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Objective Prevalence of silent obstructive sleep apnea (OSA) in patients with dentofacial deformities is unknown, although OSA is severe risk of airway obstruction in perioperative orthognathic surgery or complication after surgery. The aim of this study was to investigate prevalence and risk factors of silent OSA in patients with dentofacial deformities. Methods We analyzed 72 patients (24 male, 48 female) with dentofacial deformities without previous OSA symptoms. Polysomnography was performed before orthognathic surgery. Prevalence and risk factors of silent OSA were statistically analyzed as related to Apnea hypopnea index (AHI). Results Mean AHI was 1.6 (range: 0-12.1) /h. Three patients of 72 patients (4.1%) were diagnosed silent OSA. AHI during REM sleep phase 3.7 (0-32.3) was higher than AHI during NREM sleep phase 1.0 (0-9.7). AHI of male patients was higher than that of female. AHI was increased according to high BMI. AHI was higher in deep bite than open bite, edge to edge bite and nomal bite. AHI of mandibular asymmetry cases were higher than that of symmetry cases. Conclusions The prevalence of silent OSA was 4.1%. Obesity, male, deep bite, mandibular asymmetry and REM sleep phase were risk factors of silent OSA.

The incidence of obstructive sleep apnea (OSA) immediately after surgery in patients with dentofacial deformities without previous OSA remains unknown. We aimed to perioperatively evaluate factors associated with oxygen desaturation index (ODI) during sleep, 7 days after bilateral splitting ramus osteotomy (BSSRO) in patients without previous OSA. Fifty-one patients (15 males, 36 females) with dentofacial deformities, scheduled to undergo BSSRO, were included. Polysomnography was performed before orthognathic surgery. Perioperative OSA was evaluated with peripheral arterial tonometry on the day of surgery and 1, 2, 3, 4, and 7 days postoperatively. Rapid eye movement (REM) sleep periods and the ODI were measured. Factors associated with perioperative ODI after surgery were statistically analyzed. REM sleep periods were significantly decreased on the day of surgery and significantly increased at 4 and 7 days postoperatively, compared to the preoperative period. ODI increased on the day of surgery, decreased after 1 day, and increased again at 4 and 7 days postoperatively. ODI on the day of surgery was significantly increased due to increased preoperative ODI, overjet, and SN-MP angle and decreased SNA and SNB angle. ODI at 7 days postoperatively was significantly increased due to increased REM sleep periods and decreased SN-MP and gonial angle. ODI was increased in response to REM sleep periods 7 days after BSSO. Airway management in patients with dentofacial deformity should be given more attention by preoperative assessment for OSA, even in the absence of previous OSA, until 7 days postoperatively due to REM rebound.

In the helium gas dilution method, functional residual capacity (FRC) is calculated from a helium concentra- tion equilibrium curve. In this study, we analyzed the helium concentration equilibrium curves of healthy patients, clarified the determinants of the equilibrium concentration, and studied the effects of an uneven lung distribution. We collected data from 200 patients (92 males and 108 females) whose FRC values had been measured at our institution over the past 6 years. Their FRC values ranged from 80% to 120%, and theit other pulmo- nary function values were within the normal range. In the compartmental model analysis, we discovered that the helium concentration equilibrium curve was composed of one compartment, and that it did not have a polyphasic structure. Each 0.25-minute (15-second) segment of the helium concentration equilibrium curve obtained from the patients was evaluated using univariate and multivariate regression analyses. The helium concentration equilibrium curve decreased exponentially over the time course of the analysis, and the multiple correlation coefficient for the relationship between the 0.25-minute to 0.75-minute segments and the 1.00-minute to 1.50-minute segments in the final model was 0.949. Finally, we examined the influence of an uneven peripheral lung distribution. A model based on the con- centration change seen between the initial and middle periods during at rest ventilation indicated that the latter parameter was not affected by the ventilation volume of the peripheral lung. [Original].

Objective Partial expiratory flow-volume curves have the potential to detect mild bronchoconstriction be- cause they are not affected by the modulatory effects of deep inspiration. The aim of this study was to inves- tigate the relationship between the efficacy of bronchodilator therapy (BDT) in treating the cough and to as- sess the increase in the expiratory flow of the partial flow-volume curve at 40% above the residual volume level (PEF40) caused by treatment with a short-acting beta-2 agonist (SABA) in patients with chronic nonpro- ductive cough. Methods We measured the reversibility of PEF40 caused by a SABA in 42 patients with chronic nonproduc- tive cough at visit 1 (day 0). The patients received BDT for six days. The visual analogue scale (VAS) was used to assess the efficacy of BDT in treating coughing at visit 2 (day 7) (0 mm, 'no cough;' 100 mm, 'no change in coughing'). Results Reversibility of the PEF40 was correlated (r=0.690, p

There have been a number of inconsistent previous reports indicating that mood disorder patients are relatively sensitive or conversely insensitive to physical pain. However, there have been few such studies examining pain using neurophysiological techniques. The present study was performed to investigate the differences in tactile sense recognition between mood disorder patients and control subjects using a tactile sense recognition P300 measuring system. Tactile stimuli were delivered to the index finger as frequent stimuli and to the ring finger as infrequent stimuli. Subjects were requested to press a button promptly and accurately in response to infrequent stimuli. N140 and P300 were measured in the event-related potential to infrequent stimulus paradigm. The subjects evaluated stimuli on a visual analog scale (VAS). The amplitudes of P300 were smaller for the mood disorder patients than for control subjects. The VAS scores of mood disorder patients were significantly higher than those of control subjects. In mood disorder patients, the amplitude of P300 was negatively correlated with the HAM-D score. These results suggest dysfunction of tactile sense recognition in mood disorder patients. In addition, the amplitude of P300 may be useful as a biological marker for psychological conditions in mood disorder patients.

We investigated possible functional changes in the vascular system accompanying the morphological change in prolonged nonpulsatile left heart bypass (LHB). Three adult goats underwent pulsatile LHB. Two weeks postoperatively, the pulsatile ventricular assist device was replaced with a centrifugal pump and nonpulsatile LHB was subsequently conducted for 4 weeks. The mean aortic pulse pressure was 39 and 16 mmHg during the pulsatile and nonpulsatile LHB, respectively. Systemic vascular resistance (SVR) and plasma norepinephrine levels were measured at the end of pulsatile LHB (PUL), and at the end of 1st, 2nd, 3rd, and 4th week of nonpulsatile LHB (NP1w, NP2w, NP3w, NP4w, respectively). At each point, 50 μg/kg nitroglycerin and 1μg/kg norepinephrine were injected and the minimal and maximal values of SVR after injection were calculated as parameters reflecting the vascular tonus and contractility. The SVR and plasma nor epinephrine level did not significantly change during the entire course (SVR: 1106, 895, 982, 920, and 938 dyne·sec·cm−5; norepinephrine level: 0.3, 0.2, 0.1, 0.2, and 0.1 ng/ml; at PUL, NP1w, NP2w, NP3w, and NP4w, respectively). The minimal value of SVR after nitroglycerin injection remained unchanged, indicating that vascular tonus was stable during the entire course (618, 687, 623, 560, 653 dyne·sec·cm−5, respectively). In contrast, the maximal value of SVR after norepinephrine injection at NP3w and NP4w (1695 and 1759 yne·sec·cm−5) became significantly reduced compared to that at PUL (2346 dyne·sec·cm−5). These results indicated that prolonged nonpulsatile left heart bypass did not affect the vascular tonus, but significantly diminished the vascular contractility.

The purpose of this experiment is to clarify the mechanism of drag reduction in the natural swimming of fish, whales and dolphins. It is well known that the change in their shape and the local deformation of their skin contribute to drag reduction, especially in the case of dolphins. Therefore, in order to understand the interaction between a deformable surface and the local flow pattern, RFFRC (rigid front flexible rear cylinder) models of a simplified marine animal were studied in a water tunnel. The laser light sheet method was used to visualize the flow field around the models. The vortex pair shedding period from the models, the deformation of the models' cross-sectional form and models' drag were measured simultaneously. The following results were obtained. For some types of RFFRC which could be deformed easily in response to a change in the local flow pattern with vortex shedding, the increase in flow velocity in the wake was observed. In the case the St number was about 20% higher than that of a rigid cylinder. Although, the drag that some types of RFFRC had was higher than that of the rigid one. However, the other types of RFFRC which could not quickly deform show no difference in St number, whereas the mean drag of this type was about 20% lower and the time variation of the drag became smaller than that of the rigid cylinder.

The purpose of this study is to clarify the mechanism of decreasing the drag in natural swimming of fish, whale and dolphin. A cylinder which has Elasto-flexible surface simplified marine creature was placed in a water tunnel, and using Laser Light Sheet method to visualize flow field around the model, vortex pair shedding period from the model, deformation of its cross-sectional form and hydrodynamical drag of the model were simultaneously measured. As a result, the following were found: the rigid front flexible rear cylinder model has showed about 20% higher St number than rigid cylinder model. The local deformation of the surface changed local flow pattern and wake due to some interaction between flexible surface and vortex. Time variation of the drag of the Rigid Front Flexible Rear Cylinder (RFFRC) became smaller than rigid one.

ホットパックは痛みを除去し筋緊張を和らげるために最も一般的に用いられる温熱療法である。しかしながら、臨床上では全く経験的に使用されており、それを再利用するのに適正な浸潰時間についての報告はない。本研究の目的はホットパックの適正なハイドロコレーター内浸潰時間を見いだすことにある。本研究のために、一日中浸されたホットパックを背部に30分間適用した。内ひとつのホットパックは再びハイドロコレーター内に浸され、その申心温度を測定した。さらに、他のホットパックはそれぞれ5、10、15そして20分の浸潰時間でハイドロコレーター内に浸され、その後、それぞれを背部に置き、直下の皮膚表面の温度を測定した。

Wall shear stress (WSS) has been considered to play an important role in the physiological and metabolic functions of the vascular endothelial cells. We investigated the effects of the pulse rate and the maximum flow rate on the WSS to clarify the influence of pulsatility. Water was perfused in a 1/2 inch transparent straight cylinder with a nonpulsatile centrifugal pump and a pulsatile pneumatic ventricular assist device (VAD). In nonpulsatile flow (NF), the flow rate was changed 1 to 6 L/min by 1 L/min increments to obtain standard values of WSS at each flow rate. In pulsatile flow (PF), the pulse rate was controlled at 40, 60, and 80 bpm, and the maximum flow rate was varied from 3.3 to 12.0 L/min while the mean flow rate was kept at 3 L/min. The WSS was estimated from the velocity profile at measuring points using the laser illuminated fluorescence method. In NF, the WSS was 12.0 dyne/cm2 at 3 L/min and 33.0 dyne/cm2 at 6 L/min. In PF, the pulse rate change with the same mean, and the maximum flow rate did not affect WSS. On the other hand, the increase in the maximum flow rate at the constant mean flow rate of 3 L/min augmented the mean WSS from 13.1 to 32.9 dyne/cm2. We concluded that the maximum flow rate exerted a substantial augmentative effect on WSS, and the maximum flow rate was a dominant factor of pulsatility in this effect.

We investigated the functional changes of the systemic vascular system due to prolonged nonpulsatile left heart bypass (NPLHB). Three adult goats underwent pulsatile left heart bypass (PLHB). Two weeks later the PLHB was changed to the NPLHB, which was conducted for 4 weeks. The aortic pulse pressure was 39 and 16 mm Hg during the PLHB and NPLHB, respectively. Systemic vascular resistance (SVR) and the plasma norepinephrine level were measured at the end of PLHB (PUL), and in the 1st, 2nd, 3rd, and 4th weeks of NPLHB (NP1w, NP2w, NP3w, and NP4w). At each point, 1 microg/kg norepinephrine was injected, and the elevation of the SVR (deltaSVR) was calculated. The SVR and the plasma norepinephrine level did not change significantly during the entire course. However, deltaSVR decreased during NPLHB and became significantly lower at NP3w and NP4w than that at PUL (NP3w: 839 +/- 164, NP4w: 746 +/- 268, and PUL: 1,239 +/- 324 dyne x s x cm(-5)). These results strongly indicated that prolonged NPLHB significantly diminished the constrictive function of the vascular system.

A novel integrated heart-lung assist device has been developed as a simple to use portable cardiopulmonary support system. The device comprises a centrifugal pump and an artificial lung, which is located around the pump, in an all in one system. The special membrane employed precludes plasma breakthrough in protracted use and enables preprimed setup. Test lungs consisting of the same membrane preserved gas exchange function well after 3 months of preprimed storage. The entire blood contacting surface is treated with covalent heparin bonding to impart good antithrombogenicity. Heparin bonded test lungs could be continuously perfused without systemic anticoagulation as long as 36 days in a venoarterial bypass chronic animal study using goats. The prototype device (diameter, 126 mm; height, 59 mm; membrane area, 0.85 m2; priming volume, 180 ml) demonstrated 9 L/min pump output at a 400 mm Hg pressure head and 180 ml/min oxygen and 110 ml/min carbon dioxide transfer rates at 5 L/min blood flow. We conclude that this device has potential to be the next generation cardiopulmonary support system.

We investigated the changes in cardiac autonomic nervous activities during long-term nonpulsatile left heart bypass (NLHB) by analyzing heart rate variability. A pulsatile ventricular assist device was installed in 3 goats, and pulsatile left heart bypass (PLHB) was conducted for 2 weeks. Then, NLHB was maintained for the following 4 weeks. The segmental data of the R-R intervals (R-Rs) was analyzed by maximum entropy spectral analysis. Changes in evaluated parameters from the last week of PLHB to the 4th week of NLHB were as follows: the mean R-Rs increased from 511 ms to 692 ms; the coefficient of variation of R-R increased from 10.2 to 14.1%; the power of the low frequency band (LF) increased from 747 ms2 to 2,855 ms2; the power of the high frequency band (HF) increased from 512 ms2 to 1,270 ms2; and the ratio of LF to HF increased from 2.6 to 6.5. These results indicated that the cardiac autonomic nervous activity, both sympathetic and parasympathetic, increased during long-term NLHB.

We have been developing an electrohydraulic total artificial heart system. The system comprises an intrathoracic pumping unit composed of diaphragm type ellipsoidal blood pumps and an energy converter in addition to an electronics unit. The in vivo performance of the pumping unit was evaluated in a series of animal implantations with 3 calves weighing 62-85 kg. An interatrial shunt 4.5 mm in diameter was made in the atrial septum to compensate left-right imbalance. Two calves died early postoperatively, one of external controller power failure and the other of interatrial shunt stenosis due to thrombus formation. One calf, however, survived over 10 days under stable circulatory conditions. No abnormality was found in the oxygen metabolic condition or in major organ functions. The generation and dissipation of heat from the device was acceptable. This animal died of device malfunction caused by energy converter bearing breakdown. The device demonstrated a good anatomic fit without compromising the great vessels and adjacent tissues. It is concluded that the pumping unit has a sufficient in vivo basic performance although appropriate countermeasures are to be implemented against the detected problems concerning mechanical durability and interatrial shunt patency.

We applied two different flow visualization techniques to obtain detailed information on the inside flow of the diaphragm blood pump of our electrohydraulic total artificial heart system to determine the optimum washout effect that would result in better antithrombogenicity. Major orifice directions of the inflow and outflow Bjork-Shiley valves of the left blood pump were independently changed to create 17 varied patterns. The character and velocity of the main flow at the diaphragm-housing junction were acquired using a laser light sheet method with polyethylene tracers. Wall shear flow, a major factor governing washout in the blood pump, was estimated by a newly developed paint erosion method. In this method, quantitative evaluation for an index of washout effect was made by calculating the residual ratio of the paint on the blood pump inner surface at 30 sec of pumping. When a single circular flow was consistently observed by the laser light sheet method, the paint residual ratio become low, indicating washout was relatively good. At the lowest paint residual ratio, the center of the circular flow observed by the laser light sheet method was located at the geometric center of the blood chamber. In conclusion, the flow pattern inside the blood pump could be characterized by combined use of these two flow visualization techniques, and the significant role of circular flow in better washout was clarified.

We investigated the morphological changes in the aorta due to reduced systemic pulse pressure in prolonged nonpulsatile left heart bypass (LHB). Nineteen adult goats were divided into 3 groups, the nonpulsatile group in which nonpulsatile LHB was conducted, the pulsatile group in which pulsatile LHB was conducted, and the control group used as the normal control. The average aortic pulse pressures were 12, 47, and 37 mm Hg, respectively. The descending aorta was subjected to morphological examination. In the nonpulsatile group, the wall was significantly thinner, and the volume ratio of smooth muscle cells (SMCs) was much lower. In terms of the SMC type classification, the proportion of SMCs with low activity and low contractility was higher, and the cell density of the SMCs was increased compared to those in the other groups. These results indicate that prolonged nonpulsatile LHB causes morphological atrophic changes in the aorta.

The authors evaluated the basic performance of an interatrial shunt (IAS) made by punching a hole in the atrial septum, in accommodating the left-right imbalance in our electrohydraulic total artificial heart (EHTAH) system. In an in vitro study conducted in a closed mock circuit connected with the EHTAH, the interatrial pressure gradient changed in compliance with the amount of bronchial flow and the size of the IAS. The IAS of 4.4 mm diameter or larger maintained the interatrial pressure gradient within physiologically permissible limits when the amount of bronchial flow was 5% of cardiac output or less. A left-to-right one-way valve made of a piece of pericardium, a possible option in this IAS method, successfully prevented right-to-left reverse shunt flow through the IAS. In a chronic in vivo study using a calf implanted with the EHTAH for 10 days, a 4.5 mm IAS without the one-way valve demonstrated satisfactory dynamic left-right balancing capacity with a stable interatrial pressure gradient of 4 +/- 1 mmHg over a wide range of atrial pressures. No thrombus was found in or around the IAS at autopsy. The authors conclude that the IAS is a simple and promising means of left-right balancing in the EHTAH system.

We have developed a novel image measurement technique called paint erosion method (PEM) to estimate wall shear stress (WSS). In the PEM, the WSS is estimated from the paint erosion rate obtained by the instantaneous change of light transmission power on the image. In this study, we attempted to depict WSS distribution of the diaphragm-type pulsatile blood pump in our total artificial heart by the PEM, and further compared the obtained WSS distribution with in vivo thrombus deposition area. The average WSS contour map inside the blood pumps were successfully obtained by using the PEM, and in vivo thrombus deposition area coincided with the low WSS of less than 2.7 Pa. We concluded that WSS mapping based on the PEM provides useful information for predicting the preference area of in vivo thrombus formation in a pulsatile blood pump and facilitates improving its antithrombogenicity from the viewpoint of flow dynamics.