities were: (1) developing a national dataset; (2) obtaining health economic data to illustrate the burden of amputation to the healthcare system and to patients; and (3) improving strategies related to outcome measurement in patients with limb loss (e.g. identifying, validating, and/or developing outcome measures). Strategies for moving these priorities into action were also developed. CONCLUSIONS: The consensus-workshop provided an initial roadmap for limb loss research in Canada, and the event served as an important catalyst for stakeholders to initiate collaborations for moving identified priorities into action. Given the increasing number of people undergoing an amputation, there needs to be a stronger Canadian collaborative approach to generate the necessary research to enhance evidence-based clinical care and policy decision-making.IMPLICATIONS FOR REHABILITATIONLimb loss is a growing concern across North America, with lower-extremity amputations occurring due to complications arising from diabetes being a major cause.To advance knowledge about limb loss and to improve clinical care for this population, stronger connections are needed across the continuum of care (acute, rehabilitation, community) and across sectors (clinical, advocacy, industry and research).There are new surgical techniques, technologies, and rehabilitation approaches being explored to improve the health, mobility and community participation of people with limb loss, but further research evidence is needed to demonstrate efficacy and to better integrate them into standard clinical care.