Choosing appropriate patient-reported outcomes instrument for glaucoma research: a systematic review of vision instruments

PURPOSE: To identify vision Patient-Reported Outcomes instruments relevant to glaucoma and assess their content validity.

METHODS: MEDLINE, MEDLINE in Process, EMBASE and SCOPUS (to January 2009) were systematically searched. Observational studies or randomised controlled trials, published in English, reporting use of vision instruments in glaucoma studies involving adults were included. In addition, reference lists were scanned to identify additional studies describing development and/or validation to ascertain the final version of the instruments. Instruments' content was then mapped onto a theoretical framework, the World Health Organization International Classification of Functioning, Disability and Health. Two reviewers independently evaluated studies for inclusion and quality assessed instrument content.

RESULTS: Thirty-three instruments were identified. Instruments were categorised into thirteen vision status, two vision disability, one vision satisfaction, five glaucoma status, one glaucoma medication related to health status, five glaucoma medication side effects and six glaucoma medication satisfaction measures according to each instruments' content. The National Eye Institute Visual Function Questionnaire-25, Impact of Vision Impairment and Treatment Satisfaction Survey-Intraocular Pressure had the highest number of positive ratings in the content validity assessment.

CONCLUSION: This study provides a descriptive catalogue of vision-specific PRO instruments, to inform the choice of an appropriate measure of patient-reported outcomes in a glaucoma context.

Dialogic Instruments: Virtuosity (Re)Located in Improvised Performance

This paper introduces a series of new musical instruments that have been designed to
address questions relating to performative virtuosity in the area of ensemble-based
improvisation. The intentionally exploited inconsistent nature of these instruments
raises questions around traditional notions of instrument mastery and opens up
possible methods of recon?guring the performer-instrument relationship.

Assessing the needs of informal caregivers to cancer survivors: a review of the instruments

Objective: Cancer may impact negatively on an informal caregiver's health long after treatment has ended. This review identifies the self-report measures currently in use to measure caregivers need for support and determines their scientific soundness and clinical utility.

Method: A systematic electronic database search of Medline, CINAHL, PsychINFO, BNI ProQuest was conducted. The psychometric properties and clinical utility of needs assessment tools for caregivers of cancer survivors (excluding advanced disease) were extracted and summarised.

Results: Seven cancer survivor caregiver needs assessment tools were identified. Data on instrument development was well reported, although variability was noted in their structure and content. The majority demonstrated some degree of reliability and validity; only two were evaluated for test–retest reliability (CaSPUN and SPUNS) with only the SPUNS showing a high degree of reliability over time. The Health Care Needs Survey (HCNS), Needs Assessment of Family Caregivers-Cancer (NAFC-C) and Cancer Caregiving Tasks Consequences and Needs Questionnaire (CaTCoN) have been validated at various stages of the cancer continuum. Minimal data was available on responsiveness.

Conclusion: All assessment tools identified require further psychometric analysis. For research purposes, the use of the SPUNS (with its acceptable test–retest reliability) appears most appropriate; although its length may be of concern for clinical use; therefore, the shorter SCNS-P&C is likely to be more suitable for use clinically. At present, the NAFC-C demonstrates a great potential in both the research and clinical environments; however, it requires further psychometric testing before it can be fully recommended. Further analysis is necessary on ideal response formats and the meaning of a total needs score.

Sound Synthesis for Contact-Driven Musical Instruments via Discretisation of Hamilton's Equations

Physical modelling of musical instruments involves studying nonlinear interactions between parts of the instrument. These can pose several difficulties concerning the accuracy and stability of numerical algorithms. In particular, when the underlying forces are non-analytic functions of the phase-space variables, a stability proof can only be obtained in limited cases. An approach has been recently presented by the authors, leading to unconditionally stable simulations for lumped collision models. In that study, discretisation of Hamilton’s equations instead of the usual Newton’s equation of motion yields a numerical scheme that can be proven to be energy conserving. In this paper, the above approach is extended to collisions of distributed objects. Namely, the interaction of an ideal string with a flat barrier is considered. The problem is formulated within the Hamiltonian framework and subsequently discretised. The resulting nonlinearmatrix equation can be shown to possess a unique solution, that enables the update of the algorithm. Energy conservation and thus numerical stability follows in a way similar to the lumped collision model. The existence of an analytic description of this interaction allows the validation of the model’s accuracy. The proposed methodology can be used in sound synthesis applications involving musical instruments where collisions occur either in a confined (e.g. hammer-string interaction, mallet impact) or in a distributed region (e.g. string-bridge or reed-mouthpiece interaction).

Simulation of Distributed Contact in String Instruments: a Modal Expansion Approach

Impactive contact between a vibrating string and a barrier is a strongly nonlinear phenomenon that presents several challenges in the design of numerical models for simulation and sound synthesis of musical string instruments. These are addressed here by applying Hamiltonian methods to incorporate distributed contact forces into a modal framework for discrete-time simulation of the dynamics of a stiff, damped string. The resulting algorithms have spectral accuracy, are unconditionally stable, and require solving a multivariate nonlinear equation that is guaranteed to have a unique solution. Exemplifying results are presented and discussed in terms of accuracy, convergence, and spurious high-frequency oscillations.