The ultrasound Doppler fetal heart rate measurement is the gold standard of fetal heart rate counting. However, the existing fetal heart rate extraction algorithms are not designed specifically to suppress the high maternal interference during the second stage of labor, and false detection occurrences are common during labor. With this background, a method combining time-frequency frame template library optimal selecting and non-linear template matching is proposed. The method contributes a template library, and the optimal template can be selected to match the signal frame. After the short-time Fourier transform of the signal, the difference between the signal and the template is optimized by leaky rectified linear unit (LReLU) function frame by frame. The heart rate was calculated from the peak of the matching curve and the heart rate was calculated. By comparing the proposed method with the autocorrelation method, the results show that the detection accuracy of the proposed method is improved by 20% on average, and the non-linear template matching of 23% samples is at least 50% higher than the autocorrelation method. This paper designs the algorithm by analyzing the characteristics of the interference and signal mixing. We hope that this paper will provide a new idea for fetal heart rate extraction which not only focuses on the original signal.
ObjectiveTo observe the morphologic characteristics of color Doppler flow imaging (CDFI) and blood stream in patients with retinopathy of prematurity, and provide the new clinical diagnostic gist.MethodsCDFI was performed on 78 patients (156 eyes) with ROP at Ⅳ and Ⅴ stage, who had the diseases history such as prematurity and low birthweight which had been diagnosed by indirect ophthalmoscope, underwent the examination of CDFI. Morphologic characteristics of the results of CDFI and features of blood flow of the pathological changes were observed. ResultsIn the patients with ROP at the Ⅳ stage, a weak zonal echo originated from one side of peripheral wall of eye ball in the vitreous body, and extended to the echo of post pole and wall of eye ball and joined the echo of optic disc. In the patients with ROP at the V stage, lumplike echo connected closely with echo of lens and the circumambience was surrounded; the focus looked like lotus when combined with retinal detachment: the swelled “corona” wrapped and tightly connected with the lens, and the thin “caulis” showed weak zonal echo which attached to the optic disc. The features of blood flow showed the signal of blood stream connected with central retinal artery at the “caulis”, which was analyzed by Doppler spectrum as the bloodflow spectrum of artery and vein in the same direction which was the same as the central retinal artery and vein.ConclusionsIn patients with ROP at the IV and V stage, the results of CDFI mainly shows zonal or lumplike echo, in which the bloodflow signal extended with central retinal artery could be seen. The morphological changes of CDFI and the features of blood flow are useful in diagnosis of ROP. (Chin J Ocul Fundus Dis, 2005,21:282-284)
OBJECTIVE: To investigate the location of transverse rectus abdominis musculocutaneous (TRAM) flap perforators on abdomen skin and the peak systolic flow velocities of the perforators. METHODS: A series of 94 consecutive patient’s TRAM flap perforators were detected by color-flow duplex Doppler scanning peroperatively. Perforator locations were tabulated on the abdomen skin according to their vertical position relative to the umbilicus and their lateral location relative to the abdominal midline. RESULTS: The perforators on both left and right side of TRAM flap were quite not symmetry. The peri-umbilical region contained 81.1% of the perforators. All perforators were detected with peak systolic flow velocities ranging from 5 to 81 cm/s. CONCLUSION: The preoperative color-flow Doppler localization of TRAM flap perforators improves the surgeon’s ability to design the flap in order to capture the dominant vessels, and select single- or double-pedicle and free TRAM flaps based on each patient’s individual characteristics.
Objective To determine the affected factors of intraorbital hemodynamic results in diabetic retinopathy (DR) and the risk factors related to the occurrence of DR. Methods Posterior ciliary artery (PCA), central retinal artery (CRA), central retinal vein (CRV), and vortex vein (VV) of 68 patients with DR were measured by color Doppler flow image (CDFI). Thirty-one hemodynamic parameters, including systolic velocity, diastolic velocity, mean velocity, resistive index, pulsatility index and accelerative velocity of ophthalmic artery (OA), and other variates (blood pressure, blood sugar, gender, age, duration of the disease, and so on) were collected and clustered in a principal components analys is following a forward, stepwise logistic regression on these components. Results Nine principal components were extracted from 37 original variates, reflecting the velocity of OA, velocity of PCA, resistance of OA, velocity of CRA,resistance of CRA, resistance of PCA, time-related factor, venous drainage factor and gender factor, respectively. In the result of logistic regression, resistance of OA, velocity of CRA, resistance of PCA, time-related factor, and venous drainage factor were the risk factors related to DR. Conclusion The first risk factor affecting DR is time, and intraorbital hemodynamic abnormity influencing the development of diabetic retinopathy may be the increase of resistance of OA, decrease of velocity of CRA, decrease of resistance of PCA, and increase of venous drainage. (Chin J Ocul Fundus Dis，2004，20：98-100)
Objective To explore the value of color Doppler ultrasonography and plasma D-dimer in diagnosis of lower limb deep venous thrombosis (DVT).Methods The clinical data of 70 cases of patients with lower limb DVT diagnosed clinically were retrospectively studied. The lower limb venous of each patient was examined by color Doppler ultrasonography and the plasma level of D-dimer were measured, furthermore the plasma levels of D-dimer in different phase and different type of thrombosis were compared. Results The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of plasma D-dimer and ultrasonography examination in lower limb DVT were 100%, 66.7%, 97.0%, 100%, and 97.1%, and 98.4%, 83.3%, 98.4%, 83.3%, and 97.1%, respectively. The plasma D-dimer in acute phase 〔(6 451±4 012.22) μg/L〕 and subacute phase 〔(2 063±1831.35) μg/L〕 of lower limb venous thrombosis were significantly higher than that in normal control group 〔(310±66.70) μg/L〕, Plt;0.01 and Plt;0.05, which was not different from that in chronic phase 〔(466±350.52) μg/L〕. Meanwhile, the plasma D-dimer in mixed limb venous thrombosis group 〔(4 464±3 753.16) μg/L〕 and central limb venous thrombosis group 〔(2 149±1 911.53) μg/L〕 were significantly higher than that in control group (Plt;0.05 and Plt;0.01), which was not different from that in peripheral limb venous thrombosis group 〔(560±315.62) μg/L〕. Conclusion Color Doppler ultrasonography is an optimal method and the plasma D-dimer is a predictive index in diagnosis of lower limb DVT.
Objective To observe the characteristics of collateral circulation blood flow of ipsilateral ophthalmic artery in patients with internal carotid artery occlusion. Methods The imaging data of 20 patients with internal carotid artery occlusion were analyzed retrospectively. There were 11 males and 9 females, aged from 30 to 65 years, with an average age of (45±3) years. All the patients underwent digital subtraction angiography and transcranial Doppler examination, and 6 patients underwent simultaneous magnetic resonance angiography. The blood supply and collateral circulation of the ipsilateral ophthalmic artery were observed . Results All the patients had unilateral internal carotid artery occlusion. The blood supply of the ipsilateral internal carotid artery and ophthalmic artery comes from the collateral circulation between the middle meningeal artery branches of the external carotid artery and the ophthalmic artery in 18 patients (90.0%); it also comes from the anterior communicating artery of the contralateral internal carotid artery in 16 patients (80.0%); and the posterior communicating artery of the contralateral internal carotid artery in 12 patients (60.0%), respectively. Conclusion The blood flow of the ipsilateral ophthalmic artery mainly comes from the middle meningeal artery branch of the ipsilateral external carotid artery, also comes from the anterior and posterior communicating arteries of the contralateral internal carotid artery.
ObjectiveTo evaluate the dynamic changes of blood flow and blood pressure of acute hindlimb ischemia of rats by laser Doppler flowmetry (LDF) and laser Doppler perfusion imaging (LDPI). MethodsThe acute hindlimb ischemia model of rats was established by resection of rats femoral arteries of left hindlimb. The blood flow and blood pressure between operated and nonoperated hindlimbs were examined by LDF on 2, 7, 14, 28, and 49 d after operation. And the blood flow was evaluated by LDPI on 7 d after operation. ResultsAll rats survived after operation and no hindlimb necrosis occurred. The mean score was 2 on 14 d after operation and 1 on 49 d after operation. The ratio of blood flow between operated and nonoperated hindlimbs on 2 d after operation significantly increased from 1 to 1.31±0.439 (P=0.021). The ratio of blood flow on 7 d (0.82±0.538) and 14 d (0.93±0.294) after operation was significantly lower than that on 2 d after operation (P=0.032 and P=0.019), although the difference between the two former was not significant (P=0.502). Furthermore, the ratio of blood flow on 28 d after operation reached the bottom (0.41±1.970), which was obviously lower than that on 2, 7, and 14 d after operation (P=0.004, P=0.007, and P=0.006). The blood flow of operated hindlimbs recovered approximately the value before operation (0.98±0.093), which was significantly lower than that on 2 d (P=0.010), higher than that on 28 d (P=0.005), but not different from that on 7 d and 14 d after operation (P=0.126 and P=0.382). The ratio of blood pressure between operated and nonoperated hindlimbs on 2 d after operation significantly increased from 1 to 0.47±0.375 (P=0.031). The ratio of blood pressure decreased on 7 d after operation (0.44±0.118), which was not different from that on 2 d after operation (P=0.203). Furthermore, the ratio of blood pressure on 14 d after operation reached the bottom (0.35±0.115), which was obviously lower than that on 2 d and 7 d after operation (P=0.001 and P=0.036). On 28 d after operation, the ratio of blood pressure increased (0.54±0.146), which was significantly higher than that on 14 d after operation (P=0.008), while not different from that on 2 d (P=0.493) and 7 d after operation (P=0.551). The ratio of blood pressure recovered approximately the value before operation (0.97±0.094), which was significantly higher than that on 2, 7, 14, and 28 d (P=0.013, P=0.021, P=0.002, and P=0.031). ConclusionAcute hindlimb ischemia model of rats can be established by resection of rats femoral arteries of left hindlimb and the most serious stage of hindlimb ischemia is on 14-28 d after operation. LDF and LDPI are of importance for monitoring the dynamic changes of rats hindlimb ischemia after operation.
Objective To investigate the clinical application of high-frequency color Doppler ultrasound (HFCDU) in detecting perforators in the deep adipose layers for harvesting super-thin anterolateral thigh flap (ALTF). Methods Between August 2019 and January 2023, 45 patients (46 sides) with skin and soft tissue defects in the foot and ankle were treated, including 29 males and 16 females, aged from 22 to 62 years, with an average of 46.7 years. The body mass index ranged from 19.6 to 36.2 kg/m2, with an average of 23.62 kg/m2. The causes of injury included traffic accident injury in 15 cases, heavy object crush injury in 20 cases, mechanical injury in 8 cases, heat crush injury in 1 case, and chronic infection in 1 case. There were 20 cases on the left side, 24 cases on the right side, and 1 case on both sides. After thorough debridement, the wound size ranged from 5 cm×4 cm to 17 cm×11 cm. All patients underwent free super-thin ALTF transplantation repair. HFCDU was used to detect the location of the perforators piercing the deep and superficial fascia, as well as the direction and branches of the perforators within the deep adipose layers before operation. According to the preoperative HFCDU findings, the dimensions of the super-thin ALTF ranged from 6 cm×4 cm to 18 cm×12 cm. The donor sites of the flaps were directly sutured. Results A total of 55 perforators were detected by HFCDU before operation, but 1 was not found during operation. During operation, a total of 56 perforators were found, and 2 perforators were not detected by HFCDU. The positive predictive value of HFCDU for identifying perforator vessels was 98.2%, and the sensitivity was 96.4%. Among the 54 perforators accurately located by HFCDU, the orientation of the perforators in the deep adipose layers was confirmed during operation. There were 21 perforators (38.9%) traveled laterally and inferiorly, 12 (22.2%) traveled medially and inferiorly, 14 (25.9%) traveled laterally and superiorly, 5 (9.3%) traveled medially and superiorly, and 2 (3.7%) ran almost vertically to the body surface. Among the 54 perforators accurately located by HFCDU, 35 were identified as type 1 perforators and 12 as type 2 perforators (HFCDU misidentified 7 type 2 perforators as type 1 perforators). The sensitivity of HFCDU in identifying type 1 perforators was 100%, with a positive predictive value of 83.3%. For type 2 perforators, the sensitivity was 63.2%, and the positive predictive value was 100%. The surgeries were successfully completed. The super-thin ALTF had a thickness ranging from 2 to 6 mm, with an average of 3.56 mm. All super-thin ALTF survived, however, 1 flap experienced a venous crisis at 1 day after operation, but it survived after emergency exploration and re-anastomosis of the veins; 1 flap developed venous crisis at 3 days after operation but survived after bleeding with several small incisions; 3 flaps had necrosis at the distal edge of the epidermis, which healed after undergoing dressing changes. All 45 patients were followed up 6-18 months (mean, 13.6 months). Three flaps required secondary defatting procedures, while the rest had the appropriate thickness, and the overall appearance was satisfactory. Conclusion Preoperative application of HFCDU to detect the perforator in the deep adipose layers can improve the success and safety of the procedure by facilitating the harvest of super-thin ALTF.
Objective To investigate a method of improving design of the skin flap pedicled with descending branch of lateral femoral circumflex artery, in order to increase the accuracy of preoperative Doppler location. Methods Firstly, the interspace between rectus femoris and vastus lateralis was regarded as line A, and the point of intersection between line A and the vertical line through the midpoint of the line between anterior superior iliac spine and lateral margin of patella was point A. And then the line between the midpoint of groin and point A was regarded as line B. Based on this , the perforating point of cutaneous branch could be located by Doppler along the line B. From November 2001 to October 2004, this method was used in 38 skin flaps of 37 cases, being all males and 16-48 years old. The area of the flap ranged from 7 cm×6 cm to 24 cm×16 cm. Results All the perforatingpoint of cutaneous branch were located outward the line A. The rate that the preoperative Doppler location was consistent with the utility point of formatting skin flap was 97.4%. All the cases were followed up postoperatively 1-20 months. Among the cases, 36 skin flaps of 35 cases was successful and only 2 skin flaps partially necrosed, which healed after changing dressings or skin graft.Out of 35 cases, the sensation restoration of the skin flap was S2-S3 in 6 cases owing to the anastomosis of lateral femoral cutaneous nerve and a skin nerve of the recipient site, while that of the other cases was S0-S1. Conclusion Preoperative Doppler location and improving design of lineB can be a useful instruction for the design of skin flap pedicled with descending branch of lateral femoral circumflex artery.
ObjectiveTo investigate the application of high frequency color Doppler ultrasound (HFCDU) combined with wide-field imaging in the preoperative navigation of anterolateral thigh perforator flap graft.MethodsBetween January 2017 and March 2018, 28 patients with skin and soft tissue defects were treated, including 22 males and 6 females, with an average age of 33.5 years (range, 17-66 years). The causes of injury included 2 cases of scald scar, 7 cases of heavy object crushing injury, 12 cases of traffic accident injury, 4 cases of fall injury, 2 cases of machine injury, and 1 case of infection ulcer. Injury sites included 6 cases of hand and wrist, 12 cases of lower leg, 10 cases of foot. After debridement, the wound area ranged from 6.0 cm×3.5 cm to 24.0 cm×9.0 cm, and all patients were treated with free circumflex femoral artery perforator flap graft. Combo of HFCDU and wide-field imaging navigation were done preoperatively to detect the origin, quantity, course, surface location, hemodynamic characteristics, and the relationship with body area of perforator branch of lateral circumflex femoral artery. According to the perforator information displayed by wide-field imaging of source artery, the dominant perforator was determined to be a pedicle for designed flap. The flap size ranged from 7.0 cm×4.5 cm to 26.0 cm×7.0 cm. The flap donor area was sutured directly.ResultsThe dominant perforator was successfully detected by HFCDU combined with wide-field imaging in 28 patients before operation. The existence of the perforator was confirmed during operation, and the location was accurate. The course characteristics of the perforate were consistent with the results of wide-field imaging. The grafted flaps survived completely among 27 patients after operation. Necrosis at the edge of the flap was observed in 1 patient, which healed after dressing change. All patients were followed up 3-12 months, with an average of 9 months. All the flaps have good blood supply, good elasticity and shape. The donor areas healed perfectly.ConclusionUsing HFCDU and wide-field imaging navigation for designing of anterolateral thigh perforator flaps can clearly show the characteristics of perforators, hemodynamic information, and the relationship with body area, so that the surgeons can understand the perforators more accurately and intuitively, and improve the success and efficiency of flap graft surgery.