Within-socket Myoelectric Prediction of Continuous Ankle Kinematics for Control of a Powered Transtibial Prosthesis

Objective. Powered robotic prostheses create a need for natural-feeling user interfaces and robust control schemes. Here, we examined the ability of a nonlinear autoregressive model to continuously map the kinematics of a transtibial prosthesis and electromyographic (EMG) activity recorded within socket to the future estimates of the prosthetic ankle angle in three transtibial amputees. Approach. Model performance was examined across subjects during level treadmill ambulation as a function of the size of the EMG sampling window and the temporal \u27prediction\u27 interval between the EMG/kinematic input and the model\u27s estimate of future ankle angle to characterize the trade-off between model error, sampling window and prediction interval. Main results. Across subjects, deviations in the estimated ankle angle from the actual movement were robust to variations in the EMG sampling window and increased systematically with prediction interval. For prediction intervals up to 150 ms, the average error in the model estimate of ankle angle across the gait cycle was less than 6°. EMG contributions to the model prediction varied across subjects but were consistently localized to the transitions to/from single to double limb support and captured variations from the typical ankle kinematics during level walking. Significance. The use of an autoregressive modeling approach to continuously predict joint kinematics using natural residual muscle activity provides opportunities for direct (transparent) control of a prosthetic joint by the user. The model\u27s predictive capability could prove particularly useful for overcoming delays in signal processing and actuation of the prosthesis, providing a more biomimetic ankle response

Frequency stability characterization of a broadband fiber Fabry-Perot interferometer

An optical etalon illuminated by a white light source provides a broadband comb-like spectrum that can be employed as a calibration source for astronomical spectrographs in radial velocity (RV) surveys for extrasolar planets. For this application the frequency stability of the etalon is critical, as its transmission spectrum is susceptible to frequency fluctuations due to changes in cavity temperature, optical power and input polarization. In this paper we present a laser frequency comb measurement technique to characterize the frequency stability of a custom-designed fiber Fabry-Perot interferometer (FFP). Simultaneously probing the stability of two etalon resonance modes, we assess both the absolute stability of the etalon and the long-term stability of the cavity dispersion. We measure mode positions with MHz precision, which corresponds to splitting the FFP resonances by a part in 500 and to RV precision of ~1 m/s. We address limiting systematic effects, including the presence of parasitic etalons, that need to be overcome to push the metrology of this system to the equivalent RV precision of 10 cm/s. Our results demonstrate a means to characterize environmentally-driven perturbations of etalon resonance modes across broad spectral bandwidths, as well as motivate the benefits and challenges of FFPs as spectrograph calibrators.Comment: 15 pages, 9 figures, accepted to Opt. Expres

Top Tips for healthier providers of health-care in Merseyside and Cheshire

Top tips for healthier providers of health-care aims to support organisations in focusing on the actions they can take to improve the health their patients, their staff, and the wider community that they serve. It builds on a previous report that was carried out by Liverpool Public Health Observatory in 2006, which focused on hospitals. The report is a review of secondary data, alongside examples of local delivery from Merseyside and Cheshire

Rapid Health Impact Assessment for Royal Liverpool and Broadgreen University Hospitals Trust - ‘A New Health Service for Liverpool, World Class Hospitals, World Class Services’

The overall aim of this HIA was to maximise the health benefits, which could result from implementation of the proposals by the Royal Liverpool and Broadgreen Hospitals to redesign its services, develop a new hospital to replace the Royal Liverpool University Hospital (RLUH) on its existing site, and make further investment at Broadgreen Hospital. In order to do this, the following objectives had to be achieved; Identify and profile the population groups who will be affected by the proposal. Identify the potential positive and negative health impacts of the proposal and set out clearly who will be affected by these impacts. Make recommendations for the elimination or mitigation of negative impacts (or compensation for those affected). Make recommendations for the maximisation of positive impacts

Health needs assessment for ex-Armed Forces personnel

Liverpool Health Observatory (LPHO) was commissioned to undertake a health needs assessment (HNA) for ex-Armed Forces personnel, and their families, in Cheshire and on Merseyside. The HNA focuses on personnel aged under 65. It includes a brief review of relevant literature, as well as a description of provision for ex-Armed Forces personnel at a local and national level

Rapid Health and Equality Impact Assessment (HEqIA)of Mersey Care NHS Trust’s Outline Business Case for Mental Health and Learning Disability Services

The aim of this assessment is to look at the health and equality impacts of Mersey Care's Outline Business Case which aims to: Establish home treatment as the norm; Refocusing in-patient services around patients who are acutely ill with shorter lengths of stay; Developing a local Psychiatric intensive Care in-patient Unit (PICU); Strengthen community and primary care services. The results of this Health and Equality Impact Assessment will be used to feed the Outline Business Cas