Organ curvature sensing using pneumatically attachable flexible rails in robotic-assisted laparoscopic surgery.

In robotic-assisted partial nephrectomy, surgeons remove a part of a kidney often due to the presence of a mass. A drop-in ultrasound probe paired to a surgical robot is deployed to execute multiple swipes over the kidney surface to localise the mass and define the margins of resection. This sub-task is challenging and must be performed by a highly-skilled surgeon. Automating this sub-task may reduce cognitive load for the surgeon and improve patient outcomes. The eventual goal of this work is to autonomously move the ultrasound probe on the surface of the kidney taking advantage of the use of the Pneumatically Attachable Flexible (PAF) rail system, a soft robotic device used for organ scanning and repositioning. First, we integrate a shape-sensing optical fibre into the PAF rail system to evaluate the curvature of target organs in robotic-assisted laparoscopic surgery. Then, we investigate the impact of the PAF rail's material stiffness on the curvature sensing accuracy, considering that soft targets are present in the surgical field. We found overall curvature sensing accuracy to be between 1.44% and 7.27% over the range of curvatures present in adult kidneys. Finally, we use shape sensing to plan the trajectory of the da Vinci surgical robot paired with a drop-in ultrasound probe and autonomously generate an Ultrasound scan of a kidney phantom.

Dynamic physiological temperature and pressure sensing with phase-resolved low-coherence interferometry.

We report the development and characterisation of highly miniaturised fibre-optic sensors for simultaneous pressure and temperature measurement, and a compact interrogation system with a high sampling rate. The sensors, which have a maximum diameter of 250 µm, are based on multiple low-finesse optical cavities formed from polydimethylsiloxane (PDMS), positioned at the distal ends of optical fibres, and interrogated using phase-resolved low-coherence interferometry. At acquisition rates of 250 Hz, temperature and pressure changes of 0.0021 °C and 0.22 mmHg are detectable. An in vivo experiment demonstrated that the sensors had sufficient speed and sensitivity for monitoring dynamic physiological pressure waveforms. These sensors are ideally suited to various applications in minimally invasive surgery, where diminutive lateral dimensions, high sensitivity and low manufacturing complexities are particularly valuable.

Asthma after childhood pneumonia: six year follow up study.

OBJECTIVE: To establish the long term cumulative prevalence of asthma in children admitted to hospital with pneumonia and to examine the hypothesis that some children admitted to hospital with pneumonia may be presenting with undiagnosed asthma. DESIGN: Prospective study of a cohort of children previously admitted to hospital with pneumonia, followed up by postal questionnaires to their general practitioners and the children or their parents. SETTING: General practices in southwest England. PARTICIPANTS: 78 children admitted to the Royal Devon and Exeter Hospital between 1989 and 1991 with a diagnosis of pneumonia confirmed on independent review of x ray films. MAIN OUTCOME MEASURES: Any diagnosis of asthma, use of any treatment for asthma, and asthma symptom scores. RESULTS: On the basis of a 100% response rate from general practitioners and 86% from patients or parents, the cumulative prevalence of asthma was 45%. A diagnosis of asthma was associated with a family history of asthma (odds ratio 11.23; 95% confidence interval 2.57 to 56.36; P=0.0002). Mean symptom scores were higher for all children with asthma (mean score 2.4; chi(2)=14.88; P=0. 0001) and for children with asthma not being treated (mean 1.4; chi(2)=6.2; P=0.01) than for those without asthma (mean 0.2). CONCLUSIONS: A considerable proportion of children presenting to a district general hospital with pneumonia either already have unrecognised asthma or subsequently develop asthma. The high cumulative prevalence of asthma suggests that careful follow up of such children is worth while. Asthma is undertreated in these children; a structured symptom questionnaire may help to identify and reduce morbidity due to undertreatment.

Intra-abdominal bleeding caused by spontaneous rupture of an accessory spleen: the CT findings.

Accessory spleens are common. Their clinical importance lies in the need to include their removal when performing a splenectomy for primary haematological disorders, or as the source of 'preservable' splenic tissue in cases of ruptured primary spleen. Rupture of a normal spleen almost always occurs because of trauma, spontaneous rupture is rare. In pathological spleens, however, 'spontaneous' rupture is more widely reported, although it is argued that minor trauma is often still responsible in these cases. We report a case of spontaneous isolated rupture of a histologically normal accessory spleen and show the CT findings.

Corticosteroid prophylaxis for patients with increased risk of adverse reactions to intravascular contrast agents: a survey of current practice in the UK.

There is no definite experimental evidence that prophylactic corticosteroids reduce the frequency or severity of adverse effects from low-osmolar contrast agents in patients at increased risk of reaction. There is no consensus in terms of how prophylaxis should be conducted. We have studied current radiologists' practice in the UK by sending postal questionnaires to 212 radiologists randomly selected from a list of current consultants who are Fellows of the Royal College of Radiologists. One hundred and seventy (80.2%) of the 212 questionnaires were completed. The majority of radiologists routinely use non-ionic low osmolar contrast media for intravenous administration, only 30 (17.6%) routinely using conventional ionic agents and six (3.5%) ionic low osmolar agents. All 170 use low osmolar contrast media for those patients perceived to be at increased risk of adverse reactions. Seventy-six radiologists (44.7%) never use steroid cover. There is no consistent practice amongst the 94 consultants (55.3%) who do use steroid cover. The indications for prophylaxis vary, as do the corticosteroid used and the dose regime employed. The total dose used varied from the equivalent of 7.5 mg to 400 mg of prednisolone, and the duration of prophylaxis varied from a single dose to a 4 day course. One hundred and forty-two radiologists (83.5%) would welcome nationally agreed guidelines for the use of steroid cover. The great variation in the use of steroid cover in the UK reflects the lack of clear evidence of its benefit in combination with low osmolar contrast media.

NAD metabolism and mitogen stimulation of human lymphocytes.

The NAD concentration in eukaryotic cells is an important parameter for many aspects of metabolism including differentiation. As reported by other workers, the NAD content of resting human peripheral blood lymphocytes was low and increased dramatically over a period of 3 days after stimulation with the mitogen phytohemagglutinin (PHA). However, simultaneous measurement of the mean cell volumes showed that the average NAD concentration in fresh quiescent lymphocytes (401 +/- 128 microM) (SD, n = 7) was similar to that observed for other cell types. Furthermore, because of the increase in cell volume which occurred on mitogen stimulation, the NAD concentration in stimulated lymphocytes was only 2-3-fold higher than in fresh resting cells. This increase was also observed in lymphocytes incubated without mitogen and was apparently due to the level of NAD precursors in the culture medium and serum supplement. Hence, the NAD concentration in resting and stimulated lymphocytes is comparable to that of other eukaryotic cells and the variations in NAD content reported earlier have been widely misinterpreted.