Kevin K.C. Hung

Wearable medical devices for tele-home healthcare

The worlds ageing population and prevalence of chronic diseases have lead to high demand for tele-home healthcare, in which vital-signs monitoring is essential. An overview of state-of-art wearable technologies for remote patient-monitoring is presented, followed by case studies on a cuffless blood pressure meter, ring-type heart rate monitor, and Bluetooth/spl trade/-based ECG monitor. Aim of our project is to develop a tele-home healthcare system which utilizes wearable devices, wireless communication technologies, and multisensor data fusion methods. As an important part of this system, a cuffless BP meter has been developed and tested on 30 subjects in a total of 71 trials over a period of five months. Preliminary results show a mean error (ME) of 1.82 mmHg and standard deviation of error (SDE) of 7.62 mmHg in systolic pressure; while ME and SDE in diastolic pressure are 0.45 mmHg and 5.27 mmHg, respectively.

A near-infrared heart rate measurement IC with very low cutoff frequency using current steering technique

A near-infrared heart-rate measurement IC that processes the photoplethysmographic signal was designed using a 0.35-/spl mu/m CMOS technology. The IC consists of a current-to-voltage (I-V) converter, a buffer, a sample-and-hold circuit, a second-order continuous-time low-pass filter (CT-LPF), a comparator, and a timing circuit that is used to pulse the external light-emitting diode with a very low duty cycle to reduce its power consumption. The current steering technique is employed in the design of the CT-LPF to meet the requirement for very low cutoff frequency. The circuit operates from a 3-V lithium battery, occupies a core area of 0.46 mm/sup 2/ and has a power consumption of 4.5 mW. The measurement results corroborate with simulation results and show that the CT-LPF can achieve a cutoff frequency of as low as 0.25 Hz. This demonstrates the feasibility of current steering technique in the design of filter for low-frequency application.

Usage of Bluetooth/sup TM/ in wireless sensors for tele-healthcare

The small size and low power consumption of the radio module, use of spread spectrum, and the design for shortrange transmission make Bluetooth/spl trade/ an attractive option in medical sensors. Since Bluetooth/spl trade/ will continue to be a feature found in many devices it is worthwhile to investigate in its use in wireless medical sensors for home-based tele-healthcare. A wireless stethoscope has been implemented using Bluetooth/spl trade/ and PCM encoding. Preliminary results show that it is a feasible solution for transmission of heart and lung sounds. Design of a Bluetooth/spl trade/ wireless ECG is also proposed.

EMS systems in China.

The prehospital emergency service is the initial part of the Emergency Medical Service System (EMSS) in China, and is the de facto overall emergency medical service for China. As the EMSS in China continues to undergo rapid development, it faces the challenge of providing rapid response times with adequate coverage for this highly populated country. The recent Sichuan earthquake on 12 May 2008 tested the ability of the EMSS response. This article focuses on the prehospital emergency service of the EMSS and discusses the strengths and weaknesses of the current system.

Typhoon Haiyan and beyond

www.thelancet.com Vol 382 December 7, 2013 1873 Submissions should be made via our electronic submission system at http://ees.elsevier.com/ thelancet/ iloperidone, and lurasidone—are at the bottom of the efficacy and all-cause discontinuation figures, although there are no known pharmacological differences to explain these findings. Here, we suggest that they form a subclass of antipsychotics with administration issues that lower total drug exposure. We believe that pharmacokinetics can explain the diff erences in effi cacy of antipsychotics. First, some antipsychotics have characteristics that require more collaboration by patients during administration, which complicates drug regimen implementation in a population where half do not adhere to their treatment. Ziprasidone has to be taken with 500 calories, lurasidone with 350 calories, and asenapine has to melt under the tongue, cannot be swallowed, and cannot be exposed to drinks, food, or smoking for 10 min. Moreover, ziprasidone and asenapine require twice daily dosing, another unfavourable factor for implementation. Second, titration of iloperidone, ziprasidone, and aripiprazole is challenging in clinical practice— patients have intolerable side-eff ects before reaching therapeutic doses. In clinical trials with a fixed timepoint at 6 weeks, the titration delay can lower the fi nal score on effi cacy and aff ect results in a multiple-treatments meta-analysis. Furthermore, the lack of personalised titration schedules can lead to early discontinuation. We argue that, apart from clozapine, all antipsychotics could be equally eff ective if compared using therapeutic blood levels. Regulatory bodies should require these blood concentrations to approve future psychotropics. Comparing values for patients who received personalised medicine would give a better picture of the reality.

Travel health risk perceptions and preparations among travelers at Hong Kong International Airport.

Four levels of pre-travel health preparations were defined to allow the measurement of general travel health preparations by the traveling public. A cross-sectional survey of 770 travelers using Hong Kong International Airport was conducted. Important gaps were found in the self-preparation domain. Length of travel was the only factor associated with higher levels of health preparations after adjusting for potential confounders. Targeted health education should be considered to improve health risk perceptions among travelers in Hong Kong and other similar metropolitan cities that are critical hubs for commercial air transport.

A near-infrared heart rate sensor IC with very low cutoff frequency using current steering technique

In this paper, a near-infrared (NIR) heart-rate sensor IC, which will be used for portable biomedical application, was designed. This sensor consists of a current-to-voltage (I-V) converter, sample-and-hold (S/H) circuit, continuous time low-pass filter (CT-LPF), comparator and clock generation circuitry. Both switched-capacitor and current steering technique are used. The current steering technique is employed in the design of the CT-LPF due to the very low cutoff frequency requirement. As a result, only 20pF and 38pF capacitors are used to implement a 2/sup nd/ order filter with cutoff frequency of 18Hz. The circuit consumes 4.2mW when operating from a 3-V battery and occupies a core area of 0.46mm/sup 2/. The design was fabricated using 0.35/spl mu/m CMOS technology and simulation results show that the circuit works properly.

Predictors of Flight Diversions and Deaths for In-flight Medical Emergencies in Commercial Aviation

In-flight medical emergencies are clinically challenging and may result in aircraft diversions, which are costly and inconvenient, or in-flight deaths. We provide an updated description of in-flight medical emergencies and systematically examine predictors of medical flight diversions and in-flight deaths.

Disease pattern and chronic illness in rural China: The Hong Kong Red Cross basic health clinic after 2008 Sichuan earthquake

Medical teams might have difficulties preparing for deployment to rural towns due to a lack of prior information. The study objective was to identify the health needs and chronic disease prevalence of rural Chinese following a major earthquake.

Medical volunteers in commercial flight medical diversions.

BACKGROUND In-flight medical emergencies are difficult to manage and medical volunteers can be valuable when these events occur. The study objective was to examine the role of medical volunteers in medical emergencies which resulted in medical flight diversions. METHODS This was a retrospective cohort study of medical diversions in a large Hong Kong commercial airline from December 2003 to November 2008. This study is derived from a database of in-flight medical events which has been previously reported. The presence of medical volunteers, the need for diversion, and the outcome for all in-flight medical events were recorded. The records of the medical diversion incidents were reviewed in detail and symptom-based categorization applied. RESULTS Medical volunteers were available in 1439 (35.4%) of the 4068 medical events and in 39 (84.8%) of the 46 cases which required medical diversions. Suspected stroke cases, as categorized under the nonspecific category, was the most common, followed by chest pains and deaths. CONCLUSIONS Medical volunteers presented more often for more serious events, and may be due to the airline medical incident policy and medical legal concerns for volunteers. This study identified measures which may reduce medical diversions, including cabin crew training for stroke screening, and promote the use of the Medical Information Form (MEDIF) and indemnity forms. Recommendations for medical diversion may require more specialized training than is currently given in undergraduate medical courses, and may benefit from better communication with ground-based medical advice services.