Hybridized neural networks for non-invasive and continuous mortality risk assessment in neonates.

Premature birth is the primary risk factor in neonatal deaths, with the majority of extremely premature babies cared for in neonatal intensive care units (NICUs). Mortality risk prediction in this setting can greatly improve patient outcomes and resource utilization. However, existing schemes often require laborious medical testing and calculation, and are typically only calculated once at admission. In this work, we propose a shallow hybrid neural network for the prediction of mortality risk in 3-day, 7-day, and 14-day risk windows using only birthweight, gestational age, sex, and heart rate (HR) and respiratory rate (RR) information from a 12-h window. As such, this scheme is capable of continuously updating mortality risk assessment, enabling analysis of health trends and responses to treatment. The highest performing scheme was the network that considered mortality risk within 3 days, with this scheme outperforming state-of-the-art works in the literature and achieving an area under the receiver-operator curve (AUROC) of 0.9336 with standard deviation of 0.0337 across 5 folds of cross-validation. As such, we conclude that our proposed scheme could readily be used for continuously-updating mortality risk prediction in NICU environments.

A hybrid neural network for continuous and non-invasive estimation of blood pressure from raw electrocardiogram and photoplethysmogram waveforms.

BACKGROUND AND OBJECTIVES: Continuous and non-invasive blood pressure monitoring would revolutionize healthcare. Currently, blood pressure (BP) can only be accurately monitored using obtrusive cuff-based devices or invasive intra-arterial monitoring. In this work, we propose a novel hybrid neural network for the accurate estimation of blood pressure (BP) using only non-invasive electrocardiogram (ECG) and photoplethysmogram (PPG) waveforms as inputs. METHODS: This work proposes a hybrid neural network combines the feature detection abilities of temporal convolutional layers with the strong performance on sequential data offered by long short-term memory layers. Raw electrocardiogram and photoplethysmogram waveforms are concatenated and used as network inputs. The network was developed using the TensorFlow framework. Our scheme is analysed and compared to the literature in terms of well known standards set by the British Hypertension Society (BHS) and the Association for the Advancement of Medical Instrumentation (AAMI). RESULTS: Our scheme achieves extremely low mean absolute errors (MAEs) of 4.41 mmHg for SBP, 2.91 mmHg for DBP, and 2.77 mmHg for MAP. A strong level of agreement between our scheme and the gold-standard intra-arterial monitoring is shown through Bland Altman and regression plots. Additionally, the standard for BP devices established by AAMI is met by our scheme. We also achieve a grade of 'A' based on the criteria outlined by the BHS protocol for BP devices. CONCLUSIONS: Our CNN-LSTM network outperforms current state-of-the-art schemes for non-invasive BP measurement from PPG and ECG waveforms. These results provide an effective machine learning approach that could readily be implemented into non-invasive wearable devices for use in continuous clinical and at-home monitoring.

Determining respiratory rate from photoplethysmogram and electrocardiogram signals using respiratory quality indices and neural networks.

Continuous and non-invasive respiratory rate (RR) monitoring would significantly improve patient outcomes. Currently, RR is under-recorded in clinical environments and is often measured by manually counting breaths. In this work, we investigate the use of respiratory signal quality quantification and several neural network (NN) structures for improved RR estimation. We extract respiratory modulation signals from the electrocardiogram (ECG) and photoplethysmogram (PPG) signals, and calculate a possible RR from each extracted signal. We develop a straightforward and efficient respiratory quality index (RQI) scheme that determines the quality of each moonddulation-extracted respiration signal. We then develop NNs for the estimation of RR, using estimated RRs and their corresponding quality index as input features. We determine that calculating RQIs for modulation-extracted RRs decreased the mean absolute error (MAE) of our NNs by up to 38.17%. When trained and tested using 60-sec waveform segments, the proposed scheme achieved an MAE of 0.638 breaths per minute. Based on these results, our scheme could be readily implemented into non-invasive wearable devices for continuous RR measurement in many healthcare applications.

Continuous and automatic mortality risk prediction using vital signs in the intensive care unit: a hybrid neural network approach.

Mortality risk prediction can greatly improve the utilization of resources in intensive care units (ICUs). Existing schemes in ICUs today require laborious manual input of many complex parameters. In this work, we present a scheme that uses variations in vital signs over a 24-h period to make mortality risk assessments for 3-day, 7-day, and 14-day windows. We develop a hybrid neural network model that combines convolutional (CNN) layers with bidirectional long short-term memory (BiLSTM) to predict mortality from statistics describing the variation of heart rate, blood pressure, respiratory rate, blood oxygen levels, and temperature. Our scheme performs strongly compared to state-of-the-art schemes in the literature for mortality prediction, with our highest-performing model achieving an area under the receiver-operator curve of 0.884. We conclude that the use of a hybrid CNN-BiLSTM network is highly effective in determining mortality risk for the 3, 7, and 14 day windows from vital signs. As vital signs are routinely recorded, in many cases automatically, our scheme could be implemented such that highly accurate mortality risk could be predicted continuously and automatically, reducing the burden on healthcare providers and improving patient outcomes.

Motion reduction for quantitative brain sodium MR imaging with a navigated flexible twisted projection imaging sequence at 9.4 T.

Quantitative measurement of the tissue sodium concentration (TSC) provides a metric for tissue cell volume fraction for monitoring tumor responses to therapy and neurodegeneration in the brain as well as applications outside the central nervous system such as the fixed charge density in cartilage. Despite the low detection sensitivity of the sodium MR signal compared to the proton signal and the requirement for a long repetition time to minimize longitudinal magnetization saturation, acquisition time has been reduced to less than 10 min for a nominal isotropic voxel size of 3.3 mm with the improved acquisition efficiency of twisted projection imaging (TPI) at 9.4 T. However, patient motion can degrade the accuracy of the quantification even within these acquisition times. Our goal has been to improve the robustness of quantitative sodium MR imaging by minimizing the impact of motion that may occur even in cooperative patients. We present a method to spatially encode a lower resolution navigator echo after encoding the free induction decay signal for the quantitative image at no time penalty. Both the imaging and navigator data are sampled with flexTPI readout trajectories. Navigator images are generated at a higher temporal resolution (∼1 min) albeit at lower spatial resolution (8 mm) than the quantitative high-resolution images. The multiple volumes of navigator echo images are then aligned to extract the translational and rotational motion parameters assuming rigid-body motion. These parameters are used to align the k-space data during the acquisition of each volume of the quantitative images. Our results show significantly reduced image blurring with this method when the subject's head moved randomly by up to 7° between the navigator acquisitions.

Complementing a Clinical Trial With Human-Computer Interaction: Patients' User Experience With Telehealth.

BACKGROUND: The use of telehealth to monitor patients from home is on the rise. Telehealth technology is evaluated in a clinical trial with measures of health outcomes and cost-effectiveness. However, what happens between a technology and the patients is not investigated during a clinical trial-the telehealth technology remains as a "black box." Meanwhile, three decades of research in the discipline of human-computer interaction (HCI) presents design, implementation, and evaluation of technologies with a primary emphasis on users. HCI research has exposed the importance of user experience (UX) as an essential part of technology development and evaluation. OBJECTIVE: This research investigates the UX of patients with type 2 diabetes mellitus (T2D) with a telehealth in-home monitoring device to manage T2D from home. We investigate how the UX during a clinical trial can be researched and what a clinical trial can learn from HCI research. METHODS: We adopted an ethnographic philosophy and conducted a contextual inquiry due to time limitations followed by semistructured interviews of 9 T2D patients. We defined the method as Clinical User-experience Evaluation (CUE). The patients were enrolled in a telehealth clinical trial of T2D; however, this research was an independent study conducted by information technologists and health researchers for a user-centered evaluation of telehealth. RESULTS: Key analytical findings were that patients valued the benefits of in-home monitoring, but the current device did not possess all functionalities that patients wanted. The results include patients' experiences and emotions while using the device, patients' perceived benefits of the device, and how patients domesticated the device. Further analysis showed the influence of the device on patients' awareness, family involvement, and design implications for telehealth for T2D. CONCLUSIONS: HCI could complement telehealth clinical trials and uncover knowledge about T2D patients' UX and future design implications. Through HCI we can look into the "black box" phenomenon of clinical trials and create patient-centered telehealth solutions.

A Randomized Controlled Trial using iTClamp, Direct Pressure, and Balloon Catheter Tamponade to Control Neck Hemorrhage in a Perfused Human Cadaver Model.

BACKGROUND: Penetrating neck wounds are common in the civilian and military realms. Whether high or low velocity, they carry a substantial morbidity and mortality rate. OBJECTIVES: We endeavored to ascertain whether the iTClamp is equivalent to direct manual pressure (DMP) and Foley catheter balloon tamponade (BCT). METHODS: Using a perfused cadaver, a 4.5-cm wound was made in Zone 2 of the neck with a 1-cm carotid arteriotomy. Each of the hemorrhage control modalities was randomized and then applied to the wound separately. Time to apply the device and fluid loss with and without neck motion was recorded. RESULTS: There was no significant difference between the fluid loss/no movement (p > 0.450) and fluid loss/movement (p > 0.215) between BCT and iTClamp. There was significantly more fluid lost with DMP than iTClamp with no movement (p > 0.000) and movement (p > 0.000). The iTClamp was also significantly faster to apply than the Foley (p > 0.000). CONCLUSIONS: The iTClamp and BCT were associated with significantly less fluid loss than DMP in a perfused cadaver model. The iTClamp required significantly less time to apply than the BCT. Both the iTClamp and the BCT were more effective than simple DMP. The iTClamp offers an additional option for managing hard-to-control bleeding in the neck.

Residual Tumor Volume, Cell Volume Fraction, and Tumor Cell Kill During Fractionated Chemoradiation Therapy of Human Glioblastoma using Quantitative Sodium MR Imaging.

PURPOSE: Spatial and temporal patterns of response of human glioblastoma to fractionated chemoradiation are described by changes in the bioscales of residual tumor volume (RTV), tumor cell volume fraction (CVF), and tumor cell kill (TCK), as derived from tissue sodium concentration (TSC) measured by quantitative sodium MRI at 3 Tesla. These near real-time patterns during treatment are compared with overall survival. EXPERIMENTAL DESIGN: Bioscales were mapped during fractionated chemoradiation therapy in patients with glioblastomas (n = 20) using TSC obtained from serial quantitative sodium MRI at 3 Tesla and a two-compartment model of tissue sodium distribution. The responses of these parameters in newly diagnosed human glioblastomas undergoing treatment were compared with time-to-disease progression and survival. RESULTS: RTV following tumor resection showed decreased CVF due to disruption of normal cell packing by edema and infiltrating tumor cells. CVF showed either increases back toward normal as infiltrating tumor cells were killed, or decreases as cancer cells continued to infiltrate and extend tumor margins. These highly variable tumor responses showed no correlation with time-to-progression or overall survival. CONCLUSIONS: These bioscales indicate that fractionated chemoradiotherapy of glioblastomas produces variable responses with low cell killing efficiency. These parameters are sensitive to real-time changes within the treatment volume while remaining stable elsewhere, highlighting the potential to individualize therapy earlier in management, should alternative strategies be available.

SERIAL transmit - parallel receive (STxPRx) MR imaging produces acceptable proton image uniformity without compromising field of view or SAR guidelines for human neuroimaging at 9.4 Tesla.

PURPOSE: Non-uniform B1+ excitation and high specific absorption rates (SAR) compromise proton MR imaging of human brain at 9.4 T (400.5 MHz). By combining a transmit/receive surface coil array using serial transmission of individual coils with a total generalized variation reconstruction of images from all coils, acceptable quality human brain imaging is demonstrated. METHODS: B0 is shimmed using sodium MR imaging (105.4 MHz) with a birdcage coil. Proton MR imaging is performed with an excitation/receive array of surface coils. The modified FLASH pulse sequence transmits serially across each coil within the array thereby distributing SAR in time and space. All coils operate in receive mode. Although the excitation profile of each transmit coil is non-uniform, the sensitivity profile estimated from the non-transmit receive coils provides an acceptable sensitivity correction. Signals from all coils are combined in a total generalized variation (TGV) reconstruction to provide a full field of view image at maximum signal to noise (SNR) performance. RESULTS: High-resolution images across the human head are demonstrated with acceptable uniformity and SNR. CONCLUSION: Proton MR imaging of the human brain is possible with acceptable uniformity at low SAR at 9.4 Tesla using this serial excitation and parallel reception strategy with TGV reconstruction.

Use of the iTClamp versus standard suturing techniques for securing chest tubes: A randomized controlled cadaver study.

OBJECTIVES: Tube thoracostomy (TT) is a common yet potentially life-saving trauma procedure. After successful placement however, securing a TT through suturing is a skillset that requires practice, risking that the TT may become dislodged during prehospital transport. The purpose of this study was to examine if the iTClamp was a simpler technique with equivalent effectiveness for securing TTs. MATERIALS AND METHODS: In a cadaver model, a 1.5 inch incision was utilized along the upper border of the rib below the 5th intercostal space at the anterior axillary line. TTs (sizes 28Fr, 32Fr, 36Fr and 40Fr) were inserted and secured with both suturing and iTClamp techniques according to the preset randomization. TT were then functionally tested for positive and negative pressure as well as the force required to remove the TT (pull test-up to 5 lbs). Time to secure the TT was also recorded. RESULTS: When sutured is placed by a trained surgeon, the sutures and iTClamp were functionally equivalent for holding a positive and negative pressure. Mean pull force for both sutures and iTClamp exceeded the 5 lb threshold; there was no significant difference between the groups. Securing the TT with the iTClamp was significantly faster (p < 0.0001) with the iTClamp having a mean application time of 37.0 ±â€¯22.8 s and using a suture had a man application time of 96.3 ±â€¯29.0 s. CONCLUSION: The iTClamp was effective in securing TTs. The main benefit to the iTClamp is that minimal skill is required to adequately secure a TT to ensure that it does not become dislodged during transport to a trauma center.

Hemorrhagic Cholecystitis after Warfarin Use for Deep Vein Thrombosis.

Hemorrhagic cholecystitis is an uncommon form of acute cholecystitis which can be rapidly fatal. It may be hard to detect as it frequently presents with symptoms found in other, more common diagnoses. We report the case of a 63 year old man recently started on anticoagulation for deep vein thrombosis who was found to have hemorrhagic cholecystitis.

Evaluation of Skin Damage from Accidental Removal of a Hemostatic Wound Clamp (The iTClamp).

BACKGROUND: Controlling bleeding early in the prehospital and military setting is an extremely important and life-saving skill. Wound clamping is a newly introduced technique that may augment both the effectiveness and logistics of wound packing with any gauze product. As these devices may be inadvertently removed, the potential consequences of such were examined in a simulated, extreme, inadvertent disengagement. METHODS: The wound clamp used was an iTClamp (Innovative Trauma Care; Edmonton, Alberta, Canada) that was applied and forcefully removed (skin-pull) from the skin of both a human cadaver and swine. Sixty skin-pull tests were sequentially performed to measure the pull weight required to remove the device, any potential skin and device damage, how the device failed, and if the device could be re-applied. RESULTS: Observations of the skin revealed that other than the expected eight small needle holes from device application, no other damage to the skin was sustained in 98.3% of cases. Conversely, of the 60 devices pulled, 93.3% of the devices sustained no damage and all could be re-applied. Four (6.7%) of the devices remained in place despite a maximum pull weight >22lb F (pound-force). The mean pull weights for pin bar pull were (lb F ): vertical 9.2 (SD=5.0); perpendicular 2.5 (SD=1.7); and parallel 5.3 (SD=3.1). For the encompassed pull position group, mean pull weights were (lb F ): vertical 5.7 (SD=2.3); perpendicular 3.0 (SD=2.5); and parallel 14.5 (SD=3.5). The overall mean for all groups was 6.7 (SD=5.2). The two main reasons that the iTClamp was pulled off were because the friction lock let go or the needles slipped out of one side of the skin due to the angle of the pull. CONCLUSION: Inadvertent, forcible removal of the iTClamp created essentially no skin damage seen when the wound clamp was forcibly removed from either cadaver or swine models in a variety of positions and directions. Thus, the risks of deployment in operational environments do not seem to be increased. Mckee JL , Lakshminarasimhan P , Atkinson I , LaPorta AJ , Kirkpatrick AW . Evaluation of skin damage from accidental removal of a hemostatic wound clamp (the iTClamp). Prehosp Disaster Med. 2017;32(6):651-656.

Diffusion in Colocation Contact Networks: The Impact of Nodal Spatiotemporal Dynamics.

Temporal contact networks are studied to understand dynamic spreading phenomena such as communicable diseases or information dissemination. To establish how spatiotemporal dynamics of nodes impact spreading potential in colocation contact networks, we propose "inducement-shuffling" null models which break one or more correlations between times, locations and nodes. By reconfiguring the time and/or location of each node's presence in the network, these models induce alternative sets of colocation events giving rise to contact networks with varying spreading potential. This enables second-order causal reasoning about how correlations in nodes' spatiotemporal preferences not only lead to a given contact network but ultimately influence the network's spreading potential. We find the correlation between nodes and times to be the greatest impediment to spreading, while the correlation between times and locations slightly catalyzes spreading. Under each of the presented null models we measure both the number of contacts and infection prevalence as a function of time, with the surprising finding that the two have no direct causality.

Quantitative sodium MRI of the human brain at 9.4 T provides assessment of tissue sodium concentration and cell volume fraction during normal aging.

Sodium ion homeostasis is a fundamental property of viable tissue, allowing the tissue sodium concentration to be modeled as the tissue cell volume fraction. The modern neuropathology literature using ex vivo tissue from selected brain regions indicates that human brain cell density remains constant during normal aging and attributes the volume loss that occurs with advancing age to changes in neuronal size and dendritic arborization. Quantitative sodium MRI performed with the enhanced sensitivity of ultrahigh-field 9.4 T has been used to investigate tissue cell volume fraction during normal aging. This cross-sectional study (n = 49; 21-80 years) finds that the in vivo tissue cell volume fraction remains constant in all regions of the brain with advancing age in individuals who remain cognitively normal, extending the ex vivo literature reporting constant neuronal cell density across the normal adult age range. Cell volume fraction, as measured by quantitative sodium MRI, is decreased in diseases of cell loss, such as stroke, on a time scale of minutes to hours, and in response to treatment of brain tumors on a time scale of days to weeks. Neurodegenerative diseases often have prodromal periods of decades in which regional neuronal cell loss occurs prior to clinical presentation. If tissue cell volume fraction can detect such early pathology, this quantitative parameter may permit the objective measurement of preclinical disease progression. This current study in cognitively normal aging individuals provides the basis for the pursuance of investigations directed towards such neurodegenerative diseases.

A meta-synthesis of behavioral outcomes from telemedicine clinical trials for type 2 diabetes and the Clinical User-Experience Evaluation (CUE).

A worldwide demographic shift is in progress and the aged population proportion is projected to more than double across the next four decades. Our current healthcare models may not be adequate to handle this shift in demography, which may have serious consequences for the ageing population who are more prone to chronic diseases. One proposed remediation is to provide in-home assisted healthcare with technology-intervened approaches. Telemedicine, telehealth, e-health are paradigms found in scientific literature that provide clinical treatment through a technology intervention. In evidence-based medical science, these technology interventions are evaluated through clinical trials, which are targeted to measure improvements in medical conditions and the treatment's cost effectiveness. However, effectiveness of a technology also depends on the interaction pattern between the technology and its' users, especially the patients. This paper presents (1) a meta-synthesis of clinical trials for technology-intervened treatments of type 2 diabetes and (2) the Clinical User-Experience Evaluation (CUE). CUE is a recommendation for future telemedicine clinical trials that focuses on the patient as the user from Human-Computer Interaction (HCI) perspective and was developed as part of this research. The clinical trials reviewed were interpreted from a technology perspective and the non-medical or non-biological improvements of the users (patients) rather than the medical outcome. Results show that technology-intervened treatments provide positive behavior changes among patients and are potentially highly beneficial for chronic illness management such as type 2 diabetes. The results from the CUE method show how it complements clinical trials to capture patients' interaction with a technology.

Evaluation of the iTClamp 50 in a human cadaver model of severe compressible bleeding.

BACKGROUND: Uncontrolled hemorrhage is a significant cause of preventable death. The iTClamp 50 is a temporary wound closure device designed to control bleeding within seconds of an injury. This study evaluates the ability of the iTClamp to control compressible bleeding in a human cadaver model. METHODS: Sterile water was pumped through the major arteries to mimic blood flow. Full-thickness, elliptical segments of skin were excised; arteriotomies or complete transections were performed on the major arteries in the thigh (distal femoral), groin (common femoral), neck (carotid), and arm (brachial). Scalp wounds were created by making a 4.4-cm linear incision to the level of the bone. Fluid losses from the wounds were compared with and without the iTClamp applied and with and without movement of the cadaver. Angiographic images of pressure-injected contrast were obtained of the neck and groin wounds. Hematoma volumes and needle penetration depth into the skin were measured. RESULTS: In all wounds tested, application of the iTClamp significantly reduced fluid loss in all wounds studied (p < 0.05), and movement of the cadaver did not affect the function of the iTClamp. For example, in one groin wound, the average fluid loss during 1 minute was reduced from 728.4 ± 79.3 mL to 5.6 ± 3.4 mL. Distal flow was maintained during application of the iTClamp, as illustrated in angiographic images obtained of the iTClamp applied to the neck and groin wounds. The average needle penetration depth into the skin was 4.21 ± 0.02 mm; furthermore, the iTClamp did not cause any visible skin damage or skin tearing. CONCLUSION: The iTClamp is effective at controlling fluid loss from open wounds within multiple compressible areas. The iTClamp does not occlude distal flow, and aside from small needle punctures, there was no other visible skin damage or skin tearing.

Feasibility of 39-potassium MR imaging of a human brain at 9.4 Tesla.

PURPOSE: To demonstrate the feasibility of performing 39-potassium MR imaging of a human brain. METHODS: 39-Potassium magnetic resonance imaging of a human brain was performed at 9.4 T using a flexible twisted projection imaging acquisition with a nominal isotropic spatial resolution of 10 mm in 40 min using a single-tuned birdcage radiofrequency coil. Co-registered sodium imaging with a nominal isotropic spatial resolution of 3.5 mm was performed on the same subject in 10 min. RESULTS: The 39-potassium flexible twisted projection imaging imaging had a signal-to-noise ratio of 5.2 in brain paranchyma. This qualitative imaging showed the expected features when compared to co-registered high- and low-resolution sodium imaging of the same subject. CONCLUSION: Potassium MR images may offer complementary information to that of sodium MR images by sampling the intracellular rather that interstitial environment. Quantification will require additional improvement in signal-to-noise ratio to produce clinically useful bioscales as are developing for sodium MR imaging.

The iTClamp controls junctional bleeding in a lethal swine exsanguination model.

OBJECTIVE: Severe hemorrhage is a leading cause of death and difficult to control even by trained medical personnel. Current interventions have significant limitations in the prehospital setting; therefore, a need exists for a new and effective treatment. iTraumaCare has designed a temporary wound closure device, the iTClamp, which controls external hemorrhage from open wounds within compressible zones. The device approximates the wound edges, sealing the skin within a pressure bar, enabling creation of a hematoma and subsequent clot formation. The objective of this study is to test the effectiveness of the iTClamp to control external bleeding due to a major vascular injury to the groin in an in vivo swine model. METHODS: Twenty Yorkshire-cross male swine were enrolled in this study. A complex groin injury was created by complete excision of the femoral artery and vein along with some surrounding muscle. The animals were divided into four treatment groups: control (no treatment), early iTClamp treatment, late iTClamp treatment, and standard gauze treatment. Survival rate, survival time, and blood loss were the primary endpoints. Physiologic parameters (heart rate, blood pressure, oxygen saturation) were monitored throughout the experiment and blood samples were collected to analyze partial thromboplastin time and fibrinogen. RESULTS: All (100%) of the animals treated with the iTClamp lived through the end of the experiment, compared to 60% in standard gauze treated and 0% of untreated control animals (early and late iTClamp vs. control and standard gauze, Fisher's exact, p = 0.003). Both the early iTClamp and late iTClamp treatment groups survived significantly longer than the untreated control pigs (Mann-Whitney U-test, p < 0.009). External blood loss was significantly lower in animals treated with the iTClamp (early) compared to no treatment (Mann-Whitney U-test, p < 0.008). There was no significant change in physiologic or hematologic parameters between treatment groups. CONCLUSIONS: The iTClamp showed statistically significant improvement in survival, survival time, and estimated blood loss when compared to no treatment. This proof-of-concept study demonstrates the potential of the iTClamp to control severe bleeding and prevent blood loss.

PCr/ATP ratio mapping of the human head by simultaneously imaging of multiple spectral peaks with interleaved excitations and flexible twisted projection imaging readout trajectories at 9.4 T.

Quantitative (31)P magnetic resonance imaging of the whole human brain is often time-consuming even at low spatial resolution due to the low concentrations, long T(1) relaxation times, and low detection sensitivity of phosphorus metabolites. We report herein the results of combining the increased detection sensitivity of an ultra-high field 9.4 T scanner designed for human imaging with a new pulse sequence termed simultaneously imaging of multiple spectral peaks with interleaved excitations and flexible twisted projection imaging readout trajectories to rapidly sample multiple resonances in the (31)P spectrum. The phosphocreatine and γ-adenosine triphosphate images, obtained simultaneously from the entire human head, are demonstrated at 1.5 cm isotropic nominal resolution in a total acquisition time of 33 min. The phosphocreatine/γ-adenosine triphosphate ratio calculated for brain parenchyma (1-2) and the superficial temporalis muscle (3-5) are in agreement with literature values.

SEMAT--the next generation of inexpensive marine environmental monitoring and measurement systems.

There is an increasing need for environmental measurement systems to further science and thereby lead to improved policies for sustainable management. Marine environments are particularly hostile and extremely difficult for deploying sensitive measurement systems. As a consequence the need for data is greatest in marine environments, particularly in the developing economies/regions. Expense is typically the most significant limiting factor in the number of measurement systems that can be deployed, although technical complexity and the consequent high level of technical skill required for deployment and servicing runs a close second. This paper describes the Smart Environmental Monitoring and Analysis Technologies (SEMAT) project and the present development of the SEMAT technology. SEMAT is a "smart" wireless sensor network that uses a commodity-based approach for selecting technologies most appropriate to the scientifically driven marine research and monitoring domain/field. This approach allows for significantly cheaper environmental observation systems that cover a larger geographical area and can therefore collect more representative data. We describe SEMAT's goals, which include: (1) The ability to adapt and evolve; (2) Underwater wireless communications; (3) Short-range wireless power transmission; (4) Plug and play components; (5) Minimal deployment expertise; (6) Near real-time analysis tools; and (7) Intelligent sensors. This paper illustrates how the capacity of the system has been improved over three iterations towards realising these goals. The result is an inexpensive and flexible system that is ideal for short-term deployments in shallow coastal and other aquatic environments.