Merits of duplicate LAN cabling in hospitals.

Our hospital wired three LAN cables separately to improve the data distribution range. One LAN is between the various sections of the hospital (hospital LAN), another is within each section (section LAN), and the other is connected to the Internet (open LAN). The section LAN was connected to the hospital LAN to enable data exchange. Data from the section LAN for common use is collected through the hospital LAN and stored in the central server The duplicate cabling and separate LANs increased the independence of each LAN and the system within each section. The section systems can be changed at anytime without the necessity of reconstructing the whole hospital information system. The data transfer speed of each cable increased. Hospital information processing systems often use a distributed-processing centralized management system. Because of advances in technology, each section can now take responsibility for developing their own system, making the responsibility of the information processing section responsible for hospital information systems more limited than previously. Herein, we show the merits of separate cable installation.

Energy consumption during level walking with arm and knee immobilized.

OBJECTIVE: To determine whether there is an increase in energy use for able-bodied subjects with their arm and/or knee immobilized, while walking on a level surface at comfortable walking speed (CWS). DESIGN: Prospective, quantitative, with randomly sequenced experimental trials. SETTING: Rehabilitation center. PARTICIPANTS: Ten healthy subjects, none of whom had gait abnormality. INTERVENTION: Subjects walked on a treadmill at CWS under 4 conditions: (1) without an arm or knee immobilized (N); (2) with an arm immobilized (AI); (3) with a knee immobilized (KI); and (4) with both arm and ipsilateral knee immobilized (KAI). MAIN OUTCOME MEASURES: Breath-by-breath oxygen cost; differences in energy consumption in trials during which constraints were used were compared with energy consumed under the N condition and the percentage of change was calculated. RESULTS: Mean oxygen cost increased by 22.7% with a knee immobilized compared with N values (mean difference,.044 mL x kg(-1) x m(-1), p <.0001), and increased by 24.7% with a knee and arm immobilized (mean difference,.048 mL x kg(-1) x m(-1), p <.0001). However, no significant differences existed in oxygen cost with AI compared with N, or with KAI compared with KI. The differences in CWS between the stages followed a similar pattern. CONCLUSIONS: Arm immobilization does not increase energy expenditure during level walking at CWS, and does not further increase energy expenditure when the ipsilateral knee also is immobilized.

Measuring leg-length discrepancy by the "iliac crest palpation and book correction" method: reliability and validity.

OBJECTIVE: To determine the reliability and validity of a clinical measurement of leg-length discrepancy (LLD), by using the iliac crest palpation and book correction (ICPBC) method. DESIGN: Intra- and interrater reliability and validity determinations. SETTING: Rehabilitation center. PARTICIPANTS: Thirty-four healthy subjects, none of whom had an apparent LLD, as determined by iliac crest palpation. INTERVENTIONS: We induced a simulated LLD (7-53 mm) for each subject. To measure the LLD, the examiner performed the ICPBC method by palpating the iliac crests and correcting identified differences with a book opened to the required number of pages. The thickness of the book correction was measured. MAIN OUTCOME MEASURES: Reliability LLD measurement (n = 20), by using the ICPBC method to measure the LLD; construct validity (n = 34), comparing ICPBC measurement with the extent of the induced LLD; and concurrent validity (n = 14), the difference in heights of the superior aspect of the femoral heads from standing radiographs. RESULTS: The intraclass correlation coefficients (ICCs) for the intrarater and interrater reliabilities were.98 and.91, respectively. The ICCs for the construct and concurrent validities were.62 and.76, respectively. The ICPBC method underestimated the induced LLD by a mean difference +/- standard deviation of 3.8 +/- 10.3mm (p =.055) and the radiologic measure by 5.1 +/- 8.6 mm (p =.043). CONCLUSIONS: The ICPBC technique for measuring LLD is highly reliable and moderately valid. When there is no history of pelvic deformity and the iliac crests can be readily palpated, we recommend using iliac crest palpation to detect LLD, and the book correction to quantify it.

Possible electromagnetic interference with electronic medical equipment by radio waves coming from outside the hospital.

Electromagnetic interference (EMI) with electronic medical equipment by radio waves from mobile telephone handsets has been reported and is currently receiving wide attention. The possibility of EMI with electronic medical equipment by radio waves coming into the hospital has also been pointed out. But so far, there are no reports measuring the frequency distribution of electric field intensity induced by incoming radio waves. Therefore, we measured electric field intensity induced by radio waves coming into our 11-floor hospital, which was under construction. The maximum intensity observed was about 200 V/m at 2.79 GHz, from airport surveillance radar waves. The maximum intensity induced by radio waves from cellular phone base stations was 1.78 V/m. These data show that various frequencies of radio waves are common in this urban area, and that they induce strong electricfield intensity. This strong electric field intensity might cause EMI with electronic medical equipment. Measurement of the electromagnetic environment should be done by each hospital in urban areas to prevent EMI with electronic medical equipment.

A simple computerized program for the calculation of the required sample size necessary to ensure statistical accuracy in medical experiments.

We developed a sample size estimation program (SSEP) with which medical researchers can easily estimate the appropriate sample size for a specific significance level and statistical power using their favorite WWW browsers. SSEP can estimate the sample sizes for six statistical methods by Monte-Carlo simulation: Student's t-test, Welch's t-test, Analysis of variance, Wilcoxon's rank sum test, Kruskal-Wallis test, and the Cochran-Armitage test for linear trends. The SSEP simulation programs were created using the SAS software macro language. Medical researchers can interactively use this program and determine reliable sample sizes when planning new prospective clinical studies and animal experiments.

Comparative pharmacodynamic analysis of Q-T interval prolongation induced by the macrolides clarithromycin, roxithromycin, and azithromycin in rats.

In order to evaluate the arrhythmogenic potency of macrolide antibiotics in a quantitative manner, we analyzed the influence of clarithromycin (CAM), roxithromycin (RXM), and azithromycin (AZM) on Q-T intervals from pharmacokinetic and pharmacodynamic points of view and in comparison with the potency of erythromycin (EM) previously reported by us for rats. Male Sprague-Dawley rats were anesthetized, and CAM (6.6, 21.6, and 43.2 mg/kg of body weight/h), RXM (20 and 40 mg/kg/h), and AZM (40 and 100 mg/kg/h) were intravenously injected for 90 min to obtain the time courses of drug concentrations in plasma and the changes in the Q-T intervals during and after the drug injections. Distinct Q-T interval prolongation of up to 10 ms was observed with CAM at its clinical concentrations. RXM and AZM evoked Q-T interval prolongation at concentrations higher than their clinical ranges. The potencies for Q-T interval prolongation, assessed as the slope of the concentration-response relationship, were 6.09, 0.536, and 0.989 ms. ml/microg for CAM, RXM, and AZM, respectively. There was hysteresis between the change in the Q-T intervals and the time course of the plasma concentration of each drug. The rank order of clinical arrhythmogenicity was estimated to be EM > CAM > RXM > AZM, as assessed from the present results and our previous report for EM. In conclusion, RXM and AZM were estimated to be less potent at provoking arrhythmia than EM and CAM. These results should be useful for making a safer choice of an appropriate agent for patients with electrocardiographic risk factors.

Advantages of low output mobile communication systems in hospitals.

Mobile telephone systems using radio waves with very low power outputs rarely interfere with electronic medical equipment, which allows them to be safely installed in hospitals. The Personal Handy-phone System, PHS, which was developed and is widely used in Japan, is one such system. It has many useful functions including voice communication, string message transfer, e-mail, an answering system limited to selected persons or groups, paging, automatic call transfer, and handset positioning. In this paper we discuss the benefits of these functions confer to hospital communication systems.

Electromagnetic interference with electronic medical equipment induced by automatic conveyance systems.

Electromagnetic interference (EMI) with electronic medical equipment induced by automatic conveyance systems is estimated. We measured the electric intensities of electromagnetic waves transmitted by three self-controlled electric truck systems. We also observed EMI with an infusion pump and a syringe pump set 1 m from the rail. The maximum electric field intensity was observed at the supplied current frequency in two systems with non-contact power supply mechanisms. The highest value, 137.0 dB microV/m, was measured just beside the rail. This is higher than the international electromagnetic immunity standard limit for electronic medical equipment. EMI may occur if electronic medical equipment is used within 2 m of the rail when the system contains an inductive power supply mechanism. With a contact power supply mechanism, the electric field intensity was much lower than that of the immunity standard. EMI should not occur even when electronic medical equipment is used just beside the rail.

A question and answer E-mail system for responding to query from the general public with which the system manager can identify delayed replies.

We constructed a question and answer system for direct delivery of E-mail queries from the general public to the proper hospital representative and with which the system administrator can monitor E-mail replies. The system consists of two sub-systems; one is an E-mail questionnaire sub-system that automatically delivers E-mail queries to the proper person and an E-mail reply monitor sub-system with which the system administrator can monitor the E-mail replies. The monitor system compares the origin address of the E-mail reply and the destination address on a questionnaire filled out at the time the query is made. In a test of the system, 56 queries were received in 31 days, with 37 replied to. The interval from receipt of an E-mail query to reply was calculated. Nineteen replies were submitted within 2 days.

A simple client-server system using a personal computer as the server.

Hospital information systems have recently grown into huge, complex systems. As a result, the cost of development and maintenance of application programs has increased and become a serious problem. We have constructed an order entry system using server-client architecture as part of a hospital intranet information system in which a personal computer is used as a server. Using a commercial database management system and software development tools, an easily maintained order entry system was developed within only three months by one programmer. Since slow response when the number of clients increased was possible, we measured turn-around times when one or ten clients accessed simultaneously. Turn-around times were 8 and 10 sec, respectively. Because we expect much better performance from personal computers in the near future, application systems using personal computers as Intranet servers will be cost and time effective and easy to develop and maintain.

An easily customized, random allocation system using the minimization method for multi-institutional clinical trials.

In a randomized clinical trial, random allocation of patients to treatment groups should be done to balance in the distribution of prognostic factors. Random allocation in a multi-institutional randomized clinical trial is conducted by a coordinating center, independent of the medical institution the attending doctor uses for his/her practice. This study provides a sophisticated system for doing an exact random allocation of patients to treatment groups. The minimization method proposed by Pocock was applied to this system to balance the distribution of prognostic factors between two treatment groups, even when the number of registered patients is relatively small (S.J. Pocock, Allocation of patients to treatment in clinical trial, Biometrics 35 (1979) 183-197). Furthermore, Zelen's method is used to balance the number of patients allocated to the two groups within each institution (M. Zelen, The randomization and stratification of patients to clinical trials, J. Chron. Dis. 27 (1974) 365-375.). This system was created by the 'PERL&RSQUO; language for writing common gateway interface (CGI) script, and can therefore, be easily extended to include data entry function by attending doctors as well as the random allocation function. This system is being used effectively in thirteen multi-institutional randomized clinical trials for stomach, colon-rectum and breast cancers in Japan.

Influence of extracellular K+ concentrations on quinidine-induced K+ current inhibition in rat ventricular myocytes.

Hypokalaemia is one of the important risk factors for development of torsades de pointes. We recently reported that hypokalaemia increased the electrocardiographic QT interval in rats treated with quinidine, but did not alter the arrhythmogenic potency of quinidine. In this study, we have investigated the influence of extracellular potassium concentration ([K+]o) on the inhibition of several types of cardiac potassium currents by quinidine. Such types of currents include the delayed rectifier potassium current (I(K)), the transient outward current (Ito), and the inward rectifier potassium current (I(K1)), as measured in isolated rat ventricular cells using patch-clamp techniques. Concentration-dependent effects of quinidine on I(K), Ito, and I(K1) were evaluated under both normal ([K+]o = 5.4 mM) and hypokalaemic ([K+]o = 3.5 mM) conditions. In contrast to both I(K) and Ito, which were barely influenced by changes in [K+]o, I(K1) was significantly inhibited by hypokalaemia. Furthermore, while quinidine suppressed both I(K) and Ito in a concentration-dependent manner, the inhibitory potency of quinidine on these currents was not influenced by changes in [K+]o. The respective normal and hypokalaemic IC50 values for quinidine were 11.4 and 10.0 microM (I(K)), and 17.6 and 17.3 microM (Ito). Although higher concentrations of quinidine were required to inhibit I(K1), the inhibitory potency of quinidine was also found to be insensitive to changes in [K+]o. Thus, in rats, the inhibitory potency of quinidine for the K+ current-types I(K), Ito and I(K1) is barely influenced by changes in [K+]o. These findings are consistent with our previous report showing that the QT-prolonging potency of quinidine was not altered under hypokalaemic conditions. However, whilst hypokalaemia does not affect I(K) or Ito, it can inhibit I(K1) and can result in QT prolongation in-vivo.

Determination of erythromycin, clarithromycin, roxithromycin, and azithromycin in plasma by high-performance liquid chromatography with amperometric detection.

In this study, a high-performance liquid chromatographic method was developed for the quantitative determination of erythromycin (EM), roxithromycin (RXM), and azithromycin (AZM) in rat plasma with amperometric detection under a standardized common condition using clarithromycin (CAM) as an internal standard. This method was also proved to be applicable for the determination of CAM by employing RXM as an internal standard. Each drug was extracted from 150 microl of plasma sample spiked with internal standard under an alkaline condition with tert.-butyl methyl ether. The detector cell potential for the oxidation of the drugs was set at +950 mV. The linearity of the calibration curves were preserved over the concentration ranges of 0.1-10 microg/ml for EM and RXM, and 0.03-3.0 microg/ml for CAM and AZM. Coefficients of variation and relative error were less than 9% and +/-7%, respectively. The analytical method presented here was proved to be useful for the investigation of the pharmacokinetic characteristics of EM, CAM, RXM, and AZM in rats.

A screening gate to prevent entry of mobile telephone handsets in the speaking/stand-by mode into prohibited and restricted areas.

Electromagnetic interference to electronic equipment by mobile telephone handsets is well known. We present an automatic screening gate that detects concealed mobile telephone handsets and classifies them by type. The screening method used in the gate does not require any additions to or reconstruction of mobile telephone systems.

Inhibitory effects of the antihistamines epinastine, terfenadine, and ebastine on potassium currents in rat ventricular myocytes.

We examined and compared the inhibitory effects of three non-sedating antihistamines, terfenadine, ebastine, and epinastine, on delayed rectifier potassium current (IK) and transient outward potassium current (Ito) of rat isolated ventricular myocytes, using a patch clamp technique. Terfenadine, ebastine and epinastine were found to inhibit IK with IC50 values of 5.96, 15.3 and 145 microM, respectively. Ito was suppressed by epinastine with an IC50 value of 69.5 microM. The order of arrhythmogenicity, assessed by the inhibition of IK, was ranked as terfenadine > ebastine > epinastine, consistent with that of the potencies of each drug for QT prolongation reported in rats.

A keyword search system for medical doctors to introduce their patients to specialists.

We developed an online keyword search system on a WWW server to help medical doctors to introduce their patients to specialists. The system stores special knowledge and advanced techniques of 287 medical specialists in Kyushu University Hospital. The data set was presented by the medical specialists themselves. Specialists can rewrite their data set using the browser anytime to keep their data set up to date. In addition, the specialists are reminded to keep their data set up to date by direct mail once a year. The system does not use any database management systems. We used only two text files and the "grep" command, one of the basic commands of the UNIX system. Then, it takes less than 1 sec to search one medical specialist's data set from 200 specialists' data sets. The system is useful not only inside the hospital but also for practitioners in the local area.

Pharmacodynamic analysis of the electrocardiographic interaction between disopyramide and erythromycin in rats.

Disopyramide (DP) is known to induce QT prolongation and Torsades de Pointes (TdP) when administered concomitantly with erythromycin (EM). To define and evaluate quantitatively the arrhythmogenic risk of the concomitant administration of DP and EM, we investigated the influence of EM on the pharmacokinetics and pharmacodynamics of DP in rats. The time profiles of change in QT interval and plasma concentration of each drug were evaluated during and after constant intravenous infusion of DP (6.0 or 15.0 mg/kg/h), EM (4.0 or 8.0 mg/kg/h), and coadministration of DP and EM (DP 6.0 mg/kg/h plus EM 4.0 mg/kg/h). Each agent induced QT prolongation at plasma concentrations within the therapeutic range in humans. DP-induced QT prolongation was proportional to its plasma concentration. In the case of EM, the Emax model with an "effect compartment" could explain the relationship between plasma EM concentrations and changes in QT interval. Although coadministration of EM with DP gave enhanced QT prolongation compared to dosing with DP alone, EM did not affect the pharmacokinetics of DP. In conclusion, it was shown that a pharmacodynamic interaction contributes to the electrocardiographic adverse reaction (i.e., QT prolongation) induced by coadministration of DP and EM in rats.

Hospital construction materials: poor shielding capacity with respect to signals transmitted by mobile telephones.

Electromagnetic interference (EMI) with electronic medical equipment by the handsets of mobile telephones is a well documented problem in hospitals. To gain information about how to build an EMI-free hospital and how to make rooms safe for mobile telephone handset use in the hospital building the authors measured the shielding capacities of a concrete wall, concrete blocks, a steel door, and steel-surfaced partition panels. The shielding capacities of these materials were 2-7 dB for the concrete wall, 6-8 dB for the concrete blocks, 19-27 dB for the steel door, and 20-37 dB for the steel-surfaced partition panels. These results indicate that care should be taken to shield electronic equipment from signals coming from neighboring rooms and from those under and above any patient room in which such equipment is in use. Electricity-conductive paint, electricity-conductive wallpaper, and electricity-conductive cloth are examples of inexpensive materials that can increase shielding capacity.

Effects of hypokalaemia on arrhythmogenic risk of quinidine in rats.

Plasma potassium concentration plays an important role in the induction of arrhythmia and is closely related to the arrhythmogenicity of various drugs. We quantitatively analyzed the influence of plasma potassium concentration on QT intervals before drug administration and on drug-induced QT prolongation, to estimate the risk of drug-induced arrhythmia under hypokalaemic conditions. The hypokalaemic models were produced by intraperitoneal administration of furosemide and hydrochlorothiazide in male Sprague-Dawley rats. The relationship between the changes in QT intervals and time profiles of plasma quinidine (QND) concentration were analyzed during constant intravenous infusion of QND (10 or 30 mg/kg/h) and post infusion in normal and hypokalaemic rats. The plasma QND concentration reached the therapeutic range (3-7 microg/ml) at the high infusion rate (30 mg/kg/h). No pharmacokinetic differences between normal and hypokalaemic rats were observed. QND induced QT prolongation in parallel with the plasma concentration without hysteresis. Although the potency of QND for QT prolongation was not affected by hypokalaemia, the QT intervals before drug administration were significantly prolonged in hypokalaemic rats (65.90 +/- 1.40 vs 56.60 +/- 0.748 msec, mean +/- SEM, p < 0.0001). Thus, the prolongation of QT intervals before drug administration may act as a risk factor of arrhythmia under hypokalaemic conditions.

Remote connection to the Kyushu University Medical Center LAN using digital and analog telephone lines.

SOHO (Small Office/Home Office) has recently become popular, as it makes working at home possible. Computers or Local Area Networks(LAN) connected to the office network from home are necessary for the implementation of this concept. Kyushu University has begun a service connecting home computers to the campus LAN for researchers, staff and students of the Faculty of Medicine. We have two different telephone connection methods. One connects the campus LAN and the home computer LAN using routers through the Integrated Services Digital Network (ISDN). The other connects computers at home to the workstation in the university, using modems and the PPP (Point to Point Protocol) through a public telephone analog line. This paper outlines our university SOHO connection system and discusses the merits and demerits of using telephone line connections.