Use Of Calipers Research Articles

A machine-vision system for automated quality control of welded rings

In this paper we describe the development and application of an intelligent measuring control system with integrated robot vision, to enable the solving of complex assembly and quality control tasks with high accuracy and speed. The existing quality-control procedure for welded rings involves a visual observation of the inner surface of the welded ring and the use of calipers. As explained in Section “Determination of the control goals”, this leads to limitation of the ring accuracy and the ability to detect faults. To overcome these limitations we have developed a non-contact control method implemented in the machine-vision system. The development and application of machine-vision is a multifold problem. It requires a great amount of expert knowledge, experience and innovation. We present a machine-vision system consisting of a mathematical algorithm developed for accurate measurement of the diameter and roundness of welded rings, to be used along with physical measurements. The principle of the measuring method and the required equipment are given in Section “Main idea of the measurement”. Section “Theoretical description of the algorithm” contains the mathematical formulation implemented in a computer algorithm for the measured parameters. Section “Algorithm verification and the necessary corrections” describes analytical experiments conducted to verify the accuracy of the algorithm and derive necessary corrections. Three systems with different range of quality and accuracy are compared and discussed at the end of the paper. The developed machine-vision measuring system was successfully implemented in industrial application, thus eliminating human subjectivity.

Establishing Intracranial Brain Tumor Xenografts With Subsequent Analysis of Tumor Growth and Response to Therapy using Bioluminescence Imaging

Transplantation models using human brain tumor cells have served an essential function in neuro-oncology research for many years. In the past, the most commonly used procedure for human tumor xenograft establishment consisted of the collection of cells from culture flasks, followed by the subcutaneous injection of the collected cells in immunocompromised mice. Whereas this approach still sees frequent use in many laboratories, there has been a significant shift in emphasis over the past decade towards orthotopic xenograft establishment, which, in the instance of brain tumors, requires tumor cell injection into appropriate neuroanatomical structures. Because intracranial xenograft establishment eliminates the ability to monitor tumor growth through direct measurement, such as by use of calipers, the shift in emphasis towards orthotopic brain tumor xenograft models has necessitated the utilization of non-invasive imaging for assessing tumor burden in host animals. Of the currently available imaging methods, bioluminescence monitoring is generally considered to offer the best combination of sensitivity, expediency, and cost. Here, we will demonstrate procedures for orthotopic brain tumor establishment, and for monitoring tumor growth and response to treatment when testing experimental therapies.

Establishing Intracranial Brain Tumor Xenografts With Subsequent Analysis of Tumor Growth and Response to Therapy using Bioluminescence Imaging

Transplantation models using human brain tumor cells have served an essential function in neuro-oncology research for many years. In the past, the most commonly used procedure for human tumor xenograft establishment consisted of the collection of cells from culture flasks, followed by the subcutaneous injection of the collected cells in immunocompromised mice. Whereas this approach still sees frequent use in many laboratories, there has been a significant shift in emphasis over the past decade towards orthotopic xenograft establishment, which, in the instance of brain tumors, requires tumor cell injection into appropriate neuroanatomical structures. Because intracranial xenograft establishment eliminates the ability to monitor tumor growth through direct measurement, such as by use of calipers, the shift in emphasis towards orthotopic brain tumor xenograft models has necessitated the utilization of non-invasive imaging for assessing tumor burden in host animals. Of the currently available imaging methods, bioluminescence monitoring is generally considered to offer the best combination of sensitivity, expediency, and cost. Here, we will demonstrate procedures for orthotopic brain tumor establishment, and for monitoring tumor growth and response to treatment when testing experimental therapies.

Some Methods of Propensity‐Score Matching had Superior Performance to Others: Results of an Empirical Investigation and Monte Carlo simulations

Propensity-score matching is increasingly being used to reduce the impact of treatment-selection bias when estimating causal treatment effects using observational data. Several propensity-score matching methods are currently employed in the medical literature: matching on the logit of the propensity score using calipers of width either 0.2 or 0.6 of the standard deviation of the logit of the propensity score; matching on the propensity score using calipers of 0.005, 0.01, 0.02, 0.03, and 0.1; and 5 --> 1 digit matching on the propensity score. We conducted empirical investigations and Monte Carlo simulations to investigate the relative performance of these competing methods. Using a large sample of patients hospitalized with a heart attack and with exposure being receipt of a statin prescription at hospital discharge, we found that the 8 different methods produced propensity-score matched samples in which qualitatively equivalent balance in measured baseline variables was achieved between treated and untreated subjects. Seven of the 8 propensity-score matched samples resulted in qualitatively similar estimates of the reduction in mortality due to statin exposure. 5 --> 1 digit matching resulted in a qualitatively different estimate of relative risk reduction compared to the other 7 methods. Using Monte Carlo simulations, we found that matching using calipers of width of 0.2 of the standard deviation of the logit of the propensity score and the use of calipers of width 0.02 and 0.03 tended to have superior performance for estimating treatment effects.

Monitoring therapeutic response to TKIs in breast cancer by use of imaging peptides

11002 Background: Rapid assessment of cancer response to a therapeutic regimen can determine efficacy early in the course of treatment. Here we simultaneously assess response in all sites of disease within days of starting therapy by use of peptide ligands selected for their ability to discern responding from non-responding cancers. Methods: MDA-MB-231 breast cancer was studied in the cerebrum, lung, Liver and axilla of nude mice. The tumor bearing mice were treated with VEGFR TKIs for one hour. Cy7-labeled HVGGSSV peptide was injected intravenously 4 hours after treatment. The peptide binding (relative radiance) was correlated to tumor response (tumor volume fold change). mice were treated with SU11248 doses of 0, 4 or 40 mg/Kg daily for 14 days. Tumor volumes were measured by use of calipers. Peptide was imaged by use of near infrared (NIR) using Xenogen IVIS. Results: HVGGSSV peptide binding was not detected in untreated tumors. Tumors treated with TKIs showed NIR imaging of peptide binding within 24 hours of injection. The NIR images show Cy7 labeled peptide binding within treated tumors but no binding to untreated control tumors. All tumors showed significant increase in radiance compared to untreated controls (p<0.05). The sensitivity of detecting responsive tumors was 40 out of 42 responding mouse tumors detected by HVGGSSV radiance. In comparison, 0 of 26 non-responding or untreated tumors showed increased peptide radiance within tumors (p<0.001). To determine whether radiance from peptide binding in tumors correlated with tumor response, we studied the dose-dependent response to SU11248 in MDA-MB231. Tumors responded to high dose treatment (40 mg/kg SU11248), but not 4 mg/kg, when treated with SU11248 alone. After the first treatment, Cy7-labeled peptide was injected intravenously into tumor-bearing mice. NIR images were captured and radiance from peptide binding in tumors was measured. A linear correlation (R2=0.8684) was found for peptide binding and tumor response to treatment. Conclusions: Rapid noninvasive assessment of cancer response promises to speed drug development and minimize the duration of treatment with ineffective regimens in cancer patients. No significant financial relationships to disclose.

Comparative Study Of Intra-Operative Pelvimetry With Calipers And X-Ray Pelvimetry

The pelvic measurement of patients who have had a caesarean section was done using Pelvic Calipers (intra-operative) and x-ray methods. In the former method, during Caesarean sections and after closure of the lower uterine segment incision, a pair of pelvic calipers was used to measure the true conjugate of the pelvis. In the other method and same subject, between the 5th and 7th post-operative days when the patient could stand up right, an erect lateral pelvimetry was done (if this was not done prior to delivery) and the true conjugate was measured independently by the radiologist. For those who had x-ray pelvimetry prior to delivery, the true conjugate was measured from the previous radiograph. The average age and height of the patients were 27.5yrs and 160cm respectively. Cephalo-pelvic disproportion was the indication for sixteen (42%) of the primary Caesarean sections. The mean true conjugate diameter of the pelvis (cm) obtained by intra-operative pelvimetry and x-ray pelvimetry were 10.80 (SD 1.28) and 10.90 (SD 1.27) respectively. The difference between the two values was not significant (t < 1.98). The values of true conjugate obtained by both methods showed the same variation with height, age and parity. Patients with cephalo-pelvic disproportion had statistically smaller true conjugate than others when assessed by both methods. There is a strong correlation between intra-operative use of calipers and x-ray method in the measurement of true conjugate. It is thus concluded that intra-operative pelvic measurements using a pair of pelvic calipers (which is a direct measurement) could replace x-ray measurements in assessing pelvic size. Keywords: Pelvic measurement, caesarean section, X-ray pelvimetry. Annals of Biomedical Science Vol. 4 (1) 2005: pp. 19-24

Field Note—Comparison of Three Dendrometers in Measuring Diameter at Breast Height Field Note

Abstract Three dendrometers—d-tape, calipers, and Biltmore stick—were used to measure diameter at breast height (dbh), and discrepancies that occurred among these instruments were compared. Three methods of dbh estimation with calipers—the quadratic, arithmetic, and geometric mean of the major and minor axis diameter—were compared. Trees were grouped into four broad dbh classes of 1–5, 6–10, 11–15, and 16–20 in. and three species—northern red oak, sugar maple, and white ash—to determine the effect of tree size and species on discrepancies. The d-tape consistently recorded a larger dbh than the three caliper methods, but was not statistically different nor practically important. The differences in recorded dbh between the d-tape and calipers increased with tree size and were similar among northern red oak and sugar maple trees, but dbh differences in white ash trees were significantly less than in the other two species. The Biltmore stick's accuracy in classifying trees into the same dbh class as determined by the d-tape decreased as tree size increased. When examined by species, the Biltmore stick was less accurate in this regard with northern red oak and most accurate with sugar maple. Because the geometric principle of the d-tape assumes a tree to have a circular shape, its diameter estimation and subsequent basal area will usually be greater than the true diameter and area. The use of calipers reduces this bias, but the differences are not statistically significant.

Measurement methods used for the determination of dimensional accuracy and stability of denture base materials

The literature relating to methods of measurement of dimensional accuracy and stability of denture base materials is reviewed. The papers are presented chronologically together with information on the measurement technique used and the reported level of accuracy. Most authors utilized optical measuring apparatus, with the use of calipers being the second most popular method.

Useful adjuncts for vitreoretinal surgery.

Many vitreoretinal procedures are performed in offices and hospitals where cost control is important. We describe three useful devices and techniques that facilitate these procedures at minimal expense and often greater convenience. These include an accurate method for localising the pars plana without the use of callipers, an inexpensive, reliable, pressure regulated air pump for fluid-air exchange, and an easy method for intraocular injection of silicone oil through 20 gauge instrumentation without the need for expensive pumps. These procedures and techniques should prove to be useful in the treatment of vitreoretinal disease.

Fibrous dysplasia of bone and the Weil-Albright syndrome. A study of thirteen cases with special reference to the orthopaedic treatment.

Four patients with monostotic and nine with polyostotic fibrous dysplasia of bone, including one with the classical Weil-Albright syndrome and a male child who may have had this syndrome, are presented. While monostotic forms affect adults and are amenable to curative surgery, polyostotic involvement may become evident in childhood and early infancy, and represent a difficult therapeutic problem. Screening of the skeleton is essential for proper diagnosis and treatment, and should be achieved by total body scan in preference to a complete radiological survey. Biopsy is of particular importance in monostotic cases. The course of polyostotic fibrous dysplasia of bone is not predictable and depends partly upon the unassessable osteogenic potential of the bone, and also on surgery. The Weil-Albright syndrome and its variants are no worse than polyostotic fibrous dysplasia. Orthopaedic treatment deals with pathological fractures and with the prevention and correction of deformities, particularly of coxa vara. Sufficient stability of diaphyseal and metaphyseal lesions of the femur and tibia can usually be provided by intramedullary fixation, which needs to be left, or exchanged, at least until the end of adolescence. Extensive lesions of the proximal femur make aggressive surgery necessary. Pelvic involvement and destruction of the hip joint preclude surgery and require the use of calipers.

Correction of combined tibial torsion and valgus deformity of the foot.

Patients with spina bifida cystica commonly have significant disability from a combination of valgus deformity of the ankle and subtalar joints with lateral tibial torsion and plano-abduction deformity of the foot. These deformities can be corrected by a single procedure which combines a supramalleolar tibial osteotomy with a lateral inlay triple fusion. This procedure was carried out on 20 feet in 15 patients and the results were reviewed after an average of three years (range 18 months to 7 years). In 75 per cent of feet the combination of deformities was fully corrected, ulcers and callosities were eliminated in 95 per cent, the use of calipers minimised in 95 per cent, and in all patients the problem of shoe-wrecking was reduced. Complications included recurrent valgus deformity, delayed union of the tibial osteotomy and failure of midtarsal fusion.

Histamine weal formation and absorption in man.

1 The weal and flare response to intradermal histamine was measured over a range of doses in forearm skin of man. 2 The use of calipers to measure weal thickness was validated by measurement of observer and method errors. Repeated measurements at intervals of 5 min or more compressed the weals by 6% per reading. 3 Flare response reached a maximum at 5 min compared with 20 min for weal thickness and the sensitivity of the flare response was greater than the weal response at lower doses of histamine. 4 Sensitivity, lambda was comparable for the measurement of flare, weal diameter and thickness or volume. The advantage of weal thickness was in the measurement of weal formation and resorption. 5 The time course of histamine weal formation and disappearance was measured and found to have a T1/2 of 5.4 min and 87 min, respectively. 6 The T1/2 of disappearance of comparable 09% w/v NaCl solution and serum weals were 18 and 28 min respectively. 7 It is suggested that persistence of histamine weals is due to a vasoactive agent other than histamine.

A factor analysis of body build in the rat.

Following a survey of the problems associated with the comparative study of measures of physique in domesticated and laboratory animals, techniques were developed for the measurement of body build in the adult albino laboratory rat (Rattus norvegicus). They involved anesthetisation of the animals and the use of calipers and a simple apparatus devised for the purpose. The 17 measures taken on 100 rats, 50 of each sex, are detailed and the reasons for excluding other given. Intercorrelations of all the measures and their reliability co-efficients, which were judged satisfactory, are presented. The tables of intercorrelations, one for each sex, were factor analysed separately, and rotations to simple structure performed. Two factors were identified, one having factor saturations on measures of body length and the other similarily defining body width. This pattern was similar for the two sexes and a single index of body build was therefore proposed in which the length of the rear foot is divided by the width of the shoulder girdle and multiplied by 100 to avoid decimals. The use of the index in other investigations is mentioned.

A study of 49 patients with acute spinal extradural abscess.

Forty-nine patients (25 female, 24 male) whose abscess was diagnosed at laminectomy were studied. Their ages ranged from 11 to 69 years. The interval between the onset of the paralysis and operation varied between a few hours and three months. Forty-six patients had dorsal and three had cervical neurological syndromes. All patients suffered back pain. Where the records showed it, 31 of the abscesses were infected with Staphylococcus aureus. There was a history of peripheral sepsis in 26 patients and no evidence of sepsis in 21. There was a history of trauma only, probably affecting the back, in eight patients; and of trauma and peripheral sepsis in three. Only five patients walked without the use of calipers post-operatively; one of these subsequently deteriorated.

THE USE OF CALIPERS BY SPINAL‐INJURY PATIENTS AFTER DISCHARGE FROM A REHABILITATION CENTRE

This paper presents a survey of the use of calipers by spinal-Injury patients after their discharge from the Mount Wilga Rehabilitation Centre, Sydney. Information was obtained from a postal questionnaire sent to 135 e×-patlents who had attended the Rehabilitation Centre over a ten-year period.

Interpretation of the Heaving of a Well by the Use of Caliper Logging

By the use of caliper logging the diameter of a drilled well is measured quantitatively. Combining these results with geology and drilling method, the conclusions about the heaving are obtained as follows:(1) There are two causes for the heaving: the property of stratum and the drilling method.(2) Certain stratum has tendency to heave. It depends on clay mineral in the stratum.(3) Stratum heaves under unfavorable drilling conditions such as a slow drilling rate, reaming, and the use of unsuitable mud fluid.