Abstract：
:The acoustic power of high-intensity focused ultrasound (HIFU) is an important parameter that should be measured prior to each treatment to guarantee effective and safe outcomes. A new calibration technique was developed that involves estimating the pressure distribution, calculating the acoustic power using an underwater pressure blast sensor, and compensating the contribution of harmonics to the acoustic power. The output of a clinical extracorporeal HIFU system (center frequency of ~1 MHz, p+ = 2.5-57.2 MPa, p(-) = -1.8 to -13.9 MPa, I(SPPA) = 513-22,940 W/cm(2), -6 dB size of 1.6 × 10 mm: lateral × axial) was measured using this approach and then compared with that obtained using a radiation force balance. Similarities were found between each method at acoustic power ranging from 18.2 W to 912 W with an electrical-to-acoustic conversion efficiency of ~42%. The proposed method has advantages of low weight, smaller size, high sensitivity, quick response, high signal-to-noise ratio (especially at low power output), robust performance, and easy operation of HIFU exposimetry measurement.
journal_name
Med Eng Physjournal_title
Medical engineering & physicsauthors
Zhou Ydoi
10.1016/j.medengphy.2015.01.014subject
Has Abstractpub_date
2015-03-01 00:00:00pages
335-40issue
3eissn
1350-4533issn
1873-4030pii
S1350-4533(15)00023-5journal_volume
37pub_type
杂志文章abstract：:In this study, we applied multi-channel mechanomyographic (MMG) recordings in combination with linear and nonlinear analyses to investigate muscular and musculotendinous effects of high intensity eccentric exercise. Twelve accelerometers arranged in a 3 × 4 matrix over the dominant elbow muscles were used to detect MM...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2014.09.003
更新日期：2014-12-01 00:00:00
abstract：:Patients affected by motor disorders of the hand and having residual voluntary movements of fingers or wrist can benefit from self-rehabilitation exercises performed with so-called dynamic hand splints. These systems consist of orthoses equipped with elastic cords or springs, which either provide a sustained stretch o...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2013.10.015
更新日期：2014-02-01 00:00:00
abstract：:An ambulatory monitoring system has been developed to measure the weight-bearing achieved by a patient on their fractured leg. The system is lightweight, portable, and can monitor weight-bearing continuously over an extended period of time. In addition to mean weight-bearing, the system can also determine temporal par...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/s1350-4533(98)00061-7
更新日期：1998-10-01 00:00:00
abstract：:The role and effect of preserved antegrade pulmonary blood flow (APBF) at the time of bidirectional cavopulmonary anastomosis (BCPA) in the management of single-ventricle physiology is controversial. We investigated the influence of APBF on the fluid dynamics of BCPA connection using computational fluid dynamics (CFD)...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2008.07.004
更新日期：2009-03-01 00:00:00
abstract：:Long distance travel is associated with increased risk of deep vein thrombosis (DVT). There is an increased risk of travel related DVT in passengers with a predisposition to thrombosis. Assisting blood circulation in the lower limb will reduce the risk of DVT. Leg exercises are recommended as a DVT preventative measur...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2005.02.002
更新日期：2005-10-01 00:00:00
abstract：:Based on an adaptive genetic fuzzy clustering algorithm, a derived fuzzy knowledge model is proposed for quantitatively estimating the systolic arterial pressure (SAP), heart rate (HR), and bispectral index (BIS) using 12 patients and it validates them according to pharmacological reasoning. Also, a genetic proportion...
journal_title：Medical engineering & physics
pub_type： 杂志文章,随机对照试验
doi：10.1016/j.medengphy.2005.04.023
更新日期：2006-03-01 00:00:00
abstract：:The analysis of the surface electromyographic (sEMG) signal is particularly attractive because it provides relatively easy access to those physiological processes that allow the muscle to generate force and movement. In this paper, one of the possible applications of recurrence plot strategy to the analysis of sEMG is...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/s1350-4533(99)00073-9
更新日期：1999-07-01 00:00:00
abstract：:A method for leakage effect reduction by a modification of the classical spectra obtained Discrete Fourier Transform is proposed. The properties of the new method are investigated analytically and validated through synthesized signals, processed by the developed complete computational procedure. This combines the prop...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/s1350-4533(97)00006-4
更新日期：1997-07-01 00:00:00
abstract：:There is an increasing awareness among the populace of the need for regular health check-up to detect diseases in their early stages and thereby administer treatments in a timely fashion. However, commercially available physiological signal monitoring devices, which may offer clues on the onset of diseases, are time-c...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2011.04.011
更新日期：2013-02-01 00:00:00
abstract：:Postural control deficits are the most disabling aspects of Parkinson's disease (PD), resulting in decreased mobility and functional independence. The aim of this study was to assess the postural control stability, revealed by variables based on the centre of pressure (CoP), in individuals with PD while performing a s...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2015.08.011
更新日期：2015-11-01 00:00:00
abstract：:Knowledge about the human skin mechanical properties is essential in several domains, particularly for dermatology, cosmetic or to detect some cutaneous pathology. This study proposes a new method to determine the human skin mechanical properties in vivo using the indentation test. Usually, the skin mechanical paramet...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2007.06.011
更新日期：2008-06-01 00:00:00
abstract：:This paper describes a novel three-wire thermal flow sensor for medical applications. The present innovation for low-frequency measurements involves the use of a pulsed-wire anemometer with a comparatively large wire diameter (12.5 microm and larger) together with a novel signal processing approach. A small wire is he...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2004.06.002
更新日期：2004-10-01 00:00:00
abstract：:We observed an anomaly in the human electroencephalogram (EEG) associated with exposure to terrestrial trunked radio (TETRA) Radiofrequency Fields (RF). Here, we characterize the time and frequency components of the anomaly and demonstrate that it is an artefact caused by TETRA RF interfering with the EEG recording eq...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2013.04.009
更新日期：2013-11-01 00:00:00
abstract：:In our previous studies, we have introduced model-based "functional biomarkers" or "physiomarkers" of cerebral hemodynamics that hold promise for improved diagnosis of early-stage Alzheimer's disease (AD). The advocated methodology utilizes subject-specific data-based dynamic nonlinear models of cerebral hemodynamics ...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2014.02.025
更新日期：2014-05-01 00:00:00
abstract：:In robotic and conventional minimally invasive surgery the risk of complications caused by collateral tissue damage remains high. This paper studies the concept of imposing damage thresholds on surgical instruments to avoid tissue overload. More specifically, the correlation between mechanical loading and damage in ca...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2010.04.002
更新日期：2010-06-01 00:00:00
abstract：:Cervical spinal instability due to ligamentous injury, degenerated disc and facetectomy is a subject of great controversy. There is no analytical investigation reported on the biomechanical response of cervical spine in these respects. Parametric study on the roles of ligaments, facets, and disc nucleus of human lower...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/s1350-4533(01)00036-4
更新日期：2001-04-01 00:00:00
abstract：:Artificial blood pumps play an increasingly important role in the treatment of end-stage cardiac failure. The fluid dynamics of blood flow through such devices crucially affects their clinical effectiveness. Specifically, if the flow of blood stagnates or slowly re-circulates thrombus formation can occur and the avoid...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/s1350-4533(00)00023-0
更新日期：2000-04-01 00:00:00
abstract：INTRODUCTION:This study compared the initial viscoelastic properties of a segmental tibial defect stabilized with intramedullary nailing and impaction bone grafting to that of a transverse fracture stabilized with intramedullary nailing. MATERIALS AND METHODS:Seven sheep tibiae were tested in compression (1000N), bend...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2013.09.003
更新日期：2014-01-01 00:00:00
abstract：:The purpose of this study was to determine the use and feasibility of accelerometry-based monitoring and to examine a discrete multi-resolution signal analysis technique to determine motoric subtypes in patients with DSM-IV delirium. Forty consecutive patients receiving palliative care (23 male, 17 female, mean age+/-...
journal_title：Medical engineering & physics
pub_type： 临床试验,杂志文章
doi：10.1016/j.medengphy.2009.10.012
更新日期：2010-03-01 00:00:00
abstract：:Subject-specific FE-models of human long bones have to predict mechanical parameters with sufficient accuracy to be applicable in a clinical setting. One of the main aspects in subject-specific FE-models of bones regarding accuracy is the modeling of the material inhomogeneity. The goal of this study was therefore to ...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2012.08.022
更新日期：2013-07-01 00:00:00
abstract：:The purpose of this study was to determine the accuracy of a radiographic model-based tracking technique that measures the three-dimensional in vivo motion of the tibio-femoral joint during running. Tantalum beads were implanted into the femur and tibia of three subjects and computed tomography (CT) scans were acquire...
journal_title：Medical engineering & physics
pub_type： 临床试验,杂志文章
doi：10.1016/j.medengphy.2008.03.003
更新日期：2009-01-01 00:00:00
abstract：:The biomechanical strength of the skeleton, and hence the risk of future fractures, depends on both the bone quantity (assessed in terms of bone mineral density) and bone quality (assessed in terms of the integrity of its internal architecture). Precise methods of measuring the calcium-equivalent density of both the t...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/1350-4533(96)00011-2
更新日期：1996-10-01 00:00:00
abstract：:This proof-of-concept study designs distal femur fracture plates from semi-rigid materials vs. traditional metals for toe-touch weight-bearing recommended to patients immediately after surgery. The two-fold goal was to (a) reduce stress shielding (SS) by increasing cortical bone stress thereby reducing the risk of bon...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2020.11.015
更新日期：2021-01-01 00:00:00
abstract：:In most computational fluid dynamic (CFD) analysis of the human lung, it has been assumed that the trachea and branches of the lung have smooth walls. In order to determine if this is a valid assumption, the effects of cartilage rings on airflow and particle deposition in the lungs was determined through conducting si...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2007.06.010
更新日期：2008-06-01 00:00:00
abstract：:Frozen clamps can hold tendons and ligaments tightly and transmit high loads, from 4 kN to 13 kN, without slippage, yet they are complex and expensive. The existing non-frozen serrated jaw clamp is simple to fabricate and use, but the maximal tensile force it can sustain is only about 2.5 kN, which is not enough in ma...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2011.11.019
更新日期：2012-05-01 00:00:00
abstract：:The natural passive flexion axis of human cadaveric knees was determined using a technique that minimized coupled tibiofemoral motions (translations and rotations), and the kinematic effects of mal-positioned flexion axes were determined. The femur was clamped in an apparatus that allowed unconstrained tibial motions ...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2019.03.009
更新日期：2019-05-01 00:00:00
abstract：:The paper described a limited part of the coagulation pathway, and in particular the inhibitory effects of activated protein C in the context of thrombin production. This is a computational modeling study with various assumption made of kinetic rates laws and their summation. The level of complexity and assumed parame...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2004.01.003
更新日期：2004-05-01 00:00:00
abstract：:We studied muscle fatigue in 19 paraplegic patients during an isometric sustained contraction. Both quadriceps (n = 38) were maximally stimulated for 126 s. We defined a nonlinear equation with four coefficients to fit the data and extract fatigue indices carrying information on the amount (asymptotic values, torque c...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/s1350-4533(97)00038-6
更新日期：1997-12-01 00:00:00
abstract：:This study concerns the effects of different drilling parameters of pilot drills and twist drills on the temperature rise of alveolar bones during dental implant procedures. The drilling parameters studied here include the feed rate and rotation speed of the drill. The bone temperature distribution was analyzed throug...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2016.08.009
更新日期：2016-11-01 00:00:00
abstract：:Understanding the load mechanics of orthopaedic implants is important to be able to predict their behaviour in-vivo. Much research, both mechanical and clinical, has been carried out on hip and knee implants, but less has been written about the mechanics of wrist implants. In this paper, the load mechanics of the Univ...
journal_title：Medical engineering & physics
pub_type： 杂志文章
doi：10.1016/j.medengphy.2016.02.008
更新日期：2016-06-01 00:00:00
