Search

Abstract: Until date, many devices have been developed for cutting human bones during orthopedic surgeries. However, bones are anisotropic material, and their machining characteristics depend on the tool feed direction. In this study, microcutting of the bovine cortical bone is performed and its structure observed under a microscope. Furthermore, the formation of cutting chips and measurement of the cutting force during bone machining are dynamically observed while considering the anisotropy of bone tissue. In particular, the fracture of secondary osteons and crack propagation in bones are observed and analyzed. The results indicate that when the cut depth exceeds 20μm and is greater than the interval of concentric lamellae, cracks are formed together with chips. A new method for bone machining is proposed. This method is based on the characteristics of crack propagation in bones and is expected to produce low mechanical stress and realize highly efficient and precise machining of living tissues such as bones. [Copyright &y& Elsevier]

To assess the thickness homogeneity of a mask blank using wavelength-modulating interferometry, novel methods for determining and verifying the thickness homogeneity using triple-surface interferometry are proposed. First, based on the optical path difference in triple-surface interferometry, the phases of main harmonics were defined, and the determination method of the back thickness variation was derived. Next, a verification method for thickness assessment was derived using the theoretical formula of the triple-surface interferometry. And then, the thickness assessment of the mask blank was conducted by wavelength-modulating Fizeau interferometer. The thickness homogeneity of the mask blank was determined by the phases of main harmonics extracted using harmonic interferometric-iterative analysis. Finally, the applicability of the verification method was evaluated by comparing the theoretical errors and standard deviations of the experimental results. • Novel determination method for back thickness homogeneity of mask blank. • Assessment of thickness homogeneity in mask blank using triple-surface interferometry. • Novel verification method for thickness assessment with triple-surface interferometry. • Confirmation of verification methods for the industrial application. [ABSTRACT FROM AUTHOR]

Wavelength-tuning interferometry has been widely used to measure and estimate the surface profile of optical components. However, in multilayer interferometry, the coupling error between the higher harmonics and the phase-shift error causes a considerable systematic error in the calculated phase. In this research, the new 7 N − 6 phase-shifting algorithm was developed using the characteristic polynomial theory. The coupling errors calculated by various types of phase-shifting algorithms were analyzed. The surface profile and optical thickness deviation of the lithium niobate crystal wafer were measured simultaneously using wavelength-tuning Fizeau interferometry and the 7 N − 6 algorithm. The experimental results were compared in terms of observed ripples and measurement repeatability. [ABSTRACT FROM AUTHOR]

Optical thickness variation is a fundamental characteristic of transparent optical devices. When measuring this variation by using a wavelength-tuning Fizeau interferometer, the measurement accuracy depends on the phase-shifting algorithm being used. Therefore, the phase-shifting algorithm should compensate for any errors incurred during the measurement, including the phase-shift error, coupling errors, and bias modulation of intensity. Among these errors, however, the coupling errors between the higher harmonics resulting from the inner reflections of the transparent plate and phase-shift error have not previously been considered. This paper presents a derivation of a 19 -sample phase-shifting algorithm that can compensate for the miscalibration and 1st-order nonlinearity of the phase shift, coupling errors, and bias modulation of intensity during wavelength tuning. The characteristics of the 19 -sample algorithm were estimated with respect to the Fourier representation in the frequency domain. The phase error of measurements performed using the 19 -sample algorithm was discussed and compared with that of measurements obtained using other conventional phase-shifting algorithms. Finally, the optical thickness variation of a fused silica parallel plate was obtained using a wavelength-tuning Fizeau interferometer and the 19 -sample algorithm. The measurement accuracy was discussed by comparing the ripples in the crosstalk noise with those calculated using other phase-shifting algorithms. The experimental results indicated that the optical thickness variation measurement accuracy for the fused silica plate was approximately 2 nm. [ABSTRACT FROM AUTHOR]

In this study, a 5 N − 4 phase shifting algorithm comprising a polynomial window function and a discrete Fourier transform is developed to measure interferometrically the surface shape of a silicon wafer, with suppression of the coupling errors between the higher harmonics and the phase shift error. A new polynomial window function is derived on the basis of the characteristic polynomial theory by locating five multiple roots on the characteristic diagram. The characteristics of the 5 N − 4 algorithm are estimated with respect to the Fourier representation in the frequency domain. The phase error of the measurements performed using the 5 N − 4 algorithm is discussed and compared with those of measurements obtained using other conventional phase shifting algorithms. Finally, the surface shape of a 4-in. silicon wafer is measured using the 5 N − 4 algorithm and a wavelength tuning Fizeau interferometer. The accuracy of the measurement is discussed by comparing the amplitudes of the crosstalk noise calculated by other algorithms. The uncertainty of the entire measurement was 34 nm, better than that of any other conventional phase shifting algorithms. [ABSTRACT FROM AUTHOR]

Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) is a promising material for dental restoratives. The fabrication method of such dental restoratives is usually as follows: (1) hot pressing of zirconia powder (2) machining of pre-sintered zirconia (3) sintering. However, the current method has disadvantages such as low geometrical accuracy and long process time. It was adopted since the fully sintered Y-TZP is extremely difficult to machine. If a suitable milling process for fully sintered Y-TZP can be established, it will enable an accurate, efficient, and cost-effective process. The milling process is important for three-dimensional free-form fabrication, which is required for manufacturing dental restoratives. In this study, we propose a thermally assisted milling process in which a fully sintered Y-TZP workpiece is directly heated to several hundred degrees by a heater to soften it and enhance its machinability. In a practical situation, the machinability must be predicted in advance to determine the proper machining conditions, including the workpiece temperature. In order to make such predictions, the machining phenomena occurring during thermally assisted machining must be understood. In addition, the quantitative relationships between the workpiece temperature, cutting conditions, and the resulting machinability must be characterized. In the present study, we conducted a series of straight-milling experiments to observe the machining phenomena and obtain the quantitative relationships between the machining conditions and the machinability of Y-TZP using the proposed thermally assisted milling process. A series of experiments were performed using the central composite design method. The results of the experiments revealed that raising the workpiece temperature significantly reduces cutting resistance and the tool wear. Although a greater amount of fracturing occurred when the workpiece was heated, the resulting roughness of the bottom surface of the grooves did not increase. Quantitative relationships between the machining conditions, including the workpiece temperature, and the machinability were established using a curve-fitting method. [ABSTRACT FROM AUTHOR]

Minimally invasive surgery (MIS) is a viable alternative to general surgery with distinct advantages. Robotically assisted MIS, has been demonstrated to achieve higher accuracy and repeatability in comparison with those of manual procedures. Despite these advantages, owing to the nature of some surgical procedures in which dexterous tissue manipulations in deep narrow areas of the human body are necessary, there is a need for further miniaturized tools with smaller bending radii. To cater to this requirement, this study proposes a new compliant mechanism based surgical robotic forceps. It can generate four degrees of freedom at the tip of the forceps including two bending motions in two perpendicular axes, grasping and rotation. A better combination of the stress distribution through the elastic material, grasping force, and range of motion was determined based on a series of finite element analyses. In addition, the manufactured prototype underwent a series of laboratory experiments to evaluate its effectiveness. Details of the mechanism, finite element analysis, prototype implementation, and evaluations are presented in this paper. [ABSTRACT FROM AUTHOR]

Micro-anastomosis is considered to be a difficult task even for skilled surgeons. Our group has developed a surgical robotic system to assist surgeons. Going further, the detection of surgically relevant objects in the microscopic view is indispensable for the automation or semi-automation of the system. This paper proposes a novel surgical thread detector inspired by an automatic crack detection method. The proposed method achieved a Dice score of 76.30% and an intersection over union (IOU) of 66.08% at 34.50 fps. [ABSTRACT FROM AUTHOR]

The value of kinematic data for skill assessment is being investigated. This is the first virtual reality simulator developed for liver surgery. This simulator was coded in C++ using PhysX and FleX with a novel cutting algorithm and used a patient data-derived model and two instruments functioning as ultrasonic shears. The simulator was evaluated by nine expert surgeons and nine surgical novices. Each participant performed a simulated metastasectomy after training. Kinematic data were collected for the instrument position. Each participant completed a survey. The expert participants had a mean age of 47 years and 9/9 were certified in surgery. Novices had a mean age of 30 years and 0/9 were certified surgeons. The mean path length (novice 0.76 ± 0.20 m vs. expert 0.46 ± 0.16 m, p = 0.008), movements (138 ± 45 vs. 84 ± 32, p = 0.043) and time (174 ± 44 s vs. 102 ± 42 s, p = 0.004) were significantly different for the two participant groups. There were no significant differences in activating the instrument (107 ± 25 vs. 109 ± 53). Participants considered the simulator realistic (6.5/7) (face validity), appropriate for education (5/7) (content validity) with an effective interface (6/7), consistent motion (5/7) and realistic soft tissue behavior (5/7). This study showed that the simulator differentiates between experts and novices. Simulation may be an effective way to obtain kinematic data. [ABSTRACT FROM AUTHOR]

Among increasing eye diseases, glaucoma may hurt the optic nerves and lead to vision loss, the treatment of which is to reduce intraocular pressure (IOP). In this research, we introduce a new concept of the surgery simulator for Minimally Invasive Glaucoma Surgery (MIGS). The concept is comprised of an anterior eye model and a fluidic circulatory system. The model made of flexible material includes a channel like the Schlemm's canal (SC) and a membrane like the trabecular meshwork (TM) covering the SC. The system can monitor IOP in the model by a pressure sensor. In one of the MIGS procedures, the TM is cleaved to reduce the IOP. Using the simulator, ophthalmologists can practice the procedure and measure the IOP. First, considering the characteristics of human eyes, we defined requirements and target performances for the simulator. Next, we designed and manufactured the prototype. Using the prototype, we measured the IOP change before and after cleaving the TM. Finally, we demonstrated the availability by comparing experimental results and target performances. This simulator is also expected to be used for evaluations and developments of new MIGS instruments and ophthalmic surgery robots in addition to the surgical training of ophthalmologists. [ABSTRACT FROM AUTHOR]

Abstract: Living bone must be cut before performing arthroplasty. For example, the distal part of the femur and the proximal part of the tibia must be cut to perform total knee arthroplasty. Osteocytes begin to necrose when the cutting temperature during such procedures exceeds 50°C. In this study, the temperature distribution inside bone was calculated theoretically using a linear heat source moving on a semi-infinite plane. Moreover, the temperature distribution on the surface layer of the cutting edge was measured using thermography. Analytical and experimental results showed that the cutting temperature could be estimated for the cortical bone and that the cutting temperature increased suddenly near the surface of bone. Consequently, the cutting temperature of bone tissue within 0.15mm of the surface layer may be above 35°C if the cutting environment is not cooled, and consequently, the bone surface is heated to more than 55°C. [Copyright &y& Elsevier]

Wavelength-scanning interferometry has been widely used for surface measurements of silicon wafers with a high reflection factor owing to its non-contact and high-resolution measurement. However, the measurement results are degraded by the second-order harmonics of the signal and nonlinearity of phase modulation in wavelength scanning. In this study, a harmonic phase-iterative technique using five-frame experimental interferograms was developed for the surface measurement of a silicon wafer, while simultaneously compensating for the second-order harmonics and nonlinear phase modulation. Considering the reflection factor of the silicon wafer and the harmonics of the signal, a harmonic phase-iterative technique was derived. Furthermore, by combining the proposed iterative technique with the harmonic convergence condition and the selected pixel technique, the harmonic phase-iterative technique was insensitive to divergence errors and considerably reduced the computational time of phase extraction. The surface of the silicon wafer was measured using the harmonic phase-iterative technique and five-frame interferograms obtained using a wavelength-scanning Fizeau interferometer. The repeatability error of the silicon wafer surface measurement was 2.617 nm. Finally, it was confirmed that the harmonic phase-iterative technique had superior phase-extraction ability in terms of residual ripples and repeatability errors compared to the conventional iterative technique and phase-modulation technique. • Development of harmonic phase-iterative technique using five interferograms. • Wafer surface measurement using developed harmonic phase-iterative technique. • Comparison of developed harmonic phase-iterative technique with other techniques. • Validity confirmation of developed phase-iterative technique. [ABSTRACT FROM AUTHOR]

Robotic assistance allows surgeons to perform dexterous and tremor-free procedures, but robotic aid is still underrepresented in procedures with constrained workspaces, such as deep brain neurosurgery and endonasal surgery. In these procedures, surgeons have restricted vision to areas near the surgical tooltips, which increases the risk of unexpected collisions between the shafts of the instruments and their surroundings. In this paper, our vector-field-inequalities method is extended to provide dynamic active-constraints to any number of robots and moving objects sharing the same workspace. The method is evaluated with experiments and simulations in which robot tools have to avoid collisions autonomously and in real-time, in a constrained endonasal surgical environment. Simulations show that with our method the combined trajectory error of two robotic systems is optimal. Experiments using a real robotic system show that the method can autonomously prevent collisions between the moving robots themselves and between the robots and the environment. Moreover, the framework is also successfully verified under teleoperation with tool–tissue interactions. [ABSTRACT FROM AUTHOR]

Purpose: Rotational acetabular osteotomy is a type of pelvic osteotomy that involves rotation of the acetabular bone to improve the bony coverage of the femoral head for patients with acetabular dysplasia. Favourable post-operative long-term outcomes have been reported in previous studies. However, there is a paucity of published data regarding three-dimensional bony coverage. The present study investigated the three-dimensional bony coverage of the acetabulum covering the femoral head in hips before and after rotational acetabular osteotomy and in normal hips.Methods: The computed tomography data of 40 hip joints (12 joints before and after rotational acetabular osteotomy; 16 normal joints) were analyzed. The three-dimensional bony coverage of each joint was evaluated using original software.Results: The post-operative bony coverage improved significantly compared with pre-operative values. In particular, the anterolateral aspect of the acetabulum tended to be dysplastic in patients with acetabular dysplasia compared to those with normal hip joints. However, greater bony coverage at the anterolateral aspect was obtained after rotational acetabular osteotomy. Meanwhile, the results of the present study may indicate that the bony coverage in the anterior aspect may be excessive.Conclusion: Three-dimensional analysis indicated that rotational acetabular osteotomy achieved favorable bony coverage. Further investigations are necessary to determine the ideal bony coverage after rotational acetabular osteotomy. [ABSTRACT FROM AUTHOR]

Concurrent use of finite element (FE) and musculoskeletal (MS) modeling techniques is capable of considering the interactions between prosthetic mechanics and subject dynamics after a total knee replacement (TKR) surgery is performed. However, it still has not been performed in terms of favorable prediction accuracy and systematic experimental validation. In this study, we presented a methodology to develop a subject-specific FE-MS model of a human right lower extremity including the interactions among the subject-specific MS model, the knee joint model with ligament bundles, and the deformable FE prosthesis model. In order to evaluate its accuracy, the FE-MS model was compared with a traditional hinge-constraint MS model and experimentally verified over a gait cycle. Both models achieved good temporal agreement between the predicted muscle force and the electromyography results, though the magnitude on models is different. A higher predicted accuracy, quantified by the root-mean-square error ( RMSE ) and the squared Pearson correlation coefficient ( r 2 ), was found in the FE-MS model ( RMSE  = 177.2 N, r 2  = 0.90) when compared with the MS model ( RMSE  = 224.1 N, r 2  = 0.81) on the total tibiofemoral contact force. The contact mechanics, including the contact area, pressure, and stress were synchronously simulated, and the maximum contact pressure, 22.06 MPa, occurred on the medial side of the tibial insert without exceeding the yield strength of the ultra-high-molecular-weight polyethylene, 24.79 MPa. The approach outlines an accurate knee joint biomechanics analysis and provides an effective method of applying individualized prosthesis design and verification in TKR. [ABSTRACT FROM AUTHOR]

Aims: Our aims were to develop a training system for camera assistants (CA), and evaluate participants' performance as CA.Methods: A questionnaire on essential requirements to be a good CA was administered to experts in pediatric endoscopic surgery. An infant-sized box trainer with several markers and lines inside was developed. Participants performed marker capturing and line-tracing tasks using a 5-mm 30° scope. A postexperimental questionnaire on the developed system was administered. The task completion time was measured.Results: The 5-point evaluation scale was used for each item in the questionnaire survey of experts. The abilities to maintain a horizontal line (mean score: 4.5) and to center the target in a specified rectangle on the monitor (4.5) as well as having a full understanding of the operative procedure (4.3) were ranked as highly important. Fifty-two participants, including 5 surgical residents, were enrolled in the evaluation experiment. The completion time of capturing the markers was significantly longer in the resident group than in the nonresident group (244 versus 124 seconds, P = .04), but that of tracing the lines was not significantly different between the groups. The postexperimental questionnaire showed that the participants felt that the line-tracing tasks (3.7) were more difficult than marker-capturing tasks (2.9).Conclusions: Being proficient in manipulating a camera and having adequate knowledge of operative procedures are essential requirements to be a good CA. The ability was different between the resident and nonresident groups even in a simple task such as marker capturing. [ABSTRACT FROM AUTHOR]

The present study was performed to establish a novel ocular surgery simulator for training in peeling of the inner limited membrane (ILM). This simulator included a next-generation artificial ILM with mechanical properties similar to the natural ILM that could be peeled underwater in the same manner as in actual surgery. An artificial eye consisting of a fundus and eyeball parts was fabricated. The artificial eye was installed in the eye surgery simulator. The fundus part was mounted in the eyeball, which consisted of an artificial sclera, retina, and ILM. To measure the thickness of the fabricated ILM on the artificial retina, we calculated the distance of the step height as the thickness of the artificial ILM. Two experienced ophthalmologists then assessed the fabricated ILM by sensory evaluation. The minimum thickness of the artificial ILM was 1.9 ± 0.3 μm (n = 3). We were able to perform the peeling task with the ILM in water. Based on the sensory evaluation, an ILM with a minimum thickness and 1000 degrees of polymerization was suitable for training. We installed the eye model on an ocular surgery simulator, which allowed for the performance of a sequence of operations similar to ILM peeling. In conclusion, we developed a novel ocular surgery simulator for ILM peeling. The artificial ILM was peeled underwater in the same manner as in an actual operation. [ABSTRACT FROM AUTHOR]

Background: Pediatric robot-assisted surgery is increasingly being performed, but it is difficult to perform this procedure in infants. A pediatric thoracoscopic model of a 1-year-old patient was developed in our previous study, and this model was used to evaluate the use of a surgical robot for infant surgery.Methods: Eight pediatric surgeons performed an intracorporeal suturing and knot-tying task using the da Vinci Xi Robotic Surgical System. The task completion time, number of needle manipulations, and force applied during suturing of the robot-assisted thoracoscopic surgery (RATS) group were compared with those of the video-assisted thoracoscopic surgery (VATS) group whose data had been collected from the same 8 surgeons in our previous study.Results: The RATS group showed a significantly shorter completion time than the VATS group in the knot-tying phase (P = .016) and in the total phase (P = .0078). The RATS group showed a significantly smaller number of manipulations than the VATS group in the total phase (P = .039). The RATS group showed a significantly smaller pushing force index than the VATS group in the suturing phase (P = .031), knot-tying phase (P = .031), and in the total phase (P = .031). A seventh rib in the model was dislocated in all RATS group cases.Conclusions: The da Vinci Surgical System might be useful in infants because of fast movement and small pushing force. However, the robotic 8 mm instruments were too large for use in the thoracic cavity of the 1-year-old infant. [ABSTRACT FROM AUTHOR]

Orthopedic oscillating saws (OOSs) are widely used for plane processing in orthopedic surgery such as knee and hip replacement. However, sawing has been associated with bone breakthrough and necrosis problems. In this paper, a novel elliptical vibration assisted OOS was designed to achieve a low cutting force under the condition of deepening cut depth and reducing cutting speed, based on the analysis of brittle fractures of the bone and elliptical vibration assisted cutting kinematics. The elliptical vibration was generated using two parallel stacked piezoelectric actuators assembled with the fixture. In order to reduce the large cutting forces due to the large cutting depth, a series of experiments was also conducted to investigate the influence of processing parameters on cutting forces. It was demonstrated that cutting forces are significantly reduced by increasing the vibration frequency and vibration amplitude, and decreasing the sawing speed in the current design. The new design could minimize the cutting forces during sawing and allow surgeons to have better control over the sawing process. [ABSTRACT FROM AUTHOR]

Objectives. To evaluate the abdominal visceral fat area (VFA), we developed novel ultrasonographic (US) methods for estimating. Methods. 100 male volunteers were recruited, and their VFA was calculated by two novel US methods, the triangle method and the ellipse method. The VFA calculated by these methods was compared with the VFA calculated by CT. Results. Both the VFA calculated by the triangle method (r=0.766, p<0.001) and the ellipse method (r=0.781, p<0.001) showed a high correlation coefficient with the VFA calculated by CT. Also, the VFA calculated by our novel methods were significantly increased in subjects with one or more metabolic risk factors than in those without any risk factors. Furthermore, the correlation coefficients obtained using the two methods were enhanced by the addition of multiple regression analysis (with the triangle method, r=0.8586, p<0.001; with the ellipse method, r=0.8642, p<0.001). Conclusions. The VFA calculated by the triangle or ellipse method showed a high correlation coefficient with the VFA calculated by CT. These US methods are easy to use, they involve no radiation exposure, and the measurements can be conducted frequently. We hope that our simple methods would be widely adopted for the evaluation of VFA. [ABSTRACT FROM AUTHOR]

The absolute optical thickness and surface shape of optical devices are considered as the fundamental characteristics when designing optical equipment. The thickness and surface shape should be measured simultaneously to reduce cost. In this research, the absolute optical thickness and surface shape of a 6–mm-thick fused silica transparent plate of diameter 100 mm was measured simultaneously by a three-surface Fizeau interferometer. A measurement method combining the wavelength tuning Fourier and phase shifting technique was proposed. The absolute optical thickness that corresponds to the group refractive index was determined by wavelength tuning Fourier analysis. At the beginning and end of the wavelength tuning, the fractional phases of the interference fringes were measured by the phase shifting technique and optical thickness deviations with respect to the ordinary refractive index and surface shape were determined. These two kinds of optical thicknesses were synthesized using the Sellmeier equation for the refractive index of fused silica glass, and the least square fitting method was used to determine the final absolute optical thickness distribution. The experimental results indicate that the all the measurement uncertainties for the absolute optical thickness and surface shape were approximately 3 nm and 35 nm, respectively. [ABSTRACT FROM AUTHOR]

As a hard and brittle material, glass is difficult to precisely cut with high efficiency. Although various attempts at ductile cutting of glass with high cutting depth have been reported, the low efficiency of the cutting process remains problematic. In order to achieve high-efficiency and precision cutting of glass, this paper proposes selective laser-assisted milling (SLAM). In this method, a fiber laser that has a wavelength out of the absorption band of glass is absorbed only into the small area where the black-body coating is put, and the selectively heated area is removed with a cutting tool. The experimental results of this study have demonstrated that SLAM reduces the arithmetic average of the roughness profile by 74% compared with conventional cutting. An observational analysis of the generated chips revealed that the application of SLAM changed the morphology of the chips from the crack type to the quasi-continuous type. These results demonstrate the feasibility of the high-efficiency and precision cutting of glass. [ABSTRACT FROM AUTHOR]

Purpose: Thoracoscopic esophageal atresia/tracheoesophageal fistula (EA/TEF) repair in neonates is technically difficult because of the small working space and fragility of tissues. This study aimed to show the construct validity of the neonatal EA/TEF simulator by video-based assessment of endoscopic suturing skill.Materials and Methods: A rapid-prototyped neonatal chest model with an artificial esophagus model similar to the actual neonatal esophagus was developed. Forty pediatric surgeons performed an endoscopic intracorporeal suturing task and a knot-tying task using the model, and a questionnaire survey was administered. Each task was video recorded and assessed using two skill assessment methods (the 29-point checklist method and the error assessment sheet method). The task completion time and the number of manipulations were measured.Results: With regard to experience in performing thoracoscopic TEF repair, the experienced surgeons (ESs, ≥3 EA/TEF repair experiences, n = 6) were significantly superior to the inexperienced surgeons (ISs, <3 experiences, n = 34) in all metrics. Upon comparison by the pediatric Endoscopic Surgical Skill Qualification (ESSQ) status, there were no significant differences in all metrics between the ESSQ-qualified (n = 15) and nonqualified (n = 25) surgeons. The qualified ESs (n = 6) were significantly superior to the qualified ISs (n = 9) in all metrics.Conclusion: Video-based endoscopic surgical skill assessment using the neonatal EA/TEF simulator could differentiate ESs from ISs. The construct validity of the simulator was demonstrated, and the simulator would be useful especially for practicing thoracoscopic EA/TEF procedures. [ABSTRACT FROM AUTHOR]

When measuring the surface shape of a transparent sample using wavelength-tuning Fizeau interferometry, the calculated phase is critically determined by not only phase-shift errors, but also by coupling errors between higher harmonics and phase-shift errors. This paper presents the derivation of a 13 -sample phase-shifting algorithm that can compensate for miscalibration and first-order nonlinearity of phase shift, coupling errors, and bias modulation of the intensity, and has strong suppression of the second reflective harmonic effect. The characteristics of the 13 -sample algorithm are estimated with respect to Fourier representation in the frequency domain. The phase error of measurement performed using the 13 -sample algorithm is discussed and compared with those of measurements obtained using other conventional phase-shifting algorithms. Finally, the surface shape of a fused silica wedge plate obtained using a wavelength tuning Fizeau interferometer and the 13 -sample algorithm are presented. The experimental results indicate that the surface shape measurement accuracy for a transparent fused silica plate is 3 nm. The accuracy of the measurement is discussed by comparing the amplitudes of the crosstalk noise calculated using other conventional algorithms. [ABSTRACT FROM AUTHOR]

Purpose: We previously developed a pediatric thoracoscopic surgical simulator and showed its construct validity. In this study, the same skill assessment experiments were conducted in an additional 31 surgeons and the results of 53 surgeons in total were analyzed.Methods: A suture pad with force sensors was placed in a rapid-prototyped pediatric chest model of a 1-year-old patient. Participants completed the endoscopic intracorporeal suturing and knot-tying task, both in the pediatric chest model setup and in a box trainer setup. The task was evaluated using eight metrics: the 29-point checklist score, error score, number of manipulations, task completion time, force index, width of the pad's slit after suturing, and right and left tool paths.Results: The 53 participants included skilled surgeons certified by the Endoscopic Surgical Skill Qualification (ESSQ) system (n = 8) and unskilled surgeons without the certification (n = 45). The skilled surgeons showed significantly better performance than the unskilled surgeons in six metrics in the pediatric chest model setup. In contrast, no significant differences between the two groups were observed in the box trainer setup. Upon comparison between the setups, the unskilled surgeons showed worse results in six metrics in the pediatric chest model than in the box trainer, whereas the skilled surgeons showed equivalent performance in both setups.Conclusions: Our pediatric thoracoscopic surgical simulator was superior to the conventional box trainer for identifying skilled surgeons. The skilled surgeons showed excellent performance even in the intricate pediatric chest model, providing quantified targets for young pediatric surgeons' training. [ABSTRACT FROM AUTHOR]

Background: Laparoscopic Kasai portoenterostomy has been performed in infants with biliary atresia at several institutions, but laparoscopic anastomosis requiring multi-directional suturing on a vertical plane of the liver remains a challenge. To assist multi-directional suturing, we developed a multi-degree-of-freedom (DOF) needle driver whose tip length was 15 mm and shaft diameter was 3.5 mm. The tip of the multi-DOF needle driver has three DOFs for grasp, flection and rotation. The aim of this study was to evaluate the performance of the multi-DOF needle driver in two kinds of in vivo experiments.Methods: Surgeons were asked to perform four-directional laparoscopic suturing on a vertical plane of the liver in six rabbits using the multi-DOF needle driver or a conventional needle driver. The needle grasping time, the needle handling time, the number of needle insertions, the number of liver lacerations, the suturing width and depth, and the area of necrotic tissues were analyzed and compared. Additionally, one surgeon was asked to perform laparoscopic hepato-jejunostomy in four rabbits to assess the feasibility of Kasai portoenterostomy using the multi-DOF needle driver.Results: The suturing depth using the multi-DOF needle driver was significantly larger than that using the conventional needle driver in both the right and downward suturing directions. No statistically significant differences were found in other metrics. Liver lacerations were observed only when suturing was performed using the conventional needle driver. The experimental laparoscopic hepato-jejunostomy using the multi-DOF needle driver was successful.Conclusions: Using the multi-DOF needle driver, uniform multi-directional suturing on a vertical plane of the liver could be performed. The short distal tip of the multi-DOF needle driver demonstrated its advantages in multi-directional suturing in a small body cavity. The multi-DOF needle driver may be able to be used to perform complex tasks in laparoscopic Kasai portoenterostomy. [ABSTRACT FROM AUTHOR]

Objectives Most methods currently used to assess surgical skill are rather subjective or not adequate for microneurosurgery. Objective and quantitative microneurosurgical skill assessment systems that are capable of accurate measurements are necessary for the further development of microneurosurgery. Methods Infrared optical motion tracking markers, an inertial measurement unit, and strain gauges were mounted on tweezers to measure many parameters related to instrument manipulation. We then recorded the activity of 23 neurosurgeons. The task completion time, tool path, and needle-gripping force were evaluated for three stitches made in an anastomosis of 0.7-mm artificial blood vessels. Videos of the activity were evaluated by three blinded expert surgeons. Results Surgeons who had recently done many bypass procedures demonstrated better skills. These skilled surgeons performed the anastomosis with in a shorter time, with a shorter tool path, and with a lesser force when extracting the needle. Conclusions These results show the potential contribution of the system to microsurgical skill assessment. Quantitative and detailed analysis of surgical tasks helps surgeons better understand the key features of the required skills. [ABSTRACT FROM AUTHOR]

Introduction: Though minimally invasive pediatric surgery has become more widespread, pediatric-specific surgical skills have not been quantitatively assessed. Material and methods: As a first step toward the quantification of pediatric-specific surgical skills, a pediatric chest model comprising a three-dimensional rapid-prototyped pediatric ribcage with accurate anatomical dimensions, a suturing skin model with force-sensing capability, and forceps with motion-tracking sensors were developed. A skill assessment experiment was conducted by recruiting 16 inexperienced pediatric surgeons and 14 experienced pediatric surgeons to perform an endoscopic intracorporeal suturing and knot-tying task in both the pediatric chest model setup and the conventional box trainer setup. Results: The instrument motion measurement was successful in only 20 surgeons due to sensor failure. The task completion time, total path length of instruments, and applied force were compared between the inexperienced and experienced surgeons as well as between the box trainer and chest model setups. The experienced surgeons demonstrated better performance in all parameters for both setups, and the pediatric chest model was more challenging due to the pediatric features replicated by the model. Conclusion: The pediatric chest model was valid for pediatric skill assessment, and further analysis of the collected data will be conducted to further investigate pediatric-specific skills. [ABSTRACT FROM AUTHOR]

Purpose: Pediatric endoscopic surgery requires special surgical skills because of the small working space and tissue fragility. This article presents a video-based skill assessment method for endoscopic suturing using a pediatric chest model. Materials and Methods: A commercial suture pad was placed in a rapid-prototyped pediatric chest model of a 1-year-old patient to simulate the thoracoscopic repair of esophageal atresia type C. Twenty-eight pediatric surgeons (9 experts, 9 intermediates, and 10 trainees) performed an endoscopic intracorporeal suturing and knot-tying task both in the pediatric chest model and in a box trainer. The tasks were video-recorded and rated by two blinded observers using the 29-point checklist method and a suturing errors score sheet method. The task completion time and the number of needle manipulations were measured. Results: The expert group showed better performance than the intermediate and trainee groups in the pediatric chest model, and the differences were larger than those in the box trainer. Significant differences between the expert and the trainee groups were observed in the items related to safety such as the skills for keeping the needle in view at all times. Significant differences between the expert and intermediate groups were observed in the items related to task quality and efficiency such as the smoothness of knot tying and the number of needle manipulations. Conclusions: Video-based skill assessment of endoscopic suturing using the pediatric chest model and a box trainer distinguished pediatric endoscopic surgeons according to their clinical experience, and pediatric-specific skills were identified. [ABSTRACT FROM AUTHOR]

The quality of blank masks should be assessed with nano-scale accuracy to achieve the efficiency improvement of semiconductor devices. In this study, we proposed a harmonic fringe-iterative method that uses seven-frame interferograms for simultaneous thickness and surface assessment of blank masks. The incorporation of the noble convergence formula and pixel array into the proposed method was found to eliminate harmonics-related errors and significantly increase the computational ability. For verification, the numerical simulation and simultaneous assessment of a blank mask using a multi-surface Fizeau interferometer with wavelength scanning were performed using a seven-frame harmonic fringe-iterative method. The results of the simulations and experiments verify that the harmonic fringe-iterative method has a better phase-extraction ability than the conventional fringe-iterative and Fourier window methods in terms of computational ability and suppression of non-target harmonic signals and nonlinearity of phase-modulation errors. • Development of harmonic phase-iterative technique using seven interferograms. • Simultaneous measurement of thickness and surface. • Comparison of developed harmonic phase-iterative technique with other techniques. • Validity confirmation of developed phase-iterative technique. [ABSTRACT FROM AUTHOR]

During the thickness assessment of an optical flat with wavelength-tuning interferometry, the second-order harmonics generated by double reflection inside the optical flat and nonlinear wavelength tuning reduce the accuracy of interferometric assessment. In this study, a harmonic phase-iterative analysis was proposed for the thickness assessment with the elimination of the effects of double reflection and nonlinearity. The harmonic phase-iterative analysis was derived by combining the intensity signal, including the harmonic components, with the partial least-squares method. Then, the proposed iterative analysis was integrated with the harmonic convergence condition and the selected pixel technique to improve the computational ability of the phase-iterative analysis. For evaluation, a numerical simulation and experimental thickness assessment using wavelength-tuning Fizeau interferometer were performed employing a five-frame harmonic phase-iterative analysis. The standard deviation of the experimental thickness assessment was 2.561 nm, which was smaller than those by other phase-detection technique. Based on the simulated and experimental results, it can be seen that the proposed harmonic phase-iterative analysis could determine the target phase with enhanced computational ability and compensation for the combined error between the second-order harmonics and the nonlinearity of the wavelength tuning. [ABSTRACT FROM AUTHOR]

Highlights: [•] A mechanistic model is developed to predict thrust force and torque. [•] Only four calibration experiments are required for the model. [•] The model can predict drilling forces nicely in a wide range of drilling conditions. [Copyright &y& Elsevier]

Highlights: [•] UV laser-assisted precision cutting of Y-TZP was proposed. [•] The distance between the tooledge and the laser spot was determined to be 20μm. [•] The specific cutting force decreased by 35%. [•] The number of large cracks on the workpiece decreased from 14 to 3. [•] The tool edge breakage was suppressed. [ABSTRACT FROM AUTHOR]

Purpose: We have developed a thin needle driver with multiple degrees-of-freedom (DOFs) for neonatal laparoscopic surgery. The tip of this needle driver has three DOFs for grasp, deflection and rotation. Our aim was to evaluate the performance of the multi-DOF needle driver in vertical plane suturing. Methods: Six pediatric surgeons performed four directional suturing tasks in the vertical plane using the multi-DOF needle driver and a conventional one. Assessed parameters were the accuracy of insertion and exit, the depth of suture, the inclination angle of the needle and the force applied on the model. Results: In left and right direction sutures, the inclination angle of the needle with the multi-DOF needle driver was significantly smaller than that with the conventional one ( p = 0.014, 0.042, respectively). In left and right direction sutures, the force for pulling the model with the multi-DOF needle driver was smaller than that with the conventional one ( p = 0.036, 0.010, respectively). Conclusion: This study showed that multi-directional suturing on a vertical plane using the multi-DOF needle driver had better needle trajectories and was less invasive as compared to a conventional needle driver. [ABSTRACT FROM AUTHOR]

In orthopedic operations, no sound solutions exist to avoid conditions like tool breakage, bone fracture/cracks and thermal necrosis for lacking understanding of the mechanics of the bone cutting process. In this work, analysis of variance (ANOVA) and regression analysis were performed to investigate effects of cutting conditions on cutting and thrust forces based on a full factorial design. Then applicability of Merchant's analysis for calculating cutting force with respect to rake angle and feed was evaluated by comparison with experiments. Finally, the friction coefficient was evaluated by calculation. ANOVA shows that forces are much more sensitive to feed, cutting direction and rake angle than to cutting speed. Regression equations including all four factors were obtained by introduction of dummy variables. Cutting forces from experiments and from Merchant's analysis are partially comparable (maximum relative error = 34%) when feed and rake angle are changed. Friction coefficient was affected by rake angle and cutting direction. Cutting speed had little effect on the coefficient. These results can deepen the understanding of the mechanics of the bone-cutting process and assist the development of innovative cutting devices and selection of favorable cutting conditions for the procedure. [ABSTRACT FROM AUTHOR]

Abstract: The absolute optical thickness of a 140-mm2 mask blank glass plate 3.1mm thickness was measured by three-surface interferometry using a wavelength-tuning Fizeau interferometer. The interference order was determined by the excess fraction method. The wavelength of a tunable laser diode was scanned linearly from 632 to 642nm, and a CCD detector recorded 2000 interference images. Two kinds of optical thicknesses measured by discrete Fourier analysis and phase-shifting were synthesized to obtain the optical thickness with respect to the ordinary refractive index. The optical thickness defined by the group refractive index at the 637nm central wavelength was measured by wavelength scanning. The optical thickness deviation defined by the ordinary refractive index was measured using tunable phase-shifting. The systematic errors caused by nonlinearity in the wavelength tuning were corrected through correlation analysis between the theoretical and observed interference fringes. [Copyright &y& Elsevier]

Aims: The aims of this study were to develop a thin needle driver with multiple degrees of freedom and to evaluate its efficacy in multidirectional suturing compared with a conventional needle driver. Materials and Methods: The tip (15 mm) of the novel user-friendly needle driver (3.5 mm in diameter) has three degrees of freedom for grasping, rotation, and deflection. Six pediatric surgeons performed two kinds of suturing tasks in a dry box: three stitches in continuous suturing that were perpendicular or parallel to the insertion direction of the instrument, first using the novel instrument, then using a conventional instrument, and finally using the novel instrument again. The accuracy of insertion and exit compared with the target points and the procedure time were measured. Results: In the conventional and novel procedures the mean gaps from the insertion point to the target in perpendicular suturing were 0.8 mm and 0.7 mm, respectively; in parallel suturing they were 0.8 mm and 0.6 mm, respectively. The mean gaps from the exit point to the target in perpendicular suturing were 0.6 mm and 0.6 mm for conventional and novel procedures, respectively; in parallel suturing they were 0.6 mm and 0.8 mm, respectively. The procedure time for perpendicular suturing was 33 seconds and 64 seconds for conventional and novel procedures, respectively ( P=.02); for parallel suturing it was 114 seconds and 91 seconds, respectively. Conclusions: Our novel needle driver maintained accuracy of suturing; parallel suturing with the novel driver may be easier than with the conventional one. [ABSTRACT FROM AUTHOR]

Conventional surgical navigation requires for surgeons to move their sight and conscious off the surgical field when checking surgical tool’s positions shown on the display panel. Since that takes high risks of surgical exposure possibilities to the patient’s body, we propose a novel method for guiding surgical tool position and orientation directly in the surgical field by a laser beam. In our navigation procedure, two cross-sectional planar laser beams are emitted from the two laser devices attached onto both sides of an optical localizer, and show surgical tool’s entry position on the patient’s body surface and its orientation on the side face of the surgical tool. In the experiments, our method gave the surgeons precise and accurate surgical tool adjusting and showed the feasibility to apply to both of open and percutaneous surgeries. [ABSTRACT FROM PUBLISHER]

Introduction: The objective of our research was to design and develop a novel needle driver with multiple degrees of freedom (DOFs) for pediatric laparoscopic surgery. Pediatric laparoscopic surgery has many advantages for patients, but the difficulty of the operation is increased due to many restrictions. For example, the motion of the needle driver is restricted by the insertion points, and the operation workspace is smaller in children than in adults. Material and methods: A needle driver with 3 DOFs and a 3.5-mm diameter is proposed and implemented in this study. Grasping DOF is achieved using a piston mechanism actuated by a wire. Deflection and rotation DOFs are actuated by gears. Results: Experiments were conducted to evaluate the workspace and ligation force, and the results confirmed that the needle driver meets all the necessary requirements. Finally, a first reaction of a pediatric surgeon on the suturing and ligaturing capabilities of the prototype is reported. Conclusion: A multi-DOF needle driver with a new mechanism was proposed for pediatric laparoscopic surgery and a first prototype was developed. It is expected that further elaboration of the developed first prototype of the needle driver may contribute to the advancement of pediatric laparoscopic surgery. [ABSTRACT FROM AUTHOR]

Purpose: To elucidate the merits of robotic application for vitreoretinal maneuver in comparison to conventional manual performance using an in-vitro eye model constructed for the present study. Methods: Capability to accurately approach the target on the fundus, to stabilize the manipulator tip just above the fundus, and to perceive the contact of the manipulator tip with the fundus were tested. The accuracies were compared between the robotic and manual control, as well as between ophthalmologists and engineering students. Results: In case of manual control, ophthalmologists were superior to engineering students in all the 3 test procedures. Robotic assistance significantly improved accuracy of all the test procedures performed by engineering students. For the ophthalmologists including a specialist of vitreoretinal surgery, robotic assistance enhanced the accuracy in the stabilization of manipulator tip (from 90.9 µm to 14.9 µm, P = 0.0006) and the perception of contact with the fundus (from 20.0 mN to 7.84 mN, P = 0.046), while robotic assistance did not improve pointing accuracy. Conclusions: It was confirmed that telerobotic assistance has a potential to significantly improve precision in vitreoretinal procedures in both experienced and inexperienced hands. [ABSTRACT FROM AUTHOR]

The absolute optical thickness and the surface shape of a glass plate of 7-in. square and 3.1mm thick was simultaneously measured by three-surface interferometry using a wavelength tuning Fizeau interferometer. The wavelength of a tunable diode laser is scanned linearly from 632 to 642 nm, at which the initial and the final phases of the interference fringes for the surface shape and for the optical thickness were separated and measured by a tunable phase-shifting technique. The number of phase variations in the interference fringes during the scanning is counted by discrete Fourier analysis, in which systematic errors caused by a nonlinearity in the wavelength scanning is corrected by a correlation analysis between the observed and theoretical interference fringes. Experimental results demonstrate that the systematic errors in the measured value were 15 nm for the surface shape and 0.6 μm for the absolute optical thickness. [ABSTRACT FROM AUTHOR]

AIM: To evaluate the performance of a parallel robotic system by comparison with the conventional manual procedure using an animal model. METHODS: A new parallel robotic system was developed that features a small cylindrical manipulator (base diameter 76 mm, height 240 mm). The performance of the new system was evaluated for its capability to assist in retinal vessel microcannulation. The test scenario was as follows: (1) introduce the microcannula into a harvested porcine eye attached loosely on the orbital fossa of an artificial face model through a 20G scleral port at the pars plana; (2) cannulate the retinal vessels (inner diameter 60–80 µm); and (3) inject indocyanine green dye into the eye endovascularly. The success rate and procedure quality of the robotic system were evaluated by comparison with the conventional manual procedure. RESULTS: Retinal vessel microcannulation and dye injection were achieved by the robotic system twice in four attempts, and by the conventional manual procedure either not at all or incompletely in all six attempts. Dye leakage was not observed with the robotic system, indicating that microcannulation was minimally invasive; in contrast, dye leakage was always observed with the manual procedure. CONCLUSIONS: The new system is more accurate than the conventional manual procedure for the tests on a porcine eye model. [ABSTRACT FROM AUTHOR]

We propose an automated needle hydrophone-based scanning system to measure high-resolution 3-D acoustic pressure distributions generated by high-intensity focused ultrasound (HIFU). The hardware consists of a host computer, subsystems for HIFU generation, and an oscilloscope to sample the pressure response from a sensor in a water tank. Software was developed to control the hardware subsystems, to search for the initial scan position, and to design the scanning path and volume. A preoperative scanning plan with three perpendicular planes is used to manipulate the position of the HIFU transducer and to automate the acquisition of the spatial acoustic pressure distribution. The post-processing process displays the scanning results, compensates time delays caused by continuous linear scans, and quantifies the focal region. A method to minimize the displacement error induced by the time delay improves the scanning speed of a conventional needle hydrophone-based scanning system. Moreover, a noise-robust, automatic-focus searching algorithm using Gaussian function fitting reduces the total number of iterations and prevents the initial scanning position search from diverging. Finally, the minimum-volume enclosing ellipsoid approximation is used to quantify the size and orientation of the 3-D focal region thresholded by the minimum pressure of interest for various input conditions and to test the reproducibility of the scanning system. [ABSTRACT FROM AUTHOR]

Abstract: Optimal control of the machining process in orthopedic surgery can not only increase productivity but also ensure safety during tool usage. The authors have developed a technology for a force control system. The system has two modes of operation: the “air-cutting mode” and the “force control mode.” In the air-cutting mode, tool feed is scheduled by predicting the air and bone-cutting zones from the CAD/CAM system. In the force control mode, the software monitors the cutting force and the cutting temperature, and it controls the feed override according to the difference between the real and the desired cutting force. The software is installed on a robot controller, and its effectiveness is evaluated with a urethane bone. [Copyright &y& Elsevier]

In the present paper, we describe a method for constructing a remote ultrasound diagnostic system. Remote diagnosis can be realized using a communication network. We have developed a master-slave type remote medical system to diagnose shoulder diseases, such as dialysis-related amyloid arthropathy (DRAA), by ultrasonographic images. Proper positioning, orientation, and contact force between the ultrasound probe and the affected area of the patient are required in order to acquire proper diagnostic images. Safety and manipulability are also required when operating the remote medical system through a communication network. Therefore, the system has impedance control capability for positioning of the master and slave manipulators in order to convey the contact force and enhance manipulability. In addition, the system has continuous-path control capability for the orientation of the slave manipulator in order to realize smooth and accurate motion of the ultrasound probe, even if the sampling rate of the transmission of the orientation data of the master manipulator is not sufficient. The results of remote diagnostic experiments demonstrated that a healthcare professional could diagnose real patients through a communication network using the constructed system. [ABSTRACT FROM AUTHOR]

A new method for fluoroscopic tracking of a proximal bone fragment in femoral fracture reduction is presented. The proposed method combines 2-D and 3-D image registration from single-view fluoroscopy with tracking of the head center position of the proximal femoral fragment to improve the accuracy of fluoroscopic registration without the need for repeated manual adjustment of the C-arm as required in stereo-view registrations. Kinematic knowledge of the hip joint, which has a positional correspondence with the femoral head center and the pelvis acetabular center, allows the position of the femoral fragment to be determined from pelvis tracking. The stability of the proposed method with respect to fluoroscopic image noise and the desired continuity of the fracture reduction operation is demonstrated, and the accuracy of tracking is shown to be superior to that achievable by single-view image registration, particularly in depth translation. [ABSTRACT FROM AUTHOR]

Wavelength scanned interferometry allows the simultaneous measurement of top surface shape and optical thickness variation of a transparent object consisting of several parallel surfaces. Interference signals from these surfaces can be separated in frequency space, and their phases are detected by discrete Fourier analysis. However, these signal frequencies are shifted from the detection frequency by the refractive index dispersion of the object and a nonlinearity of the wavelength scanning. The Fourier analysis is sensitive to the detuning of the signal frequency and suffers from the multiple-beam interference noise. Conventional error-compensating algorithms cannot be applied to an object consisting of more than three reflecting surfaces. We derive a new 2 N-1 sample error-compensating algorithm, which allows the phase detection of any order of harmonic frequency among the interference signals. The new algorithm suppresses the effect of signal frequency detuning as well as the multiple-beam interference noise and can be applied to the measurement of complex objects consisting of more than three reflecting surfaces. [ABSTRACT FROM AUTHOR]

In measurements of the variations in the thickness and surface profile of optical flats using wavelength-tuning fringe analysis, an interference signal can be detected based on the modulation frequency of the signal. However, the modulation frequency can deviate from the predetermined value through the refractive-index dispersion of the optical flat. In this study, two types of noble 25-frame phase-detection algorithms that can compensate for the effect of refractive-index dispersion were developed using Fourier analysis. The behaviors of the 25-frame algorithms were visualized on both the frequency domain and complex plane. The dispersion-resistance ability and signal-to-noise ration of the 25-frame algorithm were estimated by calculating the PV errors and using the frequency-transfer-function paradigm, respectively. Finally, the variations in the thickness and surface profile of the optical flat were measured using a wavelength-tuning Fizeau interferometer and the proposed 25-frame algorithms. The standard deviations of the thickness and surface measurements were 1.654 nm and 8.368 nm, respectively, which were much smaller than those of the conventional phase-detection algorithms. [ABSTRACT FROM AUTHOR]

Fringe analysis using phase modulation through wavelength scanning is extensively utilized for profiling the surface and thickness variation of glass plates. However, the nonlinearity of the phase-modulation error during wavelength scanning causes an offset error in the calculated phase. Therefore, in this research, two types of 19-frame phase-extraction formulas were derived for simultaneous profiling of the thickness variation and surface of a glass plate, focusing on eliminating the offset phase error. These new formulas were visualized in the frequency domain using the Fourier description. The ability of these formulas to eliminate the offset error was confirmed through numerical error analysis. Finally, the surface and thickness variation of a glass plate were simultaneously profiled using the large-aperture Fizeau interferometer and the new 19-frame formulas. The standard deviations obtained for thickness variation and surface profiling were 4.687 and 14.421 nm, respectively, which were lower than those obtained when using other phase-extraction formulas. • 19-frame formula for thickness profiling that can eliminate the offset error. • 19-frame formula for surface profiling. • Numerical error analysis of 19-frame algorithm with comparisons to other formulas. • Simultaneous thickness and surface profiling by 19-frame formulas and interferometer. [ABSTRACT FROM AUTHOR]