Dynamic Facial Prosthetics for Sufferers of Facial Paralysis

BackgroundThis paper discusses the various methods and the materialsfor the fabrication of active artificial facial muscles. Theprimary use for these will be the reanimation of paralysedor atrophied muscles in sufferers of non-recoverableunilateral facial paralysis.MethodThe prosthetic solution described in this paper is based onsensing muscle motion of the contralateral healthy musclesand replicating that motion across a patient’s paralysed sideof the face, via solid state and thin film actuators. Thedevelopment of this facial prosthetic device focused onrecreating a varying intensity smile, with emphasis ontiming, displacement and the appearance of the wrinklesand folds that commonly appear around the nose and eyesduring the expression.An animatronic face was constructed with actuations beingmade to a silicone representation musculature, usingmultiple shape-memory alloy cascades. Alongside theartificial muscle physical prototype, a facial expressionrecognition software system was constructed. This formsthe basis of an automated calibration and reconfigurationsystem for the artificial muscles following implantation, soas to suit the implantee’s unique physiognomy.ResultsAn animatronic model face with silicone musculature wasdesigned and built to evaluate the performance of ShapeMemory Alloy artificial muscles, their power controlcircuitry and software control systems. A dual facial motionsensing system was designed to allow real time control overmodel – a piezoresistive flex sensor to measure physicalmotion, and a computer vision system to evaluate real toartificial muscle performance.Analysis of various facial expressions in real subjects wasmade, which give useful data upon which to base thesystems parameter limits.ConclusionThe system performed well, and the various strengths andshortcomings of the materials and methods are reviewedand considered for the next research phase, when newpolymer based artificial muscles are constructed andevaluated.Key WordsArtificial Muscles, facial prosthetics, stroke rehabilitation,facial paralysis, computer vision, automated facialrecognition

Shape Memory Alloys in Facial Nerve Paralysis

BackgroundThe Facial Nerve can be damaged at a peripheral level by a stroke or, for example by trauma or infection within the face or the ear. In these cases the facial muscles are paralysed with little or no chance of spontaneous recovery. This research focuses on the potential utilisation of a Shape Memory Alloy (SMA) to replace the function of the Facial Nerve, which will allow in conjunction with passive reconstructive methods, a patient to regain limited but active movement of the mouth corner. Paralysis of the mouth corner is a very disabling both functionally and cosmetically, speech and swallowing are hampered and the patient loses saliva, with presents a social problem.  MethodsThis work addresses the design activity by implementing a methodology utilising integrated methods for achieving successful product engineering. Research and development is related to the investigation of the utilisation of an SMA to supplement the “passive” technique. Operational design and development work has already been undertaken in relation to a SMA being controlled by a dedicated electronic control interface and power supply. The interface measures the active potential of the healthy Zygomatic muscle by means of electromyography (EMG) and produces a signal to control the actuation of the SMA. The research centres on the entire device ultimately being implantable, similar to a pacemaker or deep brain stimulator. Results To identify the key parameters of the EMG sensing device the system testing strategy needed to ascertain the output signal from the device for a range of facial movements. Data was collected relating to five different ‘levels’ of smile with a sampling period of 30 seconds for each ‘level’.  Experimental work confirmed that there is definite viability for the precise control of an SMA system based on EMG data. The next stage            of development will address the issue of a ‘tuneable’ dedicated controller for this specific SMA control application and will also examine the potential integration and control of Electroactive Polymers (EAP’s).  Conclusions The first stages in assessing both the strengths and limitations of SMA’s towards resolving biomechanical problems and relieving disability have been undertaken. Experimental work to date has confirmed there is definite viability for the precise control of an SMA system based on EMG data. A considerable amount of research and developmental work has still to be undertaken before the system can be considered effective for precise control. The research and experimental work undertaken to date provides a firm foundation for the further development of the EMG/SMA control system for an animatronic head and, in addition will potentially provide proof of principle for effective and real time EMG/SMA or EMG/EAP control

Performance analysis for difficult airway equipment: Standardising for success

Airway management and intubation procedures continue to challenge anaesthetists. This design insight paper discusses the design development of an innovative tip pressure and shape retention testing system

Development of a Novel Steerable Bougie

BackgroundThis paper describes the development of a new airway access device that will improve the speed and safety associated with bougie assisted endotracheal intubation in anaesthesia and critical care. Case of need, design specification and fabrication of the steerable bougie mechanism is discussed.AimsIdentify the need for a novel Steerable Bougie whilst considering technology readiness levels associated with medical device design. Analyse and produce suitable mechanisms, utilising smart materials to increase device functionality ensuring successful patient intubation procedures.MethodsThis work describes the total design activity that contributes to the successful design and manufacture of medical devices through research and development, from case of need research to smart material actuation mechanisms. Research focuses on identifying a suitable control mechanism to allow a steerable tip to be integrated into a bougie with a control device attached to the laryngoscope.ResultsData collected from a user group survey supported the development of a novel bougie, with better shape retention, variable rigidity within the tip, and an integrated steerable function. Analysis of several mechanisms, artificial muscles and smart materials identified a cost effective steerable mechanism that can be incorporated into a steerable bougie.ConclusionUsers have defined a need for a new steerable bougie for endotracheal intubation. Controlling smart materials and mechanisms within the predefined dimensions identified strengths and weaknesses associated with steerable functions. The performance of the selected mechanism for incorporation in the steerable bougie requires a high level of control to accurately steer a device within the human airway

Performance Analysis System For Endotracheal Tube Introducers: Standardising For Success

Including healthcare professionals in the design of medical devices/testing systems can have a significant impact on their success or failure

Efficiency of nanoparticle reinforcement using finite element analysis of titanium alloy mandible plate

Nanoparticles in the form nanotubes and nanoplatelets have been compared for von Mises stresses by using them as low-composition reinforcements in titanium alloy–based mandible plate for different compositions and orientations. A finite element model has been designed to reconstruct a fractured human mandible with a titanium alloy mandible plate. A 500 N compressive force was applied on the mandible, and stress distribution across the plate sections was analysed for aligned two-dimensional random and three-dimensional random orientations for both tubes and platelets. Carbon material as graphene has been used for tube and platelet in the form of nanotubes and nanoplatelets, respectively. Using properties of graphene as the filler in titanium alloy plate, for both nanoplatelets and nanotubes, the stresses reduced between 5% and 25% for nanoplatelets and nanotubes graphene–titanium composite plates in comparison to non-reinforced plates, at critically stressed sections. Nanotubes exhibited stress reduction of nearly 23.4% for aligned configurations, while nanoplatelets exhibited stress reduction up to 21.2% for two-dimensional and three-dinemsional random configurations in comparison to non-reinforced titanium plates. Hence, it has been suggested that nanotubes exhibited superior mechanical reinforcement potential beyond that of aligned nanoplatelets, while nanoplatelets provided enhanced mechanical reinforcements for random configurations. Therefore, for biomedical implant applications nanocomposite materials can be designed with the same dimensional form but with lower compositions of filler materials by simply manipulating the appropriate orientations

Relations Between Timing Features and Colors in the X-Ray Binary 4U 0614+09

We study the correlations between timing and X-ray spectral properties in the low mass X-ray binary 4U 0614+09 using a large (265-ks) data set obtained with the Rossi X-ray Timing Explorer. We find strong quasi-periodic oscillations (QPOs) of the X-ray flux, like the kilohertz QPOs in many other X-ray binaries with accreting neutron stars, with frequencies ranging from 1329 Hz down to 418 Hz and, perhaps, as low as 153 Hz. We report the highest frequency QPO yet from any low mass X-ray binary at 1329+-4 Hz, which has implications for neutron star structure. This QPO has a 3.5-sigma single-trial significance, for an estimated 40 trials the significance is 2.4-sigma. Besides the kilohertz QPOs, the Fourier power spectra show four additional components: high frequency noise (HFN), described by a broken power-law with a break frequency between 0.7 and 45 Hz, very low frequency noise (VLFN), which is fitted as a power-law below 1 Hz, and two broad Lorentzians with centroid frequencies varying from 6 to 38 Hz and 97 to 158 Hz, respectively. We find strong correlations between the frequencies of the kilohertz QPOs, the frequency of the 6 to 38 Hz broad Lorentzian, the break frequency of the HFN, the strength of both the HFN and the VLFN and the position of the source in the hard X-ray color vs. intensity diagram. The frequency of the 97 to 158 Hz Lorentzian does not correlate with these parameters. We also find that the relation between power density and break frequency of the HFN is similar to that established for black hole candidates in the low state. We suggest that the changing mass accretion rate is responsible for the correlated changes in all these parameters.Comment: ApJ, referee

Menstrual blood-derived mesenchymal stem cells: women's attitudes, willingness, and barriers to donation of menstrual blood

Background: Menstrual blood contains mesenchymal stem cells (MenSC), considered a potential “off-the-shelf” treatment for a range of diseases and medical conditions. Samples of menstrual blood can be collected painlessly, inexpensively, and as frequently as every month for cell therapy. While there has been considerable previous research into the clinical advantages of MenSC, there is currently little understanding of potential donors' attitudes regarding menstrual blood donation and MenSC. Methods: One hundred women 18 years of age or over were surveyed to understand attitudes and potential barriers to menstrual blood donation. The questionnaire assessed participant age and brief medical history (giving birth, donating blood, donating stem cells), menstrual experience (period rating, preferred menstrual hygiene products), and whether participants would donate MenSC or accept MenSC therapy. Results: MenSC was met with a generally positive response, with 78% of menstruating women willing to donate menstrual blood. No significant relationship was recognized between willingness to donate menstrual blood with age, history of childbirth or blood donation, menstruation perception, and preferred menstrual hygiene product. Women rated their period experience better after being made aware of the ability to donate menstrual blood, meaning MenSC therapy can be beneficial for donors as well as patients. Conclusions: Considering women's attitudes to MenSC and donation of menstrual blood, the future of MenSC therapy is positive; women are generally willing to donate menstrual blood, independent of age, perception of periods, and history of childbirth and blood donation

Utilising the Intel RealSense camera for measuring health outcomes in clinical research

Applications utilising 3D Camera technologies for the measurement of health outcomes in the health and wellness sector continues to expand. The Intel® RealSense™ is one of the leading 3D depth sensing cameras currently available on the market and aligns itself for use in many applications, including robotics, automation, and medical systems. One of the most prominent areas is the production of interactive solutions for rehabilitation which includes gait analysis and facial tracking. Advancements in depth camera technology has resulted in a noticeable increase in the integration of these technologies into portable platforms, suggesting significant future potential for pervasive in-clinic and field based health assessment solutions. This paper reviews the Intel RealSense technology’s technical capabilities and discusses its application to clinical research and includes examples where the Intel RealSense camera range has been used for the measurement of health outcomes. This review supports the use of the technology to develop robust, objective movement and mobility-based endpoints to enable accurate tracking of the effects of treatment interventions in clinical trials

Patient-maintained versus anaesthetist-controlled propofol sedation during elective primary lower limb arthroplasty performed under spinal anaesthesia: a randomised controlled trial

Background: Patient-maintained propofol sedation (PMPS) allows patients to titrate their own target-controlled infusion (TCI) delivery of propofol sedation using a handheld button. The aim of this randomised controlled trial was to compare PMPS with anaesthetist-controlled propofol TCI sedation (ACPS) in patients undergoing elective primary lower limb arthroplasty surgery under spinal anaesthesia. Methods: In this single-centre, open-label, investigator-led study, adult patients were randomly assigned to either PMPS or ACPS during their surgery. Both sedation regimes used Schnider effect-site TCI modelling. The primary outcome measure was infusion rate adjusted for weight (expressed as mg kg-1 hr-1). Secondary outcomes measures included depth of sedation, occurrence of sedation-related adverse events and time to medical readiness for discharge from the post-anaesthesia care unit (PACU). Results: Eighty patients (48 females) were randomised. Patients using PMPS used 39.3% less propofol during the sedation period compared to patients in group ACPS (1.56 (0.57) vs 2.56 (1.33) mg kg-1 hr-1; p < 0.001), experienced fewer discrete episodes of deep sedation (0 vs 6, p = 0.0256), fewer airway/breathing adverse events (odds ratio (95% CI) 2.94 (1.31 –6.64); p = 0.009) and were ready for discharge from PACU more quickly (8.94 (5.5) vs 13.51 (7.2) minutes; p = 0.0027). Conclusion: PMPS during lower limb arthroplasty under spinal anaesthesia results in reduced drug exposure and fewer episodes of sedation related adverse events compared to ACPS. To facilitate further investigation of this procedural sedation technique, PMPS-capable TCI infusion devices should be submitted for regulatory approval for clinical use