Phototherapy Equipment Research Articles

The use of clinical broadband UV radiometers for optical radiation hazard measurements

The implementation of the UK Control of Artificial Optical Radiation at Work Regulations2010 requires the employer to perform a risk assessment of workers’ exposure to UVradiation from phototherapy equipment in the hospital environment. The objective of thisstudy was to demonstrate that, where the source spectrum is known, an assessment ofexposure to UV sources commonly used in hospitals, including assessment of reflections andtransmission through personal protective equipment, may be performed with sufficientreliability by radiometer measurement rather than by complex spectroradiometricmeasurements. An intercomparison of radiometer and spectroradiometer measurementsof exposure to UV sources was carried out. Direct exposure was considered, aswell as exposure to reflected or scattered beams and that transmitted througheyewear. Assessment by radiometer of direct exposure and exposure to reflectionsdemonstrated an acceptable measurement error in the context of the inherent uncertaintyin the assumptions of the exposure scenario. Assessment of transmitted beamsmay result in a greater measurement error due to spectral mismatch; however,for typical exposure scenarios the error remained acceptable in comparison withthe exposure limit value. The methodology presented reduces the complexityof the measurement of UV hazard levels for common phototherapy equipment.

Irradiance Readings of Phototherapy Equipment: Nigeria

Phototherapy devices (n = 63) at twelve nurseries in Nigeria were evaluated. Irradiance was measured using the BiliBlanket Meter II. Irradiance readings ranged from 0.5 to 18.4 μW/cm(2)/nm; phototherapy units varied widely, including locally made units, reconditioned machines, and modern equipment. Imported "intact" machines with all blue bulbs had higher irradiance readings than locally made devices using primarily daylight bulbs (2.5-18.4 μW/cm(2)/nm vs 0.5-4.2 μW/cm(2)/nm). The distance between infant and phototherapy units ranged from 45 to 60 cm, far exceeding the recommended distance of about 10 cm. Only 6% of the machines provided irradiance of >10 μW/cm(2)/nm. None delivered intensive phototherapy (irradiance ≥ 30 μW/cm(2)/nm). Phototherapy devices in developing countries should be assessed for irradiance, and the infant be placed at a distance of about 10 cm from the device. Phototherapy devices with adequate irradiance would reduce the need for exchange blood transfusion and the burden of acute bilirubin encephalopathy in developing countries.

A review of home phototherapy for psoriasis

Phototherapy is a mainstay in the treatment of psoriasis and other photoresponsive dermatoses and home phototherapy has broadened therapeutic options. To describe the history of home phototherapy, the technological advances in the safety and efficacy of the equipment available, and the associated issues of cost, convenience, adherence, and quality of life. We conducted a literature review of home phototherapy, broad-band UVB, narrow-band UVB, and PUVA phototherapy using PUBMED. A Google search of home phototherapy equipment and technology was also undertaken. Technological advances in home phototherapy equipment have allowed for more treatment options and improvements in safety and efficacy. One randomized, controlled trial found results comparable to office-based phototherapy. Home phototherapy is convenient, cost-effective, and associated with better quality of life compared to outpatient phototherapy treatment. One trial found that adherence to home phototherapy regimens was better than to oral retinoids. Home phototherapy is a well-tolerated, efficacious, economical and patient friendly therapeutic option. Advantages of home phototherapy include improved quality of life, greater convenience, lower cost, and less time lost from work and social activities. Dermatologists should strongly consider home phototherapy as a first-line treatment option for appropriately selected psoriasis patients.

Potencial hidrogeniônico de soluções de cloridrato de dobutamina expostas a condições ambientais de unidades de cuidados intensivos neonatais

OBJECTIVE: To verify the hydrogen-ion potential (pH) of dobutamine hydrochloride solutions under environmental conditions similar to those of neonatal intensive care units. METHODS: We analyzed the pH of the drug diluted in 5% dextrose in water or 0.9% NaCl under different conditions of temperature (22 and 37 °C) and light (dark, fluorescent light bulbs, and phototherapy equipment), using colorless and amber intravenous sets at time intervals of 0, 1, 24, 48, 72, and 96 hours. RESULTS: The pH values of the marketed form of the drug and the diluted drug were similar. The pH means were 3.45±0.19 at 22 °C and 3.55±0.20 at 37 °C. The average of the pH according to light conditions were as follows: in the dark = 3.62±0.09, under room light = 3.63±0.07, and exposed to phototherapy = 3.31±0.16. Solutions stored in colorless intravenous sets had a lower mean (3.41±0.24) than those kept in amber intravenous sets (3.52±0.15). We found lower pH values in the solutions exposed to phototherapy using colorless intravenous sets (3.17±0.03) than in those using amber intravenous sets (3.55±0.03). CONCLUSION: There was higher variation in the pH of the solutions exposed to phototherapy, and the use of amber intravenous sets reduced such effect.

Hydrogen-ion potential of dobutamine hydrochloride solutions exposed to environmental conditions of neonatal intensive care units

To verify the hydrogen-ion potential (pH) of dobutamine hydrochloride solutions under environmental conditions similar to those of neonatal intensive care units. We analyzed the pH of the drug diluted in 5% dextrose in water or 0.9% NaCl under different conditions of temperature (22 and 37 degrees C) and light (dark, fluorescent light bulbs, and phototherapy equipment), using colorless and amber intravenous sets at time intervals of 0, 1, 24, 48, 72, and 96 hours. The pH values of the marketed form of the drug and the diluted drug were similar. The pH means were 3.45+/-0.19 at 22 degrees C and 3.55+/-0.20 at 37 degrees C. The average of the pH according to light conditions were as follows: in the dark = 3.62+/-0.09, under room light = 3.63+/-0.07, and exposed to phototherapy = 3.31+/-0.16. Solutions stored in colorless intravenous sets had a lower mean (3.41+/-0.24) than those kept in amber intravenous sets (3.52+/-0.15). We found lower pH values in the solutions exposed to phototherapy using colorless intravenous sets (3.17+/-0.03) than in those using amber intravenous sets (3.55+/-0.03). There was higher variation in the pH of the solutions exposed to phototherapy, and the use of amber intravenous sets reduced such effect.

Irradiance of phototherapy equipment in maternity wards in Maceió

The effectiveness of neonatal hyperbilirubinaemia treatment depends directly on the amount of energy emitted by light (irradiance). This cross-sectional study aimed to determine the irradiance of phototherapy equipment in maternity wards in Maceió, AL, Brazil. All equipment in use in the neonatal units in Maceió was included in the study, totaling 36 devices, except those in maintenance. The measurement of irradiance was carried out with a radiometer. We observed that 72.20% of the equipment presented efficient irradiance and 27.76% were inefficient. The conclusion is that the majority of phototherapy devices are emitting the minimum required irradiance for neonatal jaundice treatment.

Examples for the importance of radiophysical measurements in clinical phototherapy

Optimal UV therapy requires regular surveillance of the variables that influence therapeutic success. In daily practice, phototherapy equipment is often operated with an attitude of "autocontrol." This implies that thorough control measurements of the emission spectra and calibration of UV fluences are not routinely performed. For both quality control and patient safety, it is essential to regularly check whether a UV source is providing the right target spectrum with the correct dose to the skin. We have exemplarily taken three UV sources currently used in clinical practice and performed radiophysical measurements, i. e. determined emission spectra, radiation output and correctness of dose calculation. All three sources revealed either a largely inhomogeneous distribution pattern of radiation intensity, variation of radiation intensity over time or insufficient filtering of the UV lamp emission spectrum. Furthermore the dose calculation procedures had to be revised because of significant differences between the estimated and the administered UV doses. Radiophysical measurement of all UV-equipment in clinical use is a simple and effective way to improve the safety and reliability of phototherapy. Such measurements help to uncover technical flaws in radiation sources and prevent unnecessary side effects and UV exposure risks for the patient.

Establishing an infant warming and phototherapy procurement framework

The NHS Purchasing and Supply Agency (NHS PASA) within the UK has developed a national procurement agreement for infant warming and neonatal phototherapy equipment (IWF) as part of a remedy set down by the Competition Commission. This framework agreement was designed to stabilise prices and encourage more manufacturers to supply quality products to the United Kingdom. On 1st March 2005 the IWF was launched and the NHS PASA website now lists all current UK suppliers, details of their contracted products and the agreed prices for purchases by NHS organisations. The framework agreement speeds up the procurement process as NHS trusts do not need to conduct their own competitive tender exercise. The single source of information on companies supplying warming and phototherapy devices helps NHS staff easily locate new and smaller companies marketing these products. Two new manufacturers are now selling incubators in the UK. Extensive use of the comparative pricing information will enable market forces to stabilise prices.

In vivo spectroscopy of jaundiced newborn skin reveals more than a bilirubin index

The aims of this study were to improve the algorithms for calculating a transcutaneous bilirubin index (TcB), to follow the bilirubin concentrations during phototherapy and to evaluate possible changes in skin optical parameters such as pigmentation and erythema during phototherapy. Reflectance measurements were performed on 51 jaundiced newborns, of which 10 were subjected to phototherapy. The measurements were collected with a diode array spectrophotometer with an integrating sphere accessory, and a TcB was calculated from the measured spectra using algorithms based on diffusion theory. The newborns' birthweights were > or = 2000 g and their gestational age was > or = 35.5 wk. They had no substantial illnesses, and no newborns were submitted to the study until their second day. Heel prick blood samples were analysed for total serum bilirubin (Sbr) by the diazo reaction method. Phototherapy equipment was either an overhead lamp or lightbed. Measurements from the forehead gave the best correlation between TcB and Sbr (r = 0.81, p < 0.05). However, during phototherapy no significant correlation between TcB and Sbr was observed. A correlation (r = 0.45, p < 0.05) was found between phototherapy and melanin index obtained from the patients' back. Reflectance spectroscopy is useful in assessing bilirubin concentrations before phototherapy, and can also reveal changes in skin parameters such as pigmentation occurring as a result of phototherapy.

A device for minimizing the risk of overexposure of patients undergoing phototherapy.

Phototherapy irradiation cabinets normally rely on one timer or dose meter in order to control the ultraviolet (UV) exposure of patients. Faults may occur in the electronic control, or the operator may set the prescribed dose incorrectly. If this happens, a patient will receive an exposure different from that intended, which in the case of overexposure may result in severe burning resulting in hospitalization. Some phototherapy equipment has secondary devices (e.g. mechanical timer) for controlling the dose in case the primary system fails. We have designed and built a secondary dose meter that sounds an alarm if an overdose is about to occur. The unique feature of our device is that it measures the irradiance level within the cabinet and uses this value in combination with the dose set by the operator, to calculate the alarm time. Using the measured irradiance value in this manner ensures that the calculated exposure time compensates for variations in UV output as the lamps age.

An evaluation of the characteristics and performance of neonatalphototherapy equipment

This paper reviews the current state of knowledge and practice in neonatalphototherapy, and assesses methods of evaluating the characteristics andperformance of different equipment.Artificial lighting (usually fluorescent) has been used for the past 30years in the treatment of neonatal jaundice. Widely differing light outputsand spectra are used, making comparison and evaluation difficult forclinicians. Manufacturers of neonatal phototherapy equipment have nostandard for assessing the performance of their equipment, and informationthat is supplied is at best confusing or deceptive to the users. Bestpractice is usually based on empirical data from equipment in use, butthere is wide agreement that present phototherapy is sub-optimal, i.e. does not achieve maximum rate of bilirubin clearance for minimumtherapeutic dose.Several studies in the last ten years have emphasized the importance ofboth the wavelength and intensity of light for optimal phototherapy. Theseare discussed and a technique is proposed for normalizing the output ofdifferent systems to make comparison easier and to enable optimaltreatments to be designed.

Urocanic Acid Photochemistry and Photobiology

Urocanic acid (2-propenoic acid, 3-[ lH-imidazol-4(5)-yl], UA)? is one of the smallest molecules to have stimulated global interest among biologists, environmentalists, photochemists, photobiologists, medicinal chemists and immunologists. Its history can be traced back more than a century to when it was first found in the urine of dogs (1). Interest in the molecule remained dormant until the middle of the century but rekindled in the late 1940s when it was detected in animal skin and sweat. This led to the proposal that UA acts as a natural sunscreen, possibly as a specific photoprotecting agent for DNA because of the overlap of the UA and DNA absorption spectra (2). Since 1983 there has been an explosive growth in UA research, primarily as a consequence of the proposal by De Fabo and Noonan (3) that the cis photoisomer (cUA) of trans-UA (tUA) could be responsible for the phenomenon of photoimmunosuppression. In a recent literature survey we found that about 25 research papers have appeared every year over the last decade involving UA. Several comprehensive reviews of the molecule's photobiology, photochemistry and photophysics have appeared (4-

An insight into the contributions of self-shielding and lamp reflectors to patient exposure in phototherapy units

Calibration of phototherapy equipment can prove to be difficult. One problem is that the self-shielding produced by a patient reduces the irradiance relative to that determined when the cabinet is empty. A model has been developed to determine the factor to apply to the irradiance measured with the cabinet empty to give the irradiance with the patient present, i.e. the self-shielding correction factor. The model assumes that the cabinet consists of a number of discrete infinite line sources backed by perfect mirrors. The patient is treated as a barrier that prevents some of these sources being seen by the detector in the mirror it faces. The model was tested using a Waldmann 8001 K unit and three UV meters for UVA and UVB sources. The measurements suggested some modifications to the model - for UVA multiple reflections were important and for UVB the reflectors were only 30% efficient. The correction factors obtained were 0.87 for UVA and 0.96 for UVB.

Home phototherapy for the jaundiced full-term newborn

This article addresses not only the use of home phototherapy equipment but also gives practical and useful information on setting program guidelines. It includes background information on jaundice as well as criteria for admission and discharge from a home phototherapy program.

Insensible water loss from the skin during phototherapy in term and preterm infants.

The rate of evaporation from the skin was measured before and during phototherapy in 10 full-term and seven preterm infants (gestational age 29-33 weeks). The method for measurement of rate of evaporation was non-invasive and was based on determination of the water vapour pressure gradient close to the skin surface. All infants were studied naked in an incubator with an ambient relative humidity of 50% and with a controlled environment with respect to temperature and air velocity. In the term infants the mean rate of evaporation, measured from an interscapular skin area, was 3.1 g/m2h both before and after 30 min of phototherapy. In the preterm infants the corresponding value was 9.8 g/m2h before and 9.7 g/m2h after 120 min of phototherapy. Thus, in thermally stable infants, non-ionizing radiation from phototherapy equipment does not increase water loss from the skin.

Does Non-ionizing Radiant Energy Affect Determination of the Evaporation Rate by the Gradient Method?

A study was performed to investigate whether measurements of the evaporation rate from the skin of newborn infants by the gradient method are affected by the presence of non-ionizing radiation from phototherapy equipment or a radiant heater. The evaporation rate was measured experimentally with the measuring sensors either exposed to or protected from non-ionizing radiation. Either blue light (phototherapy) or infrared light (radiant heater) was used; in the former case the evaporation rate was measured from a beaker of water covered with a semipermeable membrane, and in the latter case from the hand of an adult subject, aluminium foil or with the measuring probe in the air. No adverse effect on the determinations of the evaporation rate was found in the presence of blue light. Infrared radiation caused an error of 0.8 g/m2h when the radiant heater was set at its highest effect level or when the ambient humidity was high. At low and moderate levels the observed evaporation rate was not affected. It is concluded that when clinical measurements are made from the skin of newborn infants nursed under a radiant heater, the evaporation rate can appropriately be determined by the gradient method.

Nursing care to the premature some basics procedures

The basics procedures of nursing care to the premature are presented here. They are: observation of the premature during the first 24 hours of life, hidratation by bottle, feeding by nosogastric tube, care of premature after feeding, tecnnique of bathing the premature in the incubator, care of premature skin to avoid from infection, care of the umbilical stump, care of premature with moniliasis, with respiratory distress, with diarrhea, with vomitus, cleaning and preservation of the incubator, care of the premature who is receving oxigen therapy, control of humidity of the incubator, care of the premature under phototherapy, care with the phototherapy equipment.

Home Phototherapy Treatment of Neonatal Jaundice

A home phototherapy program for healthy, term newborns with hyperbilirubinemia (n = 62) was implemented, and results were compared prospectively with a group of term neonates who met enrollment criteria but were treated in-hospital (n = 55). The purpose of the study was to prospectively assess the feasibility, safety, and effectiveness of home phototherapy in treating uncomplicated neonatal jaundice. Infants were required to be greater than 24 hours old and to weigh at least 2,270 g (5 lb). Enrolling physicians were instructed to select infants whose clinical diagnoses and bilirubin levels allowed an adequate margin of error for a trial of home phototherapy and whose parents were capable of managing the added responsibilities of home therapy. At the time the phototherapy equipment was delivered and set up in their home, parents received extensive instruction, including how to record pertinent ongoing data on a home flow sheet. Serum bilirubin levels were measured at least daily. The preponderant diagnosis listed by enrolling physicians was "physiologic jaundice." No parent reported significant complications, and no infant required rehospitalization. Bilirubin levels decreased as rapidly in the home group as in the hospitalized control group, and duration of treatment averaged 2.8 days. About $18,000 was saved by treating these 62 infants at home compared with in-hospital costs in our community. We found home phototherapy to be a feasible, safe, and effective alternative to in-hospital phototherapy for otherwise healthy, jaundiced infants with motivated and capable parents.

Grounding and Electrical Leakage of Photo Therapy Equipment

I am the director of the Bio Electronics Lab at Wilson Memorial Hospital. We have a safety program in which electrical leakage on all electrical and electronic equipment is checked. Our standards are set in accordance to the American Heart Association at 5 microamps. This brings me to the purpose of this letter. We received an Air Shields photo therapy unit which is used in the prevention and treatment of neonatal hyperbilirubinemia. This lamp has a leakage of 70 micro-amps when it is ungrounded.