Updating the peak-to-valley (PV) irregularity specification for the modern world

Communicating fabrication tolerances is a vital part of the optical manufacturing process. The most common surface form tolerance is peak-to-valley (PV) irregularity, and its specification and evaluation has largely remained unchanged for decades. Fabrication, testing, and computation capabilities, however, have evolved considerably over that time, exposing PV’s extreme sensitivity to outlier data points. When everyone was using the same measurement and analysis technique (visual inspection of test plate interferograms), this sensitivity was of secondary concern to ease of computation. Today, however, numerous measurement techniques are viable for evaluating surface form, computation power is cheap, and different measurements of the same surface can easily result in wildly different PV results. This creates confusion as to whether a surface conforms to tolerance or not. To address this issue, we propose standardized methods for evaluating a PV tolerance value that are resistant to outliers. We first provide an example of the problem on an actual surface measurement and demonstrate how trimmed PV estimators can mitigate it. We review two such estimators, robust peak valley (PVr) and clipped peak-to-valley (PV%). We then review the conceptual trade-offs involved with choosing an appropriate estimator and demonstrate estimator behavior on a variety of simulated surface profiles. Finally, we explore the challenges in adopting a more reliable PV metric and outline the plans for updating the ISO 10110-5 surface form standard to achieve this

Bubble plot of fitted regression line.

<p>Bubble plot of fitted regression line.</p

Overall Forest Plot.

<p>Overall Forest Plot.</p

Funnel Plot.

<p>Funnel Plot.</p

Flow diagram records identified through database searching.

<p>Flow diagram records identified through database searching.</p

Meta-regression with single covariates.

<p>Meta-regression with single covariates.</p

Meta-regression with multiple covariates.

<p>Meta-regression with multiple covariates.</p

Investigating the effectiveness of oral ketamine on pain, mood and quality of life in treatment resistant chronic pain

Introduction: Chronic pain is defined as pain lasting longer than 3 months. This often causes persistent emotional distress and functional disability that is refractory to conventional treatments. Emerging evidence suggests that oral Ketamine therapy may have a specific role in managing treatment-resistant chronic pain. This study aimed to assess the effectiveness of oral ketamine within a tertiary chronic pain management clinic. Methods: This study was a clinic-based retrospective descriptive study of 79 patients with a broad range of chronic pain diagnoses and treated with oral ketamine over a period up to 12 years. Changes in pain, mood and quality of life (QoL) were assessed using a numerical pain severity score, the Brief Pain Inventory (BPI), the Public Health Questionnaire (PHQ-9) and American Chronic Pain Association Quality of Life (QoL) scale. Results: 73 patients were accessible for follow-up (mean daily dose and treatment duration were 193.84 mg and 22.6 months respectively). Pain scores decreased (p p Discussion: This work adds to the growing body of evidence that under the supervision of a pain specialist, oral ketamine therapy may be a safe, tolerable and effective treatment for chronic pain conditions which have not responded to other management options. Further research is required to produce a more accurate understanding of its chronic use. Key message: This real-world study shows that patients being treated with oral ketamine for chronic pain report decreased severity of pain, improved mood and increased quality of life across all conditions.</p

Investigating the effectiveness of oral ketamine on pain, mood and quality of life in treatment resistant chronic pain

Introduction: Chronic pain is defined as pain lasting longer than 3 months. This often causes persistent emotional distress and functional disability that is refractory to conventional treatments. Emerging evidence suggests that oral Ketamine therapy may have a specific role in managing treatment-resistant chronic pain. This study aimed to assess the effectiveness of oral ketamine within a tertiary chronic pain management clinic. Methods: This study was a clinic-based retrospective descriptive study of 79 patients with a broad range of chronic pain diagnoses and treated with oral ketamine over a period up to 12 years. Changes in pain, mood and quality of life (QoL) were assessed using a numerical pain severity score, the Brief Pain Inventory (BPI), the Public Health Questionnaire (PHQ-9) and American Chronic Pain Association Quality of Life (QoL) scale. Results: 73 patients were accessible for follow-up (mean daily dose and treatment duration were 193.84 mg and 22.6 months respectively). Pain scores decreased (p p Discussion: This work adds to the growing body of evidence that under the supervision of a pain specialist, oral ketamine therapy may be a safe, tolerable and effective treatment for chronic pain conditions which have not responded to other management options. Further research is required to produce a more accurate understanding of its chronic use. Key message: This real-world study shows that patients being treated with oral ketamine for chronic pain report decreased severity of pain, improved mood and increased quality of life across all conditions.</p