In medical institutions, medical device alarm systems are effectively utilized in case of emergency; however, incidents and accidents related to medical device alarm systems have occurred. In this study, we extracted incident and accident cases which occurred in relation to medical device alarm systems and investigated their occurrence factors and the strategies to prevent their recurrence.
Using the data search system on the web site of Japan Council for Quality Health Care, we extracted events which occurred in relation to medical device alarm systems, etc., and investigated the summaries of events, their occurrence factors and the strategies to prevent their recurrence.
We examined 116 events which had been identified as of April 2015. Identified events included 55 events occurring when an alarm operated and 61 events occurring without alarm signal.
There are various background and causal factors of events that are related to medical device alarm systems. This study suggested the importance of not only the management of human factors such as a lack of understanding of persons involved in the alarm system, etc., but also the need for the system service to identify the root causes of events, then to establish measures, and to carry out and evaluate them.

In response to the changes of work shift system of medical doctors, we have been working to optimize hospital management system. We conducted investigation on the management of sterile devices and it was confirmed that surgical devices were properly cleaned, disinfected and stored. The number of the events on which sterile goods were returned to the storage area after sterilization was three or less. However, a lot of devices were found to be unused after the expiration of sterilization process. This is mainly because there are too many types and numbers of surgical instruments, though those numbers should have been appropriately controlled. We streamlined the type and number of surgical instruments to be sterilized based on the results of the investigation. We also conducted an education program on staff, established an operation standard and check whether the standard was properly observed. After monitoring staff activity by the participatory evaluation, we could reduce the number of human-related events. In the course of these approaches, the present study suggested that it is possible to extend the sterile shelf life of device in use to one year and special device to two years if stored in a closed case, as a result of the consideration to combine ERSM and TRSM to define sterile storage period standard.

A patient monitor is a medical device that allows the observation of condition or an acute change in vital signs. However, as the number of alarms increases, there have been cases where alarms are dismissed or ignored. Meanwhile, web cameras have been used to observe elderly individuals who live alone and patients with dementia. However, no current patient monitoring systems use real time patient imaging. The aim of this study is to develop a monitoring system to obtain the alarm information from medical devices and patient image at bedside on smartphones. We assessed its operation by alarms and abnormal ECG’s generated by use of a Human Patient Simulator. Our system successfully received and displayed the device ID, HR, SpO₂, different 13 potential alarms from the patient monitor and captures the patient image in a simulated environment in real time. Since our system was able to display the patient image and the user could know the reason why the alarm had occurred, we believe that our system is capable of complementing existing alarm systems.

Inspection for ensuring the safe use of medical devices is an essential work for patients’ safety in clinical settings. Only basic checking appearance and operations of the intermittent pneumatic compression devices (IPCD), which can prevent venous thromboembolism, had been conducted, but any specific inspections did not. Although the vinyl tube that connects the device to pressurized sleeves worn on the lower limbs can break easily, there were no ways to conduct a thorough leak check of the tube in demand. We co-developed with a local manufacturing company an intermittent pneumatic compression device tester (IPCD tester) that can assess the air pressure value in the IPCD compressor circuit and alert the air leak. The IPCD tester can also assess the tube and its connector. We used this tester and screened troubles of the IPCDs in our hospital. The tester could detect failures of the IPCDs easily and consequently we repaired them. The tester thus prevented the broken IPCDs to be supplied to patients, which can have an enough potential to prevent the venous thromboembolism.

The topical anesthetics like as EMLA^® cream are widely used to prevent pain caused by certain skin treatment procedures. However, they need more than an hour to obtain the sufficient analgesic effect of the cream. In this study, we developed a new method for reducing the time until emerging the analgesic effect by topical anesthetics, by co-administrating both acoustic vibrations and near-infrared rays are generated by a physiotherapy apparatus.
F344/NSlc inbred rats under isoflurane anesthesia were used and the effects of the anesthetic cream (EMLA^®)were evaluated in terms of the latency of electromyography activities induced by the avoidance behaviors to noxious thermal stimulus on their tails. The cut-off period was set as 30 seconds to prevent serious tissue damage. In control rats with EMLA^® cream-coated tails wrapped with sealing film, a significant anesthetic effect was observed 20 minutes after the application (p<0.05) Conversely, in experimental rats given both acoustic vibrations and near-infrared irradiations in addition to EMLA^® cream application, a significant anesthetic effect was achieved after only 5 minutes (p<0.05) These results indicated that the acoustic vibrations and near-infrared irradiations accelerated the onset of the action of topical anesthetics. Although further optimization of parameters is required, this method would have a potential early clinical applicability.

Light Emitting Diode (LED) lamps have become widespread in the clinical settings. However, electromagnetic noise from LED lamps could be problematic. In hospitals, the reception level of signals from medical telemeters might decrease after replacing traditional lighting with LED lamps. To investigate the effects of noise radiated from LED lamps on medical telemeters, we measured the electric field intensity of 34 types of LED lamps. Many of them emit 400 MHz band noise, and some types of LED lamps had increased floor level noise of 30 dB. We also observed artifact noises on electrocardiogram and respiratory waveforms when an LED lamp was placed next to the patient monitor. This effect was observed only when a medical telemeterʼs transmitter and a LED lamp were placed quite close. When approximately 50 cm apart, patient monitorsʼ signals were received normally. In hospitals, AC power supply cables and lamps are often placed near transmission cables, including leaky coaxial cables (LCX), as antenna of the patient monitors. To prevent interference with medical telemeters, selecting low noise LED lamps and maintaining sufficient separation between LED lamps and receiving antennas or LCX is necessary.