Effects of clear visual input and change in standing sequence on standing sway related to falls during night toilet use.

AIM: The aim of this study is to provide objective evidence that clear visual input and change in standing sequence can reduce fall risk related to night toilet use among hospitalized older patients. BACKGROUND: In hospitalized older patients, falls are likely to occur during night toileting needs. METHOD: Using a stabilometer, we measured and compared maximal standing sway for 10 seconds immediately after standing with three visual input modes in two standing patterns, comparing healthy younger adults (n=22) and older patients (n=19). The three modes are no visual input (mode 1), vague (mode 2), and clear visual input (mode 3). Standing sequences A and B are defined as supine-to-standing and supine-to-sitting-to-standing, respectively. RESULTS: For a given visual mode, maximal moved distance was significantly greater for older patients than for younger adults with both standing patterns (P<0.0001). Both standing pattern B and clear visual input decreased maximal moved distance in younger adults and older patients. A greater maximal moved distance score indicated a greater fall risk. RELEVANCE TO CLINICAL PRACTICE: It is important for nurses to train older patients to turn on the light and perform standing pattern B, when going to the bathroom at night. In addition, it is advisable to confirm the placement of distinct visual markers on the way to the bathroom.

A wireless breathing-training support system for kinesitherapy.

We have developed a new wireless breathing-training support system for kinesitherapy. The system consists of an optical sensor, an accelerometer, a microcontroller, a Bluetooth module and a laptop computer. The optical sensor, which is attached to the patient's chest, measures chest circumference. The low frequency components of circumference are mainly generated by breathing. The optical sensor outputs the circumference as serial digital data. The accelerometer measures the dynamic acceleration force produced by exercise, such as walking. The microcontroller sequentially samples this force. The acceleration force and chest circumference are sent sequentially via Bluetooth to a physical therapist's laptop computer, which receives and stores the data. The computer simultaneously displays these data so that the physical therapist can monitor the patient's breathing and acceleration waveforms and give instructions to the patient in real time during exercise. Moreover, the system enables a quantitative training evaluation and calculation the volume of air inspired and expired by the lungs.

A system for monitoring cardiac vibration, respiration, and body movement in bed.

We have developed a non-invasive system for monitoring cardiac vibrations, respiration and body movement of in-bed hospitalized patients and elderly people who need constant care. These physiological parameters are recorded by 40 kHz ultrasonic transmitter and receiver, which are installed into the bed mattress. The ultrasonic transmitter diffuses an ultrasonic wave into the mattress. The diffusion of the ultrasonic energy is changed by mattress shape variations, which modulate the amplitude of the received ultrasonic signal. The amplitude is also modulated by physiological parameters such as heart pulse, respiration and body movement. The received ultrasonic signal is demodulated by an envelope detection circuit, and the physiological parameters are detected by low, high and band pass filters.

A new venous infusion pathway monitoring system.

A new infusion catheter pathway monitoring system employing linear integrated circuits and a low-power 8-bit single chip microcomputer has been developed for hospital and home use. The sensor consists of coaxial three-layer conductive tapes wrapped around the polyvinyl chloride infusion tube. The inner tape is the main electrode, which records an AC (alternating current) voltage induced on the patient's body by electrostatic coupling from the normal 100 volt, 60 Hz AC power line wiring field in the patient's room. The outside tape layer is a reference electrode to monitor the AC voltage around the main electrode. The center tape layer is connected to system ground and functions as a shield. The microcomputer calculates the ratio of the induced AC voltages recorded by the main and reference electrodes and if the ratio indicates a detached infusion, alerts the nursing station, via the nurse call system or low transmitting power mobile phone.

A new mobile phone-based ECG monitoring system.

We have developed a system for monitoring a patient's electrocardiogram (ECG) and movement during daily activities. The complete system is mounted on chest electrodes and continuously samples the ECG and three axis accelerations. When the patient feels a heart discomfort, he or she pushes the data transmission switch on the recording system and the system sends the recorded ECG waveforms and three axis accelerations of the two prior minutes, and for two minutes after the switch is pressed. The data goes directly to a hospital server computer via a 2.4 GHz low power mobile phone. These data are stored on a server computer and downloaded to the physician's Java mobile phone. The physician can display the data on the phone's liquid crystal display.

A mobile phone-based ECG monitoring system.

We have developed a telemedicine system for monitoring a patient's electrocardiogram during daily activities. The recording system consists of three ECG chest electrodes, a variable gain instrumentation amplifier, a low power 8-bit single-chip microcomputer, a 256 KB EEPROM and a 2.4 GHz low transmitting power mobile phone (PHS). The complete system is mounted on a single, lightweight, chest electrode array. When a heart discomfort is felt, the patient pushes the data transmission switch on the recording system. The system sends the recorded ECG waveforms of the two prior minutes and ECG waveforms of the two minutes after the switch is pressed, directly in the hospital server computer via the PHS. The server computer sends the data to the physician on call. The data is displayed on the doctor's Java mobile phone LCD (Liquid Crystal Display), so he or she can monitor the ECG regardless of their location. The developed ECG monitoring system is not only applicable to at-home patients, but should also be useful for monitoring hospital patients.

A new infusion pathway monitoring system utilizing electrostatic induced potential.

We have developed a new infusion pathway monitoring system employing linear integrated circuits and a low-power 8-bit single chip microcomputer. The system is available for hospital and home use and it constantly monitors the intactness of the pathway. The sensor is an electro-conductive polymer electrode wrapped around the infusion polyvinyl chloride infusion tube. This records an AC (alternating current) voltage induced on the patient's body by electrostatic coupling from the normal 100 volt, 60 Hz AC power line wiring field in the patient's room. If the injection needle or infusion tube becomes detached, then the system detects changes in the induced AC voltage and alerts the nursing station, via the nurse call system or PHS (personal handy phone System).

Partial renal ischemia elicits heterogeneous control of renal sympathetic nerve activity to ischemic and nonischemic regions of the kidney.

We tested the hypothesis that renal sympathetic nerve activity (RSNA) to the ischemic and nonischemic regions responded differently during partial ischemia of the kidney in pentobarbital-anesthetized cats. The renal artery divides into two branches at the front of the renal hilus: one branch perfuses predominantly the dorsal half of the kidney, and the other perfuses its ventral half. We identified the innervated area of a renal nerve bundle by supramaximal electrical stimulation and subsequently determined the changes in RSNA in response to occlusion of either renal arterial branch for 3 min. RSNA to the nonischemic region of the kidney gradually decreased by 23 +/- 4% during partial renal ischemia, whereas RSNA to the ischemic region of the same kidney showed no significant change. Crushing either all renal nerve bundles or only the renal nerve bundles terminated to the ischemic region abolished the decrease in RSNA to the nonischemic region. Furthermore, intra-arterial administration of a prostaglandin synthesis inhibitor (meclofenamate, 4 mg/kg) abolished the decrease in RSNA to the nonischemic region of the kidney. Following spinal transection at the level of T7, the inhibitory response in RSNA to the nonischemic region disappeared, whereas the RSNA to the ischemic region was markedly augmented by 47 +/- 17%. Thus it is likely that renal chemoreceptors activated during renal partial ischemia elicit heterogeneous control of renal sympathetic outflows to the ischemic and nonischemic regions of the same kidney, which may be determined by a net output between the supraspinal inhibitory and spinal excitatory reflexes.

A new infusion pathway intactness monitoring system.

A new infusion pathway monitoring system has been developed for hospital and home use. The system consists of linear integrated circuits and a low-power 8-bit single chip microcomputer which constantly monitors the infusion pathway intactness. An AC (alternating current) voltage is induced on the patient's body by electrostatic coupling from the normal 100 volt, 60 Hz AC power line wiring field in the patient's room. The induced AC voltage can be recorded by a main electrode wrapped around the infusion polyvinyl chloride tube. A reference electrode is wrapped on the electrode to monitor the AC voltage around the main electrode. If the injection needle or infusion tube becomes detached, then the system detects changes in the induced AC voltages and alerts the nursing station, via the nurse call system or PHS (personal handy phone system).

A new intelligent bed care system for hospital and home patients.

An intelligent bed-care system has been developed for monitoring patient movements and behavior in the hospital and at home in order to prevent injuries from falls, a major problem in health care facilities. Falls, as well as patient activity immediately preceding falls (i.e. exiting the bed), are especially dangerous when infusion extubation also occurs. This new system detects in-bed infusion fluid leaks, bleeding due to infusion-tube pullout, and urine resulting from incontinence. It employs stainless steel tape and wire noncontacting electrodes, several linear integrated circuits, and a low-power, 8-bit single-chip microcomputer The electrodes are installed between the bed mattress and sheet to record changes in an always-present alternating current (AC) voltage, which is induced on the patient's body by electrostatic coupling from a 100-V, 60-Hz alternating current power line around the bed. The microcomputer uses changes in the induced alternating current voltage to detect the patient's movements before and after leaving the bed, as well as any fluid leakage. The microcomputer alerts the nursing station, via the nurse call system or personal handy phone (PHS), that the patient is in an active state; has a dangerous posture on the bed; is contaminating the sheet due to leaking, bleeding or incontinence; or is out of bed.

A wearable, mobile phone-based respiration monitoring system for sleep apnea syndrome detection.

A new wearable respiration monitoring system has been developed for non-invasive detection of sleep apnea syndrome. The system, which is attached to a shirt, consists of a piezoelectric sensor, a low-power 8-bit single chip microcontroller, EEPROM and a 2.4 GHz low-power transmitting mobile phone (PHS). The piezoelectric sensor, whose electrical polarization voltage is produced by body movements, is installed inside the shirt and closely contacts the patient's chest. The low frequency components of body movements recorded by the sensor are mainly generated by respiration. The microcontroller sequentially stores the movement signal to the EEPROM for 5 minutes and detects, by time-frequency analysis, whether the patient has breathed during that time. When the patient is apneic for 10 sseconds, the microcontroller sends the recorded respiration waveform during and one minute before and after the apnea directly to the hospital server computer via the mobile phone. The server computer then creates apnea "filings" automatically for every patient. The system can be used at home and be self-applied by patients. Moreover, the system does not require any extra equipment such as a personal computer, PDA, or Internet connection.

A motion control function evaluation system employing a pen tablet.

We have developed a new pen tablet based system for evaluation of hand motion control function as influenced by brain disease. The system consists of a laptop computer and a pen tablet data entry device. The pen tablet is placed in front of the subject who is instructed to tap the pen at a constant location. When the subject taps the pen, the tablet transfers the pen position to the laptop computer. The computer then saves the tap position, along with the time elapsed between each tap. The subject is instructed to tap 50 times with each hand with the eyes closed. The absolute distance moved between each two successive tap positions is detected. Tapping period, total tapping time and total distance moved are also calculated. Measurements were performed on ten normal subjects and three subjects with cerebral infarction. The results indicate that cerebral infarction subjects' average total tap point distance moved and absolute distance moved are greater than in the normal subjects. Conversely, all subjects in both groups produced only normal variations in tapping period and total tapping time. Our system can therefore quantitatively evaluate hand motion control function by the total and absolute distance moved.

An ECG electrode-mounted heart rate, respiratory rhythm, posture and behavior recording system.

R-R interval, respiration rhythm, posture and behavior recording system has been developed for monitoring a patient's cardiovascular regulatory system in daily life. The recording system consists of three ECG chest electrodes, a variable gain instrumentation amplifier, a dual axis accelerometer, a low power 8-bit single-chip microcomputer and a 1024 KB EEPROM. The complete system is mounted on the chest electrodes. R-R interval and respiration rhythm are calculated by the R waves detected from the ECG. Posture and behavior such as walking and running are detected from the body movements recorded by the accelerometer. The detected data are stored by the EEPROM and, after recording, are downloaded to a desktop computer for analysis.

Cardiovascular and intravesical pressure responses during natural micturition in conscious rats.

Urinary bladder distension is known to influence the cardiovascular system under a pathophysiological condition such as spinal cord injury, hypertension, and arteriosclerosis. A reflex due to bladder distension and/or contraction is considered as one reason for the cardiovascular disturbance associated with micturition. However, it has remained unknown how much intravesical pressure (IVP) rises during micturition in daily life and to what extent mean arterial blood pressure (MAP) and heart rate (HR) respond at that time. To answer these questions, we attempted to examine the direct changes in IVP, MAP, and HR during natural micturition in freely moving conscious rats. IVP increased from the baseline value of 4 +/- 0.2 mmHg to 14 +/- 0.5 mmHg during natural micturition. Although MAP and HR began to increase before micturition, the increases in MAP and HR became significant 1-4 s before its onset. The peak increases in MAP and HR (7 +/- 0.8 mmHg and 14 +/- 3 beats/min, respectively) were delayed by 2 s from the peak IVP. Following an administration of xylocaine into the urinary bladder, the increases in MAP and HR during micturition were significantly blunted to 5 +/- 2 mmHg and 8 +/- 3 beats/min, although IVP increased the same as it did during micturition without xylocaine. Moreover, the relationship between IVP and MAP or HR during natural micturition resembled that between IVP and the vesico-cardiovascular reflex responses during isovolumic bladder contraction in anesthetized rats. Therefore it is concluded that natural micturition in freely moving conscious rats accompanies the significant cardiovascular responses despite a limited increase in intravesical pressure, to which a reflex from the urinary bladder may substantially contribute.

Changes in functional and histological distributions of nitric oxide synthase caused by chronic hypoxia in rat small pulmonary arteries.

1. Chronic hypoxia (CH) increases lung tissue expression of all types of nitric oxide synthase (NOS) in the rat. However, it remains unknown whether CH-induced changes in functional and histological NOS distributions are correlated in rat small pulmonary arteries. 2. We measured the effects of NOS inhibitors on the internal diameters (ID) of muscular (MPA) and elastic (EPA) pulmonary arteries (100-700 micro m ID) using an X-ray television system on anaesthetized rats. We also conducted NOS immunohistochemical localization on the same vessels. 3. Nonselective NOS inhibitors induced ID reductions in almost all MPA of CH rats (mean reduction, 36+/-3%), as compared to approximately 60% of control rat MPA (mean, 10+/-2%). The inhibitors reduced the ID of almost all EPA with similar mean values (approximately 26%) in both CH and control rats. On the other hand, inducible NOS (iNOS)-selective inhibitors caused ID reductions in approximately 60% of CH rat MPA (mean, 15+/-3%), but did so in only approximately 20% of control rat MPA (mean, 2+/-2%). This inhibition caused only a small reduction (mean, approximately 4%) in both CH and control rat EPA. A neuronal NOS-selective inhibitor had no effect. 4. The percentage of endothelial NOS (eNOS)-positive vessels was approximately 96% in both MPA and EPA from CH rats, whereas it was 51 and 91% in control MPA and EPA, respectively. The percentage for iNOS was approximately 60% in both MPA and EPA from CH rats, but was only approximately 8% in both arteries from control rats. 5. The data indicate that in CH rats, both functional and histological upregulation of eNOS extensively occurs within MPA. iNOS protein increases sporadically among parallel-arranged branches in both MPA and EPA, but its vasodilatory effect is predominantly observed in MPA. Such NOS upregulation may serve to attenuate hypoxic vasoconstriction, which occurs primarily in MPA and inhibit the progress of pulmonary hypertension.

Sympathetic cholinergic vasodilation of skeletal muscle small arteries.

Recently we have studied the direct vasomotor response of the hindlimb extramuscular large arteries (internal diameter, 500-1400 microm) and intramuscular small arteries (internal diameter, 50-500 microm) of in vivo thick skeletal muscle during activation of sympathetic cholinergic nerve in anesthetized cats. The hypothalamic defense area was electrically stimulated so as to induce a profound increase in femoral blood flow mediated by sympathetic cholinergic fibers. To visualize the vascular arrangement from the extramuscular large feeding arteries to small arteries in the triceps surae muscle, we developed a new X-ray TV system. The internal diameter, flow velocity, and volume flow of arterial blood vessels were directly measured before and during stimulation of the hypothalamic defense area. The major new finding is that the hypothalamic stimulation causes an intense increase in the internal diameter of small arteries in skeletal muscle, which is abolished either by cholinergic blockade or by the section of the sciatic nerve, but not by combined alpha- and beta-adrenergic blockade. In contrast, the internal diameter of the extramuscular larger arteries does not change during the hypothalamic stimulation, but their flow velocity and volume flow increase. These findings indicate that sympathetic cholinergic vasodilation occurs at intramuscular small arteries with internal diameter of 50-500 microm, which in turn increases flow velocity and volume flow of upstream blood vessels.