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Biomedical subjects

J Holmquist

Publications and source records attributed to J Holmquist.

At least 37 records · Page 2Linked to original sources
PubMed1981

Measurement of eustachian tube function using sonotubometry.

Sound transport through the Eustachian tube in normal ears has been recorded using sonotubometry (Virtanen, 1978). It was found that only 66% of the ears had sound transport through the tube when swallowing. Despite the fact that all ears had adequate aeration of the middle ear at the time of testing, 34% of the ears had no sound passage when swallowing. The explanation for this phenomenon is discussed. Also, it is concluded that this test may reflect Eustachian tube patency during swallowing--and not tubal function.

Deglutition↗
PubMed1981

TULIPS: the Uppsala-Linkoping Image Processing System.

The Uppsala-Linkoping Image Processing System, TULIPS, is described. TULIPS, a hardware-software system designed for cell image processing, was developed at Uppsala University Hospital in cooperation with the Department of Electrical Engineering at Linkoping University. The hardware part of the image processing system is built around a high-speed data bus with a capacity of about 40 M byte/sec connected to a PDP-11/55 host computer. An image memory, an LSI-11 microcomputer and a video interface for displaying the image memory content on a TV monitor are also connected to the high-speed bus. An automated microscope and a "Poulsen processor" for low resolution segmentation, both to be attached to the high-speed bus, are being developed. A monitor and an interpreter for an image processing language have been implemented on the host computer. This software system allows interactive, as well as batch, processing. The degree of user interaction is easily adapted to the user's needs. The image processing language is command oriented, and it is easily expanded by adding new commands. The system has been used both for studies in the field of quantitative microscopy and as a platform for development and testing of new image processing algorithms.

Computers↗
PubMed1981

Measurement of middle ear volume using the impedance audiometer.

Ears with chronic otitis media are characteristically associated with small mastoid air cell systems. This also indicates a small air volume in these ears, which may influence the pathophysiology and course. Therefore, it may be important to get a measure of the air volume in the middle ear mastoid air cell system. Conventional mastoid X-ray investigations have so far been used for estimating this volume. As impedance audiometry has gained in popularity during recent years, it has been postulated that this tool may be useful for measuring the volume in the middle ear and the mastoid system. In this report we present data comparing the acoustically measured size to direct volumetric and planimetric size of the mastoid air cell system on the X-ray film. Temporal bone specimens with perforation of the tympanic membrane have been investigated. A good correlation between these methods is obtained, and we conclude that impedance audiometry enables a rapid and valuable estimation of the air reservoir in the middle ear.

Acoustic Impedance Tests↗
PubMed1980

Recurrent cholesteatoma in combined approach tympanoplasty.

Forty-six ears--13 cholesteatoma ears and 33 non-cholesteatoma ears--with preoperative poor Eustachian tube function and a healed tympanic membrane more than 12 months after surgery were investigated. It was found that retractions occurred independent of previous cholesteatoma or surgical procedure. Also, retractions were associated with intratympanic negative air pressure, indicating dysfunction of the Eustachian tube.

Adult↗
PubMed1979

Analysis of reproducibility of subjective grading systems for breast carcinoma.

The inter- and intra-observer reproducibility of three grading systems for breast cancer has been analysed: those of the World Health Organisation, of Black, and of Hartveit. In addition, the components forming the basis of these grading systems were analysed separately with regard to reproducibility and interrelationship. In this analysis, degree of differentiation was also included as a parameter. The grading systems of WHO and of Black gave a stratification of the material into three categories of tumours, but that of Hartveit did not. All three systems had a low inter- and intra-observer reproducibility. Truncated component analysis indicated that the grading systems of WHO and of Black are closely related to each other and to the 'nuclear lobulation' component of Hartveit's system. The components 'pleomorphism', 'mitotic frequency', and 'hyperchromasia' of the WHO system were closely interrelated. Descriptors such as 'differentiation' and 'tubule formation' were interrelated but acted in a different direction from the others.

Breast Neoplasms↗
PubMed1979

High resolution segmentation of cervical cells.

A major problem in the automation of cervical cytology screening is the segmentation of cell images. This paper presents the present status of the work on that problem at the University of Uppsala. A dual resolution system is used. Suspect malignant cells are located at 4 mu resolution. Each such cell is rescanned at 0.5 mu resolution at two different wavelengths, 530 and 570 nm. The nucleus and the cytoplasm are isolated each by two independent methods. For the nucleus adaptive thresholding in the histogram of the 570 nm image and a contouring in a radially transformed version of that image is used. For the cytoplasm a two dimensional thresholding in the 2D histogram and a contouring in a radially transformed version of the 530 nm image is used. If the two nuclear masks agree the surrounding area is checked for disturbing objects. If also the cytoplasm masks agree and are without disturbing objects the whole cell is accepted. The result of the cytoplasm masks agree and are without disturbing objects the whole cell is accepted. The result of the segmentation is thus three categories; free cells, free nuclei and rejected objects. The shape of the objects belonging to the former two categories is checked and irregularly shaped ones are rejected as probably consisting of several overlapping nuclei. Cells passing also this test are classified as normal or malignant. The experience from using this algorithm is discussed and areas for further research are pointed out.

Cell Nucleus↗
PubMed1978

The mastoid air cell system in ear surgery.

Despite the overall high success rate of myringoplasty, the long-term results in ears with preoperative dysfunction of the Eustachian tube and with a small mastoid air cell system are disappointing. In this communication, we report an 83% healing rate after myringoplasty that included mastoidectomy with posterior and anterior tympanotomy in a selected group of patients with poor tubal function and small mastoids.

Air↗
PubMed1978

Aeration in chronic otitis media.

The mastoid air cell system must be looked upon as an air reservoir. The tympanic membrane is an air pressure regulator. The smaller the air volume of the mastoid the more pronounced is the volume displacement of the tympanic membrane. The more inefficient the Eustachian tube function, the more pronounced is the tympanic membrane displacement. The significance of these factors must be considered not only when discussing the etiology of chronic otitis media including cholesteatoma, but also when it comes to selecting procedures in restoring middle ear anatomy and physiology in chronic middle ear surgical disease.

Air↗
PubMed1978

Computer analysis of cervical cells. Automatic feature extraction and classification.

A prescreening instrument for cervical smears using computerized image processing and pattern recognition techniques requires that single cells in the specimen can be automatically isolated and analyzed. This paper describes a dual wavelength method for automatic isolation of the cytoplasm and nuclei of cells. Density-oriented, shape-oriented and texture-oriented parameters were calculated and evaluated for more than 600 cells. It is shown that the computer can be taught to distinguish between normal and atypical cells with an accuracy of ca. 97%, while human classification reproducibility is ca. 95%. In addition, an attempt to assign a measure of atypia to individual cells is described.

Cell Nucleus↗
PubMed1978

Computerized nuclear morphometry as an objective method for characterizing human cancer cell populations.

A new method for measuring differences in nuclear detail in chrome alum gallocyanin-stained nuclei of cells from human breast cancers was compared with conventional subjective grading and classification systems. The new method, termed computerized nuclear morphometry (CNM), gives a multivariate numerical score that correlates well with nuclear atypia and gives a higher reproducibility of classification than do subjective observations with conventional histological preparations. When 100 individual nuclei from each of 137 breast cancers were examined by CNM, there was a broad CNM score variation between patients but a good reproducibility for each tumor. When different parts of the same tumor were sampled, there was good reproducibility between samples, indicating that some breast cancers at least are "geometrically monoclonal." When these cancers were compared by the grading systems of WHO and Black, correlations of 0.43 and 0.48, respectively, were found. There was a poor correlation between CNM and classifications of tumor type, but in general there were high values for CNM in medullary tumors and low values in mucous tumors. Correlations between CNM and tumor progression and prognosis await future study of patients participating in the study.

Breast Neoplasms↗
PubMed1977

A software system to record and analyze digitized cell images.

This paper describes basic software for digitization and processing of microscopic cell images used at the Department of Clinical Cytology at Uppsala University Hospital. A family of programs running on a PDP-8 minicomputer which is connected to a Leitz Orthoplan microscope with two image scanners, one diode-array scanner and a moving-stage photometer, is used for data collection. The digitized image data is converted by converted by conversion program to IBM compatible format. The data structures for image processing and statistical evaluation on the IBM system are also described. Finally, some experiences from the use of the software in cytology automation are discussed.

Cell Biology↗
PubMed1977

A program system for interactive measurements on digitized cell images.

Using a high precision image scanner and a PDP-8/F minicomputer, we have developed a program system for interactive measurements on microscopic images. By giving simple keyboard commands, the operator can run the image scanner and manipulate the digitized images. The interface between the operator and the microscope-computer system is a Tektronix 4010 graphic terminal. The system allows objects to be isolated and parameters to be calculated from each object, e.g., parameters characterizing shape of the object, irregularity in light transmission over the object, area, integrated light transmission, etc. Objects are isolated and parameters are calculated under complete operator control using interactive computer graphics technique. Calculated parameters may be stored in dedicated data records, which are stored in files for later statistical analysis. The system also includes a statistical evaluation part. Technically, the system consists of a command scanner, which translates commands into internal representation, a parser, which checks the syntax of the commands, and an interpreter, which executes the commands. The system is designed so that new commands can be added easily.

Computers↗
PubMed1976

SCANCANS--an interactive scanning cell analysis system.

This paper describes a computerized, general-purpose, interactive, scanning cell-analysis system developed at the Department of Clinical Cytology of the University Hospital in Uppsala. The system uses a Leitz MPV II scanning photometer, a PDP-8 computer with 24 k of core memory and a Tektronix 4010 graphic display terminal. A command interpreter and overlay structure which makes it simple to add new capabilities to the system is described. Some examples of command strings and the kind of operations the system can perform are included. Finally, the experience gained from using the system and some plans for future extensions are discussed.

Autoanalysis↗
PubMed1976

A microspectrophotometric study of Papanicolaou-stained cervical cells as an aid in computerized image processing.

As part of a study of cytologic automation, microspectrophotometric investigation of Papanicolaou-stained cervical cells was performed, using a Leitz MPV-II scanning photometer connected to a PDP 8/F minicomputer. It was shown that the selection of one single wavelength may result in difficulties in detecting boundries between background and cytoplasm and/or between cytoplasm nucleus. A set of two wavelengths, 530 nm and 570 nm, were found to be optimal for the image processing of these cells.

Cell Nucleus↗