Point-of-care ultrasound(POCUS) is recognized as a valuable diagnostic tool,especially in resourcelimited settings(RLS).POCUS provides rapid diagnostic information that enables health professionals to make critical de...Point-of-care ultrasound(POCUS) is recognized as a valuable diagnostic tool,especially in resourcelimited settings(RLS).POCUS provides rapid diagnostic information that enables health professionals to make critical decisions at the bedside.^([1]) Despite the welldocumented benefits of POCUS,access to longitudinal,comprehensive training programs and a lack of trainee feedback are barriers to the widespread use of this technology in such settings.^([2])展开更多
The intrinsic property of MXenes to adsorb dyes with high Raman scattering cross-sections makes them promising candidates for surface-enhanced Raman scattering(SERS)biosensors.In the study,we report a vanadium carbide...The intrinsic property of MXenes to adsorb dyes with high Raman scattering cross-sections makes them promising candidates for surface-enhanced Raman scattering(SERS)biosensors.In the study,we report a vanadium carbide MXene(V_(2)CT_(x))-based SERS biosensor tag,V_(2)CT_(x)@Thi(thionine)@Au NPs(gold nanoparticles)-Ab(antibody),owing to its large interlayer spacing and superior dye adsorption capacity.The tag V_(2)CT_(x)@Thi@Au NPs-Ab was fully characterized and validated,demonstrating a significantly enhanced Raman signal through both electromagnetic and chemical enhancement mechanisms.Using a handheld Raman spectrometer as a readout tool,the developed handheld SERS biosensor was successfully applied for the detection of viral antigens.The biosensor exhibited excellent linearity(1.562–100 nM)and achieved a low limit of detection(LOD)1.562 nM.Moreover,the biosensor demonstrated good selectivity and stability for detecting the target S protein in saliva samples.Our study highlights the potential of V_(2)CT_(x)MXene as a powerful material for handheld SERS biosensors,paving the way for portable and efficient viral diagnostics.展开更多
Considering that it is difficult to monitor the measurement system and amend the test parameters on the scene in shock wave overpressure measurement and it is inconvenient to operate and carry traditional PC in outdoo...Considering that it is difficult to monitor the measurement system and amend the test parameters on the scene in shock wave overpressure measurement and it is inconvenient to operate and carry traditional PC in outdoor experiments, a new handheld terminal for shock wave pressure measurement system based on ARM is designed, The handheld terminal, whose ap- plication program is developed by the software of Qt, can control the measurement system by Wi-Fi and perform the functions of monitoring the system state, transmitting the data by wireless and displaying waveforms. To prevent data loss, USB inter- face is designed to read the data The test results show that the designed handheld terminal has good stability and reliability in several explosion experiments.展开更多
Objective To estimate the prevalence of unknown atrial fibrillation(AF)in the elderly population of the Veneto Region,Italy.Methods 1820 patients aged≥65 years with no history of AF and not anticoagulated were enroll...Objective To estimate the prevalence of unknown atrial fibrillation(AF)in the elderly population of the Veneto Region,Italy.Methods 1820 patients aged≥65 years with no history of AF and not anticoagulated were enrolled in primary-care settings.They underwent an opportunistic electrocardiogram screening with a handheld device(My Diagnostick)designed to specifically detect AF.The electrocardiogram recordings were reviewed by the researchers,who confirmed the presence of AF.Results The device detected an arrhythmia in 143 patients,which was confirmed as AF in 101/143(70.6%),with an overall prevalence of AF of 5.5%(101/1820).Prevalence of unknown AF resulted in 3.6%in patients aged 65–74 years,and 7.5%in patients age 75 or older,and increased according to CHA2 DS2-VASc score:3.5%in patients with a score of 1 or 2,5.6%in patients with a score of 3,7.0%in patients with a score of 4,and 7.2%in patients with a score≥5.The detection rate was significantly higher in patients with mild symptoms compared to asymptomatic counterparts(24.1%vs.4.0%,P<0.0001).At multivariate analysis,congestive heart failure and age≥75 years-old were independent predictors for screen-detected AF.Conclusions An opportunistic screening with handheld device revealed an unexpectedly high prevalence of unknown AF in elderly patients with mild symptoms.Prevalence increased with age and CHA2DS2-VASc score.展开更多
AIM: To explore the performance in diabetic retinopathy(DR) screening of artificial intelligence(AI) system by evaluating the image quality of a handheld Optomed Aurora fundus camera in comparison to traditional table...AIM: To explore the performance in diabetic retinopathy(DR) screening of artificial intelligence(AI) system by evaluating the image quality of a handheld Optomed Aurora fundus camera in comparison to traditional tabletop fundus cameras and the diagnostic accuracy of DR of the two modalities. METHODS: Overall, 630 eyes were included from three centers and screened by a handheld camera(Aurora, Optomed, Oulu, Finland) and a table-top camera. Image quality was graded by three masked and experienced ophthalmologists. The diagnostic accuracy of the handheld camera and AI system was evaluated in assessing DR lesions and referable DR.RESULTS: Under nonmydriasis status, the handheld fundus camera had better image quality in centration, clarity, and visible range(1.47, 1.48, and 1.40) than conventional tabletop cameras(1.30, 1.28, and 1.18;P<0.001). Detection of retinal hemorrhage, hard exudation,and macular edema were comparable between the two modalities, in principle, with the area under the curve of the handheld fundus camera slightly lower. The sensitivity and specificity for the detection of referable DR with the handheld camera were 82.1%(95%CI: 72.1%-92.2%) and 97.4%(95%CI: 95.4%-99.5%), respectively. The performance of AI detection of DR using the Phoebus Algorithm was satisfactory;however, Phoebus showed a high sensitivity(88.2%, 95%CI: 79.4%-97.1%) and low specificity(40.7%, 95%CI: 34.1%-47.2%) when detecting referable DR.CONCLUSION: The handheld Aurora fundus camera combined with autonomous AI system is well-suited in DR screening without mydriasis because of its high sensitivity of DR detection as well as its image quality, but its specificity needs to be improved with better modeling of the data. Use of this new system is safe and effective in the detection of referable DR in real world practice.展开更多
BACKGROUND:The use of ultrasound(US)within healthcare has inspired the development of new US technology.There have been few studies comparing the use of handheld US to standard US for medical education.This research a...BACKGROUND:The use of ultrasound(US)within healthcare has inspired the development of new US technology.There have been few studies comparing the use of handheld US to standard US for medical education.This research aims to determine whether a handheld US device can provide a comparable primary learning experience to that of a standard US machine.METHODS:Over two days of instruction,participants were taught and evaluated on core US fundamentals.The standard group received instruction on standard US machines,while the handheld group received instruction on handheld US devices.Participants completed a qualitative survey regarding their experience.Six hundred and four images were obtained and graded by two emergency medicine physicians.RESULTS:A total of 119 Swiss medical students were enrolled in our study.There was no statistically significant difference in the US assessment measurements,except for faster endpoint septal separation(EPSS)vascular setup time in the handheld group(P=0.001).There was no statistically significant difference in participants’perceived difficulty of US learning(P=0.198),comfort level(P=0.188),or self-estimated capability to perform US in the future(P=0.442).There was no statistically significant difference in the percentage of correctly obtained images(P=0.211)or images that were clinically useful(P=0.256).The median quality score of images obtained by the standard group was eight compared to seven in handheld group(P<0.01).CONCLUSION:Our data suggest a handheld US machine can perform as well as a standard US machine as an educational tool despite sacrifices in image quality.展开更多
Sustainable forest management heavily relies on the accurate estimation of tree parameters.Among others,the diameter at breast height(DBH) is important for extracting the volume and mass of an individual tree.For syst...Sustainable forest management heavily relies on the accurate estimation of tree parameters.Among others,the diameter at breast height(DBH) is important for extracting the volume and mass of an individual tree.For systematically estimating the volume of entire plots,airborne laser scanning(ALS) data are used.The estimation model is frequently calibrated using manual DBH measurements or static terrestrial laser scans(STLS) of sample plots.Although reliable,this method is time-consuming,which greatly hampers its use.Here,a handheld mobile terrestrial laser scanning(HMTLS) was demonstrated to be a useful alternative technique to precisely and efficiently calculate DBH.Different data acquisition techniques were applied at a sample plot,then the resulting parameters were comparatively analysed.The calculated DBH values were comparable to the manual measurements for HMTLS,STLS,and ALS data sets.Given the comparability of the extracted parameters,with a reduced point density of HTMLS compared to STLS data,and the reasonable increase of performance,with a reduction of acquisition time with a factor of5 compared to conventional STLS techniques and a factor of3 compared to manual measurements,HMTLS is considered a useful alternative technique.展开更多
This work focuses on a brief discussion of new concepts of using smartphone sensors for 3D painting in virtual or augmented reality. Motivation of this research comes from the idea of using different types of sensors ...This work focuses on a brief discussion of new concepts of using smartphone sensors for 3D painting in virtual or augmented reality. Motivation of this research comes from the idea of using different types of sensors which exist in our smartphones such as accelerometer, gyroscope, magnetometer etc. to track the position for painting in virtual reality, like Google Tilt Brush, but cost effectively. Research studies till date on estimating position and localization and tracking have been thoroughly reviewed to find the appropriate algorithm which will provide accurate result with minimum drift error. Sensor fusion, Inertial Measurement Unit (IMU), MEMS inertial sensor, Kalman filter based global translational localization systems are studied. It is observed, prevailing approaches consist issues such as stability, random bias drift, noisy acceleration output, position estimation error, robustness or accuracy, cost effectiveness etc. Moreover, issues with motions that do not follow laws of physics, bandwidth, restrictive nature of assumptions, scale optimization for large space are noticed as well. Advantages of such smartphone sensor based position estimation approaches include, less memory demand, very fast operation, making them well suited for real time problems and embedded systems. Being independent of the size of the system, they can work effectively for high dimensional systems as well. Through study of these approaches it is observed, extended Kalman filter gives the highest accuracy with reduced requirement of excess hardware during tracking. It renders better and faster result when used in accelerometer sensor. With the aid of various software, error accuracy can be increased further as well.展开更多
This paper presents a handheld 3D vision-based scanner for small objects by using Kinect. It is different from the previous color-glove-based approaches which require segmenting the target object. First, we eliminate ...This paper presents a handheld 3D vision-based scanner for small objects by using Kinect. It is different from the previous color-glove-based approaches which require segmenting the target object. First, we eliminate the noises and the outliers caused by holding hands. Second, we apply Kinect-fusion algorithm and truncated signed distance function （TSDF） to represent 3D surfaces. Third, we propose a modified integration strategy to eliminate the hand effect. Fourth, we take advantage of the parallel computation of GPUs for real-time operation. The major contributions of this paper are （1） the registration precision is improved, （2） the oflline amendment and loop closure operation are not required, and （3） concave 3D object reconstruction is feasible.展开更多
One of the emerging technologies is wireless handheld technology. Implication of these devices is enormous for business community and healthcare domain is not an exception to this phenomena. This research paper provid...One of the emerging technologies is wireless handheld technology. Implication of these devices is enormous for business community and healthcare domain is not an exception to this phenomena. This research paper provides some useful findings about the use of PDA＇s in the healthcare environment through actual usage of PDA in the healthcare ward. A qualitative and quantitative approach is adopted to explore these phenomena due to the exploratory nature of the research. Findings of this study identify some of the motivators and issues associated with the wireless handheld technology in healthcare environment. Furthermore, it is also found that these wireless handheld devices can help to improve the quality of care through better decision making processes. This study is limited to only one sate of Australian and further research is needed to see the implication of the findings to wider community and other domains in the Australian environment.展开更多
The need for visual landscape assessment in large-scale projects for the evaluation of the effects of a particular project on the surrounding landscape has grown in recent years. Augmented reality （AR） has been cons...The need for visual landscape assessment in large-scale projects for the evaluation of the effects of a particular project on the surrounding landscape has grown in recent years. Augmented reality （AR） has been considered for use as a landscape simulation system in which a landscape assessment object created by 3D models is included in the present surroundings. With the use of this system, the time and the cost needed to perform a 3DCG modeling of present surroundings, which is a major issue in virtual reality, are drastically reduced. This research presents the development of a 3D maporiented handheld AR system that achieves geometric consistency using a 3D map to obtain position data instead of GPS, which has tow position information accuracy, particularly in urban areas. The new system also features a gyroscope sensor to obtain posture data and a video camera to capture live video of the present surroundings. All these components are mounted in a smartphone and can be used for urban landscape assessment. Registration accuracy is evaluated to simulate an urban landscape from a short- to a long-range scale. The latter involves a distance of approximately 2000 m. The developed AR system enables users to simulate a Landscape from multiple and longdistance viewpoints simultaneously and to walk around the viewpoint fields using only a smartphone. This result is the tolerance level of Landscape assessment. In conclusion, the proposed method is evaluated as feasible and effective.展开更多
Handheld optical sensors recently have been introduced to the agricultural market.These handheld sensors are able to provide operators with Normalized Difference Vegetative Index(NDVI)data when cloud cover prevents ac...Handheld optical sensors recently have been introduced to the agricultural market.These handheld sensors are able to provide operators with Normalized Difference Vegetative Index(NDVI)data when cloud cover prevents acquisition of satellite or aerial images.This research addressed the sensitivity of the GreenSeeker handheld optical sensor to changes in orientation and height above a ryegrass canopy.Planter boxes were oriented both parallel and perpendicular to the light beam from the sensor head and heights of 30.5 cm(12”),61.0 cm(24”),91.5 cm(36”),122 cm(48”)and 152 cm(60”)were tested.Results indicated that the sensor was highly sensitive(P<0.0001)to both height above canopy and orientation of the sensor relative to the target.Operators should follow manufacturer’s recommendations on operating height range of 81-122 cm and orient the sensor head in-line with the target to obtain maximum signal response.展开更多
Objective:Due to limited imaging conditions,the quality of fundus images is often unsatisfactory,especially for images photographed by handheld fundus cameras.Here,we have developed an automated method based on combin...Objective:Due to limited imaging conditions,the quality of fundus images is often unsatisfactory,especially for images photographed by handheld fundus cameras.Here,we have developed an automated method based on combining two mirror-symmetric generative adversarial networks(GANs)for image enhancement.Methods:A total of 1047 retinal images were included.The raw images were enhanced by a GAN-based deep enhancer and another methods based on luminosity and contrast adjustment.All raw images and enhanced images were anonymously assessed and classified into 6 levels of quality classification by three experienced ophthalmologists.The quality classification and quality change of images were compared.In addition,imagedetailed reading results for the number of dubiously pathological fundi were also compared.Results:After GAN enhancement,42.9% of images increased their quality,37.5%remained stable,and 19.6%decreased.After excluding the images at the highest level(level 0)before enhancement,a large number(75.6%)of images showed an increase in quality classification,and only a minority(9.3%)showed a decrease.The GANenhanced method was superior for quality improvement over a luminosity and contrast adjustment method(P<0.001).In terms of image reading results,the consistency rate fluctuated from 86.6%to 95.6%,and for the specific disease subtypes,both discrepancy number and discrepancy rate were less than 15 and 15%,for two ophthalmologists.Conclusions:Learning the style of high-quality retinal images based on the proposed deep enhancer may be an effective way to improve the quality of retinal images photographed by handheld fundus cameras.展开更多
文摘Point-of-care ultrasound(POCUS) is recognized as a valuable diagnostic tool,especially in resourcelimited settings(RLS).POCUS provides rapid diagnostic information that enables health professionals to make critical decisions at the bedside.^([1]) Despite the welldocumented benefits of POCUS,access to longitudinal,comprehensive training programs and a lack of trainee feedback are barriers to the widespread use of this technology in such settings.^([2])
基金supported by the National Natural Science Foundation of China(No.82030065 to Qin Zhou)“Spring Goose”Talent Team Support Program of Heilongjiang Province(No.2022CYCX0202)+2 种基金Natural Science Foundation of Heilongjiang Province(Excellent Young Scholars Program,JJ2024YX0560)Funding Program for Preferential Returned Scholars of Heilongjiang Province(No.21032240006)Young Elite Scientist Sponsorship Program of Heilongjiang Province(No.20240NTJ018)
文摘The intrinsic property of MXenes to adsorb dyes with high Raman scattering cross-sections makes them promising candidates for surface-enhanced Raman scattering(SERS)biosensors.In the study,we report a vanadium carbide MXene(V_(2)CT_(x))-based SERS biosensor tag,V_(2)CT_(x)@Thi(thionine)@Au NPs(gold nanoparticles)-Ab(antibody),owing to its large interlayer spacing and superior dye adsorption capacity.The tag V_(2)CT_(x)@Thi@Au NPs-Ab was fully characterized and validated,demonstrating a significantly enhanced Raman signal through both electromagnetic and chemical enhancement mechanisms.Using a handheld Raman spectrometer as a readout tool,the developed handheld SERS biosensor was successfully applied for the detection of viral antigens.The biosensor exhibited excellent linearity(1.562–100 nM)and achieved a low limit of detection(LOD)1.562 nM.Moreover,the biosensor demonstrated good selectivity and stability for detecting the target S protein in saliva samples.Our study highlights the potential of V_(2)CT_(x)MXene as a powerful material for handheld SERS biosensors,paving the way for portable and efficient viral diagnostics.
基金The 11th Postgraduate Technology Innovation Project of North University of China(No.20141147)
文摘Considering that it is difficult to monitor the measurement system and amend the test parameters on the scene in shock wave overpressure measurement and it is inconvenient to operate and carry traditional PC in outdoor experiments, a new handheld terminal for shock wave pressure measurement system based on ARM is designed, The handheld terminal, whose ap- plication program is developed by the software of Qt, can control the measurement system by Wi-Fi and perform the functions of monitoring the system state, transmitting the data by wireless and displaying waveforms. To prevent data loss, USB inter- face is designed to read the data The test results show that the designed handheld terminal has good stability and reliability in several explosion experiments.
文摘Objective To estimate the prevalence of unknown atrial fibrillation(AF)in the elderly population of the Veneto Region,Italy.Methods 1820 patients aged≥65 years with no history of AF and not anticoagulated were enrolled in primary-care settings.They underwent an opportunistic electrocardiogram screening with a handheld device(My Diagnostick)designed to specifically detect AF.The electrocardiogram recordings were reviewed by the researchers,who confirmed the presence of AF.Results The device detected an arrhythmia in 143 patients,which was confirmed as AF in 101/143(70.6%),with an overall prevalence of AF of 5.5%(101/1820).Prevalence of unknown AF resulted in 3.6%in patients aged 65–74 years,and 7.5%in patients age 75 or older,and increased according to CHA2 DS2-VASc score:3.5%in patients with a score of 1 or 2,5.6%in patients with a score of 3,7.0%in patients with a score of 4,and 7.2%in patients with a score≥5.The detection rate was significantly higher in patients with mild symptoms compared to asymptomatic counterparts(24.1%vs.4.0%,P<0.0001).At multivariate analysis,congestive heart failure and age≥75 years-old were independent predictors for screen-detected AF.Conclusions An opportunistic screening with handheld device revealed an unexpectedly high prevalence of unknown AF in elderly patients with mild symptoms.Prevalence increased with age and CHA2DS2-VASc score.
基金Supported by the National Natural Science Foundation of China(No.81970845)European Union’s Horizon 2020 research and innovation programme under grant agreement(No.778089)。
文摘AIM: To explore the performance in diabetic retinopathy(DR) screening of artificial intelligence(AI) system by evaluating the image quality of a handheld Optomed Aurora fundus camera in comparison to traditional tabletop fundus cameras and the diagnostic accuracy of DR of the two modalities. METHODS: Overall, 630 eyes were included from three centers and screened by a handheld camera(Aurora, Optomed, Oulu, Finland) and a table-top camera. Image quality was graded by three masked and experienced ophthalmologists. The diagnostic accuracy of the handheld camera and AI system was evaluated in assessing DR lesions and referable DR.RESULTS: Under nonmydriasis status, the handheld fundus camera had better image quality in centration, clarity, and visible range(1.47, 1.48, and 1.40) than conventional tabletop cameras(1.30, 1.28, and 1.18;P<0.001). Detection of retinal hemorrhage, hard exudation,and macular edema were comparable between the two modalities, in principle, with the area under the curve of the handheld fundus camera slightly lower. The sensitivity and specificity for the detection of referable DR with the handheld camera were 82.1%(95%CI: 72.1%-92.2%) and 97.4%(95%CI: 95.4%-99.5%), respectively. The performance of AI detection of DR using the Phoebus Algorithm was satisfactory;however, Phoebus showed a high sensitivity(88.2%, 95%CI: 79.4%-97.1%) and low specificity(40.7%, 95%CI: 34.1%-47.2%) when detecting referable DR.CONCLUSION: The handheld Aurora fundus camera combined with autonomous AI system is well-suited in DR screening without mydriasis because of its high sensitivity of DR detection as well as its image quality, but its specificity needs to be improved with better modeling of the data. Use of this new system is safe and effective in the detection of referable DR in real world practice.
文摘BACKGROUND:The use of ultrasound(US)within healthcare has inspired the development of new US technology.There have been few studies comparing the use of handheld US to standard US for medical education.This research aims to determine whether a handheld US device can provide a comparable primary learning experience to that of a standard US machine.METHODS:Over two days of instruction,participants were taught and evaluated on core US fundamentals.The standard group received instruction on standard US machines,while the handheld group received instruction on handheld US devices.Participants completed a qualitative survey regarding their experience.Six hundred and four images were obtained and graded by two emergency medicine physicians.RESULTS:A total of 119 Swiss medical students were enrolled in our study.There was no statistically significant difference in the US assessment measurements,except for faster endpoint septal separation(EPSS)vascular setup time in the handheld group(P=0.001).There was no statistically significant difference in participants’perceived difficulty of US learning(P=0.198),comfort level(P=0.188),or self-estimated capability to perform US in the future(P=0.442).There was no statistically significant difference in the percentage of correctly obtained images(P=0.211)or images that were clinically useful(P=0.256).The median quality score of images obtained by the standard group was eight compared to seven in handheld group(P<0.01).CONCLUSION:Our data suggest a handheld US machine can perform as well as a standard US machine as an educational tool despite sacrifices in image quality.
基金funded by University College GhentGhent University。
文摘Sustainable forest management heavily relies on the accurate estimation of tree parameters.Among others,the diameter at breast height(DBH) is important for extracting the volume and mass of an individual tree.For systematically estimating the volume of entire plots,airborne laser scanning(ALS) data are used.The estimation model is frequently calibrated using manual DBH measurements or static terrestrial laser scans(STLS) of sample plots.Although reliable,this method is time-consuming,which greatly hampers its use.Here,a handheld mobile terrestrial laser scanning(HMTLS) was demonstrated to be a useful alternative technique to precisely and efficiently calculate DBH.Different data acquisition techniques were applied at a sample plot,then the resulting parameters were comparatively analysed.The calculated DBH values were comparable to the manual measurements for HMTLS,STLS,and ALS data sets.Given the comparability of the extracted parameters,with a reduced point density of HTMLS compared to STLS data,and the reasonable increase of performance,with a reduction of acquisition time with a factor of5 compared to conventional STLS techniques and a factor of3 compared to manual measurements,HMTLS is considered a useful alternative technique.
文摘This work focuses on a brief discussion of new concepts of using smartphone sensors for 3D painting in virtual or augmented reality. Motivation of this research comes from the idea of using different types of sensors which exist in our smartphones such as accelerometer, gyroscope, magnetometer etc. to track the position for painting in virtual reality, like Google Tilt Brush, but cost effectively. Research studies till date on estimating position and localization and tracking have been thoroughly reviewed to find the appropriate algorithm which will provide accurate result with minimum drift error. Sensor fusion, Inertial Measurement Unit (IMU), MEMS inertial sensor, Kalman filter based global translational localization systems are studied. It is observed, prevailing approaches consist issues such as stability, random bias drift, noisy acceleration output, position estimation error, robustness or accuracy, cost effectiveness etc. Moreover, issues with motions that do not follow laws of physics, bandwidth, restrictive nature of assumptions, scale optimization for large space are noticed as well. Advantages of such smartphone sensor based position estimation approaches include, less memory demand, very fast operation, making them well suited for real time problems and embedded systems. Being independent of the size of the system, they can work effectively for high dimensional systems as well. Through study of these approaches it is observed, extended Kalman filter gives the highest accuracy with reduced requirement of excess hardware during tracking. It renders better and faster result when used in accelerometer sensor. With the aid of various software, error accuracy can be increased further as well.
基金supported by the Ministry of Science and Technology of Taiwan under Grant No.MOST103-2221-E-468-006–MY1
文摘This paper presents a handheld 3D vision-based scanner for small objects by using Kinect. It is different from the previous color-glove-based approaches which require segmenting the target object. First, we eliminate the noises and the outliers caused by holding hands. Second, we apply Kinect-fusion algorithm and truncated signed distance function （TSDF） to represent 3D surfaces. Third, we propose a modified integration strategy to eliminate the hand effect. Fourth, we take advantage of the parallel computation of GPUs for real-time operation. The major contributions of this paper are （1） the registration precision is improved, （2） the oflline amendment and loop closure operation are not required, and （3） concave 3D object reconstruction is feasible.
文摘One of the emerging technologies is wireless handheld technology. Implication of these devices is enormous for business community and healthcare domain is not an exception to this phenomena. This research paper provides some useful findings about the use of PDA＇s in the healthcare environment through actual usage of PDA in the healthcare ward. A qualitative and quantitative approach is adopted to explore these phenomena due to the exploratory nature of the research. Findings of this study identify some of the motivators and issues associated with the wireless handheld technology in healthcare environment. Furthermore, it is also found that these wireless handheld devices can help to improve the quality of care through better decision making processes. This study is limited to only one sate of Australian and further research is needed to see the implication of the findings to wider community and other domains in the Australian environment.
文摘The need for visual landscape assessment in large-scale projects for the evaluation of the effects of a particular project on the surrounding landscape has grown in recent years. Augmented reality （AR） has been considered for use as a landscape simulation system in which a landscape assessment object created by 3D models is included in the present surroundings. With the use of this system, the time and the cost needed to perform a 3DCG modeling of present surroundings, which is a major issue in virtual reality, are drastically reduced. This research presents the development of a 3D maporiented handheld AR system that achieves geometric consistency using a 3D map to obtain position data instead of GPS, which has tow position information accuracy, particularly in urban areas. The new system also features a gyroscope sensor to obtain posture data and a video camera to capture live video of the present surroundings. All these components are mounted in a smartphone and can be used for urban landscape assessment. Registration accuracy is evaluated to simulate an urban landscape from a short- to a long-range scale. The latter involves a distance of approximately 2000 m. The developed AR system enables users to simulate a Landscape from multiple and longdistance viewpoints simultaneously and to walk around the viewpoint fields using only a smartphone. This result is the tolerance level of Landscape assessment. In conclusion, the proposed method is evaluated as feasible and effective.
文摘Handheld optical sensors recently have been introduced to the agricultural market.These handheld sensors are able to provide operators with Normalized Difference Vegetative Index(NDVI)data when cloud cover prevents acquisition of satellite or aerial images.This research addressed the sensitivity of the GreenSeeker handheld optical sensor to changes in orientation and height above a ryegrass canopy.Planter boxes were oriented both parallel and perpendicular to the light beam from the sensor head and heights of 30.5 cm(12”),61.0 cm(24”),91.5 cm(36”),122 cm(48”)and 152 cm(60”)were tested.Results indicated that the sensor was highly sensitive(P<0.0001)to both height above canopy and orientation of the sensor relative to the target.Operators should follow manufacturer’s recommendations on operating height range of 81-122 cm and orient the sensor head in-line with the target to obtain maximum signal response.
文摘Objective:Due to limited imaging conditions,the quality of fundus images is often unsatisfactory,especially for images photographed by handheld fundus cameras.Here,we have developed an automated method based on combining two mirror-symmetric generative adversarial networks(GANs)for image enhancement.Methods:A total of 1047 retinal images were included.The raw images were enhanced by a GAN-based deep enhancer and another methods based on luminosity and contrast adjustment.All raw images and enhanced images were anonymously assessed and classified into 6 levels of quality classification by three experienced ophthalmologists.The quality classification and quality change of images were compared.In addition,imagedetailed reading results for the number of dubiously pathological fundi were also compared.Results:After GAN enhancement,42.9% of images increased their quality,37.5%remained stable,and 19.6%decreased.After excluding the images at the highest level(level 0)before enhancement,a large number(75.6%)of images showed an increase in quality classification,and only a minority(9.3%)showed a decrease.The GANenhanced method was superior for quality improvement over a luminosity and contrast adjustment method(P<0.001).In terms of image reading results,the consistency rate fluctuated from 86.6%to 95.6%,and for the specific disease subtypes,both discrepancy number and discrepancy rate were less than 15 and 15%,for two ophthalmologists.Conclusions:Learning the style of high-quality retinal images based on the proposed deep enhancer may be an effective way to improve the quality of retinal images photographed by handheld fundus cameras.
