Biomedical subjects

Ian Robinson

Publications and source records attributed to Ian Robinson.

7 recordsLinked to original sources

PubMed2006

Effectiveness of iterative algorithms in recovering phase in the presence of noise.

Inversion of coherent X-ray diffraction patterns allows the imaging of three-dimensional density distributions. The recovery of such shapes often requires application of iterative algorithms, such as Fienup's error reduction or hybrid input/output. Since the measurement of such a pattern records the intensity in reciprocal space, any errors due to noise will probably not have a straightforward impact on the final real-space result. In this paper, the effect of the types of noise common in coherent X-ray diffraction (CXD) experiments, counting statistics, scatter from alien particles and detector noise, on the recovered real-space density projection is explored by simulating a two-dimensional CXD pattern and adding noise. It is found that an R factor measuring the reproducibility between the best and second-best real-space result is a leading indicator of performance.

Algorithms↗

PubMed2006

Weighty matters.

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Journal Article↗

PubMed2006

User involvement in healthcare technology development and assessment: structured literature review.

PURPOSE: Medical device users are one of the principal medical device technology stakeholders. The involvement of users in medical device technology development and assessment is central to meet their needs. This study aims to examine this issue. DESIGN/METHODOLOGY/APPROACH: A structured review of the literature published from 1980 to 2005 in peer-reviewed journals was carried out from a social science perspective to investigate user involvement practice in the development and assessment of medical device technologies. This was followed by a qualitative thematic analysis. FINDINGS: Medical device users include clinicians, patients, carers and others. Different kinds of medical devices are developed and assessed by user involvement. The user involvement occurs at different stages of the medical device technology lifecycle and the degree of user involvement is in the order of: design > testing and trials > deployment > concept stages. The methods most commonly used for capturing users' perspectives are usability tests, interviews and questionnaire surveys. RESEARCH LIMITATIONS/IMPLICATIONS: The relevant engineering, medical and nursing literature, which might have been useful, was not reviewed. However, useful findings emerge that apply to health care generally. ORIGINALITY/VALUE: This study shows that medical device users are not homogeneous but heterogeneous in several aspects, such as needs, skills and working environments. This is an important consideration for incorporating users' perspectives in medical device technologies.

Community Participation↗

PubMed2005

Stability of neuropathic pain symptoms in partial sciatic nerve ligation in rats is affected by suture material.

Many factors affect the development of neuropathic pain behavior in animal models. In this letter, we describe the differences in the development of neuropathic pain behavior observed when the partial sciatic nerve ligation (PNL) is performed with either a synthetic silk or chromic catgut ligation. To characterize nociceptive changes over time after surgery, neutral plate, hot plate, Von Frey, pinprick, acetone spray and cold plate testing was performed. The results indicated that a chromic catgut ligature caused cold allodynia, chemical hyperreactivity, mechanical hyperalgesia and hypersensitivity that remained present for the entire 56 days post-surgical observation period. With the synthetic silk ligature, comparable functional deficits were present in the initial phase after surgery, but several of these deficits diminished over time 21-28 days post-surgery. In conclusion, performing the PNL using chromic catgut suture thread gives rise to more robust sensory deficits than when synthetic silk is used. Therefore, the material that is used for the ligature in the partial sciatic ligation model has an effect on the outcome of the observed sensory abnormalities.

Animals↗

PubMed2004

Comparison of five different rat models of peripheral nerve injury.

Described here is a comparison of five peripheral sciatic nerve injury models in rats which all result in various degrees of neuropathic pain symptoms. They are the chronic constriction injury (CCI), the spinal nerve ligation (SNL), the partial sciatic ligation (PSL), the tibial and sural transection (TST), and the complete sciatic transection (CST) model. Behavioral testing was performed on these models over a 56-day period under strict experimental conditions to minimise variability between the surgical models and to allow for an accurate evaluation of the sensory deficits produced by each model. Overall, all five models of neuropathic pain produced signs of allodynia and hyperalgesia to various stimuli. However, the duration and magnitude of the evoked responses varied considerably between the different models.

Animals↗

PubMed2004

Development of neuropathic pain is affected by bedding texture in two models of peripheral nerve injury in rats.

It has long been known that there are numerous genetic and environmental factors that affect the in vivo research of neuropathic pain. In this letter, we describe the impact that bedding material can have on the development of neuropathic pain behaviors in rodents. In two models of neuropathic pain, the Chronic Constriction Injury (CCI) and the partial axotomy, we demonstrated that features of the sawdust on which the animals are housed during experimentation have a clear effect on the development of mechanical hyperalgesia and chemical hypersensitivity. Rats housed on coarse sawdust presented with a much-reduced response to a pinprick and acetone test compared to counterparts housed on fine sawdust. It is therefore concluded that the development of specific stimulus modalities of neuropathic pain behavior following peripheral nerve injury can be influenced in part by environmental factors, in this case bedding texture.

Animals↗

PubMed2004

Quinone bioreductive prodrugs as delivery agents.

Quinone bioreductive prodrugs were developed to target the hypoxic or the reductase- rich population of solid tumours. The mechanism of their selective activation is based on their ability to convert the quinone sub-structure to their activated semiquinone or hydroquinone species affording the active species. Recent studies on their biochemical activation process have resulted in their development as delivery agents that can effectively release a potent (but not necessarily a cytotoxic) agent under hypoxic/reductive conditions. This technology platform is currently being used to design/identify, and synthesise novel quinone bioreductive delivery agents to target cancer and other diseases where hypoxia and/or reductive enzymes play a major pathophysiological role.

Antineoplastic Agents↗