Inclination Measurements Research Articles

VARIABILITY OF MANUAL AND COMPUTERIZED METHODS FOR MEASURING CORONAL VERTEBRAL INCLINATION IN COMPUTED TOMOGRAPHY IMAGES

Objective measurement of coronal vertebral inclination (CVI) is of significant importance for evaluating spinal deformities in the coronal plane. The purpose of this study is to systematically analyze and compare manual and computerized measurements of CVI in cross-sectional and volumetric computed tomography (CT) images. Three observers independently measured CVI in 14 CT images of normal and 14 CT images of scoliotic vertebrae by using six manual and two computerized measurements. Manual measurements were obtained in coronal cross-sections by manually identifying the vertebral body corners, which served to measure CVI according to the superior and inferior tangents, left and right tangents, and mid-endplate and mid-wall lines. Computerized measurements were obtained in two dimensions (2D) and in three dimensions (3D) by manually initializing an automated method in vertebral centroids and then searching for the planes of maximal symmetry of vertebral anatomical structures. The mid-endplate lines were the most reproducible and reliable manual measurements (intra- and inter-observer variability of 0.7° and 1.2° standard deviation, SD, respectively). The computerized measurements in 3D were more reproducible and reliable (intra- and inter-observer variability of 0.5° and 0.7° SD, respectively), but were most consistent with the mid-wall lines (2.0° SD and 1.4° mean absolute difference). The manual CVI measurements based on mid-endplate lines and the computerized CVI measurements in 3D resulted in the lowest intra-observer and inter-observer variability, however, computerized CVI measurements reduce observer interaction.

Smartphone-based platform optical setup measuring π/256 optical phase difference in an interference process.

Utilizing the camera of a smartphone and simple laboratory optical components, we demonstrate an optical technique that measures an optical phase difference (OPD) of π/256 in an interference process. We develop a compact optical setup for viewing circular interference fringe patterns through the camera of the smartphone. By introducing OPD between the interfering beams, variation in fringe pattern is recorded using the smartphone camera. We envision that the proposed optical setup could emerge as an ultrasensitive optical tool for measurement of inclination of a given surface.

POIS, a Low Cost Tilt and Position Sensor: Design and First Tests.

An integrated sensor for the measurement and monitoring of position and inclination, characterized by low cost, small size and low weight, has been designed, realized and calibrated at the Geomatics Lab of the University of Calabria. The design of the prototype, devoted to the monitoring of landslides and structures, was aiming at realizing a fully automated monitoring instrument, able to send the data acquired periodically or upon request by a control center through a bidirectional transmission protocol. The sensor can be released with different accuracy and range of measurement, by choosing bubble vials with different characteristics. The instrument is provided with a computer, which can be programmed so as to independently perform the processing of the data collected by a single sensor or a by a sensor network, and to transmit, consequently, alert signals if the thresholds determined by the monitoring center are exceeded. The bidirectional transmission also allows the users to vary the set of the monitoring parameters (time of acquisition, duration of satellite acquisitions, thresholds for the observed data). In the paper, hardware and software of the sensor are described, along with the calibration, the results of laboratory tests and of the first in field acquisitions.

Efficient Drilling of Ultra-HP/HT Wells in the Gulf of Thailand

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 25392, “Efficient Drilling of Ultra-HP/HT Wells in the Gulf of Thailand,” by Joy Araujo, Schlumberger; Keittipong Kaotun, PTTEP; and Panupun Dumrongthai and A. Adrian, Schlumberger, prepared for the 2014 Offshore Technology Conference, Houston, 5–8 May. The paper has not been peer reviewed. A new measurement-while-drilling (MWD) tool has been designed that can operate reliably at 200°C and 207 MPa, providing real-time direction and inclination surveys, azimuthal gamma ray, annular and internal pressure while drilling, and shock and vibration measurements. An operator in the Gulf of Thailand used this new MWD technology to drill wells in ultrahigh-pressure/high-temperature (HP/HT) reservoirs without the need to stop operation because of temperature limitations. Savings of ½ day per well have been achieved. Introduction Offshore drilling in the Gulf of Thailand increasingly challenges logging operations, with temperatures greater than 200°C. Hundreds of wells need to be drilled per year in this environment to fulfill long-term gas contracts. High efficiency is required in such a high-volume operation. Existing commercial MWD and logging-while-drilling (LWD) technologies are only capable of operating up to 175°C, with an inherent decrease in reliability at higher temperatures. In the planned ultra-HP/HT projects, the bottomhole assembly (BHA), which includes an MWD tool for directional and inclination measurements in real time, will be pulled out of the hole once the circulating temperature reaches 175°C. Then, a new BHA, without measurement tools, will be used to continue drilling to total depth. This “blind” drilling section could be several hundred meters long, introducing risks associated with well control and well collision. The main limiting factors in having MWD/LWD tools operating in these ultra-HP/HT environments are the downhole electronic components. Industry research studies show that plastic-encapsulated components have a life expectancy of approximately 1,000 hours at 150°C; this drops to less than 100 hours at 175°C. Ceramic-encapsulated components last longer at 175°C, but they are bigger and heavier than their plastic counterparts. Because space is restricted in these tools, the best compromise yields a mix of both ceramic- and plastic-encapsulated components. To find a solution to this industrywide problem, significant effort was made over the last decade to develop custom electronics that can withstand high downhole temperatures. The newly developed MWD tool equipped with these novel electronics components was deployed in ultra-HP/HT wells. In these wells, the real-time measurements were necessary to drill the sections with operating temperatures greater than 175°C. It allowed minimization of drilling risks, enabled proper well placement, and improved drilling efficiency by eliminating one run.

Discussion of “New Method for High-Speed Railway Bridge Dynamic Deflection Measurement” by Xianlong He, Xueshan Yang, and Lizhen Zhao

Discussion of “New Method for High-Speed Railway Bridge Dynamic Deflection Measurement” by Xianlong He, Xueshan Yang, and Lizhen Zhao

Predictive value of robotic-assisted total hip arthroplasty.

Acetabular cup positioning, leg-length discrepancy, and global offset are important parameters associated with outcomes following total hip arthroplasty (THA). Deviation from an accepted range of values can lead to significant complications, including dislocation, leg-length discrepancy, impingement, accelerated bearing surface wear, and revisions. The purpose of this study was to assess whether robotic-assisted THA was reliable in predicting radiographic measurements of cup inclination and anteversion, leg-length change, and global offset change. All 61 robotic-assisted THAs that met the inclusion and exclusion criteria were performed by a single surgeon through a mini-posterior approach. Data provided by the robot were collected prospectively, and radiographic data were collected retrospectively by 2 blinded independent reviewers. The cohort in this study consisted of 27 male and 34 female patients, with an average age of 60.5 years. A strong inter- and intraobserver correlation was found for the radiographic measurements of cup inclination, cup anteversion, leg-length discrepancy, and global offset (r>0.8 with P<.001 for all). Ninety-six point seven percent of robotic-measured inclination angles and 98.4% of robotic-measured anteversion angles were within 10° of radiographic measurements. One hundred percent of robotic-measured leg-length change and 91.8% of robotic-measured global offset change were within 10 mm of radiographic measurements. Robotic-assisted THA showed good predictive value for cup inclination and anteversion angles and measurements of leg-length change and global offset change done postoperatively on plain radiographs. Further refinement of the robotic system would make it more accurate in predicting the postoperative parameters mentioned.

Technical difficulty in component sizing and positioning in humeral resurfacing: Relationship to clinical outcomes

INTRODUCTION: Resurfacing of the glenohumeral joint has gained popularity since its first introduction. Among other advantages, it is reported to allow closer replication of individual anatomy - failure of which may produce inferior clinical results. We review a cohort of patients who had undergone proximal humeral resurfacing, to evaluate certain radiological parameters of component sizing and positioning, and to correlate these with the clinical outcomes. MATERIALS AND METHODS: From January 2000 to March 2011, 51 humeral resurfacing procedures were performed in 49 patients. Patients were contacted for review, and assessed using patient-reported outcome measures. An Oxford Shoulder Score (OSS) as well as a subjective satisfaction and outcome questionnaire were completed, as well as details regarding further surgery or revision. Radiographs were evaluated for component size, offset, inclination and height. Two patients had demised, ten patients were not contactable, and in four the medical files had been lost. In the remaining 35 shoulders, the average follow-up was 5.43 years. The mean age at time of surgery was 64.8 years (range 36 to 84). RESULTS: Complications included eight revisions (average 2.4 years post-surgery), while a further one patient awaits revision. The mean OSS in the unrevised shoulders was 36.1 (range 10 to 48). There was no difference between the revised and unrevised group for peri-operative variables (pre-op diagnosis, smoking status, age, gender, surgeon involved), or any of the radiographic variables (inclination, offset, prosthesis height, increase in head size). In the unrevised group, there was no correlation between the OSS and radiographic measurements of offset, inclination or head height. Prostheses that subjectively appeared mal-sized or mal-positioned obtained better OSSs and subjective satisfaction scores. Revised cases were all subjectively satisfied post revision to stemmed total shoulder replacement. CONCLUSION: We have demonstrated difficulties in correct sizing and component placement as evident by the post-operative radiographic analysis, but are unable to correlate these with clinical scores. We have encountered a wide range of patient-reported shoulder scores and levels of satisfaction which, however unexplainably, have shown better scores for subjectively mal-sized and mal-positioned prostheses.

What asteroseismology can do for exoplanets

We describe three useful applications of asteroseismology in the context of exoplanet science: (1) the detailed characterisation of exoplanet host stars; (2) the measurement of stellar inclinations; and (3) the determination of orbital eccentricity from transit duration making use of asteroseismic stellar densities. We do so using the example system Kepler-410 (Van Eylen et al. 2014). This is one of the brightest (V = 9.4) Kepler exoplanet host stars, containing a small (2.8 Rearth) transiting planet in a long orbit (17.8 days), and one or more additional non-transiting planets as indicated by transit timing variations. The validation of Kepler-410 (KOI-42) was complicated due to the presence of a companion star, and the planetary nature of the system was confirmed after analyzing a Spitzer transit observation as well as ground-based follow-up observations.

The measurement of inclination on gravity concrete dams using the tiltmeter instrument

The measurement of inclination on gravity concrete dams using the instrument tiltmeter is described and discussed with special reference on obtained results on the dam 'Đerdap 2' acquired in the three years period. Tiltmetar way of operation is presented both through physical principle of vibrating wire sensors and through described design of the instrument. The influence of the temperature on the measurement of the slope is specially emphasized and presented through temperature correction. Processing the results of real inclination measurements on the dam 'Đerdap 2' with and without temperature correction showed the significant difference. Statistical analysis of measurement data consisted of performed regression analysis and forming of corresponding series with the expected measurement values depending on environmental conditions. At the end we give a summary conclusion on the instrument, the influence of temperature on the measurement and statistical model.

Landslides in urban residential slopes induced by strong earthquakes in Japan

Recent destructive earthquakes in urban regions, such as the 1978 Miyagiken-oki earthquake, the 1995 Kobe earthquake and the 2011 Tohoku earthquake have destabilized many gentle slopes in residential areas of large cities in Japan. Beyond the serious danger to residents of the earthquake affected areas, such landslides revealed the weaknesses of urban development in large cities of Japan. One of the typical large landslides, the Midorigaoka #4 landslide, occurred in residential fills in Sendai during the 2011 Tohoku earthquake. Inclination measurements in the landslide indicate self-dumping at weak layers in ground structure. Excess pore water pressure in the landslide increased in direct proportion to horizontal peak ground velocity during after-shocks suggesting that the landslide was initiated by the complete loss of shear strength along the slip layer during the main shock. A simple analog model, the roller slider model, can discriminate stable or unstable valley fills during strong motion of past earthquakes. The results of stability analysis by the simplified 3D method based on this model explain the degree of damage in each valley fill during the 2011 Tohoku earthquake. Considering risk mitigation against such landslides in residential lots, urban development should minimize artificial changes in landforms, especially avoiding valley fills. A new concept of a Counter line city is proposed that includes both minimization of risk and creating a favorable natural environment.

Maxillary buccal cortical plate inclination at mini-screw insertion sites.

To evaluate whether buccal cortical bone inclination varies for the maxillary alveolar processes of adult patients with decreased, normal, and increased facial heights. Cone-beam computed tomography images of 135 adult patients, including 49 hypodivergent subjects (26 women, 23 men), 40 hyperdivergent subjects (24 women, 16 men), and 46 normodivergent (25 women, 21 men) were analyzed. Cortical bone inclination measurements were made relative to the occlusal plane. Cross-sectional slices of the maxilla were taken at interdental sites from the distal aspect of maxillary canine to the mesial aspect of maxillary second molar. Analysis of variance indicated significant differences (P < .05) between the angles formed by the line tangent to the cortical bone and the occlusal plane among the vertical facial types for the regions between canine and first premolar and between second premolar and first molar at miniscrew insertion sites. The results of this study indicate that vertical facial pattern should be taken into consideration when adjusting the insertion angle of miniscrews at the maxillary buccal region.

Comparison of self-reported measure of sitting time (IPAQ) with objective measurement (activPAL)

This study compared sitting time measured by a questionnaire (International Physical Activity Questionnaire; IPAQ) with concurrently measured objective sitting time from an accelerometer-based measure of thigh inclination (activPAL).Adults (n = 69), wore an activPAL for a week, and then completed the long-form 7 d recall IPAQ questionnaire. IPAQ reported sitting time (including and excluding transportation sitting) for the week, weekdays and weekend days were compared to activPAL (criterion measure) sitting time using intraclass correlation coefficients and Bland Altman plots.Confidence intervals between the IPAQ and the activPAL were wide, while correlations between the two measures were low and non-significant (0.112–0.275). Compared to a direct measure of postural sitting (activPAL), the IPAQ underestimated sitting time across the group for the whole week, both when including (mean 2.2 h d−1) and excluding (mean 3.4 h d−1) transportation sitting. Sitting was less accurately reported on weekend days than weekdays, and at lower levels of sitting on weekdays.Agreement between the IPAQ and the activPAL, a direct measure of sitting, in this study was poor. The direction of group agreement was different to comparisons using a measure of low accelerometer counts (Actigraph) as the criterion measure in previous research. Future studies should use a direct measure of sitting as a criterion measure to validate subjective measurement tools.

THE MASS OF THE BLACK HOLE IN LMC X-3

We analyze a large set of new and archival photometric and spectroscopic observations of LMC X-3 to arrive at a self-consistent dynamical model for the system. Using echelle spectra obtained with the MIKE instrument on the 6.5m Magellan Clay telescope and the UVES instrument on the second 8.2m Very Large Telescope we find a velocity semiamplitude for the secondary star of $K_2=241.1\pm 6.2$ km s$^{-1}$, where the uncertainty includes an estimate of the systematic error caused by X-ray heating. Using the spectra, we also find a projected rotational velocity of $V_{\rm rot}\sin i=118.5\pm 6.6$ km s$^{-1}$. From an analysis of archival $B$ and $V$ light curves as well as new $B$ and $V$ light curves from the SMARTS 1.3m telescope, we find an inclination of $i=69.84\pm 0.37^{\circ}$ for models that do not include X-ray heating and an inclination of $i=69.24\pm 0.72^{\circ}$ for models that incorporate X-ray heating. Adopting the latter inclination measurement, we find masses of $3.63\pm 0.57\,M_{\odot}$ and $6.98\pm 0.56\,M_{\odot}$ for the companion star and the black hole, respectively. We briefly compare our results with earlier work and discuss some of their implications.

Measurement of the buccolingual inclination of teeth: Manual technique vs 3-dimensional software

In this study, we aimed to measure the inclination of teeth on dental casts by a manual technique with the tooth inclination protractor (TIP; MBI, Newport, United Kingdom) and a newly designed 3-dimensional (3D) software program. The correlation of the 2 techniques was evaluated, and the reliability of each technique was assessed separately. This study was conducted on 36 dental casts of normal, well-aligned Class I occlusions; we assessed 432 teeth. All casts had a normal Class I occlusion. After determining the facial axis of the clinical crown and the facial axis points on the dental casts, we measured the inclinations of the incisors and posterior teeth up to the first molars in each dental arch relative to Andrews' occlusal plane and the posterior occlusal plane using the TIP. Moreover, the casts were scanned by a structured-light 3D scanner. The inclination of teeth relative to the occlusal plane was determined using the new software. To assess the reliability, measurements of all teeth from 15 casts were repeated twice by the 2 methods. Intraclass correlation coefficient and Dahlberg's formula were used for calculation of correlation and reliability. Overall, the 2 techniques were not significantly different in the measurements of the inclinations of the teeth in both jaws. The ranges of Dahlberg's formula were 3.1° to 5.8° for the maxilla and 3.3° to 5.9° for the mandible. The overall correlation of the 2 techniques according to the intraclass correlation coefficient was 0.91. For calculation of reliability, the intraclass correlation coefficients for the TIP and the 3D method were 0.73 and 0.82, respectively. The TIP and the 3D software showed a high correlation for measurement of the inclinations of maxillary and mandibular teeth relative to the occlusal plane. Also, the reproducibility of the measurements in each method was high.

Notes on the history of geophysics in the Ottoman Empire

Abstract. In Anatolia, the history of geophysical sciences may go back to antiquity (600 BC), namely the period when Thales lived in Magnesia (Asia Minor). In the modern sense, geophysics started with geomagnetic works in the 1600s. The period between 1600 and 1800 includes the measurement of magnetic declination, inclination and magnetic field strength. Before these years, there is a little information, such as how to use a compass, in the Kitab-i Bahriye (the Book of Navigation) of Piri Reis, who is one of the most important mariners of the Ottoman Empire. However, this may not mean that magnetic declination was generally understood. The first scientific book relating to geophysics is the book Fuyuzat-i Miknatissiye that was translated by Ibrahim Müteferrika and printed in 1731. The subject of this book is earth's magnetism. There is also information concerning geophysics in the book Cihannuma (Universal Geography) that was written by Katip Celebi and in the book Marifetname written by Ibrahim Hakki Erzurumlu, but these books are only partly geophysical books. In Istanbul the year 1868 is one of the most important for geophysical sciences because an observatory called Rasathane-i Amire was installed in the Pera region of this city. At this observatory the first systematic geophysical observations such as meteorological, seismological and even gravimetrical were made. There have been meteorological records in Anatolia since 1839. These are records of atmospheric temperature, pressure and humidity. In the Ottoman Empire, the science of geophysics is considered as one of the natural sciences along with astronomy, mineralogy, geology, etc., and these sciences are included as a part of physics and chemistry.

The impact of surgeon handedness in total hip replacement.

Total hip replacement (THR) is successful and performed commonly. Component placement is a determinant of outcome. Influence of surgeon handedness on component placement has not been considered previously. This study was a radiographic assessment of component positioning with respect to handedness. Early data from 160 patients are reported. Overall, 160 primary THRs for osteoarthritis were included. Equal numbers of left and right THRs were performed by four surgeons, two right-handed and two left-handed. Postoperative radiography was assessed for THR component position by measurement of leg length inequality, acetabular inclination and centre of rotation. Surgeons' handedness was assessed using the Edinburgh inventory. For leg length inequality, no significant interaction was seen between hip side and surgeon handedness. Acetabular inclination angles showed a statistically significant difference, however, depending on hand dominance, with higher inclination angles recorded when operating on the dominant side. There was a trend towards greater medialisation of the centre of rotation on the non-dominant side although this did not reach statistical significance. Surgeon handedness appears to influence acetabular component position during THR but it is one factor of many that interact to achieve a successful outcome.

Three-dimensional planning and use of patient-specific guides improve glenoid component position: an in vitro study

Glenoid component positioning is a key factor for success in total shoulder arthroplasty. Three-dimensional (3D) measurements of glenoid retroversion, inclination, and humeral head subluxation are helpful tools for preoperative planning. The purpose of this study was to assess the reliability and precision of a novel surgical method for placing the glenoid component with use of patient-specific templates created by preoperative surgical planning and 3D modeling. A preoperative computed tomography examination of cadaveric scapulae (N = 18) was performed. The glenoid implants were virtually placed, and patient-specific guides were created to direct the guide pin into the desired orientation and position in the glenoid. The 3D orientation and position of the guide pin were evaluated by performing a postoperative computed tomography scan for each scapula. The differences between the preoperative planning and the achieved result were analyzed. The mean error in 3D orientation of the guide pin was 2.39°, the mean entry point position error was 1.05 mm, and the mean inclination angle error was 1.42°. The average error in the version angle was 1.64°. There were no technical difficulties or complications related to use of patient-specific guides for guide pin placement. Quantitative analysis of guide pin positioning demonstrated a good correlation between preoperative planning and the achieved position of the guide pin. This study demonstrates the reliability and precision of preoperative planning software and patient-specific guides for glenoid component placement in total shoulder arthroplasty.

The reliability of the anterior pelvic plane for computer navigated acetabular component placement during total hip arthroplasty: Prospective study with the EOS imaging system

IntroductionComputer navigated total hip arthroplasty is mostly based on the use of the anterior pelvic plane (APP) as a reference. EOS is a new imaging system that provides three-dimensional analysis of the pelvis in a functional position with a low dose of radiation. The aim of this study was to evaluate the reliability of the APP for placement of the cup during computer navigated THA using EOS. HypothesisThe reliability of the APP is limited for the placement of the acetabular cup during computer navigated THA. Materials and methodsThis was a prospective monocentric study using the EOS imaging system evaluating 44 patients in the standing position three months after computer navigated THA (Orthopilot™). Reproducibility of EOS measurements were analyzed using SterEOS software and the reliability of the navigation data for the position of the cup were assessed. ResultsIntra and interobserver reproducibility of the measurements of the orientation of the cup by EOS were good with correlation coefficients above 93% and 95% and confidence intervals of less than±5°. Mean cup inclination and anteversion were 41.3° and 20.9° and 44.3° and 29.5° respectively in operatively and post-operatively. The differences between measurements of operative cup inclination using computer assisted navigation and the post-operative EOS measurements were significant (P<0.05) with a correlation coefficient of less than 40%. DiscussionOur study confirms the lack of precision of the APP as a reference for positioning of the acetabular component, especially in relation to anteversion. Although for many years the APP was considered to be a global reference, in fact, it is subject to significant inter-individual variations and variations during changes in position. These factors, associated with the difficulty of determining the preoperative APP, explain the lack of reliability of this reference. Preoperative evaluation of the orientation of APP by EOS and its integration into the navigation system could help the operator position these components. Level of evidenceLevel III Prospective diagnostic case controlled study.

Improved Continuous Azimuth and Inclination Measurement by Use of a Rotary-Steerable System Enhances Downhole-Steering Automation and Kickoff Capabilities Near Vertical

Summary When kicking off at low inclination, static measurement-while-drilling (MWD) surveys are used to confirm the kickoff direction, when free of magnetic interference from offset wells. However, because MWD continuous azimuth and inclination measurements have limited accuracy when near vertical, the directional driller does not have confidence in the kickoff direction with continuous (dynamic) survey while drilling. This requires additional static surveys to be made, taking up rig time. In a novel continuous survey method used in a particular rotary-steerable system (RSS), a six-axis survey was taken continuously, both while drilling and when static, with the survey sensors being housed in a rotation-speed-controlled platform in the RSS. This algorithm was first verified in a software simulator, and it was subsequently implemented in hardware and tested in a hardware-in-the-loop (HIL)-simulator environment. The effectiveness of the new measurement method was field tested and compared with MWD static survey points. The field-test result shows that the new near-bit continuous azimuth and inclination measurement from the RSS is considerably more accurate than the MWD continuous measurements at very low inclinations less than 5°. The new survey method not only provided more-accurate kickoff from a near-vertical position but also enhanced the automated-vertical-drilling feature. In addition, improved continuous measurements around magnetic north and south allowed the closed-loop attitude-hold algorithm of the RSS to drill lateral sections more precisely in these directions. This unique measurement method has valuable applications, such as low-angle kickoff without the use of multiple static surveys because the directional driller can use the continuous azimuth and/or tool face to accurately steer the well. Equally important is that if gyro surveys are required, their number will reduce when the survey-measurement point is so close to the bit, reducing the amount of time of exposure to magnetic interference from an offset casing. When drilling out of the shoe, this survey method will allow an accurate kickoff approximately 50 ft earlier than would normally be expected when magnetic interference is cleared. In addition, the use of a continuous gravity tool face (GTF) is possible without the need for static surveys, allowing accurate low-side sidetracks to be performed even in areas of high magnetic interference. This surveying method reduces the rig time needed to kick off and provides a more reliable real-time measurement for the directional driller to ensure that the desired well trajectory is drilled through crowded platform environments.

A MEMS tilt sensor with expanded operating range and improved sensitivity

In this paper, a simple and novel method of expanding the operating range of inclinations and of increasing the sensitivity of convection-based tilt sensors is shown. Even though the previously reported convective tilt sensors fabricated in our laboratory have their own merits in performing dual-axes inclination measurement with excellent linearity and symmetric sensitivity, they showed limited operating range from −90 to 90° because of their structural limitations. However, this proposed tilt sensor has overcome the structural limitations and it detects inclinations wider than the ±90° range on two axes with symmetric sensitivity. The improved performance could be achieved by removing the membrane at the bottom of the microheater and temperature sensors for unlimited gas movement in the cavity when it tilted over the ±90° range. The operating range of the newly proposed tilt sensor expands to ±180° compared with that of the previously reported convective tilt sensor. Moreover, various designs of cavities and cap substrates were adopted to improve the sensitivity of the proposed convective tilt sensor. The mass production of the proposed convection-based tilt sensor is still feasible because it can be fabricated at a low cost because of its simple fabrication step. Its sensitivity is high and it has a very wide-angle detection range.