Present technology and future trends in point-of-care microfluidic diagnostics

This work reviews present technologies and developing trends in Point-of-Care (POC) microfluidic diagnostics platforms. First, various fluidics technologies such as pressure-driven flows, capillary flows, electromagnetically driven flows, centrifugal fluidics, acoustically driven flows, and droplet fluidics are categorized. Then three broad categories of POC microfluidic testing devices are considered: lateral flow devices, desktop and handheld POC diagnostic platforms, and emergent molecular diagnostic POC systems. Such evolving trends as miniaturization, multiplexing, networking, new more sensitive detection schemes, and the importance of sample processing are discussed. It is concluded that POC microfluidic diagnostics has a potential to improve patient treatment outcome and bring substantial savings in overall healthcare costs.

Teaching microfluidic diagnostics using Jell-O(®) chips

Microfluidics has emerged as a versatile technology that has found many applications, including DNA chips, fuel cells, and diagnostics. As the field of microfluidic diagnostics grows, it is important to introduce the principles of this technology to young students and the general public. The objective of this project was to create a simple and effective method that could be used to teach key microfluidics concepts using easily accessible materials. Similar to the poly(dimethylsiloxane) soft lithography technique, a Jell-O(®) "chip" is produced by pouring a mixture of Jell-O(®) and gelatine solution into a mold, which is constructed using foam plate, coffee stirrers, and double-sided tape. The plate is transferred to a 4°C refrigerator for curing, and then the Jell-O(®) chip is peeled off for experimental demonstrations. Three types of chips have been fabricated with different molds: a JELLO mold, a Y-channel mold, and a pH-sensor mold. Using these devices, the basics of microfluidic diagnostics can be demonstrated in one or two class periods. The method described in this chapter provides teachers with a fast and inexpensive way to introduce this technology, and students with a fun and hands-on way to understand the basics of microfluidic diagnostics.

Validation of the Whooley questions and the Beck Depression Inventory in older adults

OBJECTIVE

To analyse the psychometric properties of the Whooley questions and the 21-item Beck Depression Inventory (BDI-21) in older adults with depression and chronic health problems.

DESIGN

A population-based study.

SETTING

Community.

SUBJECTS

474 adults, aged 72-73 years, living in the city of Oulu, Finland.

MAIN OUTCOME MEASURES

The screening parameters of the Whooley questions and the BDI-21 for detecting major depression.

RESULTS

The prevalence of major depression according to the DSM-IV was 5.3% (single or recurrent episode) obtained by the Mini Neuropsychiatric Interview (MINI). The BDI-21 was best able to identify a current episode of major depression with a cut-off point of 11. The sensitivity and specificity of this cut-off point were 88.0% (95% confidence interval (95% CI) 68.8-97.5) and 81.7% (95% CI 77.8-85.2), respectively. The area under the receiver operating characteristics (ROC) curve was 0.89 (95% CI 0.83-0.96). The two Whooley screening questions had a sensitivity of 62.5% (95% CI 40.6-81.2) and either screening question plus the help question had a sensitivity of 66.7% (44.7-84.4).

CONCLUSIONS

The Beck Depression Inventory is a valid instrument for the diagnosis of depression in older adults. As a screening measure, the optimal cut-off score should be 11 or higher. Our results indicate that the sensitivity of the Whooley questions is not high enough to be used as a screening scale among the elderly.

Instrumental measures of spinal function: is it worth? A state-of-the art from a clinical perspective

In the last decades, assessment of trunk posture and motion has gained importance in clinical practice, and several instrumental non-invasive techniques have been developed to overcome limitations of manual and radiological methods. Despite the large effort spent in improving the underlying technologies, the actual role of these measures in the clinical setting remains still undefined due to a variety of issues. The main question concerns the provision of parameters providing a significant contribution to the clinical decision making. In this paper, we review the available spine surface measurement techniques from a technical viewpoint, and point out their current and potential applications according to a clinical perspective. Conclusions are drawn on the basis of both the technical features and accessibility in daily clinical practice, as well as of the validity, reliability and clinical value of the provided parameters. A well-defined clinical role is established for surface topography in the follow-up of spine sagittal plane deformities, adulthood scoliosis and spine disorders involving the spino-pelvic alignment. Conversely, further studies are required to identify reliable key parameters for use in the clinical (adolescent scoliosis, back and neck pain), occupational (measurement of spine exposure to mechanical loads) and forensic (assessment of segmental functional impairments) fields.

Statistical methods used to test for agreement of medical instruments measuring continuous variables in method comparison studies: a systematic review

Background

Accurate values are a must in medicine. An important parameter in determining the quality of a medical instrument is agreement with a gold standard. Various statistical methods have been used to test for agreement. Some of these methods have been shown to be inappropriate. This can result in misleading conclusions about the validity of an instrument. The Bland-Altman method is the most popular method judging by the many citations of the article proposing this method. However, the number of citations does not necessarily mean that this method has been applied in agreement research. No previous study has been conducted to look into this. This is the first systematic review to identify statistical methods used to test for agreement of medical instruments. The proportion of various statistical methods found in this review will also reflect the proportion of medical instruments that have been validated using those particular methods in current clinical practice.

Methodology/Findings

Five electronic databases were searched between 2007 and 2009 to look for agreement studies. A total of 3,260 titles were initially identified. Only 412 titles were potentially related, and finally 210 fitted the inclusion criteria. The Bland-Altman method is the most popular method with 178 (85%) studies having used this method, followed by the correlation coefficient (27%) and means comparison (18%). Some of the inappropriate methods highlighted by Altman and Bland since the 1980s are still in use.

Conclusions

This study finds that the Bland-Altman method is the most popular method used in agreement research. There are still inappropriate applications of statistical methods in some studies. It is important for a clinician or medical researcher to be aware of this issue because misleading conclusions from inappropriate analyses will jeopardize the quality of the evidence, which in turn will influence quality of care given to patients in the future.

Correlation and precision of serum free bilirubin concentrations determined by single and two peroxidase concentration methods in term or late-preterm newborn infants using a FDA-approved analyzer

BACKGROUND

Free bilirubin concentration (B(f)) is an index for identifying newborns at risk for developing bilirubin-induced neurotoxicity. It has been suggested that B(f) measured by a single peroxidase concentration (B(f-single)) does not equal the equilibrium concentration of B(f), which is confirmed by B(f) at two different peroxidase concentrations (B(f-two)). However, the differences between B(f-single) and B(f-two) are unknown in the serum of term or late-preterm newborn infants. Furthermore, to apply B(f-single) with savings on time and cost to the clinical setting, it is very important for us to clarify the differences between B(f-single) and B(f-two).

METHODS

Forty serum samples were obtained from 21 term or late-preterm newborns who were admitted at Kobe University Hospital. Using a peroxidase method, B(f-single) was measured at one peroxidase concentration, and B(f-two) was determined at two different peroxidase concentrations (the manufacturer's recommended peroxidase concentration and half the manufacturer's recommended peroxidase concentration). To clarify the relationship between B(f-single) and peroxidase concentrations, B(f-single) was measured at five different concentrations of peroxidase reagent. Intra-day and inter-day analyses were performed to assess the precision of B(f-single) and B(f-two).

RESULTS

1/B(f-single) increased as peroxidase concentration increased. B(f-single) was significantly lower than B(f-two) (B(f-single): 0.50 microg/dL [0.13 - 1.22 microg/dL] versus B(f-two): 0.59 microg/dL [0.15 - 1.76 microg/dL], p < 0.001), but B(f-single) was significantly correlated with B(f-two) (r = 0.953, p < 0.0001). Intra-day analysis showed that the CV was 9.7% for B(f-two) and 3.3% for B(f-single), and the inter-day CV was 12.4% for B(f-two) and 3.2% for B(f-single).

CONCLUSIONS

Although B(f-single) and B(f-two) are not identical, B(f-single) is significantly correlated with B(f-two) and it is more precise than B(f-two) in term or late-preterm newborns.

Medical devices; exception from general requirements for informed consent. Final rule

The Food and Drug Administration (FDA) is issuing a final regulation to confirm, with one change, the interim final rule (IFR) entitled "Medical Devices; Exception From General Requirements for Informed Consent." This final rule confirms the IFR's establishment of a new exception from the general requirements for informed consent to permit the use of investigational in vitro diagnostic devices to identify chemical, biological, radiological, or nuclear agents without informed consent in certain circumstances. FDA has created this exception to help ensure that individuals who may have been exposed to a chemical, biological, radiological, or nuclear agent are able to benefit from the timely use of the most appropriate diagnostic devices, including those that are investigational. This final rule adds a requirement that the investigator submit the required documentation to FDA, in addition to submitting it to the reviewing Institutional Review Board (IRB).

At the frontiers of surgery: review

The complete surgical removal of disease is a desirable outcome particularly in oncology. Unfortunately much disease is microscopic and difficult to detect causing a liability to recurrence and worsened overall prognosis with attendant costs in terms of morbidity and mortality. It is hoped that by advances in optical diagnostic technology we could better define our surgical margin and so increase the rate of truly negative margins on the one hand and on the other hand to take out only the necessary amount of tissue and leave more unaffected non-diseased areas so preserving function of vital structures. The task has not been easy but progress is being made as exemplified by the presentations at the 2nd Scientific Meeting of the Head and Neck Optical Diagnostics Society (HNODS) in San Francisco in January 2010. We review the salient advances in the field and propose further directions of investigation.

[Study on the supervision of in-vitro diagnostic reagents]

The regulatory history and status of in vitro diagnostic reagents (IVD) at home and abroad are introduced. Suggestions are also provided on the administration of IVD.

[Site inspection procedures and methods for evaluation of the quality management system of in vitro diagnostic regents]

In this paper, the procedures, logos, methods, essentials as well as notable problems for inspecting the qualification management system of in vitro diagnostic regent manufactures are discussed, with aims of promoting inspector's practical level and consequentially ensuring the quality, standard and efficacy of the inspection.

Biotech research: bringing better therapies to the people

Biotech specialists met on November 19, 2009 for their traditional 'Olten Meeting'. On their agenda: to orientate biotech research to more efficient diagnostic instruments and therapies to lead the fight against incurable diseases. A look behind the scenes of current research in Swiss biotechnology.

Photography

A look at 50 years of personal photography, from Brownie Box to Canon digital single-lens reflex cameras, recording life, people, microscope slides and orchids in their habitats and in the studio to digitising old paintings, photos and herbarium specimens. Notes on photographic techniques and the use of ring flash, with comments on long-term conservation of digital images.

[The proposed principles by GHTF of the classification and assessment for in vitro diagnostic (IVD) medical devices]

The IVD (In Vitro Diagnostic)Medical Devices are various and develop rapidly. This paper introduces briefly the principles of classification and conformity assessment for IVD medical that proposed by GHTF (Global Harmonization Task Force).

Capillary electrophoresis-mass spectrometry as a powerful tool in biomarker discovery and clinical diagnosis: an update of recent developments

Proteome analysis has emerged as a powerful technology to decipher biological processes. One of the main goals is to discover biomarkers for diseases from tissues and body fluids. However, the complexity and wide dynamic range of protein expression present an enormous challenge to separation technologies and mass spectrometry (MS). In this review, we examine the limitations of proteomics, and aim towards the definition of the current key prerequisites. We focus on capillary electrophoresis coupled to mass spectrometry (CE-MS), because this technique continues to show great promise. We discuss CE-MS from an application point of view, and evaluate its merits and vices for biomarker discovery and clinical applications. Finally, we present several examples on the use of CE-MS to determine urinary biomarkers and implications for disease diagnosis, prognosis, and therapy evaluation.

A system for symptom assessment in advanced palliative home healthcare using digital pens

Symptom control is one of the most important components of delivering effective palliative care, and adequate symptom assessment is a prerequisite for good symptom control. Patients receiving treatment in palliative home healthcare is geographically separated from the caregivers making symptom control a challenge, a challenge that could be met by the use of information and communication technology. Technologies of today offer different ways for patients to assess their symptoms at home and send the assessments to the healthcare provider. Examples are the use of a PC, a touch-tone telephone, and a digital pen, which require different kinds of infrastructure in the patient's home, and which differ in strengths and weaknesses. As part of an ongoing quality assurance work within the hospital-based home care clinic at Linköping University Hospital, the project has designed, developed and implemented an IT-support system for pain assessments for patients at home using digital pen and mobile Internet technology. A questionnaire study indicated that pain assessment using digital pens was accepted by patients and that problems mainly arose from the use of the visual-analogue scale.

Resources medical students use to derive a differential diagnosis

BACKGROUND

Deriving an appropriate differential diagnosis is a key clinical competency, but there is little data available on how medical students learn this skill. Software resources designed to complement clinical reasoning might be asset in helping them in this task.

AIMS

The goals of this study were to identify the resources third year medical students use to solve a challenging diagnostic case, and specifically to evaluate the usefulness of Isabel, a second-generation electronic diagnosis support system.

METHODS

Third year medical students (n = 117) were presented a challenging case and asked to identify and prioritize their top 3 diagnoses, report the time devoted to the exercise, and list the resources they used and their relative usefulness. Students were randomized to receive (or not) free access, instruction, and encouragement to use to a web-based decision support system (Isabel).

RESULTS

Students who identified the correct diagnosis as their first choice spent significantly more time on the case than did the other students (3.75 +/- 0.28 hours vs 2.88 +/- 0.15 hours, p < 0.05). Students used electronic resources extensively, in particular Google. Students who self-reported use of Isabel had greater success identifying the correct diagnosis (24/33 = 73% for users vs 45/84 = 53% for non-users) a difference of borderline statistical significance.

CONCLUSIONS

These findings indicate that medical trainees use a wide range of electronic decision support products to solve challenging cases. Medical education needs to adapt to this reality, and address the need to teach future clinicians how to use these tools to advantage.