Integrated interface electronics for capacitive MEMS inertial sensors

This thesis is composed of 13 publications and an overview of the research topic, which also summarizes the work. The research presented in this thesis concentrates on integrated circuits for the realization of interface electronics for capacitive MEMS (micro-electro-mechanical system) inertial sensors, i.e. accelerometers and gyroscopes. The research focuses on circuit techniques for capacitive detection and actuation and on high-voltage and clock generation within the sensor interface. Characteristics of capacitive accelerometers and gyroscopes and the electronic circuits for accessing the capacitive information in open- and closed-loop configurations are introduced in the thesis. One part of the experimental work, an accelerometer, is realized as a continuous-time closed-loop sensor, and is capable of achieving sub-micro-g resolution. The interface electronics is implemented in a 0.7-µm high-voltage technology. It consists of a force feedback loop, clock generation circuits, and a digitizer. Another part of the experimental work, an analog 2-axis gyroscope, is optimized not only for noise, but predominantly for low power consumption and a small chip area. The implementation includes a pseudo-continuous-time sense readout, analog continuous-time drive loop, phase-locked loop (PLL) for clock generation, and high-voltage circuits for electrostatic excitation and high-voltage detection. The interface is implemented in a 0.35-µm high-voltage technology within an active area of 2.5 mm². The gyroscope achieves a spot noise of 0.015 °/s/√H̅z̅ for the x-axis and 0.041 °/s/√H̅z̅ for the y-axis. Coherent demodulation and discrete-time signal processing are often an important part of the sensors and also typical examples that require clock signals. Thus, clock generation within the sensor interfaces is also reviewed. The related experimental work includes two integrated charge pump PLLs, which are optimized for compact realization but also considered with regard to their noise performance. Finally, this thesis discusses fully integrated high-voltage generation, which allows a higher electrostatic force and signal current in capacitive sensors. Open- and closed-loop Dickson charge pumps and high-voltage amplifiers have been realized fully on-chip, with the focus being on optimizing the chip area and on generating precise spurious free high-voltage signals up to 27 V

Associations Between Cohabitation, Marriage, and Suspected Crime : a Longitudinal Within-Individual Study

The effects of marriage on criminal behavior have been studied extensively. As marriages today are typically preceded by cohabiting relationships, there is a growing need to clarify how different relationship types are associated with criminality, and how these effects may be modified by relationship duration, partner's criminality, and crime type. We used Finnish longitudinal register data and between- and within-individual analyses to examine how cohabitation and marriage were associated with suspected crime. The data included 638,118 residents of Finland aged 0-14 in 2000 and followed for 17 years for a suspected crime: having been suspected of violent, drug, or any crime. Between-individual analyses suggested that those who were cohabiting or married had a 40-65% lower risk of being suspected of a crime compared to those who were single, depending on the type of crime. The within-individual analysis showed a 25-50% lower risk for suspected crime when people were cohabiting or married compared to time periods when they were single. Those in a relationship with a criminal partner had 11 times higher risk for suspected crime than those in a relationship with a non-criminal partner. Forming a cohabiting relationship with a non-criminal partner was associated with reduced criminality. The risk reduction was not fully explained by selection effects due to between-individual differences. Marriage did not introduce further reduction to criminality. Our findings demonstrate that selection effects partly explain the association between relationship status and criminality but are also compatible with a causal effect of cohabitation on reduced risk of being suspected of a crime.Peer reviewe

Analysis of weekend effect on mortality by medical specialty in Helsinki University Hospital over a 14-year period

Background: The weekend effect, the phenomenon of patients admitted at the weekend having a higher mortality risk, has been widely investigated and documented in both elective and emergency patients. Research on the issue is scarce in Europe, with the exception of the United Kingdom. We examined the situation in Helsinki University Hospital over a 14-year period from a specialty-specific approach. Materials and methods: We collected the data for all patient visits for 2000-2013, selecting patients with in-hospital care in the university hospital and extracting patients that died during their hospital stay or within 30 days of discharge. These patients were categorized according to urgency of care and specialty. Results: A total of 1,542,230 in-patients (853,268 emergency patients) met the study criteria, with 47,122 deaths in-hospital or within 30 days of discharge. Of 12 specialties, we found a statistically significant weekend effect for in-hospital mortality in 7 specialties (emergency admissions) and 4 specialties (elective admissions); for 30-day post-discharge mortality in 1 specialty (emergency admissions) and 2 specialties (elective admissions). Surgery, internal medicine, neurology, and gynecology and obstetrics were most sensitive to the weekend effect. Conclusions: The study confirms a weekend effect for both elective and emergency admissions in most specialties. Reducing the number of weekend elective procedures may be necessary. More disease-specific research is needed to find the diagnoses most susceptible. (C) 2020 Elsevier B.V. All rights reserved.Peer reviewe

Iatrogenic patient injuries in otology during a 10-year period : review of national patient insurance charts

Objective: To assess patient injury characteristics and contributing factors in otology. Methods: Data on the accepted patient-injury claims involving otorhinolaryngology (ORL), closed between 2001 and 2011, from the Finnish Patient Insurance Centre registry was retrieved. We included all injuries concerning otology, with evaluation and classification of their causes and types. Results: During the 10-year study period, a total of 44 claims were accepted as compensated patient injuries in otology. From a total of 233 patient injuries in all ORL, this amounted to 19%. In outpatient care, occurred 12 (27%) injuries and in surgical procedures 32 (73%). Five (11%) patients were children. Errors in surgical technique were identified as the primary cause of the injury in 22 (69%) operation-related cases. Failure to remove all auricular tampons or packing in postoperative control was a contributing factor in 4 (13%) injuries, a facial nerve was damaged in 9 (28%) operations, and in 12 (38%) patients, the injury resulted in severe hearing loss or deafness. Six patients (21%) needed one or more re-operations related to the injury, of which two were due to an incomplete primary operation. Conclusion: Typical compensated patient injuries in operative otology resulted from common complications of common operations in high volume centres.Peer reviewe

Weekend effect on mortality by medical specialty in six secondary hospitals in the Helsinki metropolitan area over a 14-year period

Background The weekend effect is the phenomenon of a patient's day of admission affecting their risk for mortality. Our study reviews the situation at six secondary hospitals in the greater Helsinki area over a 14-year period by specialty, in order to examine the effect of centralization of services on the weekend effect. Methods Of the 28,591,840 patient visits from the years 2000-2013 in our hospital district, we extracted in-patients treated only in secondary hospitals who died during their hospital stay or within 30 days of discharge. We categorized patients based on the type of each admission, namely elective versus emergency, and according to the specialty of their clinical service provider and main diagnosis. Results A total of 456,676 in-patients (292,399 emergency in-patients) were included in the study, with 17,231 deaths in-hospital or within 30 days of discharge. A statistically significant weekend effect was observed for in-hospital and 30-day post-discharge mortality among emergency patients for 1 of 7 specialties. For elective patients, a statistically significant weekend effect was visible in in-hospital mortality for 4 of 8 specialties and in 30-day post-discharge mortality for 3 of 8 specialties. Surgery, internal medicine, and gynecology and obstetrics were most susceptible to this phenomenon. Conclusions A weekend effect was present for the majority of specialties for elective patients, indicating a need for guidelines for these admissions. More disease-specific research is necessary to find the diagnoses, which suffer most from the weekend effect and adjust staffing accordingly.Peer reviewe

Patient injuries in pediatric otorhinolaryngology

Objectives: Patient injuries in children can have lifelong effects on the patient and a marked impact on the whole family. The aim of this study was to identify the errors and incidents leading to patient injuries in pediatric otorhinolaryngology (ORL) by evaluating accepted patient injury claims. Methods: The records of all accepted patient injury claims in ORL between 2001 and 2011 were searched from the nationwide Patient Insurance Centre registry. Pediatric injuries were reviewed and evaluated in detail, and factors contributing to injury were identified. Results: In the 10-year study period, 17 (7.6%) of the 223 patient injuries occurred in children, and of these, 15 (88%) were considered operative care. The median age of the patients was 8 years (range 3-16 years). All operations were performed as daytime elective surgery and by a fully trained specialist in 93% of the cases. One-half of the cases were routine surgeries for common ORL diseases. The most common incidences were incomplete surgery, retained gauze or foreign body, injury to adjacent anatomic structure, and insufficient charts or instructions (each occurred in 3 cases). The most frequent consequence was burn (n = 4). One child died because of post-tonsillectomy hemorrhage. Conclusions: Patient injuries in pediatric ORL are strongly related to surgery. Most injuries occurred after routine operations by a fully trained specialist. Clinicians should be aware of the most likely scenarios resulting in claims.Peer reviewe

Overstay and Readmission in Ear, Nose, and Throat Day Surgery—Factors Affecting Postanesthesia Course

Aims:Many procedures in ear, nose, and throat (ENT) day surgery are carried out under local anesthesia in Finland, whereas many other countries use general anesthesia. We investigated overstay and readmission rates in local and general anesthesia at Helsinki University Hospital.Material and Methods:We conducted a retrospective study on ENT (n = 1011) day surgery patients within a 3-month period using the hospital?s surgery database to collect data pertaining to anesthesia, overstays, readmissions, and contacts within 30 days of surgery.Objectives:We examined the effect of American Society of Anesthesiologists (ASA) class, age, sex, type of procedure, and anesthesia type on overstay, contact, and readmission rates.Results:A multivariable logistic regression model included ASA class, age, sex, type of procedure, and anesthesia (local vs general). Sex, age, and type of procedure had an effect on the outcomes of overstay, readmission, or contact. With general anesthesia, 3.2% (n = 23) had an overstay or readmission compared to 1.4% (n = 4) after local anesthesia. This was mainly explained by the number of study outcomes in tonsillar surgery that was performed only in general anesthesia.Conclusions:Day surgery could be done safely using local anesthesia, as the number of study outcomes was no greater than in general anesthesia. Sex, type of procedure, and age affected the rate of study outcomes, but ASA class and anesthesia form did not. Our overstay, contact, and readmission rates are on the same level, or lower, than in international studies.Peer reviewe

Root causes of extended length of stay and unplanned readmissions after orthopedic surgery and hand surgery : a retrospective observational cohort study

Background While previous studies have evaluated the effect of some patient characteristics (e.g. gender, American Society of Anesthesiologists (ASA) class and comorbidity) on outcome in orthopedic and hand day surgery, more detailed information on anesthesia related factors has previously been lacking. Our goal was to investigate the perioperative factors that affect overstay, readmission and contact after day surgery in order to find certain patient profiles more prone to problemed outcomes after day surgery. Methods We examined orthopedic and hand day surgery at an orthopedic day surgery unit of Helsinki University Hospital. Patient data of all adult orthopedic and hand day surgery patients (n = 542) over a 3-month period (January 1 - March 31, 2015) operated on at the unit were collected retrospectively using the hospital's surgery database. These data comprised anesthesia and patient records with a follow-up period of 30 days post-operation. Patients under the age of 16 and patients not eligible for day surgery were excluded. Patient records were searched for an outcome of overstay, readmission or contact with the emergency room or policlinic. Pearson chi-square test, Fischer's exact test and multivariable logistic regression were used to analyze the effect of various perioperative factors on postoperative outcome. Results Various patient and anesthesia related factors were examined for their significance in the outcomes of overstay, readmission or contact. Female gender (p = 0.043), total amount of fentanyl (p = 0.00), use of remifentanil (p = 0.036), other pain medication during procedure (p = 0.005) and administration of antiemetic medication (p = 0.048) emerged as statistically significant on outcome after day surgery. Conclusions Overstay and readmission in orthopedic and hand day surgery were clearly connected with female patients undergoing general anesthesia and needing larger amounts of intraoperative opioids. By favoring local and regional anesthesia, side effects of general anesthesia, as well as recovery time, will decrease.Peer reviewe