Abstract:
BACKGROUND:The pupillary light reflex characterizes the direct and consensual response of the eye to the perceived brightness of a stimulus. It has been used as indicator of both neurological and optic nerve pathologies. As with other eye reflexes, this reflex constitutes an almost instantaneous movement and is linked to activation of the same midbrain area. The latency of the pupillary light reflex is around 200 ms, although the literature also indicates that the fastest eye reflexes last 20 ms. Therefore, a system with sufficiently high spatial and temporal resolutions is required for accurate assessment. In this study, we analyzed the pupillary light reflex to determine whether any small discrepancy exists between the direct and consensual responses, and to ascertain whether any other eye reflex occurs before the pupillary light reflex. METHODS:We constructed a binocular video-oculography system two high-speed cameras that simultaneously focused on both eyes. This was then employed to assess the direct and consensual responses of each eye using our own algorithm based on Circular Hough Transform to detect and track the pupil. Time parameters describing the pupillary light reflex were obtained from the radius time-variation. Eight healthy subjects (4 women, 4 men, aged 24-45) participated in this experiment. RESULTS:Our system, which has a resolution of 15 microns and 4 ms, obtained time parameters describing the pupillary light reflex that were similar to those reported in previous studies, with no significant differences between direct and consensual reflexes. Moreover, it revealed an incomplete reflex blink and an upward eye movement at around 100 ms that may correspond to Bell's phenomenon. CONCLUSIONS:Direct and consensual pupillary responses do not any significant temporal differences. The system and method described here could prove useful for further assessment of pupillary and blink reflexes. The resolution obtained revealed the existence reported here of an early incomplete blink and an upward eye movement.
journal_name
Biomed Eng Onlinejournal_title
Biomedical engineering onlineauthors
Espinosa J,Roig AB,Pérez J,Mas Ddoi
10.1186/s12938-015-0016-6subject
Has Abstractpub_date
2015-03-13 00:00:00pages
22issn
1475-925Xpii
10.1186/s12938-015-0016-6journal_volume
14pub_type
杂志文章abstract:BACKGROUND:Understanding aneurysm growth rate allows us to predict not only the current rupture risk, but also accumulated rupture risk in the future. However, determining growth rate of unruptured intracranial aneurysms often requires follow-up of patients for a long period of time so that significant growth can be ob...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/1475-925X-8-11
更新日期:2009-06-18 00:00:00
abstract:BACKGROUND:A valveless pump generates a unidirectional net flow of fluid around a closed loop of soft viscoelastic tubing that is rhythmically compressed at one point. The tubing must have at least two sections with two different stiffnesses. When a short segment of the tube is squeezed asymmetrically at certain freque...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/1475-925X-9-42
更新日期:2010-08-31 00:00:00
abstract:BACKGROUND:We and others have previously demonstrated that adipose-derived stem cells (ASCs) transplantation improve cardiac dysfunction post-myocardium infarction (MI) under hemodynamic stress in rats. The beneficial effects appear to be associated with pleiotropic factors due to a complex interplay between the transp...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/1475-925X-13-54
更新日期:2014-05-01 00:00:00
abstract:BACKGROUND:Blood pressure (BP) is associated with early atherosclerosis and plaque rupture because the BP variability can significantly affect the blood flow velocity and shear stress over the plaque. However, the mechanical response of BP variability to the plaque remains unclear. Therefore, we investigated the correl...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/1475-925X-13-152
更新日期:2014-11-20 00:00:00
abstract::A comment on G. Litscher: Infrared thermography fails to visualize stimulation-induced meridian-like structures. Biomed. Eng. OnLine 2005, 4:38 (15 June 2005), with a response by the author. ...
journal_title:Biomedical engineering online
pub_type: 评论,信件
doi:10.1186/1475-925X-10-80
更新日期:2011-09-11 00:00:00
abstract:BACKGROUND:Frequency selectivity (FS) of the auditory system is established at the level of the cochlea and it is important for the perception of complex sounds. Although direct measurements of cochlear FS require surgical preparation, it can also be estimated with the measurements of otoacoustic emissions or behaviora...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/s12938-016-0167-0
更新日期:2016-05-10 00:00:00
abstract:BACKGROUND:We sought to compare uterine cervical electrical impedance spectroscopy measurements employing two probes of different sizes, and to employ a finite element model to predict and compare the fraction of electrical current derived from subepithelial stromal tissue. METHODS:Cervical impedance was measured in 1...
journal_title:Biomedical engineering online
pub_type: 临床试验,杂志文章
doi:10.1186/1475-925X-5-62
更新日期:2006-11-24 00:00:00
abstract:BACKGROUND:Mobile health apps (mHealth apps) are increasing in popularity and utility for the management of many chronic diseases. Although the current reimbursement structure for mHealth apps is lagging behind the rapidly improving functionality, more clinicians will begin to recommend these apps as they prove their c...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/s12938-018-0611-4
更新日期:2018-12-17 00:00:00
abstract:PURPOSE:Coronary artery bypass graft (CABG) surgery represents the standard treatment of advanced coronary artery disease. Two major types of anastomosis exist to connect the graft to the coronary artery, i.e., by using an end-to-side or a side-to-side anastomosis. There is still controversy because of the differences ...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/1475-925X-6-35
更新日期:2007-09-26 00:00:00
abstract:BACKGROUND:Image segmentation is an essential and non trivial task in computer vision and medical image analysis. Computed tomography (CT) is one of the most accessible medical examination techniques to visualize the interior of a patient's body. Among different computer-aided diagnostic systems, the applications dedic...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/s12938-018-0456-x
更新日期:2018-02-27 00:00:00
abstract::Telepointer is a powerful tool in the telemedicine system that enhances the effectiveness of long-distance communication. Telepointer has been tested in telemedicine, and has potential to a big influence in improving quality of health care, especially in the rural area. A telepointer system works by sending additional...
journal_title:Biomedical engineering online
pub_type: 杂志文章,评审
doi:10.1186/1475-925X-12-21
更新日期:2013-03-09 00:00:00
abstract:BACKGROUND:Biomechanical and clinical parameters contribute very closely to functional evaluations of the knee joint. To better understand knee osteoarthritis joint function, the association between a set of knee biomechanical data and a set of clinical parameters of an osteoarthritis population (OA) is investigated in...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/s12938-019-0676-8
更新日期:2019-05-15 00:00:00
abstract:BACKGROUND:The anterior cruciate ligament (ACL) plays an important role in stabilizing translation and rotation of the tibia relative to the femur. ACL injury alters knee kinematics and usually links to the alternation of gait patterns. The aim of this study is to develop a new method to distinguish between gait patter...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/s12938-018-0594-1
更新日期:2018-11-01 00:00:00
abstract:BACKGROUND:The challenges of glycaemic control in critically ill patients have been debated for 20 years. While glycaemic control shows benefits inter- and intra-patient metabolic variability results in increased hypoglycaemia and glycaemic variability, both increasing morbidity and mortality. Hence, current recommenda...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/s12938-019-0720-8
更新日期:2019-10-22 00:00:00
abstract:BACKGROUND:In ultrasound imaging systems, the digital transmit beamformer is a critical module that generates accurate control over several transmission parameters. However, such transmit front-end module is not typically accessible to ultrasound researchers. To overcome this difficulty, we have been developing a compa...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/1475-925X-12-24
更新日期:2013-03-20 00:00:00
abstract:BACKGROUND:Parkinson's disease (PD) and essential tremor (ET) are the two most common movement disorders but the rate of misdiagnosis rate in these disorders is high due to similar characteristics of tremor. The purpose of the study is to present: (a) a solution to identify PD and ET patients by using the novel measure...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/s12938-015-0098-1
更新日期:2015-11-04 00:00:00
abstract::Since falls are a major public health problem among older people, the number of systems aimed at detecting them has increased dramatically over recent years. This work presents an extensive literature review of fall detection systems, including comparisons among various kinds of studies. It aims to serve as a referenc...
journal_title:Biomedical engineering online
pub_type: 杂志文章,评审
doi:10.1186/1475-925X-12-66
更新日期:2013-07-06 00:00:00
abstract:BACKGROUND:Falls can cause trauma, disability and death among older people. Ambulatory accelerometer devices are currently capable of detecting falls in a controlled environment. However, research suggests that most current approaches can tend to have insufficient sensitivity and specificity in non-laboratory environme...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/1475-925X-11-9
更新日期:2012-02-16 00:00:00
abstract:BACKGROUND:The loss of the notochordal cells from the nucleus pulposus is associated with ageing and disc degeneration. However, understanding the mechanisms responsible for the loss of these cells has been hampered in part due to the difficulty of culturing and maintaining their phenotype. Furthermore, little is known...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/1475-925X-6-33
更新日期:2007-09-06 00:00:00
abstract:BACKGROUND:Intracranial pressure changes during head impact cause brain injuries such as vasogenic edema and cerebral contusion. However, the influence of impulsive pressure on endothelial function has not yet been fully studied in vitro. In this study, we developed a pressure loading device that produced positive and ...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/1475-925X-13-44
更新日期:2014-04-16 00:00:00
abstract:BACKGROUND:The main problem of tremor is the damage caused to the quality of the life of patients, especially those at more advanced ages. There is not a consensus yet about the origins of this disorder, but it can be examined in the correlations between the biological signs of aging and the tremor characteristics. ME...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/1475-925X-9-29
更新日期:2010-06-22 00:00:00
abstract:BACKGROUND:Analysis of heart rate variation (HRV) has become a popular noninvasive tool for assessing the activities of the autonomic nervous system (ANS). HRV analysis is based on the concept that fast fluctuations may specifically reflect changes of sympathetic and vagal activity. It shows that the structure generati...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/1475-925X-3-24
更新日期:2004-07-20 00:00:00
abstract:BACKGROUND:Ocular images play an essential role in ophthalmological diagnoses. Having an imbalanced dataset is an inevitable issue in automated ocular diseases diagnosis; the scarcity of positive samples always tends to result in the misdiagnosis of severe patients during the classification task. Exploring an effective...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/s12938-017-0420-1
更新日期:2017-11-21 00:00:00
abstract:BACKGROUND:In order to characterize the intracranial pressure-volume reserve capacity, the correlation coefficient (R) between the ICP wave amplitude (A) and the mean ICP level (P), the RAP index, has been used to improve the diagnostic value of ICP monitoring. Baseline pressure errors (BPEs), caused by spontaneous shi...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/1475-925X-13-99
更新日期:2014-07-23 00:00:00
abstract:OBJECTIVE:The purpose of this study was to show the effects of the tracheal gas insufflation (TGI) technique on gas exchange using helium-oxygen mixtures during high-frequency oscillatory ventilation (HFOV). We hypothesized that a helium-oxygen mixture delivered into the trachea using the TGI technique (0.3 L/min) woul...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/1475-925X-12-29
更新日期:2013-04-08 00:00:00
abstract:BACKGROUND:Peripheral ECMO is an effective cardiopulmonary support in clinical. The perfusion level could directly influence the performances and complications. However, there are few studies on the effects of the perfusion level on hemodynamics of peripheral ECMO. METHODS:The geometric model of cardiovascular system ...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/s12938-018-0493-5
更新日期:2018-05-09 00:00:00
abstract:BACKGROUND:Perfluorocarbon (PFC) vapour in the expired gases during partial liquid ventilation should be prevented from entering the atmosphere and recovered for potential reuse. This study aimed to determine how much PFC liquid could be recovered using a conventional humidified neonatal ventilator with chilled condens...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/1475-925X-6-19
更新日期:2007-05-31 00:00:00
abstract:BACKGROUND:In order to reduce the radiation dose of CT (computed tomography), compressed sensing theory has been a hot topic since it provides the possibility of a high quality recovery from the sparse sampling data. Recently, the algorithm based on DL (dictionary learning) was developed to deal with the sparse CT reco...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/s12938-016-0193-y
更新日期:2016-06-18 00:00:00
abstract:BACKGROUND:The use of flow-diverters for non-saccular cerebral posterior circulation aneurysms requires complex deployment techniques and is associated with high mortality and morbidity. Therefore, further studies are required to clarify the effect of stenting on post-treatment hemodynamics in such aneurysms. In this s...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/s12938-019-0699-1
更新日期:2019-07-24 00:00:00
abstract:BACKGROUND:Robot-assisted laparoscopic surgery offers several advantages compared with open surgery and conventional minimally invasive surgery. However, one issue that needs to be resolved is a collision between the robot arm and the assistant instrument. This is mostly caused by miscommunication between the surgeon a...
journal_title:Biomedical engineering online
pub_type: 杂志文章
doi:10.1186/s12938-016-0189-7
更新日期:2016-05-20 00:00:00