Development of a (silent) speech recognition system for patients following laryngectomy.

Surgical voice restoration post-laryngectomy has a number of limitations and drawbacks. The present gold standard involves the use of a tracheo-oesophageal fistula (TOF) valve to divert air from the lungs into the throat, which vibrates, and from this, speech can be formed. Not all patients can use these valves and those who do are susceptible to complications associated with valve failure. Thus there is still a place for other voice restoration options. With advances in electronic miniaturization and portable computing power a computing-intensive solution has been investigated. Magnets were placed on the lips, teeth and tongue of a volunteer causing a change in the surrounding magnetic field when the individual mouthed words. These changes were detected by 6 dual axis magnetic sensors, which were incorporated into a pair of special glasses. The resulting signals were compared to training data recorded previously by means of a dynamic time warping algorithm using dynamic programming. When compared to a small vocabulary database, the patterns were found to be recognised with an accuracy of 97% for words and 94% for phonemes. On this basis we plan to develop a speech system for patients who have lost laryngeal function.

Use of ultrafast computed tomography to quantitate regional myocardial perfusion: a preliminary report.

The purpose of this study was to assess the potential for rapid acquisition computed axial tomography (Imatron C-100) to quantify regional myocardial perfusion. Myocardial and left ventricular cavity contrast clearance curves were constructed after injecting nonionic contrast (1 ml/kg over 2 to 3 seconds) into the inferior vena cava of six anesthetized, closed chest dogs (n = 14). Independent myocardial perfusion measurements were obtained by coincident injection of radiolabeled microspheres into the left atrium during control, intermediate and maximal myocardial vasodilation with adenosine (0.5 to 1.0 mg/kg per min, intravenously, respectively). At each flow state, 40 serial short-axis scans of the left ventricle were taken near end-diastole at the midpapillary muscle level. Contrast clearance curves were generated and analyzed from the left ventricular cavity and posterior papillary muscle regions after excluding contrast recirculation and minimizing partial volume effects. The area under the curve (gamma variate function) was determined for a region of interest placed within the left ventricular cavity. Characteristics of contrast clearance data from the posterior papillary muscle region that were evaluated included the peak myocardial opacification, area under the contrast clearance curve and a contrast clearance time defined by the full width/half maximal extent of the clearance curve. Myocardial perfusion (microspheres) ranged from 35 to 450 ml/100 g per min (mean 167 +/- 125). Two flow algorithms derived from characteristics of the contrast clearance curves showed a good correlation with regional myocardial flow determined by microspheres: the ratio of the peak myocardial opacification from baseline to the area under the left ventricular cavity curve (r = 0.7, p less than 0.001, SEE = 44.4 ml/min), and the ratio of the left ventricular cavity to posterior papillary muscle curve areas divided by the full width/half maximal contrast transit time in the region of the posterior papillary muscle (r = 0.82, p less than 0.001, SEE = 52.2 ml/100 g per min). The form of these two flow algorithms was derived from classical indicator dilution theory. In conclusion, indices derived from these data correlated well with regional myocardial perfusion in the posterior papillary muscle region of the dog as assessed by microspheres. This approach offers promise for the quantitation of regional myocardial perfusion and myocardial flow reserve in patients.

Subcutaneous calcifications masquerading as pulmonary lesions in long-term hemodialysis. Review of nodular pulmonary opacities in the population undergoing hemodialysis.

Calcification of soft tissue frequently occurs in patients undergoing hemodialysis for chronic renal failure and involves the arteries, eyes, periarticular regions, lungs, heart, abdominal viscera, subcutaneous tissues, and skin. In this report, two such patients are described who presented with apparent pulmonary nodules on their chest roentgenograms obtained on admission. By the use of tomograms and apical lordotic views, both proved to have extrapulmonary calcific deposits in the subcutaneous tissues overlying the upper pulmonary zones. The tendency for these collections to undergo progression, regression, or pseudocavitation is illustrated. Definitive radiographic localization of lesions projecting over the pulmonary fields in patients undergoing hemodialysis is emphasized because of the significantly increased incidence of infection (including tuberculosis), septic embolism, and carcinoma.

Tentative diagnoses facilitate the detection of diverse lesions in chest radiographs.

The influence of clinical history upon detection has been frequently studied. In a unique investigation, detection of diverse abnormalities commonly encountered in practice was tested, and the influence of clinical history was conceptualized as suggesting a tentative diagnosis. Categorical prompts that were correct for specific abnormalities resulted in detection superior to that with unprompted reading. Prompts that were plausible but incorrect for abnormal and normal cases led to very few false-positive responses, and subsequent reports of specific abnormalities were as accurate as in unprompted reading. It is concluded that appropriate clinical history results in improved perceptual performance rather than simply improved decision-making.

Genetic analysis of head and neck squamous cell carcinoma and surrounding mucosa.

OBJECTIVE: Comparative genomic hybridization was performed on head and neck squamous cell carcinoma and surrounding mucosa to determine whether common chromosomal aberrations could be detected that would predispose an individual to developing a second primary tumor. DESIGN: Biopsy specimens were taken from 19 patients with squamous cell carcinoma of the head and neck, 3 samples from each person: 1 specimen from the tumor site and 1 each from 1 and 5 cm from the macroscopic tumor margin. Samples were snap frozen in liquid nitrogen. A portion of each distant sample and tissue taken from immediately adjacent to the site of the tumor specimen were sectioned and stained with hematoxylin-eosin, either to search by light microscopy for tumor cells or signs of dysplasia in the distant samples, or to determine whether the tumor specimen had substantial non-tumor cell content. Tissue adjacent to the tumor biopsy site was used because the biopsy specimens were relatively small. Comparative genomic hybridization was performed on all samples. SUBJECTS: Nineteen patients with newly diagnosed carcinomas of the head and neck. RESULTS: The tumor biopsy specimens showed no substantial nontumor cell content, and the distant specimens were all histologically normal. The tumors showed multiple mutations: mean (SD) number of deletions, 5.4 (4.3); amplifications, 5.2 (4.6). Deletion of chromosome 3p was seen in 13 of 19 cases and was associated with amplification of 3q in 10 cases. No mutations were seen in the distant biopsy specimens. CONCLUSIONS: Frequently occurring chromosomal aberrations were seen in the tumor cells, suggesting a key role for these mutations in tumor development. Screening histologically normal upper aerodigestive tract mucosa with comparative genomic hybridization does not provide information on early genetic events that predispose a patient to developing a second primary tumor.

Radio-opacity of fishbones.

Bones are the largest group of foreign bodies found in the air and food passages. Fishbones which lodge in the tonsil can be easily seen and removed relatively easily. Those lodging in the pyriform fossa are well localized by the patient and can usually be seen on mirror examination. It would be useful to know which types of fishbones are radio-opaque and therefore likely to be shown by radiographs when mirror examination is difficult or fails to reveal a foreign body. Therefore a study was undertaken to ascertain the radio-opacity of the bones of ten different species of fish eaten in the British Isles.

Candida'the cancer of silastic'.

Candida species have the propensity to colonize and erode into the surface of silastic causing a loss of function. Colonization of silastic tracheo-oesophageal speaking-valves is an important cause of valve failure post-laryngectomy: the exact nature of the colonization is unknown and light microscopic studies have not been reported previously. Microbiological examination of scrapings taken from the colonized oesophageal surface of failed speaking valves was arranged before sectioning for light microscopy. Conventional ultrathin sectioning of silastic was difficult, therefore 15 micrometre sections were cut after cooling the material to -30 degrees C. These sections were then stained with toluidine blue; Candida species taking up the stain. Microbiological examination of the colonies confirmed the predominance of Candida species in the biofilm. Light microscopy of the 15 micrometer sections revealed that the Candida colonies had invaded the silastic. This work demonstrates that the colonization of the silastic valve prosthesis in the oesophageal area is due predominantly to Candida species which actively invade the structure of the silastic. This is an important cause of speaking-valve failure post-laryngectomy.

Blood transfusion and survival after laryngectomy for laryngeal carcinoma.

Survival of patients with surgically treated malignancy may be adversely affected by blood transfusion. Immune suppression due to transfusion has been implicated but remains unproven. We conducted a study of 240 patients with squamous cell carcinoma of the larynx undergoing laryngectomy to assess the effect of per-operative blood transfusion on survival.

Recurrent unilateral tonsillitis secondary to a penetrating foreign body in the tonsil.

We report a case of an impacted foreign body in the tonsil presenting as recurrent unilateral tonsillitis. A completely embedded foreign body should be considered in cases of recurrent unilateral tonsillitis.

Osteomyelitis of the cervical spine following laryngectomy.

Only one case of osteomyelitis of the cervical spine following laryngectomy for carcinoma of the larynx has been reported in the literature to date. We report an unusual case of osteomyelitis of the cervical spine following treatment of laryngeal carcinoma by radiotherapy (RT) and subsequent laryngectomy and discuss the relevant literature.

Giant hamartoma of the oropharynx.

Giant polypoidal hamartomas of the pharynx and oesophagus are rare benign tumours of unknown origin, exceptionally arising from the oropharynx. We report the case of a 74-year-old man who developed sudden nausea and a foreign body sensation. Shortly afterwards he regurgitated a 25 x 3 x 1.5 cm pedunculated fleshy mass, still attached to the inside of his thorat. The patient was anaesthetised, the mass traced to the right tonsillar fossa and adjacent oropharyngeal wall. The pedicle was clamped and the lesion excised. Histology was consistent with a giant oropharyngeal hamartoma. We discuss the pathogenesis and potential complications of this condition. The literature is reviewed.

A multi-observer study examining the radiographic visibility of fishbone foreign bodies.

The use of plain radiographs to localize a suspected fishbone foreign body is the subject of controversy. Accordingly radiographs of 14 species of fishbone, impacted in a soft tissue phantom, were assessed by a series of observers from the ENT department (consultant surgeons, senior registrars and house officers). The agreement was assessed by graphical description of the data and tested by a Spearman's rank correlation test. The overall results showed that, for the clinician, radiography is very useful to detect the bones of: cod, haddock, lemon sole, cole fish, grey mullet and plaice; useful for red snapper, monk fish, gurnard and salmon; and unhelpful in detecting bones from herring, pike, mackerel and trout. The use of radiographs to locate these impacted fishbones can be rationalized in the light of these findings.

Isolated word recognition of silent speech using magnetic implants and sensors.

There are a number of situations where individuals wish to communicate verbally but are unable to use conventional means-so called 'silent speech'. These include speakers in noisy and covert situations as well as patients who have lost their voice as a result of a laryngectomy or similar procedure. This paper focuses on those who are unable to speak following a laryngectomy and assesses the possibility of speech recognition based on a magnetic implant/sensors system. Permanent magnets are placed on the tongue and lips and the changes in magnetic field resulting from movement during speech are monitored using a set of magnetic sensors. The sensor signals are compared to sets of pre-recorded templates using the dynamic time warping (DTW) method, and the best match is identified. Experimental trials are reported for subjects with intact larynx, typically using 500-1000 utterances used for speaker dependant training and testing. It is shown that recognition rates of over 90% are achievable for vocabularies of at least 57 isolated words: sufficient to drive command-and-control applications.

Three days in October of 1630: detailed examination of mortality during an early modern plague epidemic in Venice.

The epidemiology of medieval and early modern European plague remains highly controversial. It now seems likely that the epidemiology was not uniform throughout either the geographic or temporal boundaries of the plague in Western Europe. The Venetian plague of 1630 was extensively documented; day-by-day records were kept, and each mortality in the city was recorded in a set format. The days 23-25 October 1630, representing a period when mortality was beginning to increase sharply, are examined. In all, 1,163 deaths were recorded. They show a large preponderance of women; a mean age of 28, but a majority of cases clumped between ages 0 and 25 years; and an unequal sex ratio among children. Further, there was an identifiable smallpox epidemic raging simultaneously with plague, and more than one-quarter of all the deaths in this period of high mortality were clearly due to nonplague causes. Deaths due to wounds and associated with violence were prominent in one parish, which suggests that in times of plague the breakdown in the normal machinery of government, in everyday patterns of life, and possibly of mental well being resulted in an even more exaggerated death toll. These factors--violence, accidents, and other epidemics--have never been so definitively tied to a European plague epidemic. In addition, there are hints that plague has a marked proclivity to kill pregnant women--their deaths far outnumber those anticipated--and that plague was very localized at a given moment within Venice itself, even during times of peak mortality.