Ultrasound Vibration Research Articles

Molecular Orientation in a Variable-Focus Liquid Crystal Lens Induced by Ultrasound Vibration

A method to estimate orientation direction of liquid crystal molecules three-dimensionally under ultrasound excitation was proposed and the relationship between the ultrasound vibration and the molecular orientation was discussed. Our group have reported a technique to control orientation direction of liquid crystal molecules using ultrasound vibration which could be applied to an optical variable-focus liquid crystal lens. The lens consisted of a liquid crystal layer sandwiched by two glass circular discs and a piezoelectric ring. Ultrasound vibration induces change in the refractive index of the lens, enabling the variable-focus function. The three-dimensional orientation direction of the liquid crystal molecules in the lens was predicted from the transmitted light distributions under the crossed Nicol conditions. The liquid crystal molecules were inclined from vertical alignment by the ultrasound vibration, and larger ultrasound vibration gave larger inclination of the molecules. There was a strong correlation between the distributions of ultrasound vibration and the liquid crystal molecular orientation; the molecular orientation was changed remarkably between the antinodal and nodal parts of the ultrasound flexural vibration on the glass plate and the molecules aligned towards the antinode.

Ultrasound Measurement Using On-Chip Optical Micro-Resonators and Digital Optical Frequency Comb

Optical resonator-based ultrasound detection plays a significant role in the modern ultrasonography. It consists of two steps including the optical readout of the acoustic wave signal and the electrical demodulation of the acoustic response. In this article, we conduct innovative researches on both of them for improved performance. High quality-factor (Q-factor) chalcogenide glass (ChG) microdisk and microring resonators as optical readout configurations are designed and fabricated. High-precision digital optical frequency comb (DOFC) technique is proposed to monitor the minor resonance frequency shift. The sensitivity up to 2.86 dB/Pa and noise equivalent pressure (NEP) down to 4 Pa are obtained under the 40 KHz ultrasound vibration using a 100-μm radius Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11.5</sub> As <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">24</sub> Se <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">64.5</sub> microdisk resonator with the Q-factor of 1.15 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> . As a proof-of-concept, three cascaded SiN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> microring resonators-based ultrasound detector is fabricated and characterized to further validate the versatility of DOFC in the arrayed microcavities. Successful realization of the 3-D ultrasound detection paves the way to the development of high-performance photoacoustic imaging.

Modelling and measurement of ultrasound vibration potential distribution in an agar phantom

Ultrasound vibration potential (UVP) is an electric signal generated from the vibration of particles or ions along with the trajectory of the ultrasound pulses travelling through a colloidal suspension or ionic electrolyte. Therefore, it may be used to characterize or image the physiochemical property of particles or ions. This paper presents a modelling method based on the principle of static charged disc dipole and its equivalent circuit to model the ultrasound vibration potential distribution (UVPD) inside domains of interest. A tissue-like testing phantom (in 82 × 56 × 66 mm) embedded with one or more sample cells made from either agar or colloids with two electrodes fitted at optimized locations outside of the phantom is reported. TheUVP measurements in peak-to-peak amplitude of 162/309 μV and 419/499 μV are measured from two interfaces of a single cell setting with either KCL (1 M) or nanoparticles (SiO2 in 21 nm, 1 wt%) mixed with agar. Results from the measurement comply with the modelling of UVPD. The experimental results are evidenced from the relative changes of normalised UVP signals from setting up six interfaces of three cells. The results demonstrate the feasibility of using the static electricity modelling method to estimate UVPD. This implies the potential of UVP for medicine and engineering.

Research progress in nucleation and supercooling induced by phase change materials

The supercooling of phase change materials leads to the inability to recover the stored latent heat, which is an urgent problem to be solved during the development of phase change energy storage technology. This paper reviews the research progress of controlling the supercooling and crystal nucleation of phase change materials. The factors affecting the supercooling and crystal nucleation of phase change materials have been classified into three categories: external fields (magnetic field, ultrasound and mechanical vibration, electric field, and microwave), additives (homogeneous and heterogeneous nucleation) and other methods (porous media, wire interference, and surface tension). In this paper, the mechanism that promotes crystallization and nucleation under the action of different methods have been analyzed. Finally, according to the current research situation, the deficiencies in the current research were put forward, and the future research trends prospected.

Green synthesis of CuO nanoparticles using Lantana camara flower extract and their potential catalytic activity towards the aza-Michael reaction.

Aza-Michael addition is one of the most exploited reactions in organic chemistry. It is regarded as one of the most popular and efficient methods for the creation of the carbon–nitrogen bond, which is a key feature of many bioactive molecules. Herein, we report the synthesis of CuO nanoparticles by an alkaline hydrolysis process in the presence of the flower extract of Lantana camara, an invasive weed, followed by calcination in air at 400 °C. Microscopic results indicated that the plant extract played an important role in the modulation of the size and shape of the product. In the presence of extract, porous CuO nanostructures are formed. While mostly aggregated rod-shaped CuO nanostructures are formed in the absence of extract. The products are pure and highly crystalline possessing the monoclinic phase. The CuO nanoparticles have been used as a catalyst in the aza-Michael addition reaction in aqueous medium under ultrasound vibration. The product yield is excellent and the catalyst is reusable up to the fifth cycle. The catalyst system can be extended to various substituted substrates with excellent to moderate yields.

Improved packing of preparative biochromatography columns by mechanical vibration.

The bioprocessing industry relies on packed-bed column chromatography as its primary separation process to attain the required high product purities and fulfill the strict requirements from regulatory bodies. Conventional column packing methods rely on flow packing and/or mechanical compression. In this work, the application of ultrasound and mechanical vibration during packing was studied with respect to packing density and homogeneity. We investigated two widely used biochromatography media, incompressible ceramic hydroxyapatite, and compressible polymethacrylate-based particles, packed in a laboratory-scale column with an inner diameter of 50 mm. It was shown that ultrasonic irradiation led to reduced particle segregation during sedimentation of a homogenized slurry of polymethacrylate particles. However, the application of ultrasound did not lead to an improved microstructure of already packed columns due to the low volumetric energy input (~152 W/L) caused by high acoustic reflection losses. In contrast, the application of pneumatic mechanical vibration led to considerable improvements. Flow-decoupled axial linear vibration was most suitable at a volumetric force output of ~1,190 N/L. In the case of the ceramic hydroxyapatite particles, a 13% further decrease of the packing height was achieved and the reduced height equivalent to a theoretical plate (rHETP) was decreased by 44%. For the polymethacrylate particles, a 18% further packing consolidation was achieved and the rHETP was reduced by 25%. Hence, it was shown that applying mechanical vibration resulted in more efficiently packed columns. The application of vibration furthermore is potentially suitable for in situ elimination of flow channels near the column wall.

The impact of post manufacturing treatment of functionally graded Ti6Al4V scaffolds on their surface morphology and mechanical strength

An ultrasonic vibration post-treatment procedure was suggested for additively manufactured lattices. The aim of the present research was to investigate mechanical properties and the differences in mechanical behavior and fracture modes of Ti6Al4V scaffolds treated with traditional powder recovery system (PRS) and ultrasound vibration (USV). Scanning electron microscopy (SEM) was used to investigate the strut surface and the fracture surface morphology. X-ray computed tomography (CT) was employed to evaluate the inner structure, strut dimensions, pore size, as well as the surface morphology of additively manufactured porous scaffolds. Uniaxial compression tests were conducted to obtain elastic modulus, compressive ultimate strength and yield stress. Finite element analysis was performed for a body-centered cubic (BCC) element-based model and for CT-based reconstruction data, as well as for a two-zone scaffold model to evaluate stress distribution during elastic deformation. The scaffold with PRS post treatment displayed ductile behavior, while USV treated scaffold displayed fragile behavior. Double barrel formation of PRS treated scaffold was observed during deformation. Finite element analysis for the CT-based reconstruction revealed the strong impact of surface morphology on the stress distribution in comparison with BCC cell model because of partially molten metal particles on the surface of struts, which usually remain unstressed.

Double-parabolic-reflectors acoustic waveguides for high-power medical ultrasound

High intensity focused ultrasound therapeutics are widely used to noninvasively treat various types of primary tumors and metastasis. However, ultrasound penetration depth is shallowed with increasing frequency which limits the therapeutic accuracy for deep tissues. Although acoustic waveguides are commonly inserted into tissue for localized therapy, powerful ultrasound delivery is difficult. Here, we invent double-parabolic-reflectors acoustic waveguides, where high-power ultrasound emission and large mechanical vibration enhance the therapeutic efficiency. High-energy-density ultrasound with around 20 times amplification by two parabolic reflectors propagates through the thin waveguide between 1 to 2 MHz, and wideband large mechanical vibration at the waveguide tip from 1 kHz to 2.5 MHz accelerates the therapeutics. This fundamental work serves as a milestone for future biomedical applications, from therapeutics to diagnostics. Since the high-power ability at high frequencies, our waveguide will also open up new research fields in medical, bio, physics and so on.

Experimental Model to Assess the Efficacy and Safety of Vessel Sealing Devices in By-pass Surgery

Introduction - Energy sealing devices achieve hemostasis of blood vessels through sequential coagulation and tissue transection. The most frequently used ones are: Electrothermal Bipolar Tissue Sealing System (EB) and Harmonic Scalpel (HS). Both methods are based on denaturation and fusion of proteins of the vessel wall (mainly collagen and elastin) by controlled delivery of energy: electrothermal by radiofrequency and impedance feed-back (EB) or high frequency ultrasound vibration (HS). Although its use has been widely spread in multiple surgical fields, most vascular surgeons are not confident enough about its safety for sealing collaterals of autologous grafts during by-pass surgery. The aim of this study was to compare the efficacy and safety of EB and HS with conventional vessel ligation of saphenous vein (SV) collaterals in an experimental model. Methods - Twenty-five fragments of SV were extracted from cadaver donor (n=6) or from residual fragments during amputation or lower limb revascularization procedures (n=19). To simulate physiological conditions, a pulsatile flow circuit was performed with a roller pump, and intravascular pressure was recorded by a pressure gauge and a pressure monitor. In each fragment, two venous collateral seals were made, one by conventional ligation with 3/0 silk (control) and the other one with EB (N= 13) or HS (N= 12), after sequentially consecutive assignment. Each venous fragment was then incorporated into the pulsatile flow circuit, and the pressure was progressively increased until 300 mmHg (supraphysiological) was reached, or until sealing breakage occurred. Collateral vein diameter, burst pressures, and leakage points were recorded. A histological study with hematoxylin-eosin and Masson's trichrome stain was also performed for each energy-sealing device. A descriptive analysis and analytical statistical tests (U-Mann Whitney, Chi-square) were performed. Results - The mean diameter of the venous collaterals was 2.42±0.7mm and 2.38±0.6 mm, p = NS, for EB and HS, respectively. The mean burst pressure was slightly higher for EB than for HS (788.9±455.0 mmHg vs 602.5±363.1 mmHg, p = 0.268). In only one case (HS) the outbreak occurred in the sealing zone at pressures below 300 mmHg. In all cases for EB, the rupture occurred at supraphysiological pressures.The leakage point for HS occurred in sealed collateral in all cases (12/12). For EB, the leakage point occurred in its sealing zone in 8 of 13 fragments, and in the conventional ligation (control), in the remaining 5 fragments (p=0.016). The histological study showed no differences in the tissues coagulated by both devices. Conclusion - Vessel sealing devices are as effective and safe for the hemostasis of saphenous vein collaterals as conventional ligation. These devices may be useful given their fast sealing time and easy handling during surgical venous graft preparation for lower limb revascularization. In our study, the EB showed greater strength in the sealing of saphenous vein collaterals compared to HS, however the outbreak occurred at supraphysiological pressures, so this fact may not have clinical relevance. References-Toishi M, Yoshida K, Agatsuma H et al. Usefulness of vessel-sealing devices for <7mm diameter vessels: a randomized controlled trial for human thoracoscopic lobectomy in primary lung cancer. Interactive CardioVascular and Thoracic Surgery, 2014 (19): 448-55.-Rajbabu K, Baber NJ, Chol W et al. To knot or not to knot? Sutureless haemostasis compared to the surgeons's knot. Ann R Coll Surg Engl, 2007; 89: 359-62.-Lamberton GR, Hsi R, Jin D et al. Prospective comparision of four laparoscopic vessel ligation devices. Journal of endourology, 2008; 22: 1-6.-Lacin T, Batirel HF, Ozer K et al. Safety of a thermal vessel sealer on main pulmonary vessels. European Journal of Cardio-thoracic Surgery, 2007; 31: 482-85.

Microstructure and Formation Mechanism of Ultrasound-Assisted Transient Liquid Phase Bonded Magnesium Alloys with Ni Interlayer.

Ultrasound-assisted transient liquid phase bonding (U-TLP) has been regarded as a promising brazing process to join magnesium alloys with a Sn and Zn interlayer; however, the formation of brittle magnesium intermetallic compounds (Mg2Sn, MgZn, and MgZn2) compromises the mechanical properties of the joints. In this study, Mg alloy U-TLP joints with a Ni interlayer were evaluated based on shear strength and hardness measurement. Microstructural evolution along with ultrasonic duration time and intermetallic compound formation were characterized using X-ray diffraction and electron microscopy methods. The results show that incremental ultrasonic durations of up to 30 s lead to the microstructural evolution from the Mg2Ni layer, eutectic compounds (Mg2Ni and α-Mg) to α-Mg (Ni), accompanied by shear strength increases. The maximum value of the shear strength is 107 MPa. The role that ultrasound vibration played in brazing was evaluated, and showed that the MgO film was broken by the acoustic softening effect when the interlayer and base metal were solid. As the MgO and Mg substrate have different stress reduction τ, this plastic mismatch helps to break the oxide film. Additionally, the diffusion between the solid Mg substrate and Ni interlayer is accelerated greatly by the acoustic pressure based on the DICTRA dynamic calculation.

Surface integrity and fatigue of non-conventional machined Alloy 718

Alloy 718 is a high-strength, corrosion-resistant nickel chromium-based superalloy frequently used for applications, such as aerospace, marine, nuclear reactor and chemical industries, due to its outstanding inherent properties such as high strength and corrosion resistance at high temperatures together with good creep behaviour.Although, the use of conventional manufacturing processes is prevalent for their use on Alloy 718, alternative manufacturing technologies are gaining importance. This work compares the effects of alternative manufacturing processes, such as Abrasive water jet (AWJ), Wire Electrical Discharge Machining (WEDM) and ultrasound vibration assisted milling (UVAM) with conventional milling during the manufacture of Alloy 718 parts. Surface integrity, hardness, residual stress and fatigue strength obtained from these machining processes have been examined for cutting alloy 718. Results show that both residual stresses and surface roughness are correlated with fatigue strength. UVAM results shown an improvement on the surface integrity of the final workpiece. AWJ and WEDM show poorer results, further work on post-process technologies or process condition selection must be carry out to establish them as an alternative in Alloy 718 cutting operations.

P1016Novel surgical ablation technique using ultrasonic scalpel for atrial fibrillation in mitral valve surgery

Abstract Objective Radiofrequency, cryoablation and cut-and-sew technique have been used for surgical ablation to treat atrial fibrillation. Ultrasonicscalpel is a surgical instrument used to simultaneously cut and cauterize tissue by ultrasound vibration. This device causes minimal lateral thermal tissue damage and increases the tissue penetration depth linearly with time. These features are suitable for surgical ablation for atrial fibrillation. This study evaluated surgical ablation with ultrasonic scalpel for atrial fibrillation. Methods From October 2017 to February 2019, 46 patients (mean age: 71.8 years [46–86], 28 male) with mitral valve procedure underwent surgical ablation using ultrasonic scalpel for atrial fibrillation. The ablation lines were carried out with Cox maze procedure or pulmonary vein isolation (PVI) on cardiopulmonary bypass. Endocardial atrial wall was ablated by direct touch with blade in a few seconds at energy level 5. Pathological study of left atrial wall received ablation with ultrasonic scalpel was carried out. Results Type of preoperative atrial fibrillation was persistent in 33 and paroxysmal in 13 patients. Mean left atrial diameter was 49.0 mm (35–81). Surgical ablation using ultrasonic scalpel was carried out to left atrium only or PVI in 33 patients and both atria in 13 patients. Mean surgical ablation time was 4 minutes and 21 seconds. Mitral valve repair and replacement were performed in 33 and replacement in 13 patients, respectively. Simultaneous surgery included 43 tricuspid valve repairs, 11 aortic valve replacements, and 7 coronary artery bypass grafting. Cardiopulmonary bypass and aortic cross-clamp times were 142.6 (70–261) and 98.6 (47–202) minutes, respectively. No operative death or perioperative stroke were observed. Thirty-eight patients (82.6%) returned to sinus rhythm immediately after surgery. Sinus rhythm was maintained in 30 patients (65.2%) in the mid-term period with average 142.2 days after surgery (7–426 days). Pathological study showed the atrial walls were not ablated transmurally. No complications including bleeding and tissue injury were observed. Conclusion Surgical ablation with ultrasonic scalpel for atrial fibrillation was feasible and provided satisfactory outcomes immediately after surgery and at mid-term. This technique can be performed in a short time without complications. Interestingly, pathological study showed no transmural tissue ablation despite of successful outcomes. This may imply transmural ablation is not necessarily mandatory for surgical ablation. Long-term follow-up are required to evaluate this technique.

Process advantages of thermosonic wedge-wedge bonding using dosed tool heating

Abstract Thermosonic wire bonding has a number of advantages over “cold” ultrasonic wire bonding. Despite these potential advantages, it is rarely used besides ball-wedge and gold wedge-wedge applications, mostly due to the drawbacks and limitations of available heating technology. A recently introduced novel thermosonic process using a laser-heated bonding tool avoids most of these drawbacks. This contribution presents the results of two series of bonding tests which have used this novel process to bond aluminium and copper heavy wire to sheets of the same metal. The bond test results prove that thermosonic wedge-wedge bonding with a laser-heated tool has a number of significant advantages in both aluminium and copper wire bonding. It can be used to reduce the process time, to decrease the mechanical stress in the substrate by reducing ultrasound vibration amplitude and/or normal force, and to increase bond strength. These advantages are the same as in classic thermosonic wire bonding, but without the major disadvantage of having to heat to whole package. Because of the high thermal conductivity and capacity of the investigated metal sheet substrates, the observed positive effects of a heated tool are expected to be significantly higher on real-world substrates such as power semiconductors.

Smart and robust electrospun fabrics of piezoelectric polymer nanocomposite for self-powering electronic textiles

The present work designs a piezoelectric nanogenerator (PENG) based on the electrospun nanofibers of the piezoelectric polymer, polyvinylidene fluoride hexafluoropropylene (PVDF-HFP), by uniformly drawing the spun membranes containing cellulose nanocrystals (CNC, 2 wt%) and the Fe-doped nano ZnO (2 wt%). The hybrid nanocomposite fibers were made in double layers, with CNC/PVDF-HFP composite on one side and the Fe-doped ZnO/PVDF-HFP on the other side. This ferroelectric polymer composite exhibited maximum peak-to-peak output voltage of 12 V with a current density, 1.9 μAcm−2, which are respectively higher by 60 and 2.3 times compared to the neat polymer fibers. The PENG is tested for its energy harvesting ability by exposing it to different environments such as ultrasound vibrations and human body movements during hand tapping, elbow movements and by attaching with the textile fabrics. While the finger tapping generated peak-to-peak output voltage of 6.5 V, elbow movements resulted in 5.5 V generation. In all sorts of movements, the nanogenerator shows good output performance indicating its compatibility with textile materials. The mechanical properties, breakdown strength and dielectric properties of the material are also in accordance with its possible applications in wearable electronic textiles.

Control of the Surface Profile of a Thixotropic Fluid With Ultrasound

The viscosity and the surface profile of a thixotropic gel were controlled via ultrasound vibrations. The ultrasound device consisted of two piezoelectric lead zirconate titanate transducers glued to each end of a 60-mm-long rectangular glass substrate. It generated a 71-kHz flexural standing wave along the length. A 0.9-mm-thick thixotropic gel film made from silicone oil and hydrophobic fumed silica was formed on the glass substrate. The ultrasound vibration decreased the film viscosity, and its surface profile could be changed by the acoustic radiation force acting from the gel to the surrounding air, generated by the flexural vibration of the substrate. The transient response of the surface profile was observed by switching the ultrasound excitation ON and OFF. When the excitation was switched OFF, the gel displacement gradually decreased, but the surface profile did not return to that of the initial steady state, indicating that the viscosity recovered in time to preserve the surface profile. When a pulsed megahertz (MHz) signal was used to control the gel deformation, the surface profile rapidly approached the initial steady-state profile after the excitation.

A coupled acoustic-thermal-fluid model and numerical simulation of ultrasound vibration assisted friction surfacing

ABSTRACTBased on comprehensive consideration the friction surfacing (FS) process, a new FS technology is presented by applying the ultrasonic vibration to substrate in front of the consumable rod. A coupled acoustic-thermal-fluid model is developed and the effects of ultrasonic vibration on temperature distribution and material flow behaviour during FS are investigated and discussed quantitatively. The numerical simulation results show that the ultrasound vibration has less effect on preheat and temperature distribution in the fusion zone, whereas it could effectively reduce material viscosity, increase flow velocity and expand the flow zone of plastic material. The contributions of this study can provide a new way for FS.

Transportation and discrimination of cells using ultrasound flexural vibration of a glass substrate

Manipulation and evaluation techniques with high accuracy and selectivity for microbiological materials are required in the fields of medical and life sciences. This paper investigated on-chip discrimination of cells using ultrasound vibration. The chip consists of a rectangular glass substrate with a microchannel and two ultrasound transducers. An acoustic standing-wave field was generated in the channel and the cells were manipulated by acoustic radiation force. The moving speed of the cells in the channel was measured and the results showed a significant difference in the moving speed between the types of cells.

Influence of Ultrasound Vibrations on the Corrosion Resistance of Heat-Exchange Plates Made of AISI 316 Steel

The corrosion resistance of plates 0.4 mm in thickness made of AISI 316 stainless steel is studied under the conditions of ultrasonic vibration with a frequency of 28 kHz and a power of 50 W applied to the end of the sample. The tests are performed by the methods of potentiodynamic and galvanostatic polarization in 10 g/liter and 35 g/liter NaCl solutions at the standard temperature. According to the results of electrochemical studies, in the presence of ultrasonic vibration, the rate of dissolution of steel becomes 30 times lower as compared with the sample not subjected to vibration. These results are confirmed by the analysis of morphology of the specimen surface after testing in a scanning electron microscope. The mechanism of suppression of pitting by ultrasound is proposed. It can be described as the removal of the layer of corrosion products in the stage of formation of metastable pits with their subsequent repassivation. Ultrasound vibration proves to be a promising method for increasing the corrosion resistance of stainless steels. This method can be used to protect the plates of heat exchangers in the heat-and-water supply systems.

Adhesive cell patterning technique using ultrasound vibrations

This paper investigated an ultrasound vibration cell patterning technique. The ultrasound cell culture dish consisted of a culture dish with a glass bottom and a glass disc with a piezoelectric ring that generated a resonance flexural vibration mode on the bottom of the dish. The growth of HeLa cells on the dish was observed under ultrasound excitation for 24 h. Large ultrasound vibrations on the dish inhibited the cell growth. The acoustic field was predicted with finite element analysis and it was found that the cell growth depended strongly on both the acoustic field in the culture medium and the vibration distribution of the dish. The ultrasound vibrations did not affect the viability of the cells, and the cell growth could be controlled by the flexural vibration of the cultured dish.

A kernel smoothing algorithm for ablation visualization in ultrasound elastography

Three-dimensional visualization of tumor ablation procedures have significant clinical value because the ability to accurately visualize ablated volumes can help clinicians gauge the extent of ablated tissue necrosis and plan future treatment steps. Better control over ablation volume can prevent recurrence of tumors treated using ablative procedures. This paper presents a kernel based smoothing algorithm called MatérnSmooth to reconstruct shear wave velocity maps from data acquired through ultrasound electrode vibration elastography. Shear wave velocity estimates are acquired on several intersecting imaging planes that share a common axis of intersection collinear with the ablation needle. An objective method of choosing smoothing parameters from underlying data is outlined through simulations. Experimental validation was performed on data acquired from a tissue mimicking phantom. Volume estimates were found to be within 20% of the true value.