To assess the rel iabil ity of diabetic cutaneous ulcer surface area (DCUSA) measurement usingdigital planimetry method (A) and transparency tracing method (B). Methods Images of diabetic cutaneous ulcers from35 inpatients with diabetic skin ulcers from September 2005 to April 2007 were taken by a digital camera once a week or twice a week over a period of 12 weeks, resulting in 305 photographs; the ulcers were traced on a grid with acetate wound tracings, simultaneously. A total of 305 pairs of DCUSA which were calculated respectively throughout digital camera combined with Image J medical imaging software and transparency tracing with grid sheet by two independent observers sequentially were obtained. The intraclass correlation coefficients (ICCs, one-way random effect model) was used as an indicator of chancecorrected agreement to estimate the relative rel iabil ity for the interobserver data. Multiple l inear regression analysis was also used to measure the relationship of these two methods. Results DCUSA obtained from method A and obtained from method B was (4.84 ± 7.73) cm2 and (5.03 ± 7.89) cm2, respectively; no significant difference was found (P gt; 0.05). ICCs was high (ICCs=0.949 for method B and 0.965 for method A), indicating that the relative rel iabil ity for the interobserver was excellent. The method A were highly correlated with measurements obtained from method B (r = 0.957, P lt; 0.05). Conclusion The digital planimetry method described in this study represents a simple, practical, without any wound damage and contamination, and inexpensive technique to accurately evaluate the areas of diabetic cutaneous ulcers. The photographic technique combined with Image J medical imaging software should be considered for wound measurement.
Objective To explore the anatomical parameters of the cervical uncinate process “inflection point” through cervical CT angiography (CTA) and MRI measurements, offering a reliable and safe anatomical landmark for anterior cervical decompression surgery. Methods A retrospective analysis was conducted on the cervical CTA and MRI imaging data of normal adults who met the selection criteria between January 2020 and January 2024. The CTA dataset included 326 cases, with 200 males and 126 females, aged 22-55 years (mean, 46.7 years). The MRI dataset included 300 cases, with 200 males and 100 females, aged 18-55 years (mean, 43.7 years). Based on the CTA data, three-dimensional models of C3-C7 were constructed, and the following measurements were obtained from the superior view: uncinate process “inflection point” to vertebral artery distance (UIVD), uncinate process tip to vertebral artery distance (UTVD), uncinate process “inflection point” to “inflection point” distance (UID), uncinate process long-axis to sagittal angle (ULSA), and uncinate process “inflection point” to transverse foramen-sagittal angle (UITSA). From the anterior view, the anterior uncinate process to sagittal angle (AUSA) was measured. From the posterior view, the posterior uncinate process to sagittal angle (PUSA) was measured. Based on the MRI data, uncinate process “inflection point” to dural sac distance (UIDD) and dural sac width (DSW) were measured. The trends in measurement parameters of C3-C7 were observed, and the differences in measurement parameters between genders and between the left and right sides of the same segment were compared, as well as the difference in UID and DSW within the same segment was compared. Results The measurement parameters from C3 to C7 in the CTA data showed a general increasing trend, with no significant difference between the left and right sides within the same segment (P>0.05). The UIVD, UTVD, and UID were greater in males than in females, with significant differences observed in the UIVD and UTVD at C3 and C6 and UID at C3, C6, and C7 (P<0.05). The MRI measured DSW showed a general increasing trend from C3 to C7, and the DSW at C6 was greater in females than in males, with a significant difference (P<0.05). The UIDD showed a gradual decreasing trend, with the smallest value at C6. There was no significant difference between males and females or between the left and right sides within the same segment (P>0.05). The UID was greater than the DSW at C3-C7, and the differences were significant (P<0.05). ConclusionThe uncinate process “inflection point” is a constant anatomical structure located at the anteromedial aspect of the uncinate process tip and laterally to the dural sac. It maintains a certain safe distance from the vertebral artery. As a decompression landmark in anterior cervical spine surgery, it not only ensures surgical safety but also guarantees complete decompression.
Based on repeated experiments as well as continuous researching and improving, an efficient scheme to measure velocity and displacement of the coxa and knee movements based on video image processing technique is presented in this paper. The scheme performed precise and real-time quantitative measurements of 2D velocity or displacement of the coxa and knee using a video camera mounted on one side of the healing and training beds. The beds were based on simplified pinhole projection model. In addition, we used a special-designed auxiliary calibration target, composed by 24 circle points uniformly located on two concentric circles and two straight rods which can rotate freely along the concentric center within the vertical plane, to do the measurements. Experiments carried out in our laboratory showed that the proposed scheme could basically satisfy the requirements about precision and processing speed of such kind of system, and would be very suitable to be applied to smart evaluation/training and healing system for muscles/balance function disability as an advanced and intuitional helping method.
Due to lack of the practical technique to measure the biomechanical properties of the ocular cornea in vivo, clinical ophthalmologists have some difficulties in understanding the deformation mechanism of the cornea under the action of physiological intraocular pressures. Using Young's theory analysis of the corneal deformation during applanation tonometry, the relation between the elasticity moduli of the cornea and the applanated corneal area and the measured and true intraocular pressures can be obtained. A new applanation technique has been developed for measuring the biomechanical properties of the ocular cornea tissue in vivo, which can simultaneously acquire the data of the applanation area and displacement of the corneal deformation as well as the exerted applanation force on the cornea. Experimental results on a rabbit's eyeball demonstrated that the present technique could be used to measure the elasticity moduli and creep properties of the ocular cornea nondestructively in vivo.
In this paper, a new probe is proposed for the in vivo dielectric measurement of anisotropic tissue in radio frequency band, which could accomplish the dielectric measurement in perpendicular directions by one operation. The simulative studies are performed in the frequency range from 1–1 000 MHz in order to investigate the influence of probe dimension on the energy coupling and sensitivity of measurement. The suitable probe is designed and validated for the actual measurement in this frequency band. According to the simulation results, the energy coupling of the probe could be kept below –12 dB in the frequency range from 200–400 MHz with high sensitivity of measurement for the dielectric properties of anisotropic tissue. That indicates the new type of probe has the potential to achieve the dielectric measurement of anisotropic tissue in radio frequency band and could avoid the measurement error by multi-operations in the conventional method. This new type of probe could provide a new method for the in vivo dielectric measurement of anisotropic tissue in radio frequency band.
Objective To investigate the application of magnetic resonance imaging (MRI) in preoperative assessment of rectal cancer. Methods Combined with the literatures, the MRI features and measurements of rectal tumor staging, extramural vascular invasion, circumferential margin involvement, and the distance between distal margin of the tumor from the anorectal ring and the anal margin were described. Results On T2-weighted images (T2WI), T1 staging-tumors were those in which the normal submucosa was replaced by the iso-intensity of tumor tissue without invasion of muscularis propria; T2 staging-tumors were those with extension into the muscularis propria, but not invaded the high-intensity of mesorectal fat; T3 staging-tumors manifested as the rectal tumor penetrated into the muscularis propria and invaded the high-intensity of mesorectal fat; T4 staging-tumors manifested as the tumor invaded adjacent structures or organs. The metastatic lymph nodes were showed with irregular boundaries and mixed signals on T2WI. The tumor signals could be found in the extramural vascular on T1-weighted images (T1WI), accompanied by irregular distortion and expansion of the blood vessels. On T2WI, metastatic lymph nodes, extramural vascular invasion, and the distance between the residual tumor and the low-signal of mesorectal fascia was within 1 mm, indicated the positive circumferential margin. On T2WI, the distal margin of the tumor was located at the junction of hyperintense submucosa and iso-signal of tumor, the tip of the iso-signal puborectal muscle was the apex of the anorectal ring, and the lowest point of the iso-signal external sphincter was the anal margin. Conclusion MRI can provide reliable imaging information for preoperative staging, height measurement, and prognosis of rectal cancer, and it is helpful for early diagnosis and treatment of rectal cancer.
Multi-task learning (MTL) has demonstrated significant advantages in the field of physiological signal measurement. This approach enhances the model's generalization ability by sharing parameters and features between similar tasks, even in data-scarce environments. However, traditional multi-task physiological signal measurement methods face challenges such as feature conflicts between tasks, task imbalance, and excessive model complexity, which limit their application in complex environments. To address these issues, this paper proposes an enhanced multi-scale spatiotemporal network (EMSTN) based on Eulerian video magnification (EVM), super-resolution reconstruction and convolutional multilayer perceptron. First, EVM is introduced in the input stage of the network to amplify subtle color and motion changes in the video, significantly improving the model's ability to capture pulse and respiratory signals. Additionally, a super-resolution reconstruction module is integrated into the network to enhance the image resolution, thereby improving detail capture and increasing the accuracy of facial action unit (AU) tasks. Then, convolutional multilayer perceptron is employed to replace traditional 2D convolutions, improving feature extraction efficiency and flexibility, which significantly boosts the performance of heart rate and respiratory rate measurements. Finally, comprehensive experiments on the Binghamton-Pittsburgh 4D Spontaneous Facial Expression Database (BP4D+) fully validate the effectiveness and superiority of the proposed method in multi-task physiological signal measurement.
Hypertension is the primary disease that endangers human health. A convenient and accurate blood pressure measurement method can help to prevent the hypertension. This paper proposed a continuous blood pressure measurement method based on facial video signal. Firstly, color distortion filtering and independent component analysis were used to extract the video pulse wave of the region of interest in the facial video signal, and the multi-dimensional feature extraction of the pulse wave was preformed based on the time-frequency domain and physiological principles; Secondly, an integrated feature selection method was designed to extract the universal optimal feature subset; After that, we compared the single person blood pressure measurement models established by Elman neural network based on particle swarm optimization, support vector machine (SVM) and deep belief network; Finally, we used SVM algorithm to build a general blood pressure prediction model, which was compared and evaluated with the real blood pressure value. The experimental results showed that the blood pressure measurement results based on facial video were in good agreement with the standard blood pressure values. Comparing the estimated blood pressure from the video with standard blood pressure value, the mean absolute error (MAE) of systolic blood pressure was 4.9 mm Hg with a standard deviation (STD) of 5.9 mm Hg, and the MAE of diastolic blood pressure was 4.6 mm Hg with a STD of 5.0 mm Hg, which met the AAMI standards. The non-contact blood pressure measurement method based on video stream proposed in this paper can be used for blood pressure measurement.
Based on the imaging photoplethysmography (iPPG) and blind source separation (BSS) theory the author put forward a method for non-contact heartbeat frequency estimation. Using the recorded video images of the human face in the ambient light with Webcam, we detected the human face through software, separated the detected facial image into three channels RGB components. And then preprocesses i.e. normalization, whitening, etc. were carried out to a certain number of RGB data. After the independent component analysis (ICA) theory and joint approximate diagonalization of eigenmatrices (JADE) algorithm were applied, we estimated the frequency of heart rate through spectrum analysis. Taking advantage of the consistency of Bland-Altman theory analysis and the commercial Pulse Oximetry Sensor test results, the root mean square error of the algorithm result was calculated as 2.06 beat/min. It indicated that the algorithm could realize the non-contact measurement of heart rate and lay the foundation for the remote and non-contact measurement of multi-parameter physiological measurements.
The velocity of blood in vessels is an important indicator that reflects the microcirculatory status. The core of the measurement technology, which is based on spatiotemporal (ST) image, is to map the cell motion trace to the two-dimensional ST image, and transfer the measurement of flow velocity to the detection of trace orientation in ST image. This paper proposes a trace orientation measurement algorithm is based on Randomized Hough Transformation and projection transformation, and it is able to estimate trace orientation and flow velocity in noisy ST images. Experiments showed that the agreement between the results by manual and by the proposed algorithm reached over 90%.