Measurement of clavicular length and shortening after a midshaft clavicular fracture: Spatial digitization versus planar roentgen photogrammetry.

PURPOSE: Clavicular shortening after fracture is deemed prognostic for clinical outcome and is therefore generally assessed on radiographs. It is used for clinical decision making regarding operative or non-operative treatment in the first 2weeks after trauma, although the reliability and accuracy of the measurements are unclear. This study aimed to assess the reliability of roentgen photogrammetry (2D) of clavicular length and shortening, and to compare these with 3D-spatial digitization measurements, obtained with an electromagnetic recording system (Flock of Birds). PATIENTS AND METHODS: Thirty-two participants with a consolidated non-operatively treated two or multi-fragmented dislocated midshaft clavicular fracture were analysed. Two observers measured clavicular lengths and absolute and proportional clavicular shortening on radiographs taken before and after fracture consolidation. The clavicular lengths were also measured with spatial digitization. Inter-observer agreement on the radiographic measurements was assessed using the Intraclass Correlation Coefficient (ICC). Agreement between the radiographic and spatial digitization measurements was assessed using a Bland-Altman plot. RESULTS: The inter-observer agreement on clavicular length, and absolute and proportional shortening on trauma radiographs was almost perfect (ICC>0.90), but moderate for absolute shortening after consolidation (ICC=0.45). The Bland-Altman plot compared measurements of length on AP panorama radiographs with spatial digitization and showed that planar roentgen photogrammetry resulted in up to 37mm longer and 34mm shorter measurements than spatial digitization. CONCLUSION: Measurements of clavicular length on radiographs are highly reliable between observers, but may not reflect the actual length and shortening of the clavicle when compared to length measurements with spatial digitization. We recommend to use proportional shortening when measuring clavicular length or shortening on radiographs for clinical decision making.

Determination of phthalic acid esters in Chinese white spirit using dispersive liquid-liquid microextraction coupled with sweeping ß-cyclodextrin-modified micellar electrokinetic chromatography.

A simple method that consumes low organic solvent is proposed for the analysis of phthalic acid esters in Chinese white spirit using dispersive liquid-liquid microextraction coupled with sweeping-micellar electrokinetic chromatography. Tetrachloromethane and white-spirit-containing ethanol were used as the extraction and dispersing solvents, respectively. The electrophoresis separation buffer was composed of 5 mM ß-cyclodextrin, 50 mM sodium dodecyl sulfate and 25 mM borate buffer (pH 9.2) with 9% acetonitrile, enabling the baseline resolution of the analytes within 13 min. Under the optimum conditions, satisfactory linearities (5-1000 ng/mL, r ≥ 0.9909), good reproducibility (RSD ≤ 6.7% for peak area, and RSD ≤ 2.8% for migration time), low detection limits (0.4-0.8 ng/mL) and acceptable recovery rates (89.6-105.7%) were obtained. The proposed method was successfully applied to 22 Chinese white spirits, and the content of dibutyl phthalate in 55% of the samples exceeded the Specific Migration Limit of 0.3 mg/kg established by the domestic and international regulations.

Automated kymograph analysis for profiling axonal transport of secretory granules.

This paper describes an automated method to profile the velocity patterns of small organelles (BDNF granules) being transported along a selected section of axon of a cultured neuron imaged by time-lapse fluorescence microscopy. Instead of directly detecting the granules as in conventional tracking, the proposed method starts by generating a two-dimensional spatio-temporal map (kymograph) of the granule traffic along an axon segment. Temporal sharpening during the kymograph creation helps to highlight granule movements while suppressing clutter due to stationary granules. A voting algorithm defined over orientation distribution functions is used to refine the locations and velocities of the granules. The refined kymograph is analyzed using an algorithm inspired from the minimum set cover framework to generate multiple motion trajectories of granule transport paths. The proposed method is computationally efficient, robust to significant levels of noise and clutter, and can be used to capture and quantify trends in transport patterns quickly and accurately. When evaluated on a collection of image sequences, the proposed method was found to detect granule movement events with 94% recall rate and 82% precision compared to a time-consuming manual analysis. Further, we present a study to evaluate the efficacy of velocity profiling by analyzing the impact of oxidative stress on granule transport in which the fully automated analysis correctly reproduced the biological conclusion generated by manual analysis.

State of the art laryngeal imaging: research and clinical implications.

PURPOSE OF REVIEW: This study provides a review of the latest advances in videostroboscopy, videokymography and high-speed videoendoscopy, and outlines the development of new laryngeal imaging modalities based on optical coherence tomography, laser-depth kymography, and magnetic resonance imaging (MRI), published in the past 2 years. RECENT FINDINGS: Videostroboscopy and videokymography: Image quality has improved and several image processing and measurement techniques have been published. High-speed videoendoscopy: Significant progress has been made through increased sensitivity and frame rates of the cameras, and the development of facilitative playbacks, phonovibrography and several image segmentation and measurement methods. Clinical evidence was presented through applications in phonosurgery, comparisons with videostroboscopy, normative data, and better understanding of voice production. Optical coherence tomography: Latest developments allow the capture of dynamic high-resolution cross-sectional images of the vibrating vocal fold mucosa during phonation. Depth kymography: New laser technique allowing recording of the vertical movements of the vocal folds during phonation in calibrated spatial values. Laryngeal magnetic resonance: New methods allow high-resolution imaging of laryngeal tissue microstructure, or measuring of dynamic laryngeal structures during phonation. SUMMARY: The endoscopic laryngeal imaging techniques have made significant advances increasing their clinical value, whereas techniques providing new types of potentially clinically relevant information have emerged.

Advances in laryngeal imaging.

Imaging and image analysis became an important issue in laryngeal diagnostics. Various techniques, such as videostroboscopy, videokymography, digital kymography, or ultrasonography are available and are used in research and clinical practice. This paper reviews recent advances in imaging for laryngeal diagnostics.

Animal model of the short-term cardiorespiratory effects of intermittent vagus nerve stimulation.

PURPOSE: To develop an animal model of the effects of vagus nerve stimulation (VNS) on heart rate and respiration in studies of seizure treatment. METHODS: Nine rats implanted with ECG, EMG, and VNS electrodes and pulse generator were stimulated with 81 different sets of parameters while they slept in a plethysmographic box. RESULT: From cardiorespiratory effects of VNS, an index (alpha) was found to distinguish between weak and strong VNS doses. Weak VNS dose induced an increase in respiratory frequency and no significant change in heart rate. The effect of VNS on respiration, similar to that observed in children, can be divided into 3 phases. Strong VNS dose induced a decrease in respiratory frequency concomitant with a decrease in heart rate. Increasing the intensity of the VNS induced a proportional increase in the maximal inspiratory strength. CONCLUSION: Various VNS parameter settings induce different and concomitant cardiorespiratory variations in conscious sleeping rats. These effects correlate with the intensity of the VNS parameters. Understanding the effects of the intensity of VNS parameters may allow for further optimization of VNS parameters in patients receiving VNS.

Validation of a raw data-based synchronization signal (kymogram) for phase-correlated cardiac image reconstruction.

Phase-correlated reconstruction is commonly used in computed tomography (CT)-based cardiac imaging. Alternatively to the commonly used ECG, the raw data-based kymogram function can be used as a synchronization signal. We used raw data of 100 consecutive patient exams to compare the performance of kymogram function to the ECG signal. For objective validation the correlation of the ECG and the kymogram was assessed. Additionally, we performed a double-blinded comparison of ECG-based and kymogram-based phase-correlated images. The two synchronization signals showed good correlation indicated by a mean difference in the detected heart rate of negligible 0.2 bpm. The mean image quality score was 2.0 points for kymogram-correlated images and 2.3 points for ECG-correlated images, respectively (3: best; 0: worst). The kymogram and the ECG provided images adequate for diagnosis for 93 and 97 patients, respectively. For 50% of the datasets the kymogram provided an equivalent or even higher image quality compared with the ECG signal. We conclude that an acceptable image quality can be assured in most cases by the kymogram. Improvements of image quality by the kymogram function were observed in a noticeable number of cases. The kymogram can serve as a backup solution when an ECG is not available or lacking in quality.

What have we learned about laryngeal physiology from high-speed digital videoendoscopy?

PURPOSE OF REVIEW: The purpose of this review is to describe recent developments in high-speed videoendoscopy. The applications of this technique are highlighted and important findings regarding vocal fold physiology and voice pathology are discussed. RECENT FINDINGS: The number of applications for digital high-speed imaging has increased during recent years because of the development of camera image sensor systems with increased image resolution of video and television quality. Other improvements are related to computer processing speed and storage capacity and the development of automatic algorithms for quantification and measurements both in time and room dimensions. This is enhanced by combining high-speed videoendoscopy with laser-based measurement systems, acoustic analyses or other glottographic methods, such as flow glottography or electroglottography. High-speed videoendoscopy is currently used in studies of voice mechanisms of phonation (e.g., the voice source can be examined with a high sampling rate, from 1000 to over 8000 frames per second), and in phonation onset or offset. High-speed imaging is also useful in linguistic studies and in the examination of different artistic singing styles, such as extremely high-pitched singing, throat singing, or different pop and rock styles. High-speed videoendoscopy is also used in the examination of patients with voice disorders, particularly with irregular vocal fold vibrations, ventricular phonation, or the phonation of individuals who have had a laryngectomy. SUMMARY: Findings from studies of normal voice physiology and of voice disorders using high-speed imaging are presented and their relevance is discussed.

[Computer cardiokymography. On its way to long-term noninvasive monitoring of cardiac performance in daly life]. / Komp'iuternaia kardiokimografiia na puti k dlitel'nomu neinvazivnomu nabliudeniiu za sokratil'noi deiatel'nost'iu serdtsa cheloveka.

A functioning heart generates low-frequency and low-amplitude movements (up to 40 (mrn) of soft tissues in the percardial area. Since the 1950-s of the XX-th century cardiologists have studied these movements to employ them in the diagnostics of ischemic heart disease (IHD). Indeed, changes of the movements have found their diagnostic application in this field. If blood supply to a certain area of ventricular myocardium is insufficient the contractions in this area diminish and even ceases. After systolic increase in ventricular pressure this area dilates and forces intercostal tissues out, causing a "bulge" wave on the record. For recording the patient must be in supine position and hold the breath. High frequency electromagnetic field generator was used in an attempt to examine the heart movements. It was found that such instrument measures the thickness of the air-gap that serves as a dielectric or a "capacitor" which forms between the skin and approaching it flat inductive coil. Nevertheless, such an instrument (cardiokymograph, CKG) can reveal changes in contractions of ischemic myocardium and markedly increases the sensitivity of the exercise ECG test. However, CKG can be recorded only after termination of the test. This principal disadvantage has been overcome by software that allowed the recording of CKG during the test. A low-frequency capacitance transducer developed recently by Chinese researchers has provided a simultaneous recording of several CKG. After modifying the transducer, we have established that 1) the shape of CKGs is the same as that CKGs recorded by all our predecessors, 2) CKGs are reproducible even within a 3-month interval, 3) the enormous mechanical interference caused by respiratory movements and, to a greater extent, by the vigorous movements of the legs and trunk during veloergometry can be eliminated by digital processing of the transducer signals, and 4) pathological changes appear in CKG of patients with IHD, which enables one to stop veloergometry at lower loads, thus increasing the safety of the test. Since for large medical insurance companies very simple and inexpensive cardiokymograph are quite unprofitable, their commercially production in USA and in Germany has been stopped. However, the goal of cardiokymography: a real-time, beat-to-beat, long-term monitoring of cardiac function in daily life, remains the major factor determining the future of the method.

Quantitative study of mucosal wave via videokymography in canine larynges.

OBJECTIVES: Vocal fold mucosal wave movements are thought to be important in determining voice characteristics and quality. To see these movements, high-speed cinematography and videostroboscopy have been used clinically; however, these techniques have disadvantages that make them impractical for quantitative measurement of mucosal wave movements. This study explored the feasibility of using line-scan cameras for mucosal wave analysis. METHODS: An excised larynx bench model was used to examine the effects of elongation and changes in subglottal pressure on the amplitude, frequency, and phase difference of vocal fold mucosal movements as calculated from line-scan images. RESULTS: The data showed a positive and linear relationship between an increase in subglottal pressure and amplitude of the mucosal wave; elongation of the vocal folds appeared to decrease the amplitude of mucosal wave upheaval at each level of subglottal pressure. Similarly, increase in subglottal pressure had a positive and linear relationship with increase in frequency of vibration; elongation of the vocal folds further increased the frequency at any given subglottal pressure. Phase difference between the movements of the upper and lower margins of the mucosal lips was estimated and did not appear to be significantly affected by changes in subglottal pressure and elongation. CONCLUSION: The data presented in this study are consistent with relationships that we would expect to be true from currently accepted models of vocal fold vibration.

Evaluation of signal-averaged cardiokymography for the detection of ischaemic left ventricular dysfunction.

UNLABELLED: Cardiokymography (CKG) is a non-invasive method for the detection of patients with coronary artery disease (CAD). Issues of the present study were to evaluate the feasibility, sensitivity and specificity of a recently developed signal-averaged CKG system for detecting patients with pharmacologically induced ischaemic left ventricular wall motion abnormalities (WMA) during pharmacologic stress echocardiography (SE). Precordial CKG curves were recorded in 100 consecutive patients who underwent dobutamine-SE for suspected CAD. For interpretation, CKG curves were classified into three different types, depending on the degree of systolic outward motion. CKG test results were regarded as positive (indicating myocardial ischaemia) if there was a change of the baseline CKG type at peak pharmacologic stress. The CKG test results were positive in 18 of 27 patients with a pathologic dobutamine-SE (sensitivity 67%), but did not show any change of the prior CKG type in 57 of 69 patients with a normal SE (specificity 83%). Patients with a true positive CKG test had significantly (P<0.05) more echocardiographic segments with WMA than patients with a false negative CKG test. CONCLUSIONS: Signal-averaged CKG can detect patients with ischaemic ventricular dysfunction. Sensitivity of CKG in detecting patients with WMA depends on the extent of left ventricular ischaemia. Further studies are needed to define the diagnostic value of signal-averaged CKG in the non-invasive detection of patients with suspected CAD.

Continuous postoperative free-flap monitoring with an EKG-interfaced photoplethysmograph.

A compact battery-operated tissue-perfusion monitor has been developed which continuously displays photoplethysmograph waveforms on bedside EKG monitors. The device has been of proven utility in the postoperative monitoring of free-flap recipients.

[Comparison of methods for the relative quantification of the hump in cardiokymographic tracings]. / Methodenvergleich zur relativen Quantifizierung des Buckels kardiokymographischer Registrierungen.

Exercise stress testing in a sitting position was carried out preoperatively and three months post aortocoronary bypass surgery in 125 men. Before exercise, immediately after exercise and after 5 minutes of recovery cardiokymography (CKG) was performed in a lying position. So called "bulges" in the CGK-tracings, defined as Type I, II or III registration by non quantitative judgement so far, were set out quantitatively by evaluation of area (Flächen-method) or distance (Distanzmethod) of the bulge. We found a significant increase (p less than 0.001) of bulges according to both methods after exercise but no difference between rest and after recovery concerning the area method. The distance method showed higher values (p less than 0.05) after recovery than at rest. All mean values postoperatively were not significantly lower than the corresponding values preoperatively. Our results show, that CKG-tracings can be quantitatively assessed both by the area or by the distance method. The latter is easier to apply and has comparable results to the area method.