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Universalized point-of-care medicine demands long-term, automated, and ubiquitous solutions to monitoring patients. Ultrasound imaging can be found in nearly all fields of healthcare. Therefore, developing a platform for continuous ultrasound acquisition could transform the point-of-care arena. However, long-term monitoring using ultrasound imaging requires both the simplification of large quantities of data and a hands-free, flexible device. Here, we reduce data-heavy spectral Doppler imaging by tracking local vascular flow in vitro and in vivo as a single, clinically interpretable value over time. Imaging is performed using a novel probe designed specifically for continuous monitoring with ultrasound. This semi-conformal specialty probe was fabricated by removing the plastic casing of a commercially available probe, bending the tip of the piezoelectric transducer head at a nearly ninety-degree angle, then casting the electronic components in silicone rubber, which allowed the probe to rest comfortably on any surface. No statistically significant difference existed when comparing the Doppler fluid velocity detected by the specialty probe with two commercial probes, where velocity directly leads to calculation of vascular flow. Additionally, continuously tracked velocity over the period of an hour and during periods of fluctuating flow rates demonstrated the potential for accurate, long-term monitoring using this ultrasound device. Thus, translating this technology from bench to bedside could provide a universal solution to point-of-care medicine.

Focused ultrasound (FUS) is an emerging technique with the potential to revolutionize traditional treatment methods in the fields of oncology and neurosurgery. Recently, FUS treatments have shown potential for altering neural activity in the spinal cord, with the intent to alleviate pain. Preliminary animal studies using FUS have demonstrated the need for transducer accessories that can simplify the implementation of the transducer in the clinic. The coupling cone that was supplied with the transducer was designed for larger target tissues. Thus, surgeons have expressed a desire to adapt the cone design to be easier to use for smaller targets, such as the spinal cord. Here, we developed 3D printed cones, with smaller aperture sizes, for FUS transducers to assist surgeons in localizing the focal point of the transducers in a faster, and more intuitive manner. The cones were designed to not alter the original focal region of the transducers. This was experimentally confirmed by measuring the size of the focal region for the transducer with the new cones and comparing this data to measurements provided by the manufacturer. The new coupling cones will make the FUS transducers more ergonomic for use in stimulating the spinal cord in an animal model.

Monitoring microcirculation and visualizing microvasculature are critical for providing diagnosis to medical professionals and guiding clinical interventions. Ultrasound provides a medium for monitoring and visualization; however, there are challenges due to the complex microscale geometry of the vasculature and difficulties associated with quantifying perfusion. Here, we studied established and state-of-the-art ultrasonic modalities (using six probes) to compare their detection of slow flow in small microvasculature.Five ultrasonic modalities were studied: grayscale, color Doppler, power Doppler, superb microvascular imaging (SMI), and microflow imaging (MFI), using six linear probes across two ultrasound scanners. Image readability was blindly scored by radiologists and quantified for evaluation. Vasculature visualization was investigated both in vitro (resolution and flow characterization) and in vivo (fingertip microvasculature detection).Superb Microvascular Imaging (SMI) and Micro Flow Imaging (MFI) modalities provided superior images when compared with conventional ultrasound imaging modalities both in vitro and in vivo. The choice of probe played a significant difference in detectability. The slowest flow detected (in the lab) was 0.1885 ml/s and small microvasculature of the fingertip were visualized.Our data demonstrated that SMI and MFI used with vascular probes operating at higher frequencies provided resolutions acceptable for microvasculature visualization, paving the path for future development of ultrasound devices for microcirculation monitoring.

Magnetic target tracking is a low-cost, portable, and passive method for tracking materials wherein magnets are physically attached or embedded without the need for line of sight. Traditional magnet tracking techniques use optimization algorithms to determine the positions and orientations of permanent magnets from magnetic field measurements. However, such techniques are constrained by high latencies, primarily due to the numerical calculation of the gradient. In this study, we derive the analytic gradient for multiple-magnet tracking and show a dramatic reduction in tracking latency. We design a physical system comprising an array of magnetometers and one or more spherical magnets. To validate the performance of our tracking algorithm, we compare the magnet tracking estimates with state-of-the-art motion capture measurements for each of four distinct magnet sizes. We find comparable position and orientation errors to state-of-the-art magnet tracking, but demonstrate increased maximum bandwidths of 336%, 525%, 635%, and 773% for the simultaneous tracking of 1, 2, 3, and 4 magnets, respectively. We further show that it is possible to extend the analytic gradient to account for disturbance fields, and we demonstrate the simultaneous tracking of 1 to 4 magnets with disturbance compensation. These findings extend the use of magnetic target tracking to high-speed, real-time applications requiring the tracking of one or more targets without the constraint of a fixed magnetometer array. This advancement enables applications such as low-latency augmented and virtual reality interaction, volitional or reflexive control of prostheses and exoskeletons, and simplified multi-degree-of-freedom magnetic levitation.