| 11. |
- Jacobsson, Bo, 1960, et al.
(författare)
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Preterm delivery: an overview on epidemiology, pathophysiology and consequences for the individual and the society : Förtidsbörd största perinatala problemet - 5,7 procent av graviditeter i Sverige slutar för tidigt, inte klarlagt varför – kostar miljardbelopp varje år.
- 2019
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Ingår i: Läkartidningen. - 1652-7518. ; 116
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Tidskriftsartikel (refereegranskat)abstract
- Preterm delivery in Sweden constitutes 5.7 % of all deliveries, which is among the lowest rates in the world. There has not been any increase in the proportion of iatrogenic preterm deliveries during the last decades.The main hypothesis concerning the causality of preterm delivery is still that of the ascending infection from the vagina to the uterus and inflammation resulting in contractions, rupture of membranes and delivery. The mechanisms behind parturition at term are still elusive and this is also true for preterm delivery. The genetic contribution to preterm delivery is about 25-30 %. The first genes that are associated with preterm delivery and gestational duration have recently been published. Huge progress has been made in care of preterm born infants. Sweden has among the lowest rates of mortality and morbidity in the world, especially in the lowest gestational weeks. New modes of care, family-centered care and hospital-assisted home care, have empowered the parents and reduced the cost for care.
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| 12. |
- Mastinu, Enzo, 1987, et al.
(författare)
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Digital Controller for Artificial Limbs fed by Implanted Neuromuscular Interfaces via Osseointegration
- 2016
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Ingår i: Trent International Prosthetic Symposium 2016.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Although the development of bioelectrically controlled upper limb prosthesis started in the 1970’s, the majority of amputees do not use this technology due to its poor functionality, reliability and comfort. This study is based on the previous work conducted by Ortiz-Catalan, Håkansson, and Brånemark, who developed a permanent bidirectional interface into the human body, namely the Osseointegrated Human-Machine Gateway (OHMG).The aim of this study was to develop an Artificial Limb Controller (ALC) that decodes motor volition and provides sensory feedback using the OHMG.
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| 13. |
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| 14. |
- Clemente, Francesco, et al.
(författare)
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Touch and Hearing Mediate Osseoperception
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Osseoperception is the sensation arising from the mechanical stimulation of a bone-anchored prosthesis. Here we show that not only touch, but also hearing is involved in this phenomenon. Using mechanical vibrations ranging from 0.1 to 6 kHz, we performed four psychophysical measures (perception threshold, sensation discrimination, frequency discrimination and reaction time) on 12 upper and lower limb amputees and found that subjects: consistently reported perceiving a sound when the stimulus was delivered at frequencies equal to or above 400 Hz; were able to discriminate frequency differences between stimuli delivered at high stimulation frequencies (similar to 1500 Hz); improved their reaction time for bimodal stimuli (i.e. when both vibration and sound were perceived). Our results demonstrate that osseoperception is a multisensory perception, which can explain the improved environment perception of bone-anchored prosthesis users. This phenomenon might be exploited in novel prosthetic devices to enhance their control, thus ultimately improving the amputees' quality of life.
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| 15. |
- Fredén Jansson, Karl-Johan, 1988, et al.
(författare)
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Electro-acoustic performance of the new bone vibrator Radioear B81: A comparison with the conventional Radioear B71
- 2015
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Ingår i: International Journal of Audiology. - : Informa UK Limited. - 1499-2027 .- 1708-8186. ; 54:5, s. 334-340
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The objective is to evaluate the electro-acoustic performance of a new audiometric bone vibrator, the B81 from Radioear Corporation, USA. Comparison will be made with the widely used B71 which has well-known limitations at low frequencies. Design: The B81 is based on the balanced electromagnetic separation transducer (BEST) principle where static forces are counterbalanced so that nonlinear distortion forces are reduced and maximum hearing levels can be increased. Study sample: Maximum hearing level, total harmonic distortion (THD), frequency response, and electrical impedance were measured for six devices of each bone vibrator type on an artificial mastoid. Results: It was found that B81 reaches 10.7-22.0 dB higher maximum (@ THD. 6% or V-in. 6 V-RMS) hearing levels than B71 for frequencies below 1500 Hz, and had significantly lower THD up to 1000 Hz. There was no statistically significant difference between their frequency response, except a deviation at the mid frequencies (alpha = 0.01) where B81 was more efficient and the electrical impedances were practically the same. Conclusions: In general, B81 had an improved electro-acoustic performance compared to B71 and is compatible with same audiometers. In particular, B81 allows for sensorineural hearing loss to be measured at considerably higher hearing levels than with B71 below 1500 Hz.
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| 16. |
- Fredén Jansson, Karl-Johan, 1988, et al.
(författare)
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Magnetic resonance imaging investigation of the bone conduction implant - a pilot study at 1.5 Tesla.
- 2015
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Ingår i: Medical devices (Auckland, N.Z.). - 1179-1470. ; 8, s. 413-23
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this pilot study was to investigate if an active bone conduction implant (BCI) used in an ongoing clinical study withstands magnetic resonance imaging (MRI) of 1.5 Tesla. In particular, the MRI effects on maximum power output (MPO), total harmonic distortion (THD), and demagnetization were investigated. Implant activation and image artifacts were also evaluated.
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| 17. |
- Fredén Jansson, Karl-Johan, 1988, et al.
(författare)
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Robustness and lifetime of the bone conduction implant - a pilot study
- 2019
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Ingår i: Medical Devices: Evidence and Research. - 1179-1470. ; 12, s. 89-100
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The objective of this study was to develop methods for evaluating the mechanical robustness and estimating the lifetime of the novel bone conduction implant (BCI) that is used in a clinical study. The methods are intended to be applicable to any similar device. Materials and methods: The robustness was evaluated using tests originally developed for cochlear implants comprising a random vibration test, a shock test, a pendulum test, and an impact test. Furthermore, magnetically induced torque and demagnetization during magnetic resonance imaging at 1.5 T were investigated using a dipole electromagnet. To estimate the lifetime of the implant, a long-term age-accelerated test was performed. Results: Out of all the tests, the pendulum and the impact tests had the largest effect on the electro-acoustic performance of the BCI implant, even if the change in performance was within acceptable limits (< 20%). In comparison with baseline data, the lower and higher resonance peaks shifted down in frequency by 13% and 18%, respectively, and with a loss in magnitude of 1.1 and 2.0 dB, respectively, in these tests. Conclusion: A complete series of tests were developed, and the BCI passed all the tests; its lifetime was estimated to be at least 26 years for patients who are using the implant for 12 hours on a daily basis.
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| 18. |
- Fredén Jansson, Karl-Johan, 1988, et al.
(författare)
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Vibrotactile Thresholds on the Mastoid and Forehead Position of Deaf Patients Using Radioear B71 and B81
- 2017
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Ingår i: Ear and Hearing. - 1538-4667 .- 0196-0202. ; 38:6, s. 714-723
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The main objective of this study was to measure the vibrotactile thresholds on the mastoid process and forehead positions using patients with bilateral deafness and to compare the results from the two bone conduction vibrators Radioear B71 and B81. Design: There is a possibility that the vibrotactile sensation on the skin makes it difficult to discriminate between sound and vibration. The risk is highest for patients who have bone conduction hearing thresholds in proximity to or worse than their vibrotactile thresholds. All measurements were performed similar to regular bone conduction threshold testing using an audiometer-driven bone conduction vibrator and pulsed warble tones, but the patients were instructed to respond only when feeling vibrations of the bone conduction vibrator instead of when hearing sound. Both the posterior forehead position and the mastoid process position on the temporal bone were tested for comparative reasons. In total, 16 patients participated in the study, 31% females and 69% males of age 29 to 77 years. All subjects were cochlear implant recipients, either uni-or bilaterally implanted. They were selected based on their audiogram data showing unmeasurable unaided hearing. Results: The force level at which the vibrotactile thresholds were reached, increased with frequency from 125 up to 500 Hz, but remained constant for higher frequencies up to 2 kHz. A statistically significant difference was found between the 2 devices at 125 Hz at both the mastoid process and forehead position, where the vibrotactile threshold seem to be more sensitive for B71, possibly due to contribution of distortion components. There was no statistically significant difference in vibrotactile thresholds between the mastoid process and forehead position in absolute values (force level in dB re 1 mu N), but in terms of hearing levels (dB HL) there was an average difference of 10 and 9 dB for B71 and B81, respectively. Conclusions: The results indicate that the vibrotactile thresholds can be confounded with bone conduction hearing thresholds measurements up to 500 Hz when using a standard audiometer and in particular when measuring on the forehead position.
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| 19. |
- Lendaro, Eva, 1989, et al.
(författare)
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Real-time classification of non-weight bearing lower-limb movements using EMG to facilitate phantom motor execution: Engineering and case study application on phantom limb pain
- 2017
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Ingår i: Frontiers in Neurology. - : Frontiers Media SA. - 1664-2295. ; 8:SEP, s. Article number 470-
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Tidskriftsartikel (refereegranskat)abstract
- Phantom motor execution (PME), facilitated by myoelectric pattern recognition (MPR) and virtual reality (VR), is positioned to be a viable option to treat phantom limb pain (PLP). A recent clinical trial using PME on upper-limb amputees with chronic intractable PLP yielded promising results. However, further work in the area of signal acquisition is needed if such technology is to be used on subjects with lower-limb amputation. We propose two alternative electrode configurations to conventional, bipolar, targeted recordings for acquiring surface electromyography. We evaluated their performance in a real-time MPR task for non-weight-bearing, lower-limb movements. We found that monopolar recordings using a circumferential electrode of conductive fabric, performed similarly to classical bipolar recordings, but were easier to use in a clinical setting. In addition, we present the first case study of a lower-limb amputee with chronic, intractable PLP treated with PME. The patient's Pain Rating Index dropped by 22 points (from 32 to 10, 68%) after 23 PME sessions. These results represent a methodological advancement and a positive proof-of-concept of PME in lower limbs. Further work remains to be conducted for a high-evidence level clinical validation of PME as a treatment of PLP in lower-limb amputees.
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| 20. |
- Mastinu, Enzo, 1987, et al.
(författare)
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An Alternative Myoelectric Pattern Recognition Approach for the Control of Hand Prostheses : A Case Study of Use in Daily Life by a Dysmelia Subject
- 2018
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Ingår i: IEEE Journal of Translational Engineering in Health and Medicine. - : Institute of Electrical and Electronics Engineers (IEEE). - 2168-2372. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- The functionality of upper limb prostheses can be improved by intuitive control strategies that use bioelectric signals measured at the stump level. One such strategy is the decoding of motor volition via myoelectric pattern recognition (MPR), which has shown promising results in controlled environments and more recently in clinical practice. Moreover, not much has been reported about daily life implementation and real-time accuracy of these decoding algorithms. This paper introduces an alternative approach in which MPR allows intuitive control of four different grips and open/close in a multifunctional prosthetic hand. We conducted a clinical proof-of-concept in activities of daily life by constructing a self-contained, MPR-controlled, transradial prosthetic system provided with a novel user interface meant to log errors during real-time operation. The system was used for five days by a unilateral dysmelia subject whose hand had never developed, and who nevertheless learned to generate patterns of myoelectric activity, reported as intuitive, for multi-functional prosthetic control. The subject was instructed to manually log errors when they occurred via the user interface mounted on the prosthesis. This allowed the collection of information about prosthesis usage and real-time classification accuracy. The assessment of capacity for myoelectric control test was used to compare the proposed approach to the conventional prosthetic control approach, direct control. Regarding the MPR approach, the subject reported a more intuitive control when selecting the different grips, but also a higher uncertainty during proportional continuous movements. This paper represents an alternative to the conventional use of MPR, and this alternative may be particularly suitable for a certain type of amputee patients. Moreover, it represents a further validation of MPR with dysmelia cases.
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