Automatic system for high-throughput and high-sensitivity diagnosis of SARS-CoV-2.

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had severe consequences for health and the global economy. To control the transmission, there is an urgent demand for early diagnosis and treatment in the general population. In the present study, an automatic system for SARS-CoV-2 diagnosis is designed and built to deliver high specification, high sensitivity, and high throughput with minimal workforce involvement. The system, set up with cross-priming amplification (CPA) rather than conventional reverse transcription-polymerase chain reaction (RT-PCR), was evaluated using more than 1000 real-world samples for direct comparison. This fully automated robotic system performed SARS-CoV-2 nucleic acid-based diagnosis with 192 samples in under 180 min at 100 copies per reaction in a "specimen in data out" manner. This throughput translates to a daily screening capacity of 800-1000 in an assembly-line manner with limited workforce involvement. The sensitivity of this device could be further improved using a CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-based assay, which opens the door to mixed samples, potentially include SARS-CoV-2 variants screening in extensively scaled testing for fighting COVID-19.

Case Study: Developing an In-House Magnetic Resonance Imaging Maintenance Program.

In 2015, the Children's Hospital of Eastern Ontario (CHEO) developed an in-house magnetic resonance imaging service team. Within two years, the team achieved substantial savings in operational costs, generated new revenue, improved uptime and response time, and improved customer satisfaction within the hospital. Through careful planning and collaboration, the Clinical Engineering Department at CHEO was able to bring imaging services in house successfully, demonstrating improvements over historical original equipment manufacturer performance thresholds.

Incorporation of stochastic engineering models as prior information in Bayesian medical device trials.

Evaluation of medical devices via clinical trial is often a necessary step in the process of bringing a new product to market. In recent years, device manufacturers are increasingly using stochastic engineering models during the product development process. These models have the capability to simulate virtual patient outcomes. This article presents a novel method based on the power prior for augmenting a clinical trial using virtual patient data. To properly inform clinical evaluation, the virtual patient model must simulate the clinical outcome of interest, incorporating patient variability, as well as the uncertainty in the engineering model and in its input parameters. The number of virtual patients is controlled by a discount function which uses the similarity between modeled and observed data. This method is illustrated by a case study of cardiac lead fracture. Different discount functions are used to cover a wide range of scenarios in which the type I error rates and power vary for the same number of enrolled patients. Incorporation of engineering models as prior knowledge in a Bayesian clinical trial design can provide benefits of decreased sample size and trial length while still controlling type I error rate and power.

Reducing Accidental Dislodgement of the Percutaneous Endoscopic Gastrostomy: A Prospective Trial of the "SafetyBreak" Device.

BACKGROUND: The percutaneous endoscopic gastrostomy (PEG) is a ubiquitous feeding tube with high rates of accidental dislodgement, with significant morbidity and health care costs. We hypothesized use of a decoupling device is a safe and effective mechanism to reduce dislodgements. STUDY DESIGN: We studied a prospective cohort of 100 patients from an academic center. Enrollment included patients requiring PEG tube placement with follow up extending through an individual's lifetime use of their PEG tube. The primary endpoint was accidental dislodgement of the principally placed PEG tube. The secondary endpoint was time to accidental dislodgement of the PEG tube. RESULTS: All 100 patients received the SafetyBreak device and had complete follow-up. Half of the patients had at least a single episode of device decoupling, indicating prevention of dislodgement of the PEG. Eight patients ultimately had dislodgement, resulting in a significantly lower dislodgement rate when compared with a historical cohort (P = .036) and significantly longer survival of the PEG (log rank = 0.005). When compared with a concurrent cohort (without the device) there was also significantly lower dislodgement rate (P = .03) and a trend toward longer survival of the PEG (log rank = 0.08). CONCLUSIONS: When compared with both a historical and concurrent cohort of patients, the SafetyBreak device reduces accidental dislodgement of PEG tubes. As an increasing number of PEGs are being placed, an increasing number of patients are at risk for dislodgement. The SafetyBreak device is an innovative, economical solution to the problem of accidental dislodgement of the PEG tube.

Method for testing motion analysis laboratory measurement systems.

This paper proposes a method for comparing data from accelerometers, optical based 3D motion capture systems, and force platforms (FPs) in the context of spatial and temporal differences. Testing method is based on the motion laboratory accreditation test (MLAT), which can be used to test FP and camera based motion capture components of a motion analysis laboratory. This study extends MLAT to include accelerometer data. Accelerometers were attached to a device similar to the MLAT rod. The elevation of the rod from the plane of the floor is computed and compared with the force platform vector orientation and the rod orientation obtained by optical motion capture system. Orientation of the test device is achieved by forming nonlinear equation group, which describes the components of the measured accelerations. Solution for this equation group is estimated by using the Gauss-Newton method. This expanded MLAT procedure can be used in the laboratory setting were either FP, camera based motion capture, or any other motion capture system is used along with accelerometer measurements.

Expression of joint moment in the joint coordinate system.

The question of using the nonorthogonal joint coordinate system (JCS) to report joint moments has risen in the literature. However, the expression of joint moments in a nonorthogonal system is still confusing. The purpose of this paper is to present a method to express any 3D vector in a nonorthogonal coordinate system. The interpretation of these expressions in the JCS is clarified and an example for the 3D joint moment vector at the shoulder and the knee is given. A nonorthogonal projection method is proposed based on the mixed product. These nonorthogonal projections represent, for a 3D joint moment vector, the net mechanical action on the JCS axes. Considering the net mechanical action on each axis seems important in order to assess joint resistance in the JCS. The orthogonal projections of the same 3D joint moment vector on the JCS axes can be characterized as "motor torque." However, this interpretation is dependent on the chosen kinematic model. The nonorthogonal and orthogonal projections of shoulder joint moment during wheelchair propulsion and knee joint moment during walking were compared using root mean squares (rmss). rmss showed differences ranging from 6 N m to 22.3 N m between both projections at the shoulder, while differences ranged from 0.8 N m to 3.0 N m at the knee. Generally, orthogonal projections were of lower amplitudes than nonorthogonal projections at both joints. The orthogonal projection on the proximal or distal coordinates systems represents the net mechanical actions on each axis, which is not the case for the orthogonal projection (i.e., motor torque) on JCS axes. In order to represent the net action at the joint in a JCS, the nonorthogonal projection should be used.

A 2009 survey of the Australasian clinical medical physics and biomedical engineering workforce.

A survey of the Australasian clinical medical physics and biomedical engineering workforce was carried out in 2009 following on from a similar survey in 2006. 621 positions (equivalent to 575 equivalent full time (EFT) positions) were captured by the survey. Of these 330 EFT were in radiation oncology physics, 45 EFT were in radiology physics, 42 EFT were in nuclear medicine physics, 159 EFT were in biomedical engineering and 29 EFT were attributed to other activities. The survey reviewed the experience profile, the salary levels and the number of vacant positions in the workforce for the different disciplines in each Australian state and in New Zealand. Analysis of the data shows the changes to the workforce over the preceding 3 years and identifies shortfalls in the workforce.

[Status and challenges of medical metrology in China].

In recent years, more and more new medical devices appears, among them there are many measurement instruments related to consistency and stability of value, and safety to device. Presently China is facing the health policy reforms and medical quantity management system establishment. The primary duty of the clinical engineering is to ensure security and validity of medical devices, and preventing maintenance included of measurement and safety is important measure for the duty. The paper overviews the status in medical metrology and challenge for health policy reform in China, and gives some suggestions to resolve medical metrology.

A numerical efficient splitting method for the solution of two dimensional susceptible infected recovered epidemic model of whooping cough dynamics: Applications in bio-medical engineering.

Background and Objective The positivity property of the non-linear dynamical systems is one of the essential features in different fields of bio-medical engineering, science and many more. The state variables, involving in the models, describing the natural phenomenon such as concentration, density and population size etc. must be positive. Therefore, the computing techniques used to solve the system of non-linear differential equations must be consisted with the continuous nature of the models. But, unfortunately there are some existing techniques in the literature that do not preserve the positivity property, especially for the multi-space dimensional models. So there is a gap in the literature that should be filled up, by constructing the positivity preserving numerical algorithms. In this study, we consider a susceptible-infected-recovered (SIR) reaction diffusion epidemic model in two space dimensions from biomedical engineering and solved numerically to observe the behavior of the model. Since the state variables involved in this system are population densities therefore we design a novel computational method which is time efficient because of its splitting structure and holds the positivity as well as other important structure of epidemic system. Methods Three different computational techniques are designed to examine the numerical solution of SIR model of infectious disease. Two approaches are well-known existing computing methods named as forward Euler finite difference (FD) method and backward Euler operator splitting finite difference (OS-FD) method. The third approach is operator splitting nonstandard finite difference (OS-NSFD) method which is devised by using the NSFD rules. Results The proposed OS-NSFD technique retains efficiently the stability of equilibria as well as the positivity. Graphical behavior depicts that the existing computing methods can not get success to preserve the structure of the epidemic system of whooping cough dynamics. At the same time OS-NSFD computing method is proven to be reliable and suitable for the system of bio-medical engineering mathematically and graphically. Conclusion A reliable and novel computing technique is developed for the solution of two dimensional reaction diffusion problem. This technique preserves all the imperative characteristics of the model under study. Also the time efficiency of this method makes it easy to find the solution of physical system in two space dimension. The comparison with other techniques shows the efficacy and reliability of the designed technique.

A self-powered analog sensor-data-logging device based on Fowler-Nordheim dynamical systems.

Continuous, battery-free operation of sensor nodes requires ultra-low-power sensing and data-logging techniques. Here we report that by directly coupling a sensor/transducer signal into globally asymptotically stable monotonic dynamical systems based on Fowler-Nordheim quantum tunneling, one can achieve self-powered sensing at an energy budget that is currently unachievable using conventional energy harvesting methods. The proposed device uses a differential architecture to compensate for environmental variations and the device can retain sensed information for durations ranging from hours to days. With a theoretical operating energy budget less than 10 attojoules, we demonstrate that when integrated with a miniature piezoelectric transducer the proposed sensor-data-logger can measure cumulative "action" due to ambient mechanical acceleration without any additional external power.

Bioengineering studies of the embryo transfer procedure.

Embryo transfer (ET) is the final manual intervention in extracorporeal fertilization in which an embryo is transferred into the uterus by a transcervical catheter. The low rates of embryo implantation within the uterus are attributed, among other factors, to the ET technique, which depends on a multitude of anatomical, physiological, and mechanical aspects. We developed computational and experimental models to simulate ET to examine the contribution of mechanical features to the success of this procedure. The experimental model allowed laboratory simulations of the dispersion of the catheter load as a result of different injection speeds into a tilted uterine model. The mathematical model analyzed potential trajectories of the transferred embryos resulting from the interaction between the injection velocity and the intrauterine flows caused by uterine peristalsis. The simulations revealed the important contribution of mechanical parameters, such as the position of the uterus and the presence of air in the catheter load. The latter was found to increase the potential for the embryo to be near the fundal area during the time limit for implantation. Based on the results of our simulations, we recommended performing ET in a patient-specific position in which the fundus will be the highest point above the horizon and that the load be delivered slowly, that is, not less than 10 s. We also recommended placing the tip of the catheter at the mid cavity to avoid ectopic pregnancy.

A survey of the Australasian clinical medical physics and biomedical engineering workforce.

A survey of the medical physics and biomedical engineering workforce was carried out in 2006. 495 positions (equivalent to 478 equivalent full time (EFT) positions) were captured by the survey. Of these 268 EFT were in radiation oncology physics, 36 EFT were in radiology physics, 44 were in nuclear medicine physics, 101 EFT were in biomedical engineering and 29 EFT were attributed to other activities. The survey reviewed the experience profile, the salary levels and the number of vacant positions in the workforce for the different disciplines in each Australian state and in New Zealand. Analysis of the data identifies staffing shortfalls in the various disciplines and demonstrates the difficulties that will occur in trying to train sufficient physicists to raise staffing to an acceptable level.

Women Break an Engineering Barrier: While Other Engineering Disciplines Stumble, BME Represents a Success Story in Attracting American Women to a Male-Dominated Field.

While the field of engineering as a whole is largely male-dominated, biomedical engineering (BME) is one area poised to overturn this trend. Women in the United States were awarded only 20% of all engineering B.S. degrees in 2015; in BME, however, 40.9% of the degree recipients were women. This stands in stark contrast to the more traditional fields of mechanical and electrical engineering, where women were awarded just 13.2% and 12.5% of B.S. degrees, respectively. This trend toward more female participation in BME continues at both the M.S. and Ph.D. degree levels. In fact, in 2015, BME had the highest percentage of female engineering M.S. degree recipients in the United States of all engineering disciplines, according to the American Society for Engineering Education (Figure 1).

Determinants in the number of staff in hospitals' maintenance departments: a multivariate regression analysis approach.

To date, there are no broadly accepted or accurate models to determine appropriate staffing [levels] for clinical engineering departments (CEDs). The purpose of this study is to determine what the determinants of the staffing levels are (total number of full time equivalents (FTEs)) in CEDs in healthcare organisations. In doing so, we used a cross-sectional exploratory approach by using a multivariate regression model over a secondary source of data information from the AAMI Benchmarking Solutions-Healthcare Technology Management database. Two hundred and one healthcare organisations were included in our study. Our study revealed that on average, there are almost 14 biomedical technicians (BMETs) per clinical engineer and one FTE per 1083.72 devices (SD 545.69). The results of this study also revealed that the total number of devices and the total technology management hours devoted to these devices positively affects the number of FTEs in a CED, whereas the hospital complexity, measured by healthcare organisation patient discharges matters inversely. The most important factor that matters in the number of FTEs in CEDs was the total technology management hours devoted to devices. A value of explained variance (i.e. R2) of 85% was obtained, indicating the strong power of the prediction accuracy of our multivariate regression model.

System development for multichannel electrotactile stimulation on the lips.

Multichannel pulsatile stimulation is essential for electrotactile presentation of spatiotemporal patterns in sensory substitution through the sense of touch. In this paper, a system for multichannel electrotactile stimulation is presented for studying electrotactile sensation on the lips, a site that has been shown to be highly sensitive but never been assessed for electrotactile applications. The system utilized a demultiplexing scheme to deliver voltage-clamped pulse waveforms to 32 channels corresponding to an array of 4x8 stimulators. Initial testing of electrotactile presentation on the lips was performed in human subject experiments on threshold measurement and two-line separation. For an array of hemispherical stimulators each 700 microm in diameter, the threshold values on the lower lip were averaged at only 8.2 V and intensities for well-perceived stimulation were averaged at around 14.2 V. The testing results suggested that lips were promising sites for electrotactile applications due to their high sensitivity to electrotactile stimulation at extremely low intensities.

Pressure mapping with textile sensors for compression therapy monitoring.

Compression therapy is the cornerstone of treatment in the case of venous leg ulcers. The therapy outcome is strictly dependent on the pressure distribution produced by bandages along the lower limb length. To date, pressure monitoring has been carried out using sensors that present considerable drawbacks, such as single point instead of distributed sensing, no shape conformability, bulkiness and constraints on patient's movements. In this work, matrix textile sensing technologies were explored in terms of their ability to measure the sub-bandage pressure with a suitable temporal and spatial resolution. A multilayered textile matrix based on a piezoresistive sensing principle was developed, calibrated and tested with human subjects, with the aim of assessing real-time distributed pressure sensing at the skin/bandage interface. Experimental tests were carried out on three healthy volunteers, using two different bandage types, from among those most commonly used. Such tests allowed the trends of pressure distribution to be evaluated over time, both at rest and during daily life activities. Results revealed that the proposed device enables the dynamic assessment of compression mapping, with a suitable spatial and temporal resolution (20 mm and 10 Hz, respectively). In addition, the sensor is flexible and conformable, thus well accepted by the patient. Overall, this study demonstrates the adequacy of the proposed piezoresistive textile sensor for the real-time monitoring of bandage-based therapeutic treatments.