Hand-held CO2 Research Articles

Evaluation and application of CO2 laser fiber delivery for single port transoral robotic surgery.

Transoral robotic surgery (TORS) using the Single-Port system (SPS) relies on electrocautery, limiting its applications in the upper aerodigestive tract. We evaluated the feasibility of a CO2 delivery system for the SPS. Otolaryngology residents performed a cutting exercise using a handheld CO2 laser and participated in a cadaveric oropharyngeal dissection using the SPS with monopolar cautery (SP+EC) and CO2 laser (SP+CO2 ). Residents completed the System Usability Scale (SUS) questionnaire to evaluate these techniques. The same laser fiber was used for all combined dissections. The handheld CO2 laser, SP+EC, and SP+CO2 demonstrated similar SUS scores. On individual domain scores, SP+CO2 received less favorable ratings compared to the handheld CO2 laser for complexity, integration, and cumbersome experience (p<0.05). On subgroup stratification, less TORS experience was associated with worse SUS scores. SP-guided CO2 laser delivery is a viable alternative to electrocautery in robotic surgery, and should be considered when performing TORS.

Transects of urban CO2 measurements on a bicycle‐based atmospheric sensor

It is well known that CO2 is one of the main greenhouse gases. The traffic of non-electric vehicles is the main contributor to the emissions of this gas in the cities, enhancing the urban heat island effect and increasing the dangers of global warming. The changes in the amount of CO2 across the city occur on a small urban scale, easily measured by a person moving around the city, whether it be walking or cycling. A handheld CO2 sensor capable of recording this gas, temperature, atmospheric pressure, and relative humidity was mounted on a bicycle to analyse local variations of this gas across a couple of cycling route transects in Barcelona city and a municipality within its metropolitan area. The results presented here show local CO2 variability, with some changes in concentration of up to 90ppm over distances of a few hundred metres (less than 1km). The influence of parks, urban forests, and gardens in absorbing the gas has also been identified. The measurements obtained with this technique demonstrate that using a bicycle as a scientific vehicle is a viable way to analyse the CO2 distribution in urban and suburban areas.

Teaching Instrumental Analysis during the Pandemic: Application of Handheld CO2 Monitors to Explore COVID-19 Transmission Risks.

The COVID-19 pandemic has posed a challenge for maintaining an engaging learning environment while using remote laboratory formats. In this work, we describe a Student Choice Project (SCP) in an undergraduate instrumental analysis course that was adapted for remote learning without sacrificing research-based learning goals. We discuss the implementation and assessment of this SCP, selected student results, and student feedback. Students were provided handheld carbon dioxide monitors and charged with designing and implementing an investigation centered on COVID-19 airborne transmission. The real-time monitors provided experience with a new analytical tool that demanded considerations and analysis not common to other methods discussed in the course. Students were motivated by the ability to design their own projects and by the real-world implications of their findings. They performed well for all assessments, reported a positive experience, and recommended these monitors be added to the typical repertoire of instrumentation for the course.

Safety and usefulness of flexible hand-held laser fibers in microsurgical removal of acoustic neuromas (vestibular schwannomas)

AimsWe performed a retrospective non-randomized study to analyze the results of microsurgery of acoustic neuromas (AN) using two different flexible hand-held laser fibers, CO2 (Omniguide®) and 2μ-Thulium (Revolix jr®). MethodsFrom September 2010 to June 2015, 84 patients suffering from AN have been operated on with microsurgical technique via retrosigmoid (RS) approach. In 42 cases tumor resection was performed with the assistance of hand-held flexible laser (L-group): in 8 cases CO2-fiber and in 34 2μ-Thulium-fiber.Fortytwo patients, operated on without laser-assistance, were used as comparison group (C-group) (matched-pair-technique).Facial nerve function was assessed with the House-Brackmann (HB) scale preoperatively, 1 week postoperatively, and 6-month or more after surgery. ResultsOverall time from incision to skin suture changed in relation to size of tumor (165–575min) and was not affected by the use of laser. In 2 cases preoperative facial nerve palsy was observed. In the remaining 82 cases, at 6-month follow-up facial nerve preservation rate (HB I) was 90.2%. Hearing preservation rate (AAO-HNS A/B classes) was 68.4% (26 out of 38). Adopting a 0–3-scale, the mean surgeon satisfaction rate of usefulness of laser fiber was 2.64. ConclusionsThe use of a hand-held flexible laser fiber in AN-microsurgery seems to be safe and subjectively facilitates tumor resection especially in “difficult” conditions (e.g., highly vascularized and hard tumors). In this limited retrospective trial, the good functional outcome following conventional microsurgery had not further improved, nor the surgical time reduced by laser. Focusing its use on “difficult” (large and vascularized) cases may lead to different results in future.

Hand-held CO2 monitors could improve school air quality

Hand-held CO2 monitors could improve school air quality

Recurrence in Cholesteatoma Surgery and the Use of Laser

Objective: Cholesteatomas have a high-rate of recurrence, regardless of the surgical approach used. Our hypothesis was that use of the handheld CO2 laser would reduce recurrence of cholesteatoma by removing microscopic disease, particularly in challenging or difficult to treat areas. Method: A total of 384 mastoidectomies performed by a single-surgeon between 2006 and 2011 were reviewed (22 in the non-laser and 23 in the laser group that met the inclusion criteria). Outcome measures included recurrence rate and complication rates. Independent variables included smoking status, bilaterality and the extent of disease as assessed by Marres staging (1984). Results: Average follow-up was 25 months; average separation between the first and second stage was 8 months. There were 1 Marres stage 1, 29 stage 2, 1 stage 3, and 13 stage 4 patients and the distribution between the 2 groups was similar. There were no facial nerve paralysis cases, and 1 sensorineural (SNHL) hearing loss after the first procedure in the nonlaser group. There was no difference in the rate of recidivism noted at the second stage between the laser group (34.8%) and nonlaser group (30.4%). There was no apparent correlation between smoking status or bilaterality of disease and recurrence. Conclusion: While the safety of cholesteatoma surgery with handheld laser is confirmed without any incidence of SNHL or facial nerve paresis, in this retrospective study, there does not appear to be any reduction in the rate of recidivism. A prospective study is clearly warranted to demonstrate efficacy.

Laser-assisted microsurgical resection of thoracic intramedullary spinal cord ependymoma.

The surgical management of intramedullary spinal cord ependymomas remains a formidable challenge amongst neurosurgeons because of the potential risk of surgical morbidity. From on an oncological perspective, complete resection-if technically feasible-should be the goal of surgery, since this can result in excellent local control and progression-free survival. Advances in microsurgical techniques, intraoperative neurophysiological monitoring, and the use of lasers have contributed to our ability to achieve gross-total resection. This is also largely dependent on the presence of an identifiable surgical plane of dissection between the tumor and spinal cord, which appears to have a positive prognosis with overall neurological improvement. In this operative video manuscript, the author demonstrates an illustrative step-by-step technique for microsurgical resection of a thoracic intramedullary spinal cord ependymoma (T-3 to T-5) associated with an extensive cervicothoracic syrinx. The application of a handheld non-contact CO2 laser for performing the midline myelotomy is also highlighted. The operative technique and surgical nuances, including the surgical approach, intradural tumor removal, and closure, are illustrated in this video atlas. The video can be found here: http://youtu.be/itE2tuBFmgw .

Perspective Commentary on the Beneficial Use of a New Hand-Held CO2 Laser Fiber in the Resection of a Calcified and Vascular Intraventricular Tumor

Impaired systemic hormonal activity caused by hypothalamic and pituitary injury may contribute to neuropsychologic disturbances and poor quality of life after aneurysmal subarachnoid hemorrhage (SAH). This prospective study was designed to longitudinally evaluate long-term clinical outcome and pituitary function after SAH using dynamic tests for adrencorticotropic and somatotropic secretory capacity.Endocrine function was assessed by basal hormonal concentrations at 6–12 months and 12–24 months after SAH. At the 12–24 months follow-up, dynamic provocative evaluation of adrenocorticotropic hormone (ACTH) and growth hormone (GH) was performed using the insulin tolerance test (ITT). In patients where ITT was contraindicated, an ACTH stimulation test was used to assess ACTH capacity, and a growth hormone releasing hormone (GHRH)-arginine stimulation test was used to assess GH capacity.Of 60 patients with SAH screened, 51 were included in the study, and 44 remained to be tested at the two follow-up visits. As assessed by basal hormone concentrations alone, the prevalence of pituitary dysfunction was 34% at 6–12 months and 41% at 12–24 months. When using dynamic tests (12–24 months), impaired pituitary function was detected in 43%. The ITT detected more cases of central hypoadrenalism and GH deficiency compared with the ACTH- and GHRH-arginine-stimulation tests, respectively.Application of dynamic endocrine tests revealed a high frequency of long-term hypothalamic-pituitary dysfunction after aneurysmal SAH. The role of pituitary dysfunction in the recovery after SAH merits further evaluation.

Sinonasal and nasopharyngeal applications of the hand-held CO2 laser fiber.

Carbon dioxide (CO(2)) laser provides precision and excellent hemostasis, leading to healing with minimal discomfort and complications. In spite of the advantages, the application of CO(2) laser has been limited in the sinonasal region due to the difficulty in delivering laser energy to the deep, narrow, and confined spaces. The availability of flexible laser fibers and custom-designed hand pieces has rectified these limitations but, until this date, there are no data on their safety and efficacy profile. We conducted a retrospective chart review of patients who underwent sinonasal and nasopharyngeal surgery with a hand-held CO(2) laser at M.D. Anderson Cancer center between 2007 and 2009. Out of 12 patients, 3 patients had postradiotherapy adhesions, 2 patients had a recurrent sinonasal mucoepidermoid carcinoma and 1 patient each had a ganglioneuroblastoma of the nasopharynx involving the basisphenoid and clivus, recurrent spindle cell melanoma of the nasopharynx, juvenile nasopharyngeal angiofibroma, papilloma of the nasal cavity, pituitary adenoma, spindle cell lipoma of the nasopharynx, and intranasal Rosai-Dorfman disease. The CO(2) laser, along with conventional endoscopic techniques and instruments, was used at 6-12 W continuous mode, to excise the disease. Median blood loss was 88 mL with no laser-related complication in any patient. In sinonasal and nasopharyngeal regions, use of hand-held CO(2) laser fiber provides precision, excellent hemostasis and minimizes tissue manipulation thereby reducing risk to the underlying structures. Thus, it can be an important tool for rhinologists and skull-base surgeons, especially for revision and postradiotherapy cases.

CHEMICAL EVALUATIONS FOR CONTROL OF JAPANESE BEETLE ON GRAPES, 2010:

Treatments were evaluated for efficacy against the Japanese beetle in an experimental 'Concord' vineyard at Wooster, Ohio. Plots consisted of two grape vines, with 4 replications per treatment in a randomized block design. Treatments were applied as foliar sprays at a rate of 100 gal/acre (935 liter/ha) on 29 Jun. A hand-held CO2 sprayer operating at 45 psi (3.2 kg/cm) and equipped with a 9505-E-TeeJet nozzle was used to apply treatments. A non-ionic surfactant was added to all treatments at the rate of 0.125 vol/vol. The number of JB present within each treatment plot was recorded prior to treatment applications. Subsequent counts were taken at 1, 3, 7, and 13 DAT. In addition to the number of beetles present in each treatment a rating of the percent foliar damage was taken on 13 DAT. This was accomplished by observing damage on the five fully developed terminal leaves on 10 shoots in each treatment replicate and assigning a percentage based on the number of leaves damaged.

DETECTION OF A DEVELOPING HOT SPOT IN STORED CORN WITH A CO2 SENSOR

The primary objective of this study was to determine the effectiveness of detecting a hot spot primarily due tospoilage of high moisture corn in a stored grain bulk with a CO2 sensor installed in the headspace of the bin compared todetecting with temperature cables. Three experimental trials were conducted in a 12.5-t pilot-scale bin from September 2001to March 2002. A hot spot in the grain bulk was initiated by dripping a controlled amount of water into a confined grain massheld in five layers of cylindrical mesh trays within the grain bulk. Temperature sensors in the core of the hot spot formationmonitored its progress and confirmed biological activity, which paralleled the increasing CO2 concentration recorded by theCO2 sensor in the headspace of the bin. CO2 concentrations in the bin headspace rose from the initial base level of 500 to1500 ppm for Trial 1, 1700 ppm for Trial 2, and 2300 ppm for Trial 3 and were recorded after 400, 600, and 1800 h,respectively. There was a strong positive linear correlation between the rise in headspace CO2 concentration and the parallelrise in temperature recorded by sensors in the core of the hot spot during all three trials. Field tests of spoilage detection witha CO2 sensor conducted in 33,000- to 51,000-t grain piles and a 12,500-t cylindrical steel tank with stored corn indicatedthat a CO2 sensor was effective in detecting the occurrence of spoilage in the stored grain and detected spoilage earlier thantemperature cables. Spoilage detection was effective either by measuring CO2 concentration of the air stream from a negativedraft aeration duct with a handheld CO2 sensor, or by installing a wall-mounted CO2 sensor in the tank headspace. Our resultsshow that temperature cables alone might not be a reliable indicator of stored grain conditions and CO2 sensors could beused as an additional complimentary tool for stored grain management.

CHEMICAL EVALUATIONS FOR CONTROL OF ROSE CHAFER ON GRAPES, 2004

Treatments were evaluated for efficacy against the rose chafer in an experimental 'Clinton' vineyard at Wooster, Ohio. Plots consisted of two grape vines, with 4 replications per treatment in a RCB design. Treatments were applied as foliar sprays at a rate of 100 gpa on 8 Jun. A hand-held CO2 sprayer operating at 45 psi and equipped with a 9505-E-TeeJet nozzle was used to apply treatments. On 0, 1, 2 and 7 DAT four leaves were randomly chosen from each treatment and placed in 1 gal ice cream containers along with 10 adult beetles. The 1 gal containers were modified by placing plastic liners inside and cheese cloth over the top. After 24 hr a count of the number of dead beetles was taken. Data were analyxed using ANOVA and means were separated using an F-protected LSD (P ≤ 0.05).

PERSISTENCE OF PLANT GROWTH REGULATOR EFFECTS ON PERENNIAL PLANTS IN THE NURSERY

PERSISTENCE OF PLANT GROWTH REGULATOR EFFECTS ON PERENNIAL PLANTS IN THE NURSERY

IR Lasers and Application Systems for Myringotomy

. The study examines an Er:YAG laser (2940 nm) and different application systems of the CO2 laser (10 600 nm) with regard to their suitability for a one-shot laser myringotomy of an adequate perforation size (∼2 mm). The laser–tissue interaction of the Er:YAG laser and the CO2 laser in fresh tympanic membranes of horses (thickness: 80–100 µm) as well as in formalin-fixed human tympanic membranes (thickness: 100 µm) is studied correlating perforation diameters to the applied power/energy density and the effects demonstrated by light and scanning electron microscopy are analysed. Using the Er:YAG laser with a focused laser beam (spot diameter: 400 µm) or with a maximally defocused laser beam (spot diameter: 1600 µm) perforations of an adequte size (2 mm) can only be achieved with multiple laser pulses. Histological studies disclose only minimal thermic side effects in the adjacent tissue in both specimens. If the CO2 laser radiation is transmitted via a silver halide polycrystalline fibre (diameter: 900 µm) a maximal perforation diameter of 1300 µm is achieved with significant thermic side effects such as coagulation. Using an Acuspot™ 710 micromanipulator (focused beam diameter: 180 µm) combined with a SilkTouch™ scanner a maximal perforation diameters of 1700 µm can be achieved in horse tympanic membrane with one laser pulse. A prototype of a hand-held CO2 laser otoscope in combination with the SilkTouch™ scanner is suitable for performing laser myringotomies with a diameter of 2 mm with a single laser pulse in fresh horse tympanic membrane.

Control of European Chafer on Turf, 1997

Abstract An area of non-irrigated rough at The Country Club of Jackson in Jackson County. MI was used for this test. Plots were 4 ft X 4 ft separated by a 1-ft-wide buffer strip. Treatment grids were all laid out at the same time. Three different treatment blocks, each with its own check, were set up adjacent to each other. All treatments were replicated 6 times. Treatments 1-7 were applied on 17 Jun (Block 1). Treatments 8-14 were applied on 25 Jul (Block 2). Treatments 15-21 were applied on 29 Aug. All plots were irrigated with a sprinkler (0.5-0.7 cm water) immediately after all of the treatments were applied for the day. All liquid applications were made with a hand-held CO2 R&amp;D Sprayer with a single 8003 nozzle at 50 psi at a rate of 175 gal/A finished spray. Granular materials were applied with a hand-held “salt shaker.” The plots were evaluated between 8 Sep and 7 Oct by digging a 2.04-ft2 area from the middle of each plot and counting the number of grubs.

Bioassay Evaluation of Insecticides on Strawberry Fruit and Foliage, 1997

Abstract Four insecticides were evaluated for efficacy against pest species listed above. A 5-year-old Allstar strawberry planting located at Moreland, OH was utilized for this study. Plots consisted of an 18-ft2 area, with 4 replicates per treatment in a randomized block design. Treatments were applied as foliar spray at the rate of 100 gpa (935 1/ha) on 17 July, using a hand-held constant-pressure CO2 sprayer operating at 45 psi (3.2 kg/cm2) and equipped with a 9505-E-Tee Jet nozzle. Once the foliage dried, 3 leaves and 2 berries were sampled from the middle of each replicate and placed in ventilated 450-ml plastic containers. Five adults of each insect were added to each container. Tarnished plant bugs and spittle bugs utilized in this study were obtained from an untreated hay field. Strawberry sap beetles were obtained from laboratory-reared colonies. The number of dead insects was recorded after 24 hrs. of exposure to the treated fruit and foliage.

Field Evaluation of Insecticides on Strawberry Fruit and Foliage, 1997

Abstract Four insecticides were evaluated for efficacy against tarnished plant bug and meadow spittle bug in a commercial strawberry planting at Moreland, Ohio. Plots consisted of an 18-ft2 area, with 6 replicates per treatment in a randomized block design. Treatments were applied as foliar spray at the rate of 100 gpa (935 1/ha) on 28 May, using a hand-held constant-pressure CO2 sprayer operating at 45 psi (3.2 kg/cm2) and equipped with a 9505-E-Tee Jet nozzle. On 6 Jun, plots were examined for spittle bug masses and the number present recorded. On 10 Jun, plots were checked for tarnished plant bug damage (button berries) and the number per plot was recorded.

Chemical Evaluations for Control of Grape Berry Moth on Grapes, 1997

Abstract Treatments were evaluated for efficacy against the grape berry moth in an experimental ‘Clinton’ vineyard at Wooster, Ohio. Plots consisted of 3 grape vines, with 4 replications per treatment ia a randomized block design. Treatments were applied as foliar sprays at a rate of 100 gpa (935 liter/ha) on 16 Jul and 6 Aug. A hand-held CO2 sprayer operating at 45 psi (3.2 kg/cm2) and equipped with a 9505-E-TeeJet nozzle was used to apply treatments. The surfactant Latron CS-7 was added only to Con-firm at the rate of 1 pt. per acre. No phytotoxicity was observed in these studies. On 24 Sep, 20 grape clusters from each replicate were randomly examined to determine the number of clusters infested by grape berry moth.

Control of Banks Grass Mite in Sweet Corn, 1996

Abstract Insecticides were applied with a hand held CO2 sprayer calibrated to deliver 1 18 gpa spray material at 25 psi through four LF4 nozzles at 18 inch spacing mounted on a 4.5 foot boom. Treatments were applied on 3 Jul 1996, when the first silks were appearing on sweet corn that was approximately five feet in height. Plots were 7.5 feet by 30 feet, arranged in a RCB design replicated four times. Only the middle row of the three row plots was used for evaluation purposes. Mites were sampled prior to spraying, and again on 10 Jul (7 DAT). Sampling involved collecting five random ear leaves per plot, brushing the leaves with a Leedon Engineering Mite Brushing Machine, and counting a subsample of the extracted mites. Damage evaluations were made on 29 Jul, when sweet corn was harvest ready, by rating each plot on a 0-5 damage scale: 0 = no damage, 1 = 1-20% ears damaged by mites, 2 = 21-40% damaged ears, 3 = 41-60% damaged ears, 4 = 61-80% damaged ears and 5 = 81-100% damaged ears. Data were (X + 0.5)½ transformed before analysis of variance. Actual means are presented.

Evaluation of Mycotrol Wp9504 (Beauveria Bassiana) and Provado (Imidacloprid) to Control Tarnished Plant Bug on Cotton, 1996

Abstract The efficacy of Mycotrol and Provado alone and in combination to kill TPB caged on cotton plants was studied. Cotton was planted 17 May on the UA Cotton Branch Experiment Station, Marianna, AR. Adult TPB were collected 8 Jul from flowering mustard planted in cotton. Nylon tulle (1 mm2 mesh) sleeve cages 3 ft long by 1 ft diameter were placed over the first 6 terminal nodes of flowering cotton plants in plots 50 ft long by 4 rows in width. Cages were separated across rows by 4 rows of mustard and within rows by 10 ft. TPB were placed in cages either before or after spraying (direct and indirect application). A RCB design was used with 4 blocks and 6 cages per treatment within a block (3 direct and 3 indirect applications) with 15 TPB per cage. Treatments were applied 9 Jul at 15 gpa with a 0.04% Kinetic solution as the carrier using a hand held CO2 powered boom sprayer at 35 psi with Twin Jet 8002 VS nozzles. The check was 0.04% Kinetic solution. Three, DAT, TPB were collected. Live TPB were placed in individual 30 ml plastic cups with a 2.5 cm piece of fresh green bean and monitored for mortality 3, 5, and 7 DAT. Dead TBP were placed in sporulation chambers (9 cm Petri dishes with moist filter paper) sealed with Parafilm and examined after 1 wk to assess mycoses. ANOVA and mean separation by LSD were performed using the arcsine/square root of the proportion dead from each cage.