Signed-gradient adaptive step size LMS algorithm for biomedical applications

Gradient adaptive step size adaptive filters have been widely used to adapt different biomedical application environments and obtain useful life signals from serious ambient noise and interferences. In order to further improve the signal-to-noise ratio (SNR) of the life signals, this paper presents a class of signed-gradient adaptive step size least mean square (LMS) adaptive filters. The proposed algorithms introduce a sign function to replace the gradient of squared error in the step size updating process of the gradient adaptive step size LMS adaptive filters. The performance of both gradient and signed-gradient algorithms with dual adaptive filters is compared by extracting heartbeat signals from ambient noise in stethoscopes. Simulation results demonstrate that though the signed-gradient adaptive step size LMS algorithm converges at a slower rate at the early stage of iteration, it has a smaller mean squared error (MSE) at the stage of convergence, thus achieves a higher SNR.

For your interest? The ethical acceptability of using non-invasive prenatal testing to test 'purely for information'

Non-invasive prenatal testing (NIPT) is an emerging form of prenatal genetic testing that provides information about the genetic constitution of a foetus without the risk of pregnancy loss as a direct result of the test procedure. As with other prenatal tests, information from NIPT can help to make a decision about termination of pregnancy, plan contingencies for birth or prepare parents to raise a child with a genetic condition. NIPT can also be used by women and couples to test purely 'for information'. Here, no particular action is envisaged following the test; it is motivated entirely by an interest in the result. The fact that NIPT can be performed without posing a risk to the pregnancy could give rise to an increase in such requests. In this paper, we examine the ethical aspects of using NIPT 'purely for information', including the competing interests of the prospective parents and the future child, and the acceptability of testing for 'frivolous' reasons. Drawing on several clinical scenarios, we claim that arguments about testing children for genetic conditions are relevant to this debate. In addition, we raise ethical concerns over the potential for objectification of the child. We conclude that, in most cases, using NIPT to test for adult-onset conditions, carrier status or non-serious traits presenting in childhood would be unacceptable.

Combining apps targeting professionals and senior citizens to improve housing accessibility and influence housing provision policies

Two separate apps that address the increasingly important issue of accessible housing for senior citizens have been developed in different project settings. One of the apps was developed to facilitate the process for professional raters to assess housing accessibility in the context of individual housing adaptations. The other app was developed for senior citizens to raise their awareness of possible accessibility problems in their current dwelling and in other apartments within the available housing stock. Both apps were developed with a high degree of active user involvement in processes utilizing multiple state of the art methods. The results are two well accepted prototype apps perceived as user-friendly and appropriate for the intended user groups. By combining these two apps, our ambition is for the professional raters to benefit by gaining knowledge of their clients' perceived needs and desires, and for senior citizens to benefit by getting access to a database of professionally rated dwellings. The ultimate goal is the generation of sound knowledge reflecting the needs and desires of senior citizens and professional requirements regarding accessible housing as a means to inform and influence housing provision policies.

Mobile device for disease diagnosis and data tracking in resource-limited settings

Here we describe a low-cost mobile device that combines cell-phone and satellite communication technologies with fluid miniaturization techniques for performing all essential functions of enzyme-linked immunosorbent assay (ELISA). Disease-specific antigens are immobilized on the microfluidic surface, and disease specific antibodies are captured on the surface and visualized with silver-gold amplification. The diagnostic result is automatically determined by the device by measuring the absorbance through the silver-gold amplification in the microchannel. The results are displayed for the user and are synchronized to a remote patient record. The overall system aims to be portable, robust, low-power, and fully utilize the ability of mobile devices for bringing better health care to resource poor areas.

A critical review of the use of technology to provide psychosocial support for children and young people with long-term conditions

Advances in technology have offered health professionals alternative mediums of providing support to patients with long-term conditions. This critical review evaluated and assessed the benefit of electronic media technologies in supporting children and young people with long-term conditions. Of 664 references identified, 40 met the inclusion criteria. Supportive technology tended to increase disease-related knowledge and improve aspects of psychosocial function. Supportive technology did not improve quality of life, reduce health service use or decrease school absences. The poor methodological quality of current evidence and lack of involvement of users in product development contribute to the uncertainty that supportive technology is beneficial.

Psychological aspects of individualized choice and reproductive autonomy in prenatal screening

Probably the main purpose of reproductive technologies is to enable people who choose to do so to avoid the birth of a baby with a disabling condition. However the conditions women want information about and the 'price' they are willing to pay for obtaining that information vary enormously. Individual women have to arrive at their own prenatal testing choices by 'trading off' means and ends in order to resolve the dilemmas facing them. We know very little about how individuals make these trade-offs, so it is difficult to predict how new technologies will affect their choices and preferences. Uptake decisions can be expected to change, especially in the group of women who now are put off by some aspect of the current screening approach, where the avoidance of miscarriage risk may have provided a kind of 'psychological shelter', protecting a lot of people from having to make other decisions. Technologies such as Pre-implantation Genetic Diagnosis may remove a second 'psychological shelter' because they offer the means of avoiding the birth of an affected child without terminating a pregnancy. Even if new technologies will make some decisions easier in terms of their cognitive demands, they will also create new dilemmas and decision making will not necessarily become less stressful in emotional terms. Key challenges concern information and decision-making.

Refractive accuracy with light-adjustable intraocular lenses

PURPOSE

To evaluate efficacy, predictability, and stability of refractive treatments using light-adjustable intraocular lenses (IOLs).

SETTING

University Hospital Virgen de la Arrixaca, Murcia, Spain.

DESIGN

Prospective nonrandomized clinical trial.

METHODS

Eyes with a light-adjustable IOL (LAL) were treated with spatial intensity profiles to correct refractive errors. The effective changes in refraction in the light-adjustable IOL after every treatment were estimated by subtracting those in the whole eye and the cornea, which were measured with a Hartmann-Shack sensor and a corneal topographer, respectively. The refractive changes in the whole eye and light-adjustable IOL, manifest refraction, and visual acuity were obtained after every light treatment and at the 3-, 6-, and 12-month follow-ups.

RESULTS

The study enrolled 53 eyes (49 patients). Each tested light spatial pattern (5 spherical; 3 astigmatic) produced a different refractive change (P<.01). The combination of 2 light adjustments induced a maximum change in spherical power of the light-adjustable IOL of between -1.98 diopters (D) and +2.30 D and in astigmatism of up to -2.68 D with axis errors below 9 degrees. Intersubject variability (standard deviation) ranged between 0.10 D and 0.40 D. The 2 required lock-in procedures induced a small myopic shift (range +0.01 to +0.57 D) that depended on previous adjustments.

CONCLUSIONS

Light-adjustable IOL implantation achieved accurate refractive outcomes (around emmetropia) with good uncorrected distance visual acuity, which remained stable over time. Further refinements in nomograms and in the treatment's protocol would improve the predictability of refractive and visual outcomes with these IOLs.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

A "schizophotonic" all-in-one nanoparticle coating for multiplexed SE(R)RS biomedical imaging

SERS nanoprobes for in vivo biomedical applications require high quantum yield, long circulation times, and maximum colloidal stability. Traditional synthetic routes require high metal-dye affinities and are challenged by unfavorable electrostatic interactions and limited scalability. We report the synthesis of a new near-IR active poly(N-(2-hydroxypropyl) methacrylamide) (pHPMA). The integration of various SERS reporters into a biocompatible polymeric surface coating allows for controlled dye incorporation, high colloidal stability, and optimized in vivo circulation times. This technique allows the synthesis of very small (<20 nm) SERS probes, which is crucial for the design of excretable and thus highly translatable imaging agents. Depending on their size, the "schizophotonic" nanoparticles can emit both SERS and fluorescence. We demonstrate the capability of this all-in-one gold surface coating and SERS reporter for multiplexed lymph-node imaging.

Supramolecular hydrogels made of basic biological building blocks

As a consequence of the self-assembly of small organic molecules in water, supramolecular hydrogels are evolving from serendipitous events during organic synthesis to become a new type of materials that hold promise for applications in biomedicine. In this Focus Review, we describe recent advances in the use of basic biological building blocks for creating molecules that act as hydrogelators and the potential applications of the corresponding hydrogels. After introducing the concept of supramolecular hydrogels and defining the scope of this review, we briefly describe the methods for making and characterizing supramolecular hydrogels. We then discuss representative hydrogelators according to the categories of their building blocks, such as amino acids, nucleobases, and saccharides, and highlight the applications of the hydrogels when necessary. Finally, we offer our perspective and outlook on this fast-growing field at the interface of organic chemistry, materials, biology, and medicine. By providing a snapshot for chemists, engineers, and medical scientists, we hope that this Focus Review will contribute to the development of multidisciplinary research on supramolecular hydrogels for a wide range of applications in different fields.

Designing protein-based biomaterials for medical applications

Biomaterials produced by nature have been honed through billions of years, evolving exquisitely precise structure-function relationships that scientists strive to emulate. Advances in genetic engineering have facilitated extensive investigations to determine how changes in even a single peptide within a protein sequence can produce biomaterials with unique thermal, mechanical and biological properties. Elastin, a naturally occurring protein polymer, serves as a model protein to determine the relationship between specific structural elements and desirable material characteristics. The modular, repetitive nature of the protein facilitates the formation of well-defined secondary structures with the ability to self-assemble into complex three-dimensional architectures on a variety of length scales. Furthermore, many opportunities exist to incorporate other protein-based motifs and inorganic materials into recombinant protein-based materials, extending the range and usefulness of these materials in potential biomedical applications. Elastin-like polypeptides (ELPs) can be assembled into 3-D architectures with precise control over payload encapsulation, mechanical and thermal properties, as well as unique functionalization opportunities through both genetic and enzymatic means. An overview of current protein-based materials, their properties and uses in biomedicine will be provided, with a focus on the advantages of ELPs. Applications of these biomaterials as imaging and therapeutic delivery agents will be discussed. Finally, broader implications and future directions of these materials as diagnostic and therapeutic systems will be explored.

Synthesis and biomedical applications of copper sulfide nanoparticles: from sensors to theranostics

Copper sulfide (CuS) nanoparticles have attracted increasing attention from biomedical researchers across the globe, because of their intriguing properties which have been mainly explored for energy- and catalysis-related applications to date. This focused review article aims to summarize the recent progress made in the synthesis and biomedical applications of various CuS nanoparticles. After a brief introduction to CuS nanoparticles in the first section, we will provide a concise outline of the various synthetic routes to obtain different morphologies of CuS nanoparticles, which can influence their properties and potential applications. CuS nanoparticles have found broad applications in vitro, especially in the detection of biomolecules, chemicals, and pathogens which will be illustrated in detail. The in vivo uses of CuS nanoparticles have also been investigated in preclinical studies, including molecular imaging with various techniques, cancer therapy based on the photothermal properties of CuS, as well as drug delivery and theranostic applications. Research on CuS nanoparticles will continue to thrive over the next decade, and tremendous opportunities lie ahead for potential biomedical/clinical applications of CuS nanoparticles.

A qualitative, exploratory study of predominantly female parental perceptions of consumer health technology use by their overweight and/or obese female adolescent participating in a fee-based 4-week weight-management intervention

Consumer health technologies (CHTs) are a growing part of the continuum of care for self-management of overweight and obesity. Parents positively or negatively influence adolescent weight-management efforts and are especially important throughout continuum of care settings. User-centered design (UCD) applications have been developed to assist primary users, such as adolescents, with their weight management, but less is known about the influence of parents as secondary users across many socio-ecological environments. The purpose of this study was to use the Unified Theory of Acceptance and Use of Technology (UTAUT) to inform the design of a UCD application in a qualitative study that sought to determine parental views on how technology can support previously learned behaviors that require ongoing management and support beyond formal lifestyle interventions. Parents of overweight and obese adolescents (n=14) were interviewed about perceived usefulness and planned user-intent of CHT that was designed for adolescents. UTAUT provided theoretical parental constructs (intention, performance and effort expectancy, and social influence) interactions within several socio-ecological contexts, including the home food environment and restaurant dining experiences. Although generalizations of this qualitative study are limited by a small sample size with predominantly mothers (n=13) of overweight and obese daughters (n=12), the exploratory inquiry using a parent as a secondary consumer user can complement the adoption of applications designed by adolescents.

Segmentation of biomedical images using active contour model with robust image feature and shape prior

In this article, a new level set model is proposed for the segmentation of biomedical images. The image energy of the proposed model is derived from a robust image gradient feature which gives the active contour a global representation of the geometric configuration, making it more robust in dealing with image noise, weak edges, and initial configurations. Statistical shape information is incorporated using nonparametric shape density distribution, which allows the shape model to handle relatively large shape variations. The segmentation of various shapes from both synthetic and real images depict the robustness and efficiency of the proposed method.

Two innovative healthcare technologies at the intersection of serious games, alternative realities, and play therapy

Using game technologies and digital media for improving physical and mental health and for the therapeutic benefit and well-being of a wide range of people is an area of study that is rapidly expanding. Much research in this emerging field is centered at the intersection of serious games, alternative realities, and play therapy. In this paper the authors describe their transdisciplinary work at this intersection: i) an integrative system of psychotherapy technologies called MyPsySpace currently being prototyped in Second Life with the aim of offering new and virtual translations of traditional expressive therapies (virtual sandplay, virtual drama therapy, digital expressive therapy, and virtual safe spaces) and ii) a mature body of research entitled SoundScapes that is exploring the use of interactive video games and abstract creative expression (making music, digital painting, and robotic device control) as a supplement to traditional physical rehabilitation intervention. Aside from introducing our work to a broader audience, our goal is to encourage peers to investigate ideas that reach across disciplines-to both risk and reap the benefits of combining technologies, theories, and methods stemming from multiple disciplines.

[The use of aluminum and its compounds for the biomedical purposes]

Taking into consideration the nanodimension of functional components of living cells, the application of nanotechnology in the biomedical purposes is currently an urgent task. One of these directions is the use of aluminum nanoparticles for molecular diagnostics, targeted delivery of drugs, the development of new pharmaceuticals. The action of aluminum chloride on the regulatory mechanisms of smooth and skeletal muscle contraction and also the effect of aluminum ions on the ATPase activity and superprecipitation of actomyosin of different types of muscles is discussed.

Osteoarthritis--a case for personalized health care?

For both economic and ethical reasons, identification of the optimal treatment for each individual patient is a pressing concern, not only for the patients and their physician, but also health care payers and the pharmaceutical industry. In the field of osteoarthritis (OA) this is of particular relevance, due to the heterogeneity of the disease and the very large number of affected individuals. There is a need to pair the right patients with the right therapeutic modes of action. At present, the clinical trial failures in OA may be a consequence of both bona fide treatment failures and trial failures due to clinical design deficiencies. Tools are needed for characterization and segregation of patients with OA. Key lessons may be learned from advances with another form of arthritis, namely rheumatoid arthritis (RA). Personalized health care (PHC) may be more advantageous for a number of specific indications which are characterized by costly therapy, low response rates and significant problems associated with trial and error prescription, including the risk of serious side effects. We discuss the use of diagnostic practices guiding RA treatment, which may serve as a source of key insights for diagnostic practices in OA. We discuss the emerging concept of PHC, and outline the opportunities and current successes and failures across the RA field, as the OA field collects further data to support the hypothesis. We attempt to outline a possible path forward to assist patients, physicians, payers and the pharmaceutical industry in assuring the 'right' patients are treated with the 'right drug' in OA. Finally we highlight methods for possible segregation of OA patients that would allow identification of patient subtypes, such as OA driven by inflammation that may be ideally suited for PHC and for targeted therapies.

Use of technology when assessing adherence to diabetes self-management behaviors

During the last several decades, a proliferation of sophisticated technology has taken place to facilitate diabetes self-management and improve health outcomes. Blood glucose monitors, insulin pumps, and continuous glucose monitors have significant data storage capacity, which can be used to summarize diabetes health management and outcomes. In the absence of technology errors or failures, and in the context of the multiple psychosocial factors associated with nonadherence, these data have the potential to elucidate diabetes care because they reflect actual patient behaviors. This review provides a summary of the diabetes adherence literature in the context of current American Diabetes Association Clinical Practice Recommendations with a focus on studies that have used objective methods (ie, data derived from technology) to assess diabetes care provider and patient adherence in the areas of glucose monitoring; insulin administration and antihyperglycemic medications; medical nutrition therapy; and physical activity.

Application areas of multi-user virtual environments in the healthcare context

This study conducts a systematic literature review on the application of the three-dimensional virtual worlds (3DVW) in healthcare context. During the past decade, 3DVWs have emerged as a cutting edge technology that has much to offer to the healthcare sector. Our systematic review began with an initial set of 1088 studies published from 1990 to 2013 which have used 3DVWs for the healthcare specific purposes. We found a variety of areas of application for the 3DVWs in healthcare, and categorised them into the following categories: education, treatment, evaluation, lifestyle and simulation. The presented big picture of application areas of 3DVWs in this study can be very valuable and insightful for the researchers and healthcare community.

Grinding model and material removal mechanism of medical nanometer zirconia ceramics

Many patents have been devoted to developing medical nanometer zirconia ceramic grinding techniques that can significantly improve both workpiece surface integrity and grinding quality. Among these patents is a process for preparing ceramic dental implants with a surface for improving osseo-integration by sand abrasive finishing under a jet pressure of 1.5 bar to 8.0 bar and with a grain size of 30 µm to 250 µm. Compared with other materials, nano-zirconia ceramics exhibit unmatched biomedical performance and excellent mechanical properties as medical bone tissue and dentures. The removal mechanism of nano-zirconia materials includes brittle fracture and plastic removal. Brittle fracture involves crack formation, extension, peeling, and chipping to completely remove debris. Plastic removal is similar to chip formation in metal grinding, including rubbing, ploughing, and the formation of grinding debris. The materials are removed in shearing and chipping. During brittle fracture, the grinding-led transverse and radial extension of cracks further generate local peeling of blocks of the material. In material peeling and removal, the mechanical strength and surface quality of the workpiece are also greatly reduced because of crack extension. When grinding occurs in the plastic region, plastic removal is performed, and surface grinding does not generate grinding fissures and surface fracture, producing clinically satisfactory grinding quality. With certain grinding conditions, medical nanometer zirconia ceramics can be removed through plastic flow in ductile regime. In this study, we analyzed the critical conditions for the transfer of brittle and plastic removal in nano-zirconia ceramic grinding as well as the high-quality surface grinding of medical nanometer zirconia ceramics by ELID grinding.