Naoki Kobayashi

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Objective. Pulse dye-densitometry (PDD) is a newly developed methodfor monitoring the indocyanine green (ICG) concentration in an artery withwhich cardiac output (CO) and circulating blood volume (CBV) can bedetermined. We evaluated its accuracy for clinical use. Methods. In 7patients under general anesthesia, ICG-sensitive optical probes (805 and 890nm)(More)
BACKGROUND As the use of pulse oximeters increases, the needs for higher performance and wider applicability of pulse oximetry have increased. To realize the full potential of pulse oximetry, it is indispensable to increase the number of optical wavelengths. To develop a multiwavelength oximetry system, a physical theory of pulse oximetry must be(More)
OBJECTIVE Rapid noninvasive measurement of total hemoglobin would be extremely useful for various clinical situations. This study determined the clinical accuracy and utility for a pulse total-hemoglobinometer using four wavelengths: 660 nm (reduced hemoglobin), 805 nm (isosbestic point), 940 nm (oxygenated hemoglobin), and 1300 nm (water density). DESIGN(More)
The standard value for circulating blood volume (BV) during anesthesia was determined by a multicenter study in Japan. The significance of BV on the reduction of blood pressure after the induction of anesthesia was also examined. The study included 184 patients from eight university hospitals. After the induction of anesthesia, pulse dye-densitometry was(More)
Total hemoglobin (tHb), carboxyhemoglobin (COHb), and methemoglobin (MetHb) are usually measured with a CO-oximeter. Noninvasive and continuous measurement of these blood components is expected to decrease the pain of a patient. Therefore, we developed an instrument to measure oxygen saturation (SpO(2), tHb, COHb, and MetHb non invasively. Multiwavelength(More)
Oscillometric determination of blood pressure may be advantageous, as cuff inflation requires lower cuff pressure and shorter duration than deflation. In this observational study, we compared the blood pressure value, cuff pressure, and duration of cuff inflation between a prototype of inflationary non-invasive blood pressure (NIBP) and conventional(More)
We have developed the non-invasive blood pressure monitor which can measure the blood pressure quickly and robustly. This monitor combines two measurement mode: the linear inflation and the linear deflation. On the inflation mode, we realized a faster measurement with rapid inflation rate. On the deflation mode, we realized a robust noise reduction. When(More)
Capnometry is a method to measure carbon dioxide (CO(2)) in exhaled gas and its use during polysomnography (PSG) for diagnostic of sleep apnea-hypopnea syndrome is expanding. However, some problems exist for using capnometer in combination with other respiratory monitoring devices because capnometry requires additional sampling cannula or airway adapter(More)