Ross Venook

Peritoneal dialysis (PD) patients are at high risk for peritonitis, an infection of the peritoneum that affects 13% of PD users annually. Relying on subjective peritonitis symptoms results in delayed treatment, leading to high hospitalisation costs, peritoneal scarring, and premature transition to haemodialysis. We have developed and tested a low-cost, easy-to-use technology that uses microscopy and image analysis to screen for peritonitis across the effluent drain tube. Compared to other technologies, our prototype is made from off-the-shelf, low-cost materials. It can be set up quickly and key stakeholders believe it can improve the overall PD experience. We demonstrate that our prototype classifies infection-indicating and healthy white blood cell levels in clinically collected patient effluent with 94% accuracy. Integration of our technology into PD setups as a screening tool for peritonitis would enable earlier physician notification, allowing for prompt diagnosis and treatment...

R. Venook, G. Gold, B. Hu, G. Scott Stanford University, Stanford, CA, United States, Palo Alto Medical Foundation, Palo Alto, CA, United States Synopsis: Small, flexible RF coils are well suited for interventional applications because of their locally-high SNR and deployability. These characteristics also make such coils easily detuned/mismatched, which can hamper imaging performance. This work demonstrates an autotuning RF receive system that functions in a 1.5T GE scanner, and successfully improves SNR by ~70% with a tuning time under 1 second. Introduction and Background: Many interventional MRI applications are enabled by the high local SNR of small receive coils [1]. However, greater coupling to the tissue of interest also creates heightened sensitivity of these coils to local environment. Moreover, while flexible coils are most compliant to the constraints of in vivo use, changes in coil shape can ruin their tuning as well. Mistuning of a coil degrades its match to the preamp...

Many undergraduate educational experiences in biomedical design lack clinical immersion-based needs finding training for students. Convinced of the merits of this type of training for undergraduates, but unable to offer a quarter-long course due to faculty and administrative constraints, we developed an accelerated block-plan course, during which students were dedicated solely to our class for 3 weeks. The course focused on the earliest stages of the health technology innovation process—conducting effective clinical observations and performing comprehensive need research and screening. We grounded the course in experiential learning theory (with hands-on, collaborative, and immersive experiences) and constructivist learning theory (where students integrated prior knowledge with new material on need-driven innovation). This paper describes the design of this intensive block-plan course and the teaching methods intended to support the achievement of five learning objectives. We used p...

Bioengineering as an academic practice has developed and renewed itself in three waves, each of which remain important and contribute to human flourishing. Historically, the first wave was powered by the application of established engineering methods to human needs, primarily found in the medical clinic or agricultural field. The second wave arose in response to the emergence of tools for collecting overwhelming amounts of quantitative data about living systems, initially DNA sequence-based but increasingly diverse in type and complexity. The third wave began with the invention of genetic engineering a generation ago and is accelerating towards realizing operational mastery of living matter from both an analytical and synthetic perspective.Both the Stanford Bioengineering department and our undergraduate major arose after the emergence of all three waves. We started fresh in terms of organization and activities. We celebrate all opportunities to contribute to human flourishing, rega...

In the 1990s, interest in biomedical technologies blossomed among students across disciplines. In parallel, there was a push in academia to develop courses enabling interdisciplinary problem solving and more holistic, practice-oriented education. In response, Stanford Biodesign created a graduate course in biomedical technology innovation. Seventeen years later, we sought to gauge the impact of this course on student commitment to careers in biomedical technology, whether students took on leadership and innovation roles, and if they found the holistic innovation process we teach to be useful in their careers. We disseminated a web-based survey to collect self-reported data from students completing the course between 2003 and 2019. 186 students responded (24.8%). 62% (n = 115/186) reported a strong commitment to careers in biomedical technology before the course while 84% (n = 156/186) felt that way after. The improvement in mean scores from pre-course (3.8) to post-course (4.3) was ...

Here we adapt and evaluate a full-face snorkel mask for use as personal protective equipment (PPE) for health care workers, who lack appropriate alternatives during the COVID-19 crisis in the spring of 2020. The design (referred to as Pneumask) consists of a custom snorkel-specific adapter that couples the snorkel-port of the mask to a rated filter (either a medical-grade ventilator inline filter or an industrial filter). This design has been tested for the sealing capability of the mask, filter performance, CO2 buildup and clinical usability. These tests found the Pneumask capable of forming a seal that exceeds the standards required for half-face respirators or N95 respirators. Filter testing indicates a range of options with varying performance depending on the quality of filter selected, but with typical filter performance exceeding or comparable to the N95 standard. CO2 buildup was found to be roughly equivalent to levels found in half-face elastomeric respirators in literature...

MR imaging of patients with implanted devices has become common, with conditions for safe scanning defined in MR Conditional labeling of the medical device. This resulted from collaboration among medical device manufacturing, MR imaging scanner manufacturing, and regulatory authority communities. These efforts resulted in engineering testing standards and methods that enable evaluation and certification of devices for safe scanning of patients within prescribed MR imaging scanning conditions. This article provides a practical perspective on test methods that address distinct potential patient hazards. It also provides general guidelines for how a clinician might think about potential hazards, and guidance on common misconceptions.

ABSTRACTHere we adapt and evaluate a full-face snorkel mask for use as personal protective equipment (PPE) for health care workers, who lack appropriate alternatives during the COVID-19 crisis in the spring of 2020. The design (referred to as Pneumask) consists of a custom snorkel-specific adapter that couples the snorkel-port of the mask to a rated filter (either a medical-grade ventilator inline filter or an industrial filter). This design has been tested for the sealing capability of the mask, filter performance, CO2 buildup and clinical usability. These tests found the Pneumask capable of forming a seal that exceeds the standards required for half-face respirators or N95 respirators. Filter testing indicates a range of options with varying performance depending on the quality of filter selected, but with typical filter performance exceeding or comparable to the N95 standard. CO2 buildup was found to be roughly equivalent to levels found in half-face elastomeric respirators in li...

Objective Umbilical central lines deliver life-saving medications and nutrition for neonates; however, complications associated with umbilical catheters (UCs) occur more frequently than in adults with central lines (i.e., line migration, systemic infection). We have developed a device for neonatal UC protection and stabilization to reduce catheter exposure to bacteria compared with the standard of care: “goal post” tape configuration. This study analyzes the effect of device venting and material on bacterial load of human umbilical cords in vitro. Study Design Catheters were inserted into human umbilical cord segments in vitro, secured with plastic or silicone vented prototype versus tape, and levels of bacterial colonization were compared between groups after 7 days of incubation. Results Nonvented plastic prototype showed increased bacterial load compared with goal post (p = 0.04). Colonization was comparable between the goal post and all vented plastic prototypes (p ≥ 0.30) and w...

Introduction Central line-associated bloodstream infections (CLABSIs) in neonates with umbilical catheters occur at a rate that is 5 times higher than CLABSIs in adults with central catheters. No device currently exists tailored to the unique constraints umbilical catheters pose. The current study examined the natural progression of bacterial colonisation in goat umbilical cords and the relationship between embodiments of a novel neonatal umbilical catheter protection device and bacterial colonisation rates. The authors hypothesise that device venting is required to minimise bacterial colonisation in the unique umbilical stump environment. Methods The natural progression of bacterial colonisation in goat umbilical cord segments was studied by examining bacterial colonisation rates each day over 7 days. To understand the relationship between protection and bacterial colonisation, umbilical catheters were placed in goat umbilical cord segments and secured with 1 of 3 embodiments of a novel umbilical catheter protection device, which offered varying degrees of venting. After a 7-day period of incubation, colony counts were compared. Results Bacterial load was largest when umbilical cord segments were fresh and subsequently decreased over time. Further, bacterial colonisation rates showed a statistically significant difference between device embodiments (F(2,9)=4.26, p<0.05), with the non-vented embodiment showing the highest bacterial colonisation rate. Conclusions A device to better stabilise and protect umbilical catheters in order to reduce bloodstream infections in neonates is greatly needed. The current experiments confirm the hypothesis that completely enclosed, or non-vented, protection device will have increased bacterial growth.

Stanford Biodesign launched its Innovation Fellowship in 2001 as a first-of-its kind postgraduate training experience for teaching biomedical technology innovators a need-driven process for developing medical technologies and delivering them to patients. Since then, many design-oriented educational programs have been initiated, yet the impact of this type of training remains poorly understood. This study measures the career focus, leadership trajectory, and productivity of 114 Biodesign Innovation Fellowship alumni based on survey data and public career information. It also compares alumni on certain publicly available metrics to finalists interviewed but not selected. Overall, 60% of alumni are employed in health technology in contrast to 35% of finalists interviewed but not selected. On leadership, 72% of alumni hold managerial or higher positions compared to 48% of the finalist group. A total of 67% of alumni reported that the fellowship had been "extremely beneficial" ...

Prepolarized MRI (PMRI) with pulsed electromagnets has the potential to produce diagnostic quality 0.5- to 1.0-T images with significantly reduced cost, susceptibility artifacts, specific absorption rate, and gradient noise. In PMRI, the main magnetic field cycles between a high field (B(p)) to polarize the sample and a homogeneous, low field (B(0)) for data acquisition. This architecture combines the higher SNR of the polarizing field with the imaging benefits of the lower field. However, PMRI can only achieve high SNR efficiency for volumetric imaging with 3D rapid imaging techniques, such as rapid acquisition with relaxation enhancement (RARE) (FSE, TSE), because slice-interleaved acquisition and longitudinal magnetization storage are both inefficient in PMRI. This paper demonstrates the use of three techniques necessary to achieve efficient, artifact-free RARE in PMRI: quadratic nulling of concomitant gradient fields, electromotive force cancelation during field ramping, and phase compensation of CPMG echo trains. This paper also demonstrates the use of 3D RARE in PMRI to achieve standard T(1) and fat-suppressed T(2) contrast in phantoms and in vivo wrists. These images show strong potential for future clinical application of PMRI to extremity musculoskeletal imaging and peripheral angiography.

Cell therapy has demonstrated the potential to restore injured myocardium. A reliable in vivo imaging method to localize transplanted cells and monitor their restorative effects will enable a systematic investigation of this therapeutic modality. The dual MRI capability of imaging both magnetically labeled mouse embryonic stem cells (mESC) and their restorative effects on cardiac function in a murine model of acute myocardial infarction is demonstrated. Serial in vivo MR detection of transplanted mESC and monitoring of the mESC-treated myocardium was conducted over a 4-week period using a 1.5 T clinical scanner. During the 4-week duration, the mESC-treated myocardium demonstrated sustained improvement of the left ventricular (LV) ejection fraction and conservation of LV mass. Furthermore, no significant difference of their restorative effects on the cardiac function was created by the magnetic labeling of mESC. Thus, in vivo MRI enables simultaneous detection of transplanted mESC and their therapeutic effect on the injured myocardium.