Feasibility of a Novel ECG Electrode Placement Method in Newborn Infants.

BACKGROUND: International newborn resuscitation guidelines recommend electrocardiogram (ECG) heart rate (HR) monitoring at birth. We evaluated the application time of pre-set ECG electrodes fixed to a polyethene patch allowing adhesive-free attachment to the wet skin of the newborn chest. OBJECTIVES: Using a three-electrode pre-set ECG patch configuration, application success was calculated using video analysis and measured at three time points, the time to (1) apply electrodes; (2) detect recognizable QRS complexes after application; and (3) display a HR after application. METHOD: A prospective observational study in two UK tertiary maternity units was undertaken with 71 newborns including 23 who required resuscitation. RESULTS: The median (IQR) time for ECG patch application was 8 (6-10) seconds, detection of recognizable QRS complexes 8 (2-12) seconds, and time to output HR was 23 (15-37) seconds. CONCLUSION: Pre-set ECG chest electrodes allow rapid HR information at birth without electrode detachment or compromising skin integrity.

Finding Comfortable Routes for Ambulance Transfers of Newborn Infants.

Early inter-hospital ambulance transport of premature babies is associated with more severe brain injury. The mechanism is unclear, but they are exposed to excessive noise and vibration. Smart-routing may help minimise these exposure levels and potentially improve outcomes.An app for Android smartphones was developed to collect vibration, noise and location data during ambulance journeys. Four smartphones, with the app installed, were provided to the local neonatal transport group to attach to their incubator trolleys. An example of route comparison was performed on the roads used between Nottingham City Hospital (NCH) and Leicester Royal Infirmary (LRI).Almost 1,700 journeys were recorded over the space of a year. 39 of these journeys travelled from NCH to LRI, comprising of 9 different routes. Analysis was performed on all recorded data which travelled along each road. For routes from NCH to LRI, the route with least vibration was also the quickest. Noise levels, however, were found to increase with vehicle speed. Ambulance drivers in the study did not tend to take the quickest, smoothest or quietest route.Android smartphones are a practical method of gathering information about the in-ambulance environment. Routes were found to vary in vibration, noise and speed, suggesting these could be minimised. The next step is to combine recorded and clinical data to try and define an ideal neonatal comfort metric which can then be fed into the routing. Roll-out of the app around the UK is also planned.Clinical relevance-Transferring preterm neonatal infants to specialist units lead to worse outcomes. By reducing the levels of vibration and noise the infants are exposed to during transport, we hope to improve outcomes.

Growth Spectrum Complexity Dictates Aromatic Intensity in Coriander (Coriandrum sativum L.).

Advancements in availability and specificity of light-emitting diodes (LEDs) have facilitated trait modification of high-value edible herbs and vegetables through the fine manipulation of spectra. Coriander (Coriandrum sativum L.) is a culinary herb, known for its fresh, citrusy aroma, and high economic value. Studies into the impact of light intensity and spectrum on C. sativum physiology, morphology, and aroma are limited. Using a nasal impact frequency panel, a selection of key compounds associated with the characteristic aroma of coriander was identified. Significant differences (P < 0.05) were observed in the concentration of these aromatics between plants grown in a controlled environment chamber under the same photosynthetic photon flux density (PPFD) but custom spectra: red (100%), blue (100%), red + blue (RB, 50% equal contribution), or red + green + blue (RGB, 35.8% red: 26.4% green: 37.8% blue) wavelengths. In general, the concentration of aromatics increased with increasing numbers of wavelengths emitted alongside selective changes, e.g., the greatest increase in coriander-defining E-(2)-decenal occurred under the RGB spectrum. This change in aroma profile was accompanied by significant differences (P < 0.05) in light saturated photosynthetic CO2 assimilation, water-use efficiency (Wi), and morphology. While plants grown under red wavelengths achieved the greatest leaf area, RB spectrum plants were shortest and had the highest leaf:shoot ratio. Therefore, this work evidences a trade-off between sellable commercial morphologies with a weaker, less desirable aroma or a less desirable morphology with more intense coriander-like aromas. When supplemental trichromatic LEDs were used in a commercial glasshouse, the majority of compounds, with the exception of linalool, also increased showing that even as a supplement additional wavelength can modify the aromatic profile increasing its complexity. Lower levels of linalool suggest these plants may be more susceptible to biotic stress such as herbivory. Finally, the concentration of coriander-defining aromatics E-(2)-decenal and E-(2)-hexenal was significantly higher in supermarket pre-packaged coriander leaves implying that concentrations of aromatics increase after excision. In summary, spectra can be used to co-manipulate aroma profile and plant form with increasing spectral complexity leading to greater aromatic complexity and intensity. We suggest that increasing spectral complexity progressively stimulates signaling pathways giving rise to valuable economic traits.

Anti-confocal assessment of middle ear inflammation.

To improve the diagnostic prediction of recurrence of otitis media with effusion after surgery, an anti-confocal system combined with spectroscopic measurements is proposed to reject unwanted signals from the eardrum and assess the blood content. The anti-confocal system was experimentally evaluated on both optical middle ear phantom and human skin. Results showed effective rejection of signals from the eardrum using a central stop replacing the confocal pinhole, while still detecting signals from the middle ear mucosa. The system is sensitive to changes in blood content, but scattering and absorption characteristics of the eardrum can distort the measurement. Confocal detection of eardrum properties was shown to be a promising approach to correct measurements.

Anti-confocal versus confocal assessment of the middle ear simulated by Monte Carlo methods.

The ability to monitor the inflammatory state of the middle ear mucosa would provide clinical utility. To enable spectral measurements on the mucosa whilst rejecting background signal from the eardrum an anti-confocal system is investigated. In contrast to the central pinhole in a confocal system the anti-confocal system uses a central stop to reject light from the in-focus plane, the eardrum, with all other light detected. Monte Carlo simulations of this system show an increase in detected signal and improved signal-to-background ratio compared to a conventional confocal set-up used to image the middle ear mucosa. System parameters are varied in the simulation and their influence on the level of background rejection are presented.

Light path-length distributions within the retina.

A Monte Carlo simulation of light propagation through the retina has been developed to understand the path-length distributions within the retinal vessel. For full-field illumination, the path-length distribution within the vessel comprises directly backscattered light and light that has passed once or twice through the vessel. The origins of these light path-length distributions can be better understood by investigating different combinations of single-point illumination and detection positions. Perhaps the most significant observation is that illumination at the edges of the vessel, rather than over the whole field of view, and detection directly above the vessel capture only the light that has taken a single pass through the vessel. This path-length distribution is tightly constrained around the diameter of the vessel and can potentially provide enhancements for oxygen saturation imaging. The method could be practically implemented using an offset-pinhole confocal imaging system or structured light illumination.

Medical device design for adolescent adherence and developmental goals: a case study of a cystic fibrosis physiotherapy device.

PURPOSE: This study investigates the psychosocial aspects of adolescent medical device use and the impact on adolescent adherence and goals for the transitional years between child and adulthood. PATIENTS AND METHODS: Interviews were carried out with 20 adolescents with cystic fibrosis, investigating adolescent medical device use and experiences in relation to their personal and social lives and development through the adolescent years. The qualitative dataset was thematically examined using a content analysis method. RESULTS: The results show that adolescent users of medical technologies want their independence and capabilities to be respected. Adolescent adherence to medical device use was associated with short- and long-term motivations, where older adolescents were able to comprehend the longer-term benefits of use against short-term inconvenience more acutely than younger adolescents. It was suggested that medical devices could provide a tool for communication with families and clinicians and could support adolescents as they take responsibility for managing their condition. Themes of "fitting into teenage life" and "use in the community" were associated with adolescents' needs to form their own identity and have autonomy. CONCLUSION: This study shows that adolescent needs regarding medical device use are complex. It provides evidence to suggest that devices designed inclusively for adolescents may lead to improved adherence and also facilitate transition through the adolescent years and achievement of adolescent goals.

Laser doppler blood flow imaging using a CMOS imaging sensor with on-chip signal processing.

The first fully integrated 2D CMOS imaging sensor with on-chip signal processing for applications in laser Doppler blood flow (LDBF) imaging has been designed and tested. To obtain a space efficient design over 64 × 64 pixels means that standard processing electronics used off-chip cannot be implemented. Therefore the analog signal processing at each pixel is a tailored design for LDBF signals with balanced optimization for signal-to-noise ratio and silicon area. This custom made sensor offers key advantages over conventional sensors, viz. the analog signal processing at the pixel level carries out signal normalization; the AC amplification in combination with an anti-aliasing filter allows analog-to-digital conversion with a low number of bits; low resource implementation of the digital processor enables on-chip processing and the data bottleneck that exists between the detector and processing electronics has been overcome. The sensor demonstrates good agreement with simulation at each design stage. The measured optical performance of the sensor is demonstrated using modulated light signals and in vivo blood flow experiments. Images showing blood flow changes with arterial occlusion and an inflammatory response to a histamine skin-prick demonstrate that the sensor array is capable of detecting blood flow signals from tissue.

The effect of design on the usability and real world effectiveness of medical devices: a case study with adolescent users.

Adolescents are currently overlooked in many fields of healthcare research and as a result are often required to use medical devices that have been designed for use by either children or adults. This can lead to poor adherence and a reduction in health outcomes. This study examines the role of device design in the real-world effectiveness of a medical device used in the treatment of cystic fibrosis from the perspective of adolescent users. Interactive design interviews were carried out with 20 adolescent users of the acapella(®) physiotherapy device to investigate user requirements and themes about the user-device relationship that are important to this user group. This study found that adolescent users of the acapella(®) device do not use the device as regularly and correctly as is recommended by clinicians. A number of aspects of the current design of the acapella(®) device were identified that affect how and how often it is used. Five factors are identified that may improve the real world effectiveness of the acapella(®) device for adolescents with Cystic Fibrosis: engagement, information, confidence, aesthetics and compatibility with lifestyle.

Application of a maximum likelihood algorithm to ultrasound modulated optical tomography.

In pulsed ultrasound modulated optical tomography (USMOT), an ultrasound (US) pulse performs as a scanning probe within the sample as it propagates, modulating the scattered light spatially distributed along its propagation axis. Detecting and processing the modulated signal can provide a 1-dimensional image along the US axis. A simple model is developed wherein the detected signal is modelled as a convolution of the US pulse and the properties (ultrasonic/optical) of the medium along the US axis. Based upon this model, a maximum likelihood (ML) method for image reconstruction is established. For the first time to our knowledge, the ML technique for an USMOT signal is investigated both theoretically and experimentally. The ML method inverts the data to retrieve the spatially varying properties of the sample along the US axis, and a signal proportional to the optical properties can be acquired. Simulated results show that the ML method can serve as a useful reconstruction tool for a pulsed USMOT signal even when the signal-to-noise ratio (SNR) is close to unity. Experimental data using 5 cm thick tissue phantoms (scattering coefficient µ(s) = 6.5 cm(-1), anisotropy factor g=0.93) demonstrate that the axial resolution is 160 µm and the lateral resolution is 600 µm using a 10 MHz transducer.

An explanation for the effectiveness of the 'Draijer' algorithm for high speed laser Doppler perfusion imaging.

Laser Doppler flowmetry relies upon the use of the first moment of the power spectrum of the photocurrent and numerous methods of providing an estimate of this have been implemented. One, operating in the time domain and using only a few, simple processing steps, is claimed to be both fast and accurate (Draijer et al. in Med Biol Eng Comput 47(10):1103-1109, 2009). However, it is acknowledged that the theory underpinning its operation is intuitive. Here it is shown that this algorithm mimics the use of the analytic representation of the photocurrent and although capable of approximating the required value is certainly not equivalent mathematically.

Time-optimized X-ray micro-CT imaging of polymer based scaffolds.

Although X-ray microscopic computed tomography is widely used to assess the structural properties of polymeric tissue scaffolds its validity is dependent on the quality of the images obtained. Here, the role of resolution, integration time, image averaging, and X-ray power on the accurate determination of scaffold porosity, while aiming to minimize imaging time, was investigated. This work identified key parameters for optimization and a methodology to vary them to improve results. Based on this, guidelines were developed to assist in the selection of image acquisition parameters to allow rapid and accurate scaffold imaging as required for mass manufacture.

A user-centred approach to requirements elicitation in medical device development: a case study from an industry perspective.

The healthcare industry is dependent upon the provision of well designed medical devices. To achieve this it is recommended that user-centred design should begin early, and continue throughout device development. This is a challenge, particularly for smaller companies who may lack the necessary expertise and knowledge. The aim of this study was to conduct a rigorous yet focused investigation into the user requirements for a new medical imaging device. Open-ended semi-structured interviews were conducted with potential clinical users of the device to investigate the clinical need for the device and the potential benefits for patients and clinical users. The study identified a number of new and significant clinical needs that suggested that the concept of the device should be fundamentally changed. The clinical and organisational priorities of the clinical users were identified, as well as a number of factors that would act as barriers to the safe and effective adoption of the device. The developers reported that this focused approach to early requirements elicitation would result in an improved product, reduce the time to market, and save the time and cost of producing and evaluating an inappropriate prototype.

Low resource processing algorithms for laser Doppler blood flow imaging.

The emergence of full field laser Doppler blood flow imaging systems based on CMOS camera technology means that a large amount of data from each pixel in the image needs to be processed rapidly and system resources need to be used efficiently. Conventional processing algorithms that are utilized in single point or scanning systems are therefore not an ideal solution as they will consume too much system resource. Two processing algorithms that address this problem are described and efficiently implemented in a field programmable gate array. The algorithms are simple enough to use low system resource but effective enough to produce accurate flow measurements. This enables the processing unit to be integrated entirely in an embedded system, such as in an application-specific integrated circuit. The first algorithm uses a short Fourier transformation length (typically 8) but averages the output multiple times (typically 128). The second method utilizes an infinite impulse response filter with a low number of filter coefficients that operates in the time domain and has a frequency-weighted response. The algorithms compare favorably with the reference standard 1024 point fast Fourier transform in terms of both resource usage and accuracy. The number of data words per pixel that need to be stored for the algorithms is 1024 for the reference standard, 8 for the short length Fourier transform algorithm and 5 for the algorithm based on the infinite impulse response filter. Compared to the reference standard the error in the flow calculation is 1.3% for the short length Fourier transform algorithm and 0.7% for the algorithm based on the infinite impulse response filter.

Development of mobile psychiatry for bipolar disorder patients.

Managing bipolar disorder is an increasingly important healthcare issue as the global prevalence of this condition grows. A widely practiced method of monitoring the course of the disorder is by mood and general mental health questionnaires. However, current mobile technology provides a potential means of monitoring the behavior of individuals and this information could be of value for recognizing changes in routine that could be indicative of an upcoming bipolar episode. This article explores the potential of utilizing geospatial information and indicators of social interaction to enable mobile psychiatry.

Towards personalised ambient monitoring of mental health via mobile technologies.

Managing bipolar disorder is an important health issue that can strongly affect the patient's quality of life during occurrences of depressive or manic episodes and is therefore a growing burden to healthcare systems. A widely practised method of monitoring the course of the disorder is by mood and general mental health questionnaires, which are nowadays often implemented on mobile electronic devices.Detecting changes to daily routine and behaviour is of crucial importance as they can be symptomatic of an ongoing episode, or in the case of an external cause, may trigger such an episode.Current mobile phones and geospatial technology provide a means of monitoring aspects of daily routine and lifestyle which may be valuable in facilitating self-management of the condition.This manuscript introduces a methodology for analysing data obtained from a simple wearable system based on a mid-range mobile phone, along with trial results from a control group of three participants with no history of Bipolar Disorder. It is suggested that such an approach offers an unobtrusive, acceptable and low cost means of monitoring bipolar disorder patients that could significantly improve their care.

Time-lapsed imaging for in-process evaluation of supercritical fluid processing of tissue engineering scaffolds.

This article demonstrates the application of time-lapsed imaging and image processing to inform the supercritical processing of tissue scaffolds that are integral to many regenerative therapies. The methodology presented provides online quantitative evaluation of the complex process of scaffold formation in supercritical environments. The capabilities of the developed system are demonstrated through comparison of scaffolds formed from polymers with different molecular weight and with different venting times. Visual monitoring of scaffold fabrication enabled key events in the supercritical processing of the scaffolds to be identified including the onset of polymer plasticization, supercritical points and foam formation. Image processing of images acquired during the foaming process enabled quantitative tracking of the growing scaffold boundary that provided new insight into the nature of scaffold foaming. Further, this quantitative approach assisted in the comparison of different scaffold fabrication protocols. Observed differences in scaffold formation were found to persist, post-fabrication as evidenced by micro x-ray computed tomography (micro x-ray CT) images. It is concluded that time-lapsed imaging in combination with image processing is a convenient and powerful tool to provide insight into the scaffold fabrication process.

Experimental and theoretical evaluation of rotating orthogonal polarization imaging.

Rotating orthogonal polarization imaging is a new technique that provides quantitative measurements of the polarization properties of scattering media, such as tissue, which are free from surface reflections. The technique is investigated using both experiments and Monte Carlo simulations of a polarizing target embedded within a scattering medium. The technique is sensitive to the polarization properties of the target up to a depth of 17 mean free paths. Preliminary images of bovine tendon, lamb tendon, chicken breast, and human skin are also demonstrated.

Generation and simulated imaging of pseudo-scaffolds to aid characterisation by X-ray micro CT.

In order to assess the suitability of polymer tissue scaffolds for use in regenerative medicine, methods to characterise scaffolds are needed. This requires the scaffold's structure to be determined for which X-ray microscopic computed tomography (X-ray micro CT) is widely used. However, because scaffolds are generally made of materials with low X-ray attenuating properties the images produced are far from ideal, which makes distinguishing scaffold material from the pores within it a non-trivial process. This paper presents a method for generating computer-simulated scaffolds that resemble the form of foamed polymer tissue scaffolds. Virtual images of the scaffold are then produced via a simulated X-ray micro CT process enabling the effect of varying the key parameters in the imaging process to be investigated. Here this is assessed via the calculated porosity of the sample, this being a simple measure of a scaffold's properties. Results highlight the difficulties in using X-ray micro CT to characterise scaffolds constructed from materials with low X-ray attenuating properties and suggest strategies that may be adopted in order to improve the quality of the images produced.

Rotating orthogonal polarization imaging.

Surface reflections often present a problem in the polarization difference imaging of tissue. The technique described involves illumination in a single polarization state and detection in the orthogonal polarization state. Synchronously rotating both the illumination and orthogonal detection states provides an image free from surface reflections that is sensitive to the polarization properties of the underlying tissue. Results on tissue phantoms demonstrate that polarization sensitive measurements of a test target can be made up to a depth of 12 mean free paths within a scattering medium. Preliminary images of bovine tendon are also demonstrated.