We present the construction of the lab-on-a-chip (LOC) system, a state-of-the-art technology that uses polymer materials (i.e., poly[dimethylsiloxane]) for the miniaturization of conventional laboratory apparatuses, and show the potential use of these microfluidic devices in clinical applications. In particular, we introduce the independent unit components of the LOC system and demonstrate how each component can be functionally integrated into one monolithic system for the realization of a LOC system. In specific, we demonstrate microscale polymerase chain reaction with the use of a single heater, a microscale sample injection device with a disposable plastic syringe and a strategy for device assembly under environmentally mild conditions assisted by surface modification techniques. In this way, we endeavor to construct a totally integrated, disposable microfluidic system operated by a single mode, the pressure, which can be applied on-site with enhanced device portability and disposability and with simple and rapid operation for medical and clinical diagnoses, potentially extending its application to urodynamic studies in molecular level.
Disposable Equipment ; Lab-On-A-Chip Devices ; Micro-Electrical-Mechanical Systems ; Microfluidics ; Miniaturization ; Plastics ; Polymerase Chain Reaction ; Polymers ; Syringes ; Urodynamics

Implantable Neurostimulators ; Micro-Electrical-Mechanical Systems ; Microelectrodes

The paper proposed a new method to design and fabricate a flexible neural microelectrode arrays (MEA) for retinal prosthesis, the ion-beam technology was introduced to decrease the width of conductive wires and the distances between wires, a high density MEA (120 microelectrodes with a matrix of 10 x 12) was fabricated on a single layer of polymer from this. The MEA was proved to possess a fine electrochemical property. In vitro test, the average impedance of MEA on 1 kHz was 16 k omega +/- 2 k omega and the average phase difference was -85 degrees +/-30 degrees.
Micro-Electrical-Mechanical Systems ; Microelectrodes ; Prosthesis Design ; Visual Prosthesis

With a microsystem or micropump, the release rate of drug delivery is able to be controlled easily to maintain the therapeutic efficacy. A piezoelectric membrane-valve micropump for implantable and carryhome drug delivery system is developed and tested. The influence elements of dynamic performance of the PZT actuator and valve were analyzed, and the calculation method of resonant frequency of the membrane valve was provided. Study results showed that the output performance of the micropump depended on the coupling effect of the actuator and valve. For a given actuator, the output value and the optimal frequency of a micropump could be enhanced only by valve design. Two micropumps with different valve dimensions were fabricated for comparing examination. The smaller -valve micropump obtained higher output values (the maximum flow rate and backpressure being 3.5 ml/min and 27 KPa, respectively) and two optimal frequencies (800 Hz and 3 000 Hz). The larger -valve micropump achieved lower output values (the maximum flow rate and backpressure being 3.0 ml/min and 9 KPa, respectively) and one optimal frequency (about 200 Hz). The test results suggest that the output values and optimal frequency of micropump can be improved by changing the valve dimension, and the viewpoint that checkvalve micropump works only with low acting frequency is wrong.
Drug Delivery Systems ; instrumentation ; Equipment Design ; Humans ; Infusion Pumps, Implantable ; Micro-Electrical-Mechanical Systems ; instrumentation

It is very important to disrupt the stratum corneum structure and to create pathways allowing transport of macromolecules, as the traditional transdermal drug delivery has been severely limited by the skin barrier. With the development of the Micro Electro-Mechanical System (MEMS), it becomes possible for microneedles array to strengthen the transdermal drug delivery. In addition to the increase of the skin permeability, it can also be used to deliver drugs into skin, such as insulin and vaccine, providing a new direction for drug delivery systems. In this paper, we review the development and applications in transdermal drug delivery of microneedles' array. The commercial prospects and recommendations for the future research work are also represented.
Administration, Cutaneous ; Drug Delivery Systems ; instrumentation ; Equipment Design ; Micro-Electrical-Mechanical Systems ; Microinjections ; Needles

OBJECTIVES: Many patients with Alzheimer's disease have difficulty in taking their medicine by themselves and their poor drug adherence possibly results in aggravating various symptoms. The aim of this study was to assess the variables influencing drug adherence of Alzheimer's disease patients. METHODS: In a four-week period, 33 outpatients over 65 years old diagnosed with Alzheimer's disease were monitored. Drug adherences were assessed by the Medication Event Monitoring System (MEMS), the pill count, the clinician rating scale, and self-report. Agreements among adherence measures and the relationships between MEMS adherence and other clinical factors were assessed. RESULTS: The adherence rates for the MEMS, the pill count, the clinician rating scale and, self-report were 51.5%, 82.8%, 82.8%, and 87.9%. The Kappa coefficients were 0.382 (pill count vs. MEMS, clinician rating scale vs. MEMS) and 0.256 (self-report vs. MEMS). Males showed better adherence than females but the other clinical variables did not show significant differences between adherence group and non-adherence group. CONCLUSION: These findings suggest that clinicians should be concerned when assessing drug adherence in patients with Alzheimer's disease only by subjective reporting and pill counting since these methods may make patient's adherence underestimate. Clinicians should also take in mind that caregivers play an important role in improving adherence.
Alzheimer Disease ; Caregivers ; Dementia ; Female ; Humans ; Male ; Micro-Electrical-Mechanical Systems ; Outpatients

Various microrobots are being studied for potential biomedical applications including targeted cell transportation, precise drug delivery, opening blocked blood vessels, micro-surgery, sensing, and scaffolding. Precise magnetic field control system is a coil system for wireless control of those microrobots for personalized and minimally invasive treatments. The microrobots for possible biomedical applications are fabricated by micro-electro-mechanical systems (MEMS) and nano-electro-mechanical systems (NEMS) technologies. In this review, fabrication technologies for scaffold and ciliary microrobots will be introduced and their control methods will be discussed. Various materials are being used for the fabrication of the microrobot such as SU-8, IP-Dip, IP-L, silicon, etc. The scaffold and ciliary microrobots are fabricated by SU-8, IP-Dip, and IP-L because these materials showed the maximum performance for three-dimensional (3D) microrobots using a 3D laser lithography system. All or part of the structures are coated with nickel and titanium layers after fabrication of the structures for magnetic control and biocompatibility, respectively, of the microrobots.
Blood Vessels ; Humans ; Magnetic Fields ; Micro-Electrical-Mechanical Systems ; Nickel ; Silicon ; Titanium ; Transportation

Various microrobots are being studied for potential biomedical applications including targeted cell transportation, precise drug delivery, opening blocked blood vessels, micro-surgery, sensing, and scaffolding. Precise magnetic field control system is a coil system for wireless control of those microrobots for personalized and minimally invasive treatments. The microrobots for possible biomedical applications are fabricated by micro-electro-mechanical systems (MEMS) and nano-electro-mechanical systems (NEMS) technologies. In this review, fabrication technologies for scaffold and ciliary microrobots will be introduced and their control methods will be discussed. Various materials are being used for the fabrication of the microrobot such as SU-8, IP-Dip, IP-L, silicon, etc. The scaffold and ciliary microrobots are fabricated by SU-8, IP-Dip, and IP-L because these materials showed the maximum performance for three-dimensional (3D) microrobots using a 3D laser lithography system. All or part of the structures are coated with nickel and titanium layers after fabrication of the structures for magnetic control and biocompatibility, respectively, of the microrobots.
Blood Vessels ; Humans ; Magnetic Fields ; Micro-Electrical-Mechanical Systems ; Nickel ; Silicon ; Titanium ; Transportation

OBJECTIVE: The purpose of this study was to examine post-hospitalization outpatient drug adherence in patients with severe psychiatric illness, including bipolar disorder and schizophrenia, and to investigate factors associated with drug adherence. METHODS: Eighty-one patients diagnosed with schizophrenia or bipolar disorder who were hospitalized due to aggravation of psychiatric symptoms were monitored. At hospitalization, we conducted clinical assessments such as the Clinical Global Impression-Severity, Drug Attitude Inventory, Contour Drawing Rating Scale, Multidimensional Scale of Perceived Social Support scale, and patients' demographic factors. We measured drug adherence using the Medication Event Monitoring System (MEMS), pill count, and patients' self-report upon out-patients visits, 4 and 24 weeks after discharge. RESULTS: The mean values of the various measures of adherence were as follows: MEMS (4 weeks) 84.8%, pill count (4 weeks) 94.6%, self-report (4 weeks) 92.6%, MEMS (24 weeks) 81.6%, pill count (24 weeks) 90.6%, and self-report (24 weeks) 93.6%. The adherence agreement between MEMS, pill count, and self-report was moderate (4 weeks intra-class correlation [ICC]=0.54, 24 weeks ICC=0.52). Non-adherence (MEMS ≤0.08) was observed in 26.4% of the patients at 4 weeks and 37.7% at 24 weeks. There was a negative correlation between drug adherence assessed 4 weeks after discharge and Contour Drawing Rating Scale difference score (r=−0.282, p<0.05). A positive correlation was found between drug adherence assessed 24 weeks after discharge and Drug Attitude Inventory (r=0.383, p<0.01). CONCLUSION: Patients' attitude towards their medication and their degree of physical dissatisfaction influenced post-hospitalization drug adherence in severe psychiatric patients.
Bipolar Disorder ; Demography ; Drug Monitoring ; Hospitalization ; Humans ; Medication Adherence ; Micro-Electrical-Mechanical Systems ; Outpatients ; Schizophrenia

The paper describes how to develop a digital heart sound signal detection device based on high gain MEMS MIC that can accurately collect and store human heart sounds. According to the method of collecting heart sound signal by traditional stethoscope, the system improves the traditional stethoscope, and a composite probe equipped with a MEMS microphone sensor is designed. The MEMS microphone sensor converts the sound pressure signal into a voltage signal, and then amplifies, converts with Sigma Delta, extracts and filters the collected signal. After the heart sound signal is uploaded to the PC, the Empirical Mode Decomposition (EMD) is carried out to reconstruct the signal, and then the Independent Component Analysis (ICA) method is used for blind source separation and finally the heart rate is calculated by autocorrelation analysis. At the end of the paper, a preliminary comparative analysis of the performance of the system was carried out, and the accuracy of the heart sound signal was verified.
Heart ; Heart Sounds ; Humans ; Micro-Electrical-Mechanical Systems ; Signal Processing, Computer-Assisted ; Stethoscopes