Totally Implantable Wireless Ultrasonic Doppler Blood Flowmeters: Toward Accurate Miniaturized Chronic Monitors

Rothfuss, Michael A.; Unadkat, Jashvant D.; Gimbel, Michael L.; Mickle, Marlin H.; Sejdić, Ervin

doi:10.1016/j.ultrasmedbio.2016.11.005

Cited by 13 publications

(12 citation statements)

References 92 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This clinical problem has spurred the proposal of several potential wireless solutions. These include a totally implantable Doppler system, [19][20][21] and an implantable biodegradable arterial pressure sensor which is able to detect flow across the arterial pedicle vessel. 22,23 These innovations represent a potential improvement upon the familiar Cook-Swartz Doppler 24 which requires a wired connection between the vascular cuff and the bedside device.…”

Section: Discussion Prior Innovations For Wireless Continuous Flap Monitoringmentioning

confidence: 99%

A Wireless Near-Infrared Spectroscopy Device for Flap Monitoring: Proof of Concept in a Porcine Musculocutaneous Flap Model

Rwei

Lee

et al. 2021

J Reconstr Microsurg

View full text Add to dashboard Cite

Background Current near-infrared spectroscopy (NIRS)-based systems for continuous flap monitoring are highly sensitive for detecting malperfusion. However, the clinical utility and user experience are limited by the wired connection between the sensor and bedside console. This wire leads to instability of the flap–sensor interface and may cause false alarms. Methods We present a novel wearable wireless NIRS sensor for continuous fasciocutaneous free flap monitoring. This waterproof silicone-encapsulated Bluetooth-enabled device contains two light-emitting diodes and two photodetectors in addition to a battery sufficient for 5 days of uninterrupted function. This novel device was compared with a ViOptix T.Ox monitor in a porcine rectus abdominus myocutaneous flap model of arterial and venous occlusions. Results Devices were tested in four flaps using three animals. Both devices produced very similar tissue oxygen saturation (StO2) tracings throughout the vascular clamping events, with obvious and parallel changes occurring on arterial clamping, arterial release, venous clamping, and venous release. Small interdevice variations in absolute StO2 value readings and magnitude of change were observed. The normalized cross-correlation at zero lag describing correspondence between the novel NIRS and T.Ox devices was >0.99 in each trial. Conclusion The wireless NIRS flap monitor is capable of detecting StO2 changes resultant from arterial vascular occlusive events. In this porcine flap model, the functionality of this novel sensor closely mirrored that of the T.Ox wired platform. This device is waterproof, highly adhesive, skin conforming, and has sufficient battery life to function for 5 days. Clinical testing is necessary to determine if this wireless functionality translates into fewer false-positive alarms and a better user experience.

show abstract

Section: Discussion Prior Innovations For Wireless Continuous Flap Monitoringmentioning

confidence: 99%

A Wireless Near-Infrared Spectroscopy Device for Flap Monitoring: Proof of Concept in a Porcine Musculocutaneous Flap Model

Rwei

Lee

et al. 2021

J Reconstr Microsurg

View full text Add to dashboard Cite

show abstract

“…(2) if the if the sample volume is too small only a uniform flow profile (i.e., plug flow) can be accurately measured (Rothfuss et al, 2016). The measurement volume of the present method and pipe diameter is described in the section3.3.…”

Section: Ultrasound Doppler Principlementioning

confidence: 99%

Non-invasive measurement of oil-water two-phase flow in vertical pipe using ultrasonic Doppler sensor and gamma ray densitometer

Abbagoni

Yeung

Lao

2022

Chemical Engineering Science

View full text Add to dashboard Cite

“…Ultrasonic transducers emit acoustic waves. As a further example, the size of single-channel Doppler ultrasound systems was brought down to a size of 1.7 cm 3 (electronics and antenna only) for invasive continuous blood-flow measurements (15). Generally, tens to hundreds of transducers are necessary to scan and image the entire LV volume.…”

Section: Introductionmentioning

confidence: 99%

“…The CMUT systems have shown to be able to achieve penetration depths of 10 cm in the human tissue (13) and to measure continuous volume signals at a frequency of 60 Hz (14). As a further example, the size of single-channel Doppler ultrasound systems was brought down to a size of 1.7 cm 3 (electronics and antenna only) for invasive continuous blood-flow measurements (15).…”

Section: Introductionmentioning

confidence: 99%

Ultrasonic sensor concept to fit a ventricular assist device cannula evaluated using geometrically accurate heart phantoms

et al. 2018

View full text Add to dashboard Cite

Future left ventricular assist devices (LVADs) are expected to respond to the physiologic need of patients; however, they still lack reliable pressure or volume sensors for feedback control. In the clinic, echocardiography systems are routinely used to measure left ventricular (LV) volume. Until now, echocardiography in this form was never integrated in LVADs due to its computational complexity. The aim of this study was to demonstrate the applicability of a simplified ultrasonic sensor to fit an LVAD cannula and to show the achievable accuracy in vitro. Our approach requires only two ultrasonic transducers because we estimated the LV volume with the LV end-diastolic diameter commonly used in clinical assessments. In order to optimize the accuracy, we assessed the optimal design parameters considering over 50 orientations of the two ultrasonic transducers. A test bench was equipped with five talcuminfused silicone heart phantoms, in which the intra-ventricular surface replicated papillary muscles and trabeculae carnae. The end-diastolic LV filling volumes of the five heart phantoms ranged from 180 to 480 mL. This reference volume was altered by ±40 mL with a syringe pump. Based on the calibrated measurements acquired by the two ultrasonic transducers, the LV volume was estimated well. However, the accuracies obtained are strongly dependent on the choice of the design parameters.Orientations toward the septum perform better, as they interfere less with the papillary muscles. The optimized design is valid for all hearts. Considering this, the Bland-Altman analysis reports the LV volume accuracy as a bias of ±10% and limits of agreement of 0%-40% in all but the smallest heart. The simplicity of traditional echocardiography systems was reduced by two orders of magnitude in technical complexity, while achieving a comparable accuracy to 2D echocardiography requiring a calibration of absolute volume only. Hence, our approach exploits the established benefits of echocardiography and makes them applicable as an LV volume sensor for LVADs. K E Y W O R D Scardiac phantom, 3D printing, trabeculae, volume sensor, ultrasound, implantable, intra-cardiac echocardiography, ventricular assist device, hemodynamic monitoring 468 | DUAL et al.

show abstract

Totally Implantable Wireless Ultrasonic Doppler Blood Flowmeters: Toward Accurate Miniaturized Chronic Monitors

Cited by 13 publications

References 92 publications

A Wireless Near-Infrared Spectroscopy Device for Flap Monitoring: Proof of Concept in a Porcine Musculocutaneous Flap Model

A Wireless Near-Infrared Spectroscopy Device for Flap Monitoring: Proof of Concept in a Porcine Musculocutaneous Flap Model

Non-invasive measurement of oil-water two-phase flow in vertical pipe using ultrasonic Doppler sensor and gamma ray densitometer

Ultrasonic sensor concept to fit a ventricular assist device cannula evaluated using geometrically accurate heart phantoms

Contact Info

Product

Resources

About