Método manométrico alternativo de calibración de transductores de presión para la monitorización hemodinámica invasiva / Alternative manometric method of calibration of pressure transducers for invasive hemodynamic monitoring

Introducción: La calibración de los transductores tiene gran importancia para la medición precisa de las presiones, durante la monitorización hemodinámica invasiva de los pacientes que requieren observación estrecha en las unidades de atención al grave y en el quirófano. Objetivo: Desarrollar y validar un método de calibración para transductores de presión, sencillo, eficaz y de bajo costo. Métodos: Se desarrolló un método manométrico alternativo, basado en la ley de Pascal, para la calibración de los transductores de presión durante la monitorización hemodinámica invasiva que se realiza en la Unidad de Cuidados Intensivos de Cirugía Cardiovascular del Hospital Clínico-Quirúrgico Hermanos Ameijeiras. Este método fue validado mediante la comparación con el estándar recomendado en un total de 215 pacientes que requirieron monitorización hemodinámica invasiva entre los meses de enero y junio del 2015. Resultados: Con el método manométrico alternativo creado se obtiene el mismo resultado que con el método hidráulico recomendado por la literatura. Conclusiones: El método alternativo creado es preciso, eficaz y costo-efectivo(AU)

Introduction: Transducer calibration is very important for the accurate measurement of pressures during invasive hemodynamic monitoring of patients requiring close observation in the primary care units and in the operating room. Objective: To develop and validate a method of calibration of pressure transducers, which is simple, efficient and low-cost. Methods: An alternative manometric method, based on Pascal's law, was developed for the calibration of pressure transducers during invasive hemodynamic monitoring performed at the intensive care unit of the cardiovascular surgery department at Hermanos Ameijeiras Clinical-Surgical Hospital. This method was validated by its comparison with the recommended standard in a total of 215 patients who required invasive hemodynamic monitoring between January and June 2015. Results: With the alternative manometric method created, the same result was obtained as with the hydraulic method recommended by the literature. Conclusions: The alternative method created is accurate, efficient and cost-effective(AU)

Cyclical pattern of non-nutritive sucking in normal and high-risk neonates

En este trabajo se determinaron patrones de ciclos de succión mediante registros de la presión de succión en recién nacidos a término, prematuro normal y recién nacido con patología(hipoxia al nacer). Además, se establecieron asociaciones entreestos patrones y algunos parámetros clínicos, con el propósito de valorar la capacidad de alimentación, para orientar la estimulación específica y favorecer el alta de internación en mejorescondiciones de salud. Se evaluó a 75 neonatos de ambos sexos con consentimiento firmado, agrupados según su condición al nacer. Se determinó el peso corporal y el scorede Apgar. Se obtuvieron los registros de valores máximos y mínimos de presión utilizando un aparato “ad-hoc” (de presión-succión) que permitió medir el número de ciclos de succión. Los datos fueron analizados estadísticamente con un nivel de significación p<0.05. Los valores máximos de presiónsucciónpresentaron variaciones entre los grupos analizados. Los valores más altos de presión y el mayor número de ciclos de succión se observó en nacidos a término. Los prematuros mostraron valores de presión más bajos y menor cantidad de ciclos de succión, lo que posibilitó establecer un patrón específicopara estos grupos. Los hipoxiados exhibieron una gran variabilidad en ambos parámetros. En los neonatos normales y pretérmino hubo una correlación directa y significativa entrelos ciclos de succión y los valores de Apgar a los cinco minutos. El grupo de recién nacidos con patología debido a hipoxia no mostró la misma asociación. Estos resultados constituyen unaimportante herramienta que contribuirá a mejorar la nutrición materna neonatal y optimizar la calidad de vida de los recién nacidos de alto riesgo en nuestro medio

Blast-Induced Hearing Loss / 대한이비인후과학회지

Blast injuries are increasing worldwide from combat and explosions in heavy industry. Primary blast injury is direct injury due to the high pressure effects and pressure differentials of the blast wave itself. Alternating overpressure and underpressure imposed upon tissues of heterogenous densities, particularly air-filled organs. The ear is the first affected organ to primary blast injury because it is the body's most sensitive pressure transducer. Otologic blast injury and tympanic membrane perforation have traditionally been used as a predictor, or biomarker, of occult serious primary blast injury. Hearing loss and tinnitus are the most common ear symptoms. This review details the otologic consequences of blast exposure.

The development of a type II endoleak domesticated pig model with continuous pressure monitor / 中华外科杂志

<p><b>OBJECTIVE</b>To develop a type II endoleak porcine model with continuous pressure monitor by the strain-gauge pressure transducer and the patch.</p><p><b>METHODS</b>Nine tamed porcine was randomized as the experiment group of 6 domesticated pigs and the control group of 3 domesticated pigs. When the abdominal aortic aneurysm (AAA) was created, the 2(nd) and 3(rd) pair of infrarenal lumber arteries were preserved in the experiment group, while ligated in the control group. The stent-graft was implanted in the endovascular repair. CT angiography was performed to seek endoleak, and the angiography was performed to excluded the type I and type III endoleak. The pressure in the excluded AAA monitored by the strain-gauge pressure transducer was recorded and compared in both groups to evaluated the effect of type II endoleak in the experiment group.</p><p><b>RESULTS</b>The AAA porcine model with pressure monitor were successfully developed in all 9 porcine. The endoleak and the retrograde flow of the lumber arteries were confirmed by CT angiography in the experiment group. The ratio of the average pressure after the procedure to before the procedure was higher in the experiment group than the control group (U = 0.000, P = 0.020). The ratio of the pulse pressure after the procedure to the average pressure before the procedure was higher in the experiment group than the control group (U = 0.000, P = 0.020).</p><p><b>CONCLUSION</b>It is feasible to develop type II endoleak domesticated pig model by preserving the lumber arteries for the retrograde flow, and the AAA model with pressure monitor by the strain-gauge pressure transducer and the patch.</p>

An investigation into the effect of denture adhesives on incisal bite force of complete denture wearers using pressure transducers: a clinical study

PURPOSE: Study was conducted to determine and assess the effect of different type of denture adhesives on the incisal bite force of complete denture wearers until the dislodgement of upper denture, using pressure transducer. MATERIALS AND METHODS: 30 patients out of 100 were included in the study. Based on the Kapur's method of scoring denture retention and stability, these patients were divided into 3 groups- Group A - Clinically good dentures; Group B - Clinically fair dentures; and Group C - Clinically poor dentures. A custom made occlusal force meter was constructed based on the load cell type of pressure transducers. Different adhesives (powder, paste and adhesive strips) were used in the study. Complete denture wearers were asked to bite on the load cell and the readings of incisal bite force were recorded. The readings of incisal bite force were subjected to statistical analysis using Repeated measures ANOVA followed by post-hoc bonferroni test. RESULTS: The result suggests that denture adhesives improved the incisal bite force of complete denture wearers significantly The incisal bite force (in kg) in Group A without using adhesives, with powder adhesive, with paste adhesive and with adhesive strips was found to be 2.48 (+/- 0.16), 3.43 (+/- 0.11), 6.01 (+/- 0.11), 3.22 (+/- 0.09) respectively. The incisal bite force (in kg) in Group B without using adhesives, with powder adhesive, with paste adhesive and with adhesive strips was found to be 1.87 (+/- 0.18), 3.35 (+/- 0.14), 5.34 (+/- 0.18), 3.21 (+/- 0.12) respectively. The incisal bite force (in kg) in Group C without using adhesives, with powder adhesive, with paste adhesive and with adhesive strips was found to be 1.00 (+/- 0.17), 3.07 (+/- 0.14), 4.37 (+/- 0.26), 2.99 (+/- 0.14) respectively. CONCLUSION: Within the limitations of the study, it was concluded that the use of denture adhesive was found to be significantly effective in improving the incisal bite force of complete dentures until the dislodgement of upper denture. Fittydent paste adhesive was found to be more effective than the powder and strips adhesives. The improvement in incisal bite force was found to be higher in Group C in comparison to that of Group A and Group B.

Validation of a protocol to evaluate maximal expiratory pressure using a pressure transducer and a signal conditioner

The respiratory muscles can present fatigue and even chronic inability to generate force. So, reliable devices are necessary to their evaluation. The aim of this study is to evaluate the MEP (Maximal Expiratory Pressure) values of individuals between 20 and 25 years old and to validate a protocol using a pressure transducer and a signal conditioner comparing it with the digital manometer. We evaluated the MEP of 10 participants. They remained seated and made six respiratory maneuvers from Total Lung Capacity (TLC) to Residual Volume (RV). The results in the study showed no statistically significant differences when compared to values reported in the literature, and that the pressure transducer provides reliable values for MEP.

Os músculos respiratórios podem apresentar fadiga e até mesmo a incapacidade crônica na geração de força, sendo necessários dispositivos confiáveis para sua avaliação. O objetivo deste estudo foi avaliar a pressão expiratória máxima (PeMáx) de indivíduos entre 20 e 25 anos e validar um protocolo que utiliza um transdutor de pressão e um condicionador de sinais comparando-o com a manovacuometria. Foram avaliadas a PeMáx de 10 participantes. Estes permaneceram sentados e realizaram seis manobras respiratórias a partir da capacidade pulmonar total (CPT) até o volume residual (VR). Os resultados do estudo não apresentaram diferenças estatisticamente significativas quando comparados com os valores de normalidade descritos na literatura e mostraram que o transdutor de pressão fornece valores confiáveis para Pe máx.

Avaliação da sensibilidade cutânea em pacientes com síndrome do túnel do carpo relacionada à hemodiálise / Cutaneous sensibility assesment in hemodialysis- related carpal tunnel syndrome

OBJETIVO: Descrever a utilização do PSSD (Pressure specified sensory device) para a realização do diagnóstico de Síndrome do Túnel do Carpo. MÉTODOS: O PSSD consiste de aparelho que incorpora um transdutor de pressão com duas extremidades rombas e com regulagem de distância entre elas, acoplado a um computador capaz de determinar os limiares cutâneos de pressão. Para tanto, os pacientes foram divididos em três grupos: Grupo 1- grupo controle, pacientes sem neuropatia no membro superior ou insuficiência renal. Grupo 2- pacientes com síndrome do túnel do carpo relacionada à hemodiálise. Grupo 3 - pacientes com síndrome do túnel do carpo sem insuficiência renal. RESULTADOS: Os resultados demonstraram haver um maior benefício do uso do PSSD para o diagnóstico da síndrome para os pacientes do grupo dois em dois dos quatro parâmetros avaliados quando comparados com os pacientes do grupo 3. CONCLUSÃO: O PSSD é útil para o diagnóstico da síndrome do túnel do carpo em pacientes hemodialíticos. Nível de Evidência II. Estudos diagnósticos.

OBJECTIVE: The aim of this study is to describe the use of the PSSD (Pressure specified sensory Device) for the diagnosis of carpal tunnel syndrome.METHODS: The PSSD is a tool that incorporates a pressure transducer with two prongs, linked to a computer capable of measuring the cutaneous pressure thresholds. The patients were divided in two groups: Group 1- patients neither with superior limb neuropathy nor renal insufficiency. Group 2- patients with carpal tunnel syndrome related to hemodialysis. Group 2 - patients with carpal tunnel syndrome but no renal insufficiency.RESULTS: The results showed, for two of the four parameters measured, that the group 2 had more benefits for the diagnosis of carpal tunnel syndrome than group 3.CONCLUSION: The PSSD is useful as a diagnostic tool in hemodialysis-related carpal tunnel syndrome Level of Evidence: Level II, development of diagnostic.

Mechanism of Action of Cholecystokinin on Colonic Motility in Isolated, Vascularly Perfused Rat Colon

BACKGROUND/AIMS: It is generally believed that cholecystokinin (CCK) stimulates colonic motility, although there are controversial reports. It has also been suggested that postprandial peptide YY (PYY) release is CCK-dependent. Using a totally isolated, vascularly perfused rat colon, we investigated: (1) the roles of CCK and PYY on colonic motility, (2) to determine if CCK modulates PYY release from the colon to influence the motility and (3) to clarify whether the action of CCK and PYY on colonic motility is mediated via the influence of cholinergic input. METHODS: An isolated whole rat colon was used. Luminal pressure was monitored via microtip catheter pressure transducers from proximal and distal colon. After a control period, CCK-8 or PYY was administerd intraarterially with or without an anti-PYY serum, loxiglumide or atropine at 12, 60 and 240 pM. Each dose was given for a period of 15-minute and the contractile response was expressed as % changes over basal. PYY concentration in the portal effluent was determined by radioimmunoassay. RESULTS: Exogenous CCK-8 increased colonic motility which paralleled the increase in PYY release in the portal effluent. Exogenous PYY also significantly increased colonic motility although it was less potent than CCK. The stimulating effect of CCK-8 was significantly inhibited by an anti-PYY serum, and was completely abolished by loxiglumide, and almost completely abolished by atropine. CONCLUSIONS: CCK increases colonic motility via CCK1 receptor and it is mediated partly by PYY. Cholinergic input is required for the increased motility by either PYY or CCK.

Diagnostic and Clinical Differences in Obstructive Sleep Apnea Syndrome and Upper Airway Resistance Syndrome / 수면정신생리

It has been controversial whether upper airway resistance syndrome (UARS) is a distinct syndrome or not since it was reported in 1993. The International Classification of Sleep Disorders classified UARS under obstructive sleep apnea syndrome (OSAS) in 2005. UARS can be diagnosed when the apnea-hypopnea index (AHI) is fewer than 5 events per hour, the simultaneously calculated respiratory disturbance index (RDI) is more than 5 events per hour due to abnormal non-apneic non-hypopneic respiratory events accompanying respiratory effort related arousals (RERAs), and oxygen saturation is greater than 92% at termination of an abnormal breathing event. Although esophageal pressure measurement remains the gold standard for detecting subtle breathing abnormality other than hypopnea and apnea, nasal pressure transducer has been most commonly used. RERAs include phase A2 of cyclical alternating patterns (CAPs) associated with EEG changes. Symptoms of OSAS can overlap with UARS, but chronic insomnia tends to be more common in UARS than in OSAS and clinical symptoms similar with functional somatic syndrome are also more common in UARS. In this journal, diagnostic and clinical differences between UARS and OSAS are reviewed.

Correlation study between obstructive level diagnosed by Apnea Graph and cephalometric posterior airway space in obstructive sleep apnea hypopnea syndrome / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To study the correlation between Apnea Graph (AG) analysis of airway obstruction and cephalometric assessment of the posterior airway space in the diagnosis of obstructive level in patients with obstructive sleep apnea hypopnea syndrome (OSAHS), so as to improve the preoperative diagnostic accuracy and the therapeutic outcome.</p><p><b>METHODS</b>Thirty patients (28 males and two females) who were diagnosed with severe OSAHS (mean AHI 58.6) by overnight polysomnography in recent 3 months were enrolled. The ages of the patients ranged from 35 to 59 years old with the median age of 41.5 years old. The mean body mass index (BMI, x(-) ± s) was (28.8 ± 4.1) kg/m(2). Mean apnea-hypopnea index (AHI) was (58.6 ± 16.4)/h. The lowest oxygen saturation was averaged to 0.69 ± 0.09. All patients underwent AG study as well as cephalometric analysis preoperatively. A correlation analysis was performed between the percentage of lower level obstructions measured by AG and the posterior airway space (PAS) evaluated by cephalometric analysis.</p><p><b>RESULTS</b>All of the 30 patients had the obvious narrow PAS of 4.4 - 10.8 mm, with the average of (7.6 ± 2.1) mm. Their constituent ratios of lower level obstruction ranged from 2 to 87 percent with the median ratio of 15.5% [9.0%; 35.8%]. Among all the patients, only 2 cases had more than 50 percent obstruction of the airway at lower level, 8 cases had 30 to 40 percent obstruction, and 6 cases had the narrow PAS less than 6 mm. The constituent ratio of lower level obstructions had a negative rectilinear correlation with the data of PAS (r = -0.6511, P < 0.01), which meant the patient with a higher percentage of lower obstruction had the tendency to have a corresponding narrower PAS. Two cases whose constituent ratios of lower level obstructions were not compatible with the rectilinear tendency due to tonsillar hypertrophy were reported.</p><p><b>CONCLUSIONS</b>AG analysis of airway obstruction and cephalometric assessment of the PAS could provide comparable and consistent results for the diagnosis of obstructive level in OSAHS. However, the tonsillar hypertrophy should be considered when using AG to identify the airway obstruction.</p>

Clinical value of upper airway pressure measurement and Friedman staging system in preoperative evaluation for obstructive sleep apnea hypopnea syndrome / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To evaluate the clinical value of localization of upper airway obstructive site with pressure measurements and Friedman staging system in preoperative upper airway reconstructive surgery for obstructive sleep apnea-hypopnea syndrome (OSAHS), and to evaluate the value of Friedman staging system in predicting the upper airway obstructive site.</p><p><b>METHODS</b>One hundred and three patients with snoring, daytime sleepiness diagnosed as OSAHS by polysomnography were first classified using Friedman staging system, and then examined using whole night recording, including airway continuous pressure measurements (Apnea Graph, AG). AG transducer catheter containing two pressure and two temperature sensors used for obstruction site determination and detection of apnea events during sleep. Obstructive sites were divided into upper (retropalatal region) or lower level (retroglossal region). Using constituent ratio to reflect the obstructive proportion of different levels so as to find the correlation between Friedman staging system and localization of upper airway obstructive site with pressure measurements performed during sleep, and to evaluate the clinical value of Friedman staging system in predicting the severity of OSAHS.</p><p><b>RESULTS</b>There was statistically significant difference in the constituent ratio of retroglossal obstruction determined by AG, according to Friedman staging system, Friedman tongue position (FTP) and tonsil size grading (F = 13.876, 7.655, 10.207 respectively, P < 0.05). The constituent ratio of retroglossal obstruction between stage IV and I, II, III (P < 0.01) was significantly different. With the increasing of Friedman staging, the constituent ratio of retroglossal obstruction had the tendency of increasing. The constituent ratio of retroglossal obstruction between FTP grade 2 and grade 3, grade 4 (P < 0.05) was significantly different. With the increasing of FTP grading, the constituent ratio of retroglossal obstruction had the tendency of increasing. The constituent ratio of retroglossal obstruction between the Friedman tonsil size grade 4 and grade 1, grade 3 (P < 0.01), grade 2 (P < 0.05) was significantly different.</p><p><b>CONCLUSIONS</b>Friedman staging system, in particular the FTP grading, had a correlation with upper airway pressure measurements (AG) in determination of the lower level of upper airway obstructive site, especially the retroglossal region, which could predict the main localization of upper airway obstructive site identified by upper airway pressure measurements during the sleep.</p>

Correlation between intrasac pressure measurements of a pressure sensor and an angiographic catheter during endovascular repair of abdominal aortic aneurysm

PURPOSE: To establish a correlation between intrasac pressure measurements of a pressure sensor and an angiographic catheter placed in the same aneurysm sac before and after its exclusion by an endoprosthesis. METHODS: Patients who underwent endovascular abdominal aortic aneurysm repair and received an EndoSureTM wireless pressure sensor implant between March 19 and December 11, 2004 were enrolled in the study. Simultaneous readings of systolic, diastolic, mean, and pulse pressure within the aneurysm sac were obtained from the catheter and the sensor, both before and after sac exclusion by the endoprosthesis (Readings 1 and 2, respectively). Intrasac pressure measurements were compared using Pearson's correlation and Student's t test. Statistical significance was set at p<0.05. RESULTS: Twenty-five patients had the pressure sensor implanted, with simultaneous readings (i.e., recorded by both devices) obtained in 19 patients for Reading 1 and in 10 patients for Reading 2. There was a statistically significant correlation for all pressure variables during both readings, with p<0.01 for all except the pulse pressure in Reading 1 (p<0.05). Statistical significance of pressure variations before and after abdominal aortic aneurysm exclusion was coincident between the sensor and catheter for diastolic (p>0.05), mean (p>0.05), and pulse (p<0.01) pressures; the sole disagreement was observed for systolic pressure, which varied, on average, 31.23 mmHg by the catheter (p<0.05) and 22 mmHg (p>0.05) by the sensor. CONCLUSION: The excellent agreement between intrasac pressure readings recorded by the catheter and the sensor justifies use of the latter for detection of post-exclusion abdominal aortic aneurysm pressurization.

A Biomechanical Analysis on Disc Pressure Distribution Changes with Interspinous Spinal Spacer Insertion for Lumbar Spinal Stenosis / 대한정형외과학회잡지

PURPOSE: To assess the biomechanical effects and effectiveness of an interspinous spinal spacer (ISS) on the intradiscal pressure using in vitro biomechanical tests. MATERIALS AND METHODS: Six calf spine specimens (less than 2 weeks of age, L1-L5) were divided to two groups the intact and the surgery groups (n=3 each). For the surgery group, an ISS made from PMMA (Greek pi=12-mm) were inserted into the space between the spinous processes of L3-L4. The intradiscal pressures at the various regions of the annulus (anterior, posterior, and posterolateral locations) and the nucleus pulposus were measured using the four pressure transducers under pure compression (700 N) and extension loads (700 N+7.5 Nm). RESULTS: An increase in pressure was observed from neutral to extension at the posterior and posterolateral annulus. After inserting the ISS, the changes in pressure at the adjacent disc levels (L2-L3, L4-L5) were negligible regardless of the loading conditions (p>0.05). However, at the implanted level (L3-L4) statistically significant changes in the pressure were found under extension loading at the nucleus pulposus, posterior and posterolateral regions of the annulus with a pressure drop from 1.48 MPa, 1.42 MPa, 1.71 MPa to 1.11 MPa, 0.961 MPa, 1.08 MPa, at the respective locations (p<0.05). The relative percentage decrease were 25%, 31.7%, and 36.8%. CONCLUSION: On the implanted level, these results showed that the insertion of the ISS with PMMA can effectively reduce the intradiscal pressures by at least 25% quite uniformly over the intravertebral disc during extension. More effective reduction was observed at the posterolateral location. The pressure changes at the adjacent levels were negligible in contrast to the abnormal pressure changes that are frequently reported after conventional rigid fusion. This suggests that the likelihood of adjacent level degeneration after surgery can be minimized using the ISS insertion.

The Changes of Natural Frequency and Damping Coefficient of Disposable Pressure Transducer according to the Catheter Length and Time Assigned / 대한마취과학회지

BACKGOUND: The accuracy of a disposable blood pressure transducer (DBPT) is determined by its physical properties: natural frequency (NF) and damping coefficient (DC). We planned this study to investigate whether the NF and DC of a DBPT are altered by attaching extended catheters and evaluated changes of these physical properties over time. METHODS: Fifteen DBPT sets were connected to a monitor and recorder set. These sets were divided into three groups; five sets had catheters of normal length (Group 1), five sets had 50 cm extended catheters (Group 2), and five sets had 100 cm extended catheters (Group 3). The NF and DC of each system were measured using the fast flush (FF) test. After the DBPT sets were installed, the FF test was performed for each group at five time intervals: 4, 24, 48, 72, and 96 hours. RESULTS: The NF of Groups 2 and 3 decreased and their DC increased compared to those of Group 1. Whereas the NF of Group 3 increased over time, those of Groups 1 and 2 did not. The DC of Groups 2 and 3 decreased over time, but remained unchanged over time for Group 1. When the FF test was done at intervals longer than 24 hours, it was found that the NF, but not the DC, increased for all groups. CONCLUSIONS: Attention should be paid to interpret blood pressure using DBPTs measured by extended catheters and using DBPTs for long periods of time without FFs.

Intrasellar pressure and tumor volume in pituitary tumor: relation study / Relação entre pressão intra-selar e volume de tumor de hipófise

OBJECTIVE: To determine if there was a relationship between intrassellar pressure (ISP) and pituitary tumor volume. METHOD: Between August 2002 and May 2004, 60 patients aged between 13 and 75 years old (39 males), having a pituitary adenoma were submitted to an endoscope transseptal approach. During the surgery and before tumor resection, 2 mm of the sellaÆs floor were removed and a 1.5 mm dural opening made to place a transducer into the pituitary adenoma. The transducer was connected to a pressure monitor. RESULTS: The intrasellar pressure, ranged from 2-51 mmHg and was measured based on the classification of Hardy-Vezina. The most elevated was in the type II macro adenomas with 32.6 mmHg, sharply superior to the value of a normal intracranial pressure. CONCLUSION: These values showed that the macroadenomas confined to the sella, without destruction of the floor and integrity of the diaphragm, type II of Hardy-Vezina, presented a value of ISP much higher than intra-extrasellar macroadenomaÆs.

OBJETIVO: Determinar se existia uma relação entre a pressão intraselar (ISP) e o volume de tumor de hipófise. MÉTODO: Entre agosto de 2002 e maio de 2004, 60 pacientes com idades variando entre 13 e 75 anos (39 homens), portadores de adenoma hipofisários foram operados por via transesfenoidal. Durante o ato cirúrgico e antes da resseção do tumor, uma osteotomia de 2 mm foi realizada no assoalho selar e uma abertura de 1,5 mm na duramater para a introdução de um transdutor dentro do tumor. O transdutor foi conectado a um monitor de pressão e esta foi medida por 2 minutos. RESULTADOS: A pressão intra-selar variou entre 2-51 mmHg e a correlação entre tamanho do tumor e ISP foi baseada na classificação de Hardy-Vezina. A média da ISP mais elevada foi encontrada nos macroadenomas tipo II com 32,6 mmHg, nitidamente superior a pressão intra selar normal. CONCLUSÃO: Estes valores mostram que os macroadenomas confinados a sela sem destruição do assoalho selar e com integridade do diafragma, classificados como tipo II de Hardy-Vezina, apresentam uma ISP muito superior aos outros adenomas.

Computerized invasive measurement of time-dependent intraocular pressure

Several methods have been described to measure intraocular pressure (IOP) in clinical and research situations. However, the measurement of time varying IOP with high accuracy, mainly in situations that alter corneal properties, has not been reported until now. The present report describes a computerized system capable of recording the transitory variability of IOP, which is sufficiently sensitive to reliably measure ocular pulse peak-to-peak values. We also describe its characteristics and discuss its applicability to research and clinical studies. The device consists of a pressure transducer, a signal conditioning unit and an analog-to-digital converter coupled to a video acquisition board. A modified Cairns trabeculectomy was performed in 9 Oryctolagus cuniculus rabbits to obtain changes in IOP decay parameters and to evaluate the utility and sensitivity of the recording system. The device was effective for the study of kinetic parameters of IOP, such as decay pattern and ocular pulse waves due to cardiac and respiratory cycle rhythm. In addition, there was a significant increase of IOP versus time curve derivative when pre- and post-trabeculectomy recordings were compared. The present procedure excludes corneal thickness and error related to individual operator ability. Clinical complications due to saline infusion and pressure overload were not observed during biomicroscopic evaluation. Among the disadvantages of the procedure are the requirement of anesthesia and the use in acute recordings rather than chronic protocols. Finally, the method described may provide a reliable alternative for the study of ocular pressure dynamic alterations in man and may facilitate the investigation of the pathogenesis of glaucoma.

A new type of plantar-pressure distribution measuring system and its application / 生物医学工程学杂志

It has been shown from medical researches that many diseases are major causes of foot morbidity, which are deeply related to the abnormality of the plantar pressure distribution. In this respect, we made a new type of conductive rubber sensor and designed a dynamic contact pressure measuring system of plantar-pressure distribution with 251 testing points successfully. It includes the multipoint conductive rubber sensor, the interface circuit and the computer data collecting and progressing system. The measuring system can give the intuitional and full-scale image results with the full-court, real time testing. Also in this paper are introduced the design of the system, the testing results, and its applications in primary medical studies.

Nerve Regeneration and Detrusor Contractility after Muscle Precursor Cells Implantation in Unilateral Pelvic Nerve Transected Rat / 대한비뇨기과학회지

Purpose: Preliminary data suggest that muscle precursor cells (MPCs) play a role in the repair of injured tissues by responding to the release of unknown growth factors, which subsequently induce their differentiation toward a given lineage, such as a nerve cell. The author explored the potential use of these cells for facilitating the regeneration of the peripheral pelvic autonomic nerve. Materials and Methods: MPCs were isolated from the gastrocnemius muscle of normal rats, which were purified via the preplate technique. In this study, 15 male Sprague-Dawley rats weighting 250 to 300 grams were used. Three experimental groups were included: a control group (C, n=5), a unilateral pelvic nerve transected group, with a sham (Hank's balanced salt Solution) injection (S, n=5), and a unilateral pelvic nerve transected group, with MPCs injections (3x10(5)cells) at the site of transection (M, n=5). Two weeks after surgery, a polyethylene tube-50 connected to a pressure transducer was inserted into the dome of the bladder, and the intravesical pressures measured during electrical stimulation (20Hz, 0.05ms, 10v) of the proximal part of the transection of preganglionic pelvic nerve. Then, the rats were sacrificed, and the major pelvic ganglia (MPG) removed for immunohistochemistry of enkephalin. Results: The maximal intravesical pressures for the C, M and S groups were 28.5cmH2O, 13.5cmH2O and 8.6cmH2O, respectively (p<0.001). The pressure difference between the maximal pressure after electrical stimulation and the basal pressure before electrical stimulation for the C, M and S groups were 23.8cmH2O, 8.9cmH2O and 4.6cmH2O, respectively (p< 0.001). The intensity of pericellular immunoreactivity for enkephalin from the removed MPG was more markedly decreased in the S than C group, but was more markedly increased in the M than S group. Conclusions: MPCs can promote peripheral autonomic nerve regeneration, with good correlations between the functional and immunohistochemical results of neurorecovery effect of MPCs.

Research on the Cun-Guan-Chi Pulse Detecting System / 中国医疗器械杂志

The paper introduces the designing concept of the Cun-Guan-Chi Pulse Detecting System and its basic principles, and structural features. The system comprises 3 independent pressure sensors with same design parameters. It provides a scientific and quantitative method of detecting the pulses, which tallies well with the diagnostic method of the traditional Chinese medicine.