Three-dimensional reflector localisation and room geometry estimation using a spherical microphone array.

The analysis of room impulse responses to localise reflecting surfaces and estimate room geometry is applicable in numerous aspects of acoustics, including source localisation, acoustic simulation, spatial audio, audio forensics, and room acoustic treatment. Geometry inference is an acoustic analysis problem where information about reflections extracted from impulse responses are used to localise reflective boundaries present in an environment, and thus estimate the geometry of the room. This problem, however, becomes more complex when considering non-convex rooms, as room shape cannot be constrained to a subset of possible convex polygons. This paper presents a geometry inference method for localising reflective boundaries and inferring the room's geometry for convex and non-convex room shapes. The method is tested using simulated room impulse responses for six scenarios, and real-world room impulse responses measured in a cuboid-shaped room, using a spherical microphone array containing multiple spatially distributed channels capable of capturing both time- and direction-of-arrival. Results show that the general shape of the rooms is inferred for each case, with a higher degree of accuracy for convex shaped rooms. However, inaccuracies generally arise as a result of the complexity of the room being inferred, or inaccurate estimation of time- and direction-of-arrival of reflections.

Boundary absorption approximation in the spatial high-frequency extrapolation method for parametric room impulse response synthesis.

The spatial high-frequency extrapolation method extrapolates low-frequency band-limited spatial room impulse responses (SRIRs) to higher frequencies based on a frame-by-frame time/frequency analysis that determines directional reflected components within the SRIR. Such extrapolation can be used to extend finite-difference time domain (FDTD) wave propagation simulations, limited to only relatively low frequencies, to the full audio band. For this bandwidth extrapolation, a boundary absorption weighting function is proposed based on a parametric approximation of the energy decay relief of the SRIR used as the input to the algorithm. Results using examples of both measured and FDTD simulated impulse responses demonstrate that this approach can be applied successfully to a range of acoustic spaces. Objective measures show a close approximation to reverberation time and acceptable early decay time values. Results are verified through accompanying auralizations that demonstrate the plausibility of this approach when compared to the original reference case.

'I feel more part of the world': Participatory action research to develop post-diagnostic dementia support.

Many people living with dementia are 'on the margins', not accessing services and support, despite policy and care advancements. The COVID-19 pandemic exacerbated this, with the closure of face-to-face support during lockdowns in the UK and globally. The aim of the 'Beyond the Margins' project was to develop, implement, and evaluate a face-face programme of support with, by and for people with direct experience of dementia who are on the margins of existing services and support. In March 2020 the project was interrupted by the outbreak of the COVID-19 pandemic and it changed to an online format. The three-phase participatory action research project included 40 people living with dementia, 26 care partners and 31 health and social care practitioners. A seven-week online personal development programme called Getting On with Life (GO) was developed, delivered, and evaluated. This paper focuses on the participatory approaches used to develop and implement the GO programme, and the resulting aspects of its approach to facilitation and content. Key features include the GO Programme's principles of providing a safe and a respectful space, and the programme's values of: Everyone who comes already knows things, can learn things and can teach things; Doing things 'with' each other, rather than 'for' or 'to' each other; Personalised goals-led by the needs of participants rather than an imposed agenda. A key finding was the importance of developing post-diagnostic programmes as a 'sandwich', providing a safe space for learning that is preceded by understanding pathways to access the programme and followed by explicit consideration of the next steps in increasing social engagement.

Laparoscopic pelvic lymphadenectomy: experience of a Gynaecological Cancer Centre in the UK.

INTRODUCTION: The role of laparoscopic lymphadenectomy in the management of gynaecological cancers has been established over the last two decades, having been first described in Dargent and Selvat (L'envahissement ganglionnaire pelvin. Medsi-Mcgraw Hill, Paris, 1989). It has been shown that laparoscopic lymphadenectomy can be performed in the majority of patients and is associated with a low complication rate. However, the technique continues to be undertaken in only a relatively small number of Gynaecological Cancer Centres in the UK owing to the long learning curve and wide variations in training. MATERIALS AND METHODS: At the Royal Wolverhampton NHS Trust Gynaecological Cancer Centre in the Greater Midlands Cancer Network laparoscopic lymphadenectomy has been performed since 1999 in the management of early cervical and high grade endometrial cancers. We have undertaken a retrospective audit (1999-2009) of these 42 cases to assess the feasibility of the procedure as well as to assess the complication rate. CONCLUSION: We are presenting the first reported series of exclusive laparoscopic transperitoneal lymphadenectomies from a Gynaecological Cancer Centre in the UK.

The relationship between environmental context and attentional engagement in podcast listening experiences.

Introduction: Previous research has shown that podcasts are most frequently consumed using mobile listening devices across a wide variety of environmental, situational, and social contexts. To date, no studies have investigated how an individual's environmental context might influence their attentional engagement in podcast listening experiences. Improving understanding of the contexts in which episodes of listening take place, and how they might affect listener engagement, could be highly valuable to researchers and producers working in the fields of object-based and personalized media. Methods: An online questionnaire on listening habits and behaviors was distributed to a sample of 264 podcast listeners. An exploratory factor analysis was run to identify factors of environmental context that influence attentional engagement in podcast listening experiences. Five aspects of podcast listening engagement were also defined and measured across the sample. Results: The exploratory factor analysis revealed five factors of environmental context labeled as: outdoors, indoors & at home, evenings, soundscape & at work, and exercise. The aspects of podcast listening engagement provided a comprehensive quantitative account of contemporary podcast listening experiences. Discussion: The results presented support the hypothesis that elements of a listener's environmental context can influence their attentional engagement in podcast listening experiences. The soundscape & at work factor suggests that some listeners actively choose to consume podcasts to mask disturbing stimuli in their surrounding soundscape. Further analysis suggested that the proposed factors of environmental context were positively correlated with the measured aspects of podcast listening engagement. The results are highly pertinent to the fields of podcast studies, mobile listening experiences, and personalized media, and provide a basis for researchers seeking to explore how other forms of listening context might influence attentional engagement.

Determining the Relevant Criteria for Three-dimensional Vocal Tract Characterization.

OBJECTIVE: Soprano singers face a number of specific challenges when singing vowels at high frequencies, due to the wide spacing of harmonics in the voice source. The varied and complex techniques used to overcome these are still not fully understood. Magnetic resonance imaging (MRI) has become increasingly popular in recent years for singing voice analysis. This study proposes a new protocol using three-dimensional MRI to investigate the articulatory parameters relevant to resonance tuning, a technique whereby singers alter their vocal tract to shift its resonances nearer to a voice source harmonic, increasing the amplitude of the sound produced. METHODS: The protocol was tested with a single soprano opera singer. Drawing on previous MRI studies, articulatory measurements from three-dimensional MRI images were compared to vocal tract resonances measured directly using broadband noise excitation. The suitability of the protocol was assessed using statistical analysis. RESULTS: No clear linear relationships were apparent between articulatory characteristics and vocal tract resonances. The results were highly vowel dependent, showing different patterns of resonance tuning and interactions between variables. This potentially indicates a complex interaction between the vocal tract and sung vowels in soprano voices, meriting further investigation. CONCLUSIONS: The effective interpretation of MRI data is essential for a deeper understanding of soprano voice production and, in particular, the phenomenon of resonance tuning. This paper presents a new protocol that contributes toward this aim, and the results suggest that a more vowel-specific approach is necessary in the wider investigation of resonance tuning in female voices.

The Perception of Formant Tuning in Soprano Voices.

INTRODUCTION: At the upper end of the soprano range, singers adjust their vocal tract to bring one or more of its resonances (Rn) toward a source harmonic, increasing the amplitude of the sound; this process is known as resonance tuning. This study investigated the perception of (R1) and (R2) tuning, key strategies observed in classically trained soprano voices, which were expected to be preferred by listeners. Furthermore, different vowels were compared, whereas previous investigations have usually focused on a single vowel. METHODS: Listeners compared three synthetic vowel sounds, at four fundamental frequencies (f0), to which four tuning strategies were applied: (A) no tuning, (B) R1 tuned to f0, (C) R2 tuned to 2f0, and (D) both R1 and R2 tuned. Participants compared preference and naturalness for these strategies and were asked to identify each vowel. RESULTS: The preference and naturalness results were similar for /ɑ/, with no clear pattern observed for vowel identification. The results for /u/ showed no clear difference for preference, and only slight separation for naturalness, with poor vowel identification. The results for /i/ were striking, with strategies including R2 tuning both preferred and considered more natural than those without. However, strategies without R2 tuning were correctly identified more often. CONCLUSIONS: The results indicate that perception of different tuning strategies depends on the vowel and perceptual quality investigated, and the relationship between the formants and (f0). In some cases, formant tuning was beneficial at lower f0s than expected, based on previous resonance tuning studies.

Postmenopausal hyperandrogenism: the under-recognized value of inhibins.

We report a 70-year-old female presenting with increased libido and mild but rapid onset virilism. Investigations showed markedly elevated androstenedione and 17 hydroxyprogesterone misdirecting to possible late-onset congenital adrenal hyperplasia. High serum testosterone and oestrogens with suppressed gonadotrophins, however, indicated an androgen-secreting tumour. A normal dehydroepiandrosterone sulphate and elevated inhibins A and B indicated the tumour was ovarian in origin, which was confirmed on pelvic examination and imaging. At laparotomy, a right ovarian sertoliform endometrioid carcinoma was removed, following which the patient developed menopausal vasomotor symptoms and improvement of her virilism. Serum testosterone, oestradiol, inhibins A and B became undetectable, gonadotrophins appropriately increased and 17 hydroxyprogesterone and androstenedione normalized. We propose that inhibins may be of diagnostic value and should be included in investigative algorithms of females with virilization and hyperandrogenaemia, especially if postmenopausal. Androgen-secreting tumours must be excluded before raised 17 hydroxyprogesterone concentrations are used to diagnose late-onset congenital adrenal hyperplasia in females with new-onset virilization.

Developing the Safety Case for MediPi: An Open-Source Platform for Self Management.

mHealth and Telehealth technologies are increasingly used to provide personalised, interactive and timely access to health data, thereby helping patients take a more active role in their care process. However, similar to any intervention, the use of these technologies has to be assured to justify that they do not compromise patient safety. In this paper, we discuss the development of a safety case for MediPi; a research prototype for a low-cost open-source digital platform that collects physiological data from patients, at home, and makes it available to decision-support systems used by clinicians. We identify potential hazardous failures associated with the use of MediPi and examine current risk controls. We also explore the modular structure of the overall safety case of the platform. We conclude with a discussion of patient safety challenges related to the unsupervised nature of the care setting and the use of commercial off-the-shelf personal devices.

A description of the spread of injectate after psoas compartment block using magnetic resonance imaging.

BACKGROUND AND OBJECTIVES: Magnetic resonance imaging (MRI) provides for excellent visualization of spread of solution after peripheral nerve block. The aim of this observational study was to utilize MRI to describe the distribution of injectate (gadopentetate dimeglumine) administered for continuous psoas compartment block (PCB) performed by use of two approaches (Capdevila and modified Winnie) and to describe the spread of injectate to the lumbar plexus. METHODS: Four volunteers were enrolled in a prospective crossover study. Each volunteer underwent PCB with catheter placement performed by use of Capdevila's approach followed 1 week later by PCB, with catheter placement performed by use of a modified Winnie approach. MRI of injectate distribution was performed after each PCB. RESULTS: The catheter was unable to be inserted in 1 volunteer undergoing Winnie's approach; therefore, 7 sets of MR images were analyzed. In 6 of 7 cases (4 Capdevila and 2 Winnie) spread was primarily within the psoas muscle. Contrast surrounded the L2-3 lumbar branch of the femoral nerve at L4 and cleaved the fascial plane within the psoas muscle and spread cephalad to reach the lumbar nerve roots. In 1 case (Winnie approach) contrast spread between the psoas and quadratus lumborum muscles. Contrast surrounded the femoral and obturator nerves where they lie outside the psoas muscle at L5. CONCLUSION: The most common pattern of injectate spread seen on MRI with both approaches to PCB was spread within the body of the psoas muscle around the lumbar branches (L2-4), with cephalad spread to the lumbar nerve roots. One catheter resulted in injectate between the psoas and quadratus lumborum muscles.

Lipopolysaccharide induces nitric oxide synthase expression and platelet-activating factor increases nitric oxide production in human fetal membranes in culture.

BACKGROUND: Platelet-activating factor and nitric oxide may be involved in the initiation of human labour as inflammatory mediators. The aim of this study was to test whether platelet-activating factor and lipopolysaccharide were able to induce nitric oxide synthase expression and stimulate the production of nitric oxide in human fetal membrane explants in culture. METHODS: Fetal membranes were collected from Caesarean sections at term. RNA was extracted from membranes and subjected to a qualitative RT-PCR to assess the baseline expression of iNOS. Discs of fetal membranes were cultured for 24 hours in the presence of platelet-activating factor at a dose range of 0.1 nanomolar--1 micomolar or 1 microgram/ml lipopolysaccharide. Nitric oxide production was measured via nitrite ions in the culture medium and mRNA for iNOS was detected by RT-PCR. RESULTS: Culturing the membrane discs in medium containing serum induced nitric oxide synthase expression and platelet-activating factor significantly stimulated the production of nitric oxide under these conditions. When cultured without serum inducible nitric oxide synthase expression was induced by lipopolysaccharide, but not by platelet-activating factor. CONCLUSION: Platelet-activating factor may have a role in the initiation of labour, at term or preterm, via the increased local production of nitric oxide as an inflammatory mediator. In this model of intrauterine infection, lipopolysaccharide was found to induce iNOS expression by fetal membranes, and this mechanism could be involved in preterm labour.

Neuraxial opioid-induced pruritus: a review.

When intrathecal and epidural opioids are administered, pruritus occurs as an unwanted and troublesome side effect. The reported incidence varies between 30% and 100%. The exact mechanisms of neuraxial opioid-induced pruritus remain unclear. Postulated mechanisms include the presence of an "itch center" in the central nervous system, medullary dorsal horn activation, and antagonism of inhibitory transmitters. The treatment of intrathecal opioid-induced pruritus remains a challenge. Many pharmacological therapies, including antihistamines, 5-HT(3)-receptor antagonists, opiate-antagonists, propofol, nonsteroid antiinflammatory drugs, and droperidol, have been studied. In this review, we will summarize pathophysiological and pharmacological advances that will improve understanding and ultimately the management of this troublesome problem.

Malignant transformation of residual endometriosis after hysterectomy: a case series.

OBJECTIVE: To explore the role of long-standing hormone replacement therapy (HRT) in the malignant transformation of endometriosis. DESIGN: Short case series. Three cases of women with pelvic clearance receiving long-standing HRT studied in detail. SETTING: Teaching hospital in the United Kingdom (Gynaecological Cancer Centre) (Institutional Review Board approval was not obtained as it was not deemed necessary, this being a case series). PATIENT(S): Women with a history of pelvic clearance for endometriosis and longstanding HRT. INTERVENTION(S): HRT. MAIN OUTCOME MEASURE(S): Malignant transformation of endometriosis. RESULT(S): Long-standing HRT in all three women with pelvic clearance for endometriosis resulted in malignant transformation of residual endometriosis many years after the initial surgery. All cases presented with a new pelvic lesion. CONCLUSION(S): The diagnosis of malignant transformation needs to be considered in women with a history of endometriosis and with long-term HRT use in whom a new pelvic lesion is detected. The risk of malignant transformation in women with endometriosis after pelvic clearance receiving HRT needs to be explored further. Surveillance with CA-125 and imaging in such cases to predict recurrence or malignant transformation needs to be studied further in a research setting.

Bio-inspired evolutionary oral tract shape modeling for physical modeling vocal synthesis.

Physical modeling using digital waveguide mesh (DWM) models is an audio synthesis method that has been shown to produce an acoustic output in music synthesis applications that is often described as being "organic," "warm," or "intimate." This paper describes work that takes its inspiration from physical modeling music synthesis and applies it to speech synthesis through a physical modeling mesh model of the human oral tract. Oral tract shapes are found using a computational technique based on the principles of biological evolution. Essential to successful speech synthesis using this method is accurate measurements of the cross-sectional area of the human oral tract, and these are usually derived from magnetic resonance imaging (MRI). However, such images are nonideal, because of the lengthy exposure time (relative to the time of articulation of speech sounds) required, the local ambient acoustic noise associated with the MRI machine itself and the required supine position for the subject. An alternative method is described where a bio-inspired computing technique that simulates the process of evolution is used to evolve oral tract shapes. This technique is able to produce appropriate oral tract shapes for open vowels using acoustic and excitation data from two adult males and two adult females, but shapes for close vowels that are less appropriate. This technique has none of the drawbacks associated with MRI, because all it requires from the subject is an acoustic and electrolaryngograph (or electroglottograph) recording. Appropriate oral tract shapes do enable the model to produce excellent quality synthetic speech for vowel sounds, and sounds that involve dynamic oral tract shape changes, such as diphthongs, can also be synthesized using an impedance mapped technique. Efforts to improve performance by reducing mesh quantization for close vowels had little effect, and further work is required.