Safety Assessment of an <scp>A‐Scan</scp> Ultrasonic System for Ophthalmic Use

Petrella, Lorena; Fernandes, Paulo; Santos, Mário; Caixinha, Miguel; Nunes, Sandrina; Pinto, Carlos Eduardo Pinto de; Morgado, Miguel; Santos, Jaime; Perdigão, Fernando; Gomes, Marco

doi:10.1002/jum.15323

Cited by 5 publications

(2 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Note that the measured acoustic pressure at the focal point position is 14.57 Pa, corresponding to the spatial-peak temporal average I SPTA of 0.48 μW/mm 2 even with continuous wave excitation. When pulse waves with 5 cycles and a pulse repetition interval (PRI) of 10 ms are used, the I SPTA is smaller than 0.24 nW/mm 2 as the number of cycles decreases and the sound pressure decreases, meeting the requirements of the Food and Drug Administration (FDA) guidance for Marketing Clearance of Diagnostic Ultrasound Systems and Transducers (0.17 mW/mm 2 ) 24 . Therefore, there should be no harm to the body 25 , 26 , guaranteeing that the transducer does not damage the eyes.…”

Section: Design and Fabricationmentioning

confidence: 89%

MEMS ultrasonic transducers for safe, low-power and portable eye-blinking monitoring

et al. 2022

View full text Add to dashboard Cite

Eye blinking is closely related to human physiology and psychology. It is an effective method of communication among people and can be used in human–machine interactions. Existing blink monitoring methods include video-oculography, electro-oculograms and infrared oculography. However, these methods suffer from uncomfortable use, safety risks, limited reliability in strong light or dark environments, and infringed informational security. In this paper, we propose an ultrasound-based portable approach for eye-blinking activity monitoring. Low-power pulse-echo ultrasound featuring biosafety is transmitted and received by microelectromechanical system (MEMS) ultrasonic transducers seamlessly integrated on glasses. The size, weight and power consumption of the transducers are 2.5 mm by 2.5 mm, 23.3 mg and 71 μW, respectively, which provides better portability than conventional methods using wearable devices. Eye-blinking activities were characterized by open and closed eye states and validated by experiments on different volunteers. Finally, real-time eye-blinking monitoring was successfully demonstrated with a response time less than 1 ms. The proposed solution paves the way for ultrasound-based wearable eye-blinking monitoring and offers miniaturization, light weight, low power consumption, high informational security and biosafety.

show abstract

Section: Design and Fabricationmentioning

confidence: 89%

MEMS ultrasonic transducers for safe, low-power and portable eye-blinking monitoring

et al. 2022

View full text Add to dashboard Cite

show abstract

“…A safety evaluation of the ESUS has been previously reported [ 31 ]. The ESUS has been implemented in agreement with Portuguese Law n° 145/2009 and with Regulation (EU) 2017/745 of the European Parliament.…”

Section: Ethics Safety and Disseminationmentioning

confidence: 99%

Feasibility assessment of the Eye Scan Ultrasound System for cataract characterization and optimal phacoemulsification energy estimation: protocol for a pilot, nonblinded and monocentre study

Petrella

Nunes

Perdigão

et al. 2022

Pilot Feasibility Stud

Self Cite

View full text Add to dashboard Cite

Background Cataracts are lens opacifications that are responsible for more than half of blindness cases worldwide, and the only treatment is surgical intervention. Phacoemulsification surgery, the most frequently performed cataract surgery in developed countries, has associated risks, some of which are related to excessive phacoemulsification energy levels and times. The protocol proposed in herein will be used to evaluate the feasibility of a new experimental medical device, the Eye Scan Ultrasound System (ESUS), for the automatic classification of cataract type and severity and quantitative estimation of the optimal phacoemulsification energy. Methods The pilot study protocol will be used to evaluate the feasibility and safety of the ESUS in clinical practice. The study will be conducted in subjects with age-related cataracts and on healthy subjects as controls. The procedures include data acquisition with the experimental ESUS, classification based on the Lens Opacity Classification System III (LOCS III, comparator) using a slit lamp, contrast sensitivity test, optical coherence tomography, specular microscopy and surgical parameters. ESUS works in A-scan pulse-echo mode, with a central frequency of 20 MHz. From the collected signals, acoustic parameters will be extracted and used for automatic cataract characterization and optimal phacoemulsification energy estimation. The study includes two phases. The data collected in the first phase (40 patients, 2 eyes per patient) will be used to train the ESUS algorithms, while the data collected in the second phase (10 patients, 2 eyes per patient) will be used to assess the classification performance. System safety will be monitored during the study. Discussion The present pilot study protocol will evaluate the feasibility and safety of the ESUS for use in clinical practice, and the results will support a larger clinical study for the efficacy assessment of the ESUS as a diagnostic tool. Ultimately, the ESUS is expected to represent a valuable tool for surgical planning by reducing complications associated with excessive levels of phacoemulsification energy and surgical times, which will have a positive impact on healthcare systems and society. The study is not yet recruiting. Trial registration ClinicalTrials.gov identifier NCT04461912, registered on July 8, 2020.

show abstract