Publications by authors named "T J Flatley"

17 Publications

Remote temperature sensing by the compact thermal imager from the International Space Station.

Appl Opt 2021 Nov;60(33):10390-10401

A systematic calibration approach is presented to correlate the digital output of an infrared camera and the scene temperature. Aided by the optoelectronic properties of the camera, as few as two experimental data points are needed to establish this correlation. This approach can readily include the effects of atmospheric transmission, scene emissivity, and different background subtractions. Hence, the temperature conversion in flight can be reliably obtained from laboratory calibration. The conversion function can also be used to identify the camera's thermal sensitivity and temperature resolution, which are important information in different space missions. In applying this calibration procedure to a laboratory camera and the compact thermal imager onboard the International Space Station, its validity is confirmed.
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http://dx.doi.org/10.1364/AO.440611DOI Listing
November 2021

Strained-layer-superlattice-based compact thermal imager for the International Space Station.

Appl Opt 2019 Jul;58(20):5432-5442

The compact thermal imager (CTI) is a dual-band, strained-layer-superlattice (SLS) detector-based instrument that was installed on the exterior of the International Space Station (ISS) in conjunction with the third Robotic Refueling Mission 3 (RRM3) in 2018. The CTI serves as a pathfinder for future thermal infrared capability on Landsat. The CTI incorporates an SLS hybrid, a dual-band 3-5 and 8-10 μm, electrically switchable, 320×256 array with 30   pixels, bonded to an Indigo ISC0903 Readout Integrated Circuit (ROIC). The telescope was built around an integrated detector cryocooler assembly developed under a NASA Small Business Innovative Research award with QmagiQ, LLC. The cooler is a Ricor K508 and the front-end optics is a custom-designed, doublet lens telescope with a 150 mm focal length. The ground resolution is 80 meters/pixel from the ISS altitude of 400 km. A filter creates two spectral channels from the dual bands, 3.3-5.4 and 7.8-10.2 μm. The detector hybrid control electronics is a custom-developed system based on the Teledyne Imaging Systems SIDECAR Application-Specific Integrated Circuit. This module provides the electronic interface from the RRM3 SpaceCube on-board processor to the detector/ROIC assembly. The primary goal of this mission was to perform a technology demonstration of the SLS technology and the commercial cooler technology elevating the Technology Readiness Level (TRL) to TRL 9 on a bare-bones budget and relatively fast development cycle. Some science objectives include locating fires, approximating land surface temperatures, and monitoring evapotranspiration, sea ice, and glacier dynamics. In this paper, we will present the design of the focal plane, optics, electronics, and mechanical structure of the CTI. We will also describe the operation and qualification tests that were performed to bring the CTI to the NASA TRL 6 in preparation for the launch on a SpaceX Dragon from the Kennedy Space Center.
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http://dx.doi.org/10.1364/AO.58.005432DOI Listing
July 2019

Comparison between Hilbert-Huang transform and scalogram methods on non-stationary biomedical signals: application to laser Doppler flowmetry recordings.

Phys Med Biol 2005 Nov 19;50(21):5189-202. Epub 2005 Oct 19.

Groupe ISAIP-ESAIP, 18 rue du 8 mai 1945, BP 80022, 49180 Saint Barthélémy d'Anjou cedex, France.

A significant transient increase in laser Doppler flowmetry (LDF) signals is observed in response to a local and progressive cutaneous pressure application on healthy subjects. This reflex may be impaired in diabetic patients. The work presents a comparison between two signal processing methods that provide a clarification of this phenomenon. Analyses by the scalogram and the Hilbert-Huang transform (HHT) of LDF signals recorded at rest and during a local and progressive cutaneous pressure application are performed on healthy and type 1 diabetic subjects. Three frequency bands, corresponding to myogenic, neurogenic and endothelial related metabolic activities, are studied at different time intervals in order to take into account the dynamics of the phenomenon. The results show that both the scalogram and the HHT methods lead to the same conclusions concerning the comparisons of the myogenic, neurogenic and endothelial related metabolic activities-during the progressive pressure and at rest-in healthy and diabetic subjects. However, the HHT shows more details that may be obscured by the scalogram. Indeed, the non-locally adaptative limitations of the scalogram can remove some definition from the data. These results may improve knowledge on the above-mentioned reflex as well as on non-stationary biomedical signal processing methods.
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http://dx.doi.org/10.1088/0031-9155/50/21/016DOI Listing
November 2005

Superiorly based laminoplasty in children: average 6.8-year follow-up of 21 patients.

J Spinal Disord Tech 2003 Apr;16(2):156-62

*Department Orthopaedic Surgery, Medical College of Wisconsin; double dagger Department Neurosurgery, Children's Hospital of Wisconsin, Milwaukee, Wisconsin, U.S.A.

This study is a retrospective review of patients with pediatric laminoplasty. The objective was to determine the incidence of postlaminoplasty deformity. Long-term follow-up of patients with pediatric laminoplasty is lacking. Previous studies have shown spine deformity to be as high as 100% following laminectomy procedures. From 1986 until present, 31 superiorly based laminoplasties were performed on pediatric patients, ranging from two to 12 levels. Twenty-one of the 31 were available for complete review. A retrospective review of the radiographic deformity of these patients was conducted. Preoperative and postoperative scoliotic and kyphotic deformities were measured, and the correlating diagnoses were recorded. The average follow-up period was 6.8 years, and average age at follow-up was 11.9 years. Sixteen of 21 showed no increase in spinal deformity. Five of 21 showed nonunion at one or more levels. Five patients showed an increased deformity, of which two required surgical intervention to correct deformity. Although the technique of laminoplasty has very low morbidity (essentially no different from laminectomy), this review has not shown that this procedure eliminates postsurgical deformity. However, we recommend the use of laminoplasty in the pediatric patient because it may reduce the incidence of deformity, allow future segmental instrumentation if necessary, and has a low morbidity.
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http://dx.doi.org/10.1097/00024720-200304000-00007DOI Listing
April 2003

Intra-articular osteocartilaginous obstruction to reduction of congenital dislocation of the hip. Report of three cases.

J Bone Joint Surg Am 1988 Jun;70(5):760-8

Department of Orthopaedic Surgery, Children's Hospital, Milwaukee, Wisconsin 53201.

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June 1988
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