It is with sadness that we received the message that Karel Maršál passed away on March 6, 2023. Karel Maršál, MD, PhD, Professor Emeritus at Lund University and Director of the WHO Collaborating Center in Lund, was born in Prague, former Czechoslovakia, in 1943. After completing his undergraduate studies at Charles University in Prague, he and his fiancée Lida moved as political refugees to Sweden in 1968. They came to Malmö General Hospital in 1973, where Karel gained his specialty in obstetrics and gynecology. Already then, Malmö was a nursery for research on fetal physiology and monitoring, and Karel was soon involved. He defended his PhD thesis, “Ultrasonic Measurements of Fetal Breathing Movements in Man”, at Lund University in 1977. With the introduction of Doppler ultrasonography to measure blood flow velocity, an era of prolific research commenced, leading to a growing international collaboration under Karel's leadership. In a series of PhD theses, normal fetal circulation was mapped to form the basis for the clinical assessment of the compromised fetus, and for studying the effects of medications and smoking during pregnancy. Experimental work on fetal lambs added further insights into circulatory pathophysiology. The introduction of routine ultrasound in Malmö in 1972 paved the way for identifying and studying fetal growth restriction and its underlying circulatory changes, today a major clinical field. Karel was the Head of the Perinatal Division at the University Hospital in Malmö and his personality as an enthusiastic, persevering, and meticulous scientist earned him a professorship in Malmö in 1991. In 1997, Karel moved to Lund to become Professor in Obstetrics and Gynecology, and later head of the clinical department. In 1995, he became Honorary Professor at Charles University in Prague, Czech Republic. He also served as Director of the undergraduate program of the Medical School at Lund University and as Chief Medical Officer in the county of Skåne, Sweden. Karel was the main tutor of 21 PhD students and co-tutor of another 14 research students. He published 354 original papers, 132 book chapters and reviews, and 14 textbooks. He was editor or co-editor of the Journal of Maternal and Fetal Investigation, of Fetal and Maternal Medicine Review, and of Seminars in Fetal and Neonatal Medicine, and was a member of the editorial board of 10 international scientific journals. His primary areas of experience and research were in perinatology, obstetrics, fetal monitoring, obstetric and gynecologic ultrasound, Doppler ultrasound, fetal physiology, ultrasound safety, and obstetric quality assurance. Throughout the years, Karel's research was supported by numerous grants, among them from the prestigious Swedish Research Council. He was the principal investigator in numerous national and international multicenter studies, such as the EXPRESS study on extremely preterm infants in Sweden, and he was national coordinator for Sweden in three EU studies. Karel served as president of the International Society of Ultrasound in Obstetrics and Gynecology, he was an honorary member of various national and international institutions and a board member of European Federation of Societies for Ultrasound in Medicine and Biology, World Federation for Ultrasound in Medicine and Biology, and other societies. In the past, he was the main organizer of 15 international scientific congresses, including two world congresses on ultrasound in obstetrics and gynecology. He received several prestigious awards, such as the Ian Donald Gold Medal and the Haackert Gold Medal in Prenatal Medicine. Karel was elected Doctor Honoris Causae at universities in Olomouc, Czech Republic, and Poznan, Poland. He was course leader of 38 national and international postgraduate courses in perinatal medicine, obstetrics, ultrasound, and obstetric Doppler ultrasound. His last participation in such an event was in February 2023. Karel's wife, Lida, gave him unending support throughout his career. Had Karel not injured his leg in a skiing accident, their paths may never have crossed. He had to take a break from medical school, and when he returned to his studies, he and Lida became classmates. Innumerable mothers and children all over the globe have benefited from Karel's ground-breaking scientific work, leadership, and deeds. His 50-year career as a clinician, scientist, teacher, coach, role model, and—most of all—the best friend of the unborn baby is now at an end. Among his friends and co-workers, he will be vividly remembered as a quietly jovial, sharp-witted gentleman with a human perspective and a friendly attitude toward each of us. He is sorely missed.

OBJECTIVES:To investigate the correlation between prenatal ultrasound (US) and autopsy findings in pregnancies terminated due to isolated congenital heart defects (CHDs), including CHDs associated with heterotaxy syndrome. MATERIALS AND METHODS:The material consists of 67 fetuses with prenatally detected isolated CHDs or CHDs associated with heterotaxy syndrome at a tertiary center in Norway between 1985 and 2014. The main CHDs were categorized into subdiagnoses of CHDs in accordance with ICD-10. The US and autopsy findings were categorized according to degree of concordance. RESULTS:Gestational age at termination was 12 + 0-22 + 6 weeks. Hypoplastic left heart syndrome was the most common main diagnosis among the 67 fetuses (32.8%). There was full agreement between US and autopsy findings in 97.4% (222/228) of all subdiagnoses. The discrepant findings in three fetuses had no influence on the decision to terminate the pregnancy. CONCLUSIONS:The correlation was high between prenatal US and postmortem findings in fetuses with isolated CHDs. Meticulous assessment of cardiac anatomy is particularly necessary when the decision to terminate relies on isolated CHDs. The trend of earlier termination challenges verification of diagnoses at autopsy. Consequently, the fetus should be examined at a tertiary center with fetal medicine specialists, pediatric cardiologists and perinatal pathologists.

Following the completion of his medical studies in 1959 in his home city of Oslo, Kåre Molne was immediately introduced to research and, in 1970, completed his doctoral thesis on histometric studies of the adrenal cortex in various conditions of the adrenal cortex of mice. In 1972, he and his colleague Narve Moe received Michael Skjelderup’s Gold Medal Award from the University of Oslo for their work on estrogen excretion in connection with threatened fetal death. He authored approximately 70 papers in international journals and coauthored widely used Norwegian textbooks in obstetrics and gynecology. In 1973, he became consultant at the Department of Obstetrics and Gynecology at Rikshospitalet (National Hospital), Oslo, where his main responsibility was infertility treatment. He served as head and professor at the Department of Obstetrics and Gynecology at the University of Tromsø from 1979 to 1980. From there he went on to become head and professor at the Department of Obstetrics and Gynecology at the Norwegian University of Science and Technology (NTNU) in Trondheim (then University of Trondheim) until his retirement in 2000. During his 19 years in Trondheim, Kåre Molne took active part not only in the development of the Department of Obstetrics and Gynecology, but also in the development of the Faculty of Medicine, which became an internationally recognized institution within the expanding University of Science and Technology. Kåre Molne was a leader and visionary who clearly saw the direction and means needed to advance the various disciplines in the field of medicine. He recognized the importance of developing new knowledge through contact with colleagues from various professional backgrounds, such as engineers and technicians, and provided an environment for interdisciplinary collaboration. He personally recruited needed personnel, and then strongly supported them in their work to build a modern department that focused on women and their special needs for care and treatment. One of his key interests was infertility. The result of his establishing a competent, multi-professional team was the birth of the first Norwegian baby conceived through in vitro fertilization in Trondheim in 1984 and, in 1988, the birth of the first baby in the Nordic countries after cryopreservation of embryos. Molne was early in recognizing the potential of ultrasound in improving women’s and children’s health. Collaboration with the already internationally recognized advanced ultrasound environment at NTNU paved the way toward establishing the National Center for Fetal Medicine in Trondheim in 1990. He also saw the need to regionalize cancer treatment and established a section for gynecologic oncology. He supported the development of a laboratory for urodynamics and took great interest in establishing a unit to receive and help sexually abused women. Kåre Molne focused on building a strong academic environment in his department; during his time, a total of 14 doctoral theses were successfully completed. He combined his vision and his political network to encourage and support the success of his colleagues. Kåre Molne’s remarkable organizational and administrative abilities were soon recognized by the university in Trondheim. He became vice dean of the Medical Faculty and served in that capacity from 1984 to 1987, then served as dean from 1987 to 1993. He was a strong supporter of establishing a much-needed fourth school of medicine in Norway that provided a complete education for medical students in Trondheim. His influence in the decision to establish a new model for medical education in Trondheim ensured that students had clinical contact with patients already in their first semester. The syllabus introduced at the Faculty of Medicine at NTNU in 1993 was based on problem-based learning. The Trondheim syllabus, an integrated studies model, focused on environmental medicine, behavioral science, and practical skills, and provided a foundation for work in scientific research. The syllabus has also served as a model for other institutions. For his achievements, Professor Kåre Molne was appointed Knight 1st Class of the Royal Order of St. Olav in 1995. Kåre Molne will be remembered as an inspiring friend and colleague whose engagement led to important progress in women’s health, medical education, and research.

We compared the effect of two different doses of sucrose on neonatal pain scores during venepuncture. This randomised crossover study focused on neonates born weighing more than 1000 g from December 2014 to June 2016, who received neonatal intensive care at two hospitals: one in Empangeni, South Africa, and one in Trondheim, Norway. During two consecutive venepuncture procedures, 27 neonates from South Africa and 26 neonates from Norway were randomised to receive 0.2 mL or 0.5 mL sucrose. Half was administered two minutes before venepuncture and the rest immediately before the procedure. South Africa used 25% sucrose and Norway 24%. Pain scores were measured twice using the Premature Infant Pain Profile-Revised: during skin puncture and after the needle was removed. The mean pain scores during skin puncture were significantly lower with 0.5 mL sucrose than with 0.2 mL (5.3 versus 6.8, p=0.008), but the mean pain scores after the needle was removed were similar with both doses (4.7 versus 5.4, p=0.29). We found no significant association between weight and pain scores. We showed that neonates received better pain relief from 0.5 mL than 0.2 mL sucrose during venepuncture but not after the needle was removed.

Aim We compared the effect of two different doses of sucrose on neonatal pain scores during venepuncture. Methods Results This randomised crossover study focused on neonates born weighing more than 1000 g from December 2014 to June 2016, who received neonatal intensive care at two hospitals: one in Empangeni, South Africa, and one in Trondheim, Norway. During two consecutive venepuncture procedures, 27 neonates from South Africa and 26 neonates from Norway were randomised to receive 0.2 mL or 0.5 mL sucrose. Half was administered two minutes before venepuncture and the rest immediately before the procedure. South Africa used 25% sucrose and Norway 24%. Pain scores were measured twice using the Premature Infant Pain Profile-Revised: during skin puncture and after the needle was removed. The mean pain scores during skin puncture were significantly lower with 0.5 mL sucrose than with 0.2 mL (5.3 versus 6.8, p=0.008), but the mean pain scores after the needle was removed were similar with both doses (4.7 versus 5.4, p=0.29). We found no significant association between weight and pain scores. Conclusion We showed that neonates received better pain relief from 0.5 mL than 0.2 mL sucrose during venepuncture but not after the needle was removed.

Interleaved acquisitions used in conventional triplex mode result in a tradeoff between the frame rate and the quality of velocity estimates. On the other hand, workflow becomes inefficient when the user has to switch between different modes, and measurement variability is increased. This paper investigates the use of power spectral Capon estimator in quantitative Doppler analysis using data acquired with conventional color flow imaging (CFI) schemes. To preserve the number of samples used for velocity estimation, only spatial averaging was utilized, and clutter rejection was performed after spectral estimation. The resulting velocity spectra were evaluated in terms of spectral width using a recently proposed spectral envelope estimator. The spectral envelopes were also used for Doppler index calculations using in vivo and string phantom acquisitions. In vivo results demonstrated that the Capon estimator can provide spectral estimates with sufficient quality for quantitative analysis using packet-based CFI acquisitions. The calculated Doppler indices were similar to the values calculated using spectrograms estimated on a commercial ultrasound scanner.

The aim of the study was to investigate the accuracy of estimating fetal weight with ultrasound in pregnancies past term, using the eSnurra algorithm. In all, 419 women with pregnancy length of 290 days, attending a specialist consultation at Stavanger University Hospital, Norway, were included in a prospective observational study. Fetal weight was estimated using biparietal diameter (BPD) and abdominal circumference (AC). The algorithm implemented in an electronic calculation (eSnurra) was used to compute estimated fetal weight (EFW). Results were compared with birthweight (BW). The mean interval between the ultrasound examination and birth was 2 days (SD 1.4). The median difference between BW and EFW was −6 g (CI −40 to +25 g) and the median percentage error was –0.1% (95% CI −1.0 to 0.6%). The median absolute difference was 190 g (95% CI 170–207 g). The BW was within 10% of EFW in 83% (95% CI 79–87%) of cases and within 15% of EFW in 94% (95% CI 92–96%) of cases. Limits of agreement (95%) were from −553 g to +556 g. Using 5% false-positive rates, the sensitivity in detecting macrosomic and small for gestational age fetuses was 54% (95% CI 35–72%) and 49% (95% CI 35–63%), respectively. The accuracy of fetal weight estimation was good. Clinicians should be aware of limitations related to prediction at the upper and lower end, and the importance of choosing appropriate cut-off levels.

An automatic method able to recognize a presented section through the biparietal plane of the fetal head and a section through the fetal femur in ultrasound images is developed.Once the correct anatomical section for measurement is identified by the machine, the placement of the measurement calipers is automatically determined by fitting an active contour model to the structure of interest.The fetal biparietal diameter (BPD) and femur length (FL) are then measured automatically.The validation data set contained 167 and 197 Bmode images for BPD and FL measurements, respectively.The images were acquired using 4 different ultrasound scanners, which resulted in varied image quality and gain settings.The mean gestational age (GA) of the fetuses was 19.4 weeks, range 16 to 41 weeks.A measurement success rate of 90% was achieved for both BPD and FL.The correlation coefficients between the manual and automatic measurements were 0.995 (BPD) and 0.967 (FL), mean errors were 0.5 mm (BPD) and -1.7 mm (FL) and error range with 95% confidence interval (CI) were -3.8 -4.8 mm (BPD) and -11.4 -8.1 mm (FL).The automatic measurement results were consistent in both high and low gain settings.The intraclass correlation coefficients between manual and automatic measurements were 0.995 (95% CI; 0.981 -0.999) for BPD in high gain, 1.0 (95% CI; 0.998 -1.0) for BPD in low gain, 0.998 (95% CI; 0.991 -0.999) for FL in high gain and 0.999 (95% CI; 0.996 -1.0) for FL in low gain settings.The method was implemented on a prototype, portable ultrasound machine designed to be used in low-and middle-income countries (LMIC).The overall performance of the method supports our hypothesis that automated methods

An automatic method for measuring the fetal mean abdominal diameter (MAD) or abdominal circumference (AC) with ultrasound is proposed. From a correctly presented abdominal section suitable for MAD or AC measurement, the location of fetal abdomen is detected by image processing. Thereafter, an active contour model is converged along the abdominal boundary for measurement purposes. The validation data set contained 310 images of fetuses with gestational age (GA) from 14 to 41 weeks. The measurement success rate was 88.1%. By manually indicating the location of the abdomen, the success rate was further improved to 95.8% for the failed cases. The correlation between manual and automatic measurements was 0.95 and the intraclass correlation coefficient (ICC) was 0.976 (95% confidence interval (CI); 0.969 - 0.981). The average method execution time was 0.3 s. The mean error was lower in young fetuses (0.4%) than in older fetuses (-2.1%). The proposed cross-platform method was implemented on a portable, low-cost ultrasound machine prototype targeted for low- and middle-income countries (LMIC); the results achieved were comparable to those of other state-of-the-art automatic methods.

Objective To develop a complete, population-based system for ultrasound-based fetal size monitoring and birth-weight prediction for use in the second and third trimesters of pregnancy.Methods Using 31 516 ultrasound examinations from a population-based Norwegian clinical database, we constructed fetal size charts for biparietal diameter, femur length and abdominal circumference from 24 to 42 weeks' gestation. A reference curve of median birth weight for gestational age was estimated using 45 037 birth weights. We determined how individual deviations from the expected ultrasound measures predicted individual percentage deviations from expected birth weight. The predictive quality was assessed by explained variance of birth weight and receiver-operating characteristics curves for prediction of small-for-gestational age. A curve for intrauterine estimated fetal weight was constructed. Charts were smoothed using the gamlss non-linear regression method.Results The population-based approach, using bias-free ultrasound gestational age, produces stable estimates of size-for-age and weight-for-age curves in the range 24-42weeks' gestation. There is a close correspondence between percentage deviations and percentiles of birth weight by gestational age, making it easy to convert between the two. The variance of birth weight that can be 'explained' by ultrasound increases from 8% at 20weeks up to 67% around term. Intrauterine estimated fetal weight is 0-106 g higher than median birth weight in the preterm period.Conclusions The new population-based birth-weight prediction model provides a simple summary measure, the 'percentage birth-weight deviation', to be used for fetal size monitoring throughout the third trimester. Predictive quality of the model can be measured directly from the population data. The model computes both median observed birth weight and intrauterine estimated fetal weight. Copyright (C) 2016 ISUOG. Published by John Wiley & Sons Ltd.

OBJECTIVE:To investigate cardiac function from 14 weeks' gestation in fetuses of obese pregnant women (FOW). Animal studies have shown that maternal obesity induces fibrosis in fetal myocardium. We hypothesized that fetal cardiac function would be impaired among FOW. METHODS:A case-control study with longitudinal follow-up was performed at Trondheim University Hospital, Norway. In total, 80 pregnant women were included and the final population comprised 52 obese and 24 of normal weight (mean body mass index before pregnancy, 34.8 ± 4.1 vs 21.0 ± 2.2 kg/m(2) ; P < 0.001). The main outcome measures were global strain rate (GSR) and strain by tissue Doppler imaging, tissue Doppler velocities (TDVs) and interventricular septal thickness assessed by fetal echocardiography at gestational ages of 14, 20 and 32 weeks. RESULTS:In FOW, fetal left ventricle (LV) and right ventricle (RV) GSR and strain were significantly lower than in fetuses of normal-weight pregnant women: LV GSR was 33.3% lower at 14 weeks, 22.4% lower at 20 weeks and 22.8% lower at 32 weeks of gestation (P < 0.001) with no difference in fetal heart rate. Systolic and late diastolic TDVs for LV were significantly lower from 20 weeks' gestation and remained lower throughout pregnancy. Fetal interventricular septum was 26.6% (P < 0.001) thicker in late pregnancy in FOW compared with normal-weight pregnancies. CONCLUSIONS:At 14 weeks of gestation, we detected fetal myocardial dysfunction with reduced LV and RV GSR and strain in FOW compared with fetuses of women with normal weight. Our finding is alarming considering the high prevalence of obesity and may partly explain the predisposition of offspring to cardiovascular disease later in life.

IntroductionThe aim of the study was to investigate the accuracy of estimating fetal weight with ultrasound in pregnancies past term, using the eSnurra algorithm.Material and methodsIn all, 419 women with pregnancy length of 290 days, attending a specialist consultation at Stavanger University Hospital, Norway, were included in a prospective observational study. Fetal weight was estimated using biparietal diameter (BPD) and abdominal circumference (AC). The algorithm implemented in an electronic calculation (eSnurra) was used to compute estimated fetal weight (EFW). Results were compared with birthweight (BW).ResultsThe mean interval between the ultrasound examination and birth was 2 days (SD 1.4). The median difference between BW and EFW was -6 g (CI -40 to +25 g) and the median percentage error was -0.1% (95% CI -1.0 to 0.6%). The median absolute difference was 190 g (95% CI 170-207 g). The BW was within 10% of EFW in 83% (95% CI 79-87%) of cases and within 15% of EFW in 94% (95% CI 92-96%) of cases. Limits of agreement (95%) were from -553 g to +556 g. Using 5% false-positive rates, the sensitivity in detecting macrosomic and small for gestational age fetuses was 54% (95% CI 35-72%) and 49% (95% CI 35-63%), respectively.ConclusionThe accuracy of fetal weight estimation was good. Clinicians should be aware of limitations related to prediction at the upper and lower end, and the importance of choosing appropriate cut-off levels.

Estimation of accurate maximum velocities and spectral envelope in ultrasound Doppler blood flow spectrograms are both essential for clinical diagnostic purposes. However, obtaining accurate maximum velocity is not straightforward due to intrinsic spectral broadening and variance in the power spectrum estimate. The method proposed in this paper for maximum velocity point detection has been developed by modifying an existing method-signal noise slope intersection, incorporating in it steps from an altered version of another method called geometric method. Adaptive noise estimation from the spectrogram ensures that a smooth spectral envelope is obtained postdetection of these maximum velocity points. The method has been tested on simulated Doppler signal with scatterers possessing a parabolic flow velocity profile constant in time, steady and pulsatile string phantom recordings, as well as in vivo recordings from uterine, umbilical, carotid, and subclavian arteries. The results from simulation experiments indicate a bias of less than 2.5% in maximum velocities when estimated for a range of peak velocities, Doppler angles, and SNR levels. Standard deviation in the envelope is low-less than 2% in the case of experiments done by varying the peak velocity and Doppler angle for steady phantom and simulated flow, and also less than 2% in the case of experiments done by varying SNR but keeping constant flow conditions for in vivo and simulated flow. Low variability in the envelope makes the prospect of using the envelope for automated blood flow measurements possible and is illustrated for the case of pulsatility index estimation in uterine and umbilical arteries.

Objective A prenatal ultrasound examination and a postmortem examination provide the basis for correct diagnosis in fetuses terminated due to congenital anomalies. The aim of this study was to correlate fetal anomalies detected by ultrasound examination with those identified at autopsy following termination of pregnancy (TOP) over a 30-year period, and to evaluate the correlation between findings at different gestational ages and assess these trends over time.Methods The study group consisted of 1029 TOPs performed over a 30-year period, from 1985 to 2014. The gestational age ranged between 11 and 33 weeks. Prenatal ultrasound examinations were performed at the National Center for Fetal Medicine, St Olavs Hospital, Trondheim, Norway. Autopsies were performed at the Department of Pathology and Medical Genetics at the same hospital or a collaborating hospital.Results There was full agreement between ultrasound and autopsy findings in 88.1% (907/1029) of TOPs, and the main diagnosis was correct in 97.9% (1007/1029). When comparing the 15-year period of 2000-2014 with that of 1985-1999, the difference in the rates of full agreement and agreement in the main diagnosis was statistically significant. In 1.3% (13/1029) of cases, ultrasound findings were not confirmed at autopsy. There were no false-positive diagnoses leading to TOP. Throughout the 30-year period, there was an increase in early TOPs, whereas late TOPs declined.Conclusions Our study demonstrates that there is a clear correlation between ultrasound and autopsy findings, which is continuously improving. Despite this high correlation, there is reason to continue the practice of validation to ensure the safety of the diagnostic process leading to TOP. The trend towards an earlier termination emphasizes the necessity of such a practice. Copyright (C) 2015 ISUOG. Published by John Wiley & Sons Ltd.

General pregnancy monitoring with ultrasound includes the measurement of the biparietal diameter (BPD), femur (FL) and the mean abdominal diameter (MAD) of the fetus. This study was aimed to develop an automatic method for localization of the presented section through the abdomen and measurement of MAD. The algorithm may be run on a conventional ultrasound machine or on a tablet-based machine designed to be used in the rural areas of low- and middle-income countries (LMIC). The open source computer vision (OpenCV) library was used to process a B-mode ultrasound image to detect the location of a fetal abdomen. A Kalman based tracker (RCTL, GE Vingmed Ultrasound) was used to converge a deformable circle model along the boundary of the detected abdomen. The mean of the model's major and minor axes was considered as MAD. The method automatically localized the abdomen and measured MAD in 57 of 61 images (93%) collected from 16 - 41-week-old fetuses. The correlation and the error plots between reference and automatic MAD measurements are presented. The correlation coefficient was 0.96, mean error was -0.06 mm and the error range (95% CI) was -14.80 to 14.68 mm. The resulting errors increased with the gestational age (GA) of the fetuses due to inner shadow and lack of edge information. The method was tested to perform well both in a PC and on various mobile devices.

Clutter rejection for color flow imaging (CFI) remains a challenge due to either a limited amount of temporal samples available or nonstationary tissue clutter. This is particularly the case for interleaved CFI and B-mode acquisitions. Low velocity blood signal is attenuated along with the clutter due to the long transition band of the available clutter filters, causing regions of biased mean velocity estimates or signal dropouts. This paper investigates how adaptive spectral estimation methods, Capon and blood iterative adaptive approach (BIAA), can be used to estimate the mean velocity in CFI without prior clutter filtering. The approach is based on confining the clutter signal in a narrow spectral region around the zero Doppler frequency while keeping the spectral side lobes below the blood signal level, allowing for the clutter signal to be removed by thresholding in the frequency domain. The proposed methods are evaluated using computer simulations, flow phantom experiments, and in vivo recordings from the common carotid and jugular vein of healthy volunteers. Capon and BIAA methods could estimate low blood velocities, which are normally attenuated by polynomial regression filters, and may potentially give better estimation of mean velocities for CFI at a higher computational cost. The Capon method decreased the bias by 81% in the transition band of the used polynomial regression filter for small packet size ( N=8 ) and low SNR (5 dB). Flow phantom and in vivo results demonstrate that the Capon method can provide color flow images and flow profiles with lower variance and bias especially in the regions close to the artery walls.

During the last decade, portable ultrasound devices have been proven beneficial in a variety of situations (e.g. OB/GYN, point of care and cardiovascular applications). The aim of this work is to investigate the feasibility of implementing standard signal and image processing algorithms on a tablet device, instead of the scanner's backend unit. Furthermore, the additional benefit of using the tablet's graphical processing unit to offload the CPU intensive tasks and balance the battery consumption was tested.A plugin for streaming data over a wired or wireless TCP/IP connection from an ultrasound scanner was implemented and data sent to a tablet device which runs the image and signal processing algorithms. The use of compute shaders for further optimizations was investigated. The prototype was tested by midwives, both experienced and inexperienced in the use of ultrasound, in Norway and South Africa. Afterwards they were asked to fill out standard system usability scale forms.Conclusively, most of the backend components of an ultrasound scanner can be implemented on a tablet's GPU. Compute shaders have a significant impact on battery consumption, which can be reduced by a factor of up to 3 and as such significantly extend the scanning time of a portable system.