Laser Guidance System Research Articles

Clinical evaluation of a fluoroscopic image-based laser guidance system in bone tumor surgery: A technical note.

This study presents a laser guidance system developed to enhance surgical accuracy and reduce radiation exposure in orthopedic surgeries. The system can project the actual position corresponding to the appointed position selected by the surgeon on a fluoroscopic image using a line laser and has laser projection ability to mark the corresponding point using a line laser. The surgeon does not have to perform anatomical marker placement for calibration. Three patients with bone tumors underwent surgeries using the laser guidance system, and the projection accuracy was evaluated by measuring the distance error between the appointed and laser-marking positions. The installation time, including calibration, was also assessed for clinical usability. The average projection accuracy in bone tumor surgery was 2.86mm, and the average installation time was 7min. These results demonstrate that the laser guidance system, with a projection error of <3mm, could be useful in bone tumor surgeries.

Development concept of inter-satellite laser communication

The relevance of this research work is dictated, among other things, by the need to ensure higher requirements for the accuracy characteristics of the navigation field created by spacecraft of the GLONASS navigation system in order to meet the high requirements for the accuracy characteristics of navigation determinations over long intervals of autonomous operation of spacecraft currently put forward by consumers. The presented concept of development uses the latest achievements of laser and radio engineering both to increase the throughput, noise immunity of transmitting information, as well as to reduce the mass and power consumption of onboard equipment, and to conduct inter-satellite range measurements and synchronization of onboard time scales of spacecraft navigation systems, including and for linking the system time scale of space navigation systems (or the group orbital time scale) to the time scale of the State standard of time and frequency. Ensuring the accurate operation of the laser guidance system in space is considered one of the critically important tasks, since its full-scale tests on Earth are almost impossible. Key experimental and also experimental works are analyzed according to the problems of constructing optical links of inter-satellite communication.

Laser Target System in Combination with an Aiming Device for Percutaneous CT-Guided Interventions – An Accuracy Study

To evaluate the targeting accuracy of laser-guided punctures in combination with an aiming device for computed tomography (CT) interventions during in vitro experiments. MATERIALS ANDMETHODS: A total of 600 CT-guided punctures were performed using a laser target system, half of them with the additional help of an aiming device. Conically shaped targets in a plexiglass phantom were punctured. The planning CT data sets were acquired with 1.25, 2.5 and 5mm slice thickness. Needle placement accuracy, as well as procedural time, wasassessed. The Euclidean (ED) and normal distances (ND) were calculated at the target point. Using the aiming device, the accomplished mean ND at the target for the 1.25, 2.5 and 5mm slice thickness was 1.76mm (SD±0.92), 2.09mm (SD±1.06) and 1.93mm (SD±1.38), respectively. Without aiming device, the corresponding results were 2.55mm (SD±1.42), 2.7mm (SD±1.43) and 2.31mm (SD±1.64). At a slice thickness of 1.25mm and 2.5mm, punctures with the aiming device were significantly more accurate for both the ED and ND as compared to the punctures without aiming device (p<0.001).The mean time required to complete the procedure, including image acquisition, trajectory planning, the placement of 10 needles, and the control-CT scan was 24.8min without and 29.8min with the aiming device. The additional use of the aiming device in combination with the commercially available laser guidance system significantly increased the level of accuracy during this in vitro experiment compared to freehand passes.

Evaluation of Accuracy and Performance of a Novel, Fully Gantry Integrated 3D Laser System for Computed Tomography Guided Needle Placement: A Phantom Study.

The purpose of this phantom study was to compare the accuracy, speed and technical performance of CT guided needle placement using a conventional technique versus a novel, gantry integrated laser guidance system for both an expert and a novice. A total of 80 needle placements were performed in an abdominal phantom using conventional CT guidance and a laser guidance system. Analysis of pooled results of expert and novice showed a significant reduction of time (277 vs. 204 s, p = 0.001) and of the number of needle corrections (3.28 vs. 1.58, p < 0.001) required when using laser guidance versus conventional technique. No significant improvement in absolute (3.81 vs. 3.41 mm, p = 0.213) or angular deviation (2.85 vs. 2.18°, p = 0.079) was found. With either approach, the expert was significantly faster (conventional guidance: 207 s vs. 346 s, p < 0.001; laser guidance: 144 s vs. 264 s, p < 0.001) and required fewer needle corrections (conventional guidance: 4 vs. 3, p = 0.027; laser guidance: 2 vs. 1, p = 0.001) than the novice. The laser guidance system helped both the expert and the novice to perform CT guided interventions in a phantom faster and with fewer needle corrections compared to the conventional technique, while achieving similar accuracy.

Reducing ground and airborne drift losses in young apple orchards with PWM-controlled spray systems

Pulse Width Modulated (PWM) solenoid valves can be used to control nozzle flow rates for precision spray applications to reduce pesticide use, thereby reducing environmental risk and production cost. Field tests in a two-year-old young apple orchard were conducted to investigate spray losses to the ground and in the air for an air-blast sprayer equipped with three spray systems: 1) manually controlled constant-rate system enabled with the PWM spray system (Manual-PWM), 2) laser-guided variable-rate system enabled with the PWM spray system (Laser-PWM); and 3) conventional constant-rate system with disabled PWM valves (Disabled-PWM). Artificial targets (plastic plates and water sensitive papers) were placed under twelve trees randomly selected from four rows of the orchard to collect spray losses to the ground. Airborne spray losses were determined by using nylon screens, mounted at five heights on each of seven poles distributed at different distances from the first sprayed row. Laser-PWM and Manual-PWM produced significantly lower airborne and ground spray drift losses inside and outside the orchard than Disabled-PWM, and these losses decreased significantly as the distance away from the first sprayed row increased. Laser-PWM reduced the total airborne drift by 90.3% and total ground loss by 85.0% compared to Disabled-PWM whereas Manual-PWM decreased the same airborne and ground drift by 84.1% and 7.9%, respectively. Disabled-PWM produced detectable airborne losses that reached 88.4 m away from where the sprayer was operated. Thus, the air-blast orchard sprayer equipped with PWM solenoid valves controlled by either the automatic laser-guided system or manual system would have great potentials to improve pesticide application efficiency with significant reductions in both pesticide consumption in young apple orchards, and off-target drift loss to the environment.

Research on night vision distance imaging technology of semiconductor laser

The semiconductor laser night vision distance imaging system introduced in this paper is an active imaging system with a laser as a light source, forming an image according to the light reflection difference of the target and the background. Compared with the passive imaging system, the active imaging system has the characteristics of strong receiving signal. Under extreme conditions, it can also realize the extraction of image key information of strong reception signal. Under extreme conditions, it can also realize the extraction of image key information through range-gated technology. It is a high anti-interference capability semiconductor laser ranging imaging technology suitable for severe weather and conditions. The system can be used in laser active imaging guidance, unmanned aircraft, guidance systems and other military fields and public security, fire control, transportation and other fields.

Survey on Laser Guided Missile Systems and Implementation by Developing a Laser Guidance System

Survey on Laser Guided Missile Systems and Implementation by Developing a Laser Guidance System

Integrated Infrared Signature Management with Multispectral Selective Absorber via Single‐Port Grating Resonance

AbstractEngineering reflective or thermal signatures is essential in stealth technology for enhancing survivability. For military weapons, infrared (IR) image fusion with reflective and thermal signatures or a laser guidance system has been adopted for detecting enemies. However, the control of reflective and thermal signatures over the entire mid‐IR (MIR) range requires a complex structure. Herein, integrated IR signature (IIRS) management with a multispectral selective absorber (MSA) against IR fusion cameras and a guidance laser is presented. For multispectral engineering with a periodic metal–insulator–metal structure, the physical concept of single‐port grating resonance (SPGR) is proposed. SPGR exhibits an absorption range 6.4 times broader than that of localized surface plasmon resonance. Covering the entire MIR spectrum, the MSA designed with SPGR reduces the reflective signature by 92.2% at 1.06 µm (wavelength of guidance laser), and 64.6% by short‐wave IR (SWIR) camera, and it reduces the thermal signature by 98.0%. The IIRS management with the MSA reduces the lock‐on range by 70% and 26% for the mid‐wave IR and SWIR cameras, respectively, and provides perfect camouflage performance against the laser guidance, in contrast to stainless steel. The IIRS management with the MSA based on SPGR can be applied to multispectral camouflage.

Development of laser guidance system for UAV

Development of laser guidance system for UAV

Evaluation of the Effectiveness of Destructive Effects on Laser Guidance Systems of High-Precision Weapons

The article presents the results of theoretical and experimental studies of destructive effects on the main channels of various types of semi-active laser homing heads of high-precision ammunition. Recommendations concerning characteristics of promising intended interference were confirmed experimentally. They make it possible to determine new methods of influence on laser guidance systems for high-precision ammunition and to expand the capabilities of electronic warfare devices when protecting stationary objects

A Concept of a Compact and Inexpensive Device for Controlling Weeds with Laser Beams

A prototype of a relatively cheap laser-based weeding device was developed and tested on couch grass (Elytrigia repens (L.) Desv. ex Nevski) mixed with tomatoes. Three types of laser were used (0.3 W, 1 W, and 5 W). A neural network was trained to identify the weed plants, and a laser guidance system estimated the coordinates of the weed. An algorithm was developed to estimate the energy necessary to harm the weed plants. We also developed a decision model for the weed control device. The energy required to damage a plant depended on the diameter of the plant which was related to plant length. The 1 W laser was not sufficient to eliminate all weed plants and required too long exposure time. The 5 W laser was more efficient but also harmed the crop if the laser beam became split into two during the weeding process. There were several challenges with the device, which needs to be improved upon. In particular, the time of exposure needs to be reduced significantly. Still, the research showed that it is possible to develop a concept for laser weeding using relatively cheap equipment, which can work in complicated situations where weeds and crop are mixed.

A Concept of a Compact and Inexpensive Device for Controlling Weeds with Laser Beams

A prototype of a relatively cheap laser-based weeding device was developed and tested on couch grass (Elytrigia repens (L.) Desv. ex Nevski) mixed with tomatoes. Three types of laser were used (0.3 W, 1 W, and 5 W). A neural network was trained to identify the weed plants, and a laser guidance system estimated the coordinates of the weed. An algorithm was developed to estimate the energy necessary to harm the weed plants. We also developed a decision model for the weed control device. The energy required to damage a plant depended on the diameter of the plant which was related to plant length. The 1 W laser was not sufficient to eliminate all weed plants and required too long exposure time. The 5 W laser was more efficient but also harmed the crop if the laser beam became split into two during the weeding process. There were several challenges with the device, which needs to be improved upon. In particular, the time of exposure needs to be reduced significantly. Still, the research showed that it is possible to develop a concept for laser weeding using relatively cheap equipment, which can work in complicated situations where weeds and crop are mixed.

Analysis of LGV usage for the improvement of a customized production

The paper describes an approach for analyzing the use of a Laser-Guided Vehicle (LGV) in the context of the small and medium-sized enterprise. The use of LGVs is an efficient solution to provide more flexibility in the context of Just-In-Time production; however, the investment cost can limit this application. A methodology has been proposed in this work to analyze the technical feasibility of using an LGV in the manufacturing industry of customized products. The test case focuses on the study of a laser-guided system to optimize the handling of molds for customized production. In this scenario, an LGV is proposed to substitute manual carts used for moving molds from the warehouse to the injection machines. The traditional path included an intermediate station for pre-heating the molds in hot-air ovens. The proposed solution includes the study of an induction heating system on the LGV to optimize time and energy consumption.

UAV Flight and Landing Guidance System for Emergency Situations †.

Unmanned aerial vehicles (UAVs) with high mobility can perform various roles such as delivering goods, collecting information, recording videos and more. However, there are many elements in the city that disturb the flight of the UAVs, such as various obstacles and urban canyons which can cause a multi-path effect of GPS signals, which degrades the accuracy of GPS-based localization. In order to empower the safety of the UAVs flying in urban areas, UAVs should be guided to a safe area even in a GPS-denied or network-disconnected environment. Also, UAVs must be able to avoid obstacles while landing in an urban area. For this purpose, we present the UAV detour system for operating UAV in an urban area. The UAV detour system includes a highly reliable laser guidance system to guide the UAVs to a point where they can land, and optical flow magnitude map to avoid obstacles for a safe landing.

CIGuide: in situ augmented reality laser guidance

Purpose A robotic intraoperative laser guidance system with hybrid optic-magnetic tracking for skull base surgery is presented. It provides in situ augmented reality guidance for microscopic interventions at the lateral skull base with minimal mental and workload overhead on surgeons working without a monitor and dedicated pointing tools.Methods Three components were developed: a registration tool (Rhinospider), a hybrid magneto-optic-tracked robotic feedback control scheme and a modified robotic end-effector. Rhinospider optimizes registration of patient and preoperative CT data by excluding user errors in fiducial localization with magnetic tracking. The hybrid controller uses an integrated microscope HD camera for robotic control with a guidance beam shining on a dual plate setup avoiding magnetic field distortions. A robotic needle insertion platform (iSYS Medizintechnik GmbH, Austria) was modified to position a laser beam with high precision in a surgical scene compatible to microscopic surgery.Results System accuracy was evaluated quantitatively at various target positions on a phantom. The accuracy found is 1.2 mm ± 0.5 mm. Errors are primarily due to magnetic tracking. This application accuracy seems suitable for most surgical procedures in the lateral skull base. The system was evaluated quantitatively during a mastoidectomy of an anatomic head specimen and was judged useful by the surgeon.Conclusion A hybrid robotic laser guidance system with direct visual feedback is proposed for navigated drilling and intraoperative structure localization. The system provides visual cues directly on/in the patient anatomy, reducing the standard limitations of AR visualizations like depth perception. The custom- built end-effector for the iSYS robot is transparent to using surgical microscopes and compatible with magnetic tracking. The cadaver experiment showed that guidance was accurate and that the end-effector is unobtrusive. This laser guidance has potential to aid the surgeon in finding the optimal mastoidectomy trajectory in more difficult interventions.

Improve the Detection Range of Semi-Active Laser Guidance System by Temperature Compensation of Four-Quadrant PIN Detector.

The detection range of a semi-active laser guidance system can deviate significantly from the design value over a wide ambient temperature range. In this paper, a mathematical model of the detection range of a semi-active laser guidance system is built and the main factors affecting the detection range are analyzed. The parameter responsivity, which shows significant change, is found by applying the ambient temperature stress to the four-quadrant PIN detector and its signal processing chain. The relationship between the maximum detection range and ambient temperature is established based on a given signal-to-noise ratio, which is necessary for reliable detection. The target temperature and tolerance are setup for real-time temperature compensation for the four-quadrant PIN detector. The ambient temperature stress is applied to the system under compensation to verify the effect of compensation. The experimental results show that the ratio of the maximum variation of the detection range to the design point is 6.9% after the compensation is implemented when the ambient temperature changes from −40 °C to 60 °C, which is improved by 13.2% compared to that without compensation.

Driving control module for low cost industrial automated guided vehicle

Automatic Guided Vehicles (AGVs) are computer-controlled “driverless” mobile vehicles equipped with optical, magnetic or laser guidance systems for automated functionality, categorized as either load carrying or load towing. AGV consists of several parts, such as the frame for pulling or lifting weights, movement balancer wheels, battery housing, collision avoidance sensors, driving module and others. But, the most important part of AGV is the driving module which is a module that functions as a movement guide, consisting of path detection sensors, driving motors and controllers. This Paper presents low cost a driving control module for low cost AGV that used in automotive manufacture industry. The AGV uses Raspberry Pi instead of PLC as controller, infrared sensor to detect line and industrial standard brushless DC (BLDC) motor as main actuator. PID control applied in the movement of the BLDC motor speed so that the AGV can follow the path smoothly and precisely. As a result, the AGV can follow the path with speed 30 m/min on a straight road and 30 m/m at a turn with a deviation 5 mm off the track.

半主动寻的激光制导系统的干涉编码方法

半主动寻的激光制导系统的干涉编码方法

Investigation of an Experimental Laser Sensor-Guided Spray Control System for Greenhouse Variable-Rate Applications

Abstract. Precision variable-rate spraying technology is needed for controlled-environment plant production in greenhouses. An experimental spray system for greenhouse applications was developed for real-time control of individual nozzle outputs. The system mainly consisted of a high-speed laser scanning sensor, 12 individual variable-rate nozzles, an embedded computer, a spray control unit, and a 3.6 m long mobile spray boom. Each nozzle was coupled with a pulse-width modulated solenoid valve to discharge sprays at variable rates based on target presence and plant canopy structure. Laboratory tests were conducted to evaluate the accuracy of the spray control system in respect to spray delay time, nozzle activation, and spray volume using four target objects of different regular geometrical shapes and surface textures and two artificial plants of different canopy structures. Other experimental variables included three detection heights from 0.5 to 1.0 m and five sensor travel speeds from 1.6 to 4.8 km h-1. A high-speed video camera was used to determine the delay time and nozzle activation in discharging sprays on target objects after the laser sensor had detected the objects. The detection height and travel speed were found to have slight influence on the timing of nozzle activation. The nozzles started spraying in a range between 33 and 83 mm before reaching the target objects and stopped spraying between 13 and 84 mm after passing the objects, ensuring that the objects were fully covered by the spray. Spray volume corresponded to the object sizes well, and the spray control system performed with higher accuracy at lower travel speeds. Differences between the calculated spray volume based on the sensor detection and the actual spray volume ranged from 1.9 to 2.7 mL per object among all tested objects. The variable-rate control system reduced spray volume by 29.3% to 51.4% for all the objects compared with conventional constant-rate spraying. At the same time, the nozzles could be activated precisely by the object presence. Consequently, this experimental laser-guided system was implemented on a boom system in a commercial greenhouse for future investigations of its accuracy in variable-rate spraying to save pesticides, water, and nutrients. Keywords: Automation, Intelligent sprayer, Pesticide, Precision spray technology, Boom spray equipment.

CT-Guided Percutaneous Transthoracic Needle Biopsy Using the Additional Laser Guidance System by a Pulmonologist with 2 Years of Experience in CT-Guided Percutaneous Transthoracic Needle Biopsy

CT-Guided Percutaneous Transthoracic Needle Biopsy Using the Additional Laser Guidance System by a Pulmonologist with 2 Years of Experience in CT-Guided Percutaneous Transthoracic Needle Biopsy