Ultraviolet light control

• US 4,279,254 A
• Filed: 10/30/1978
• Issued: 07/21/1981
• Est. Priority Date: 10/30/1978
• Status: Expired due to Term

• Current Assignee: Elder Pharmaceuticals Limited
• Original Assignee: Paul B Elder Company
• Inventors: Boschetti, Armando, Snoek, David J.
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US05/956,202
• Time in Patent Office: 995 Days
• Field of Search: 128/395, 128/396, 128/372, 128/908, 315/151, 219/358, 219/502, 340/573, 340/600, 250/365, 250/372
• US Class Current: 607/94
• CPC Class Codes: G01J 1/429 applied to measurement of ultraviolet light using counting tubes G01T

Abstract

A system designed for more safely administering natural or induced light radiation to the skin of a subject, and having a control system adapted to monitor the instantaneous intensity of the ultraviolet light received by a subject being treated, wherein the instantaneous intensity is integrated and converted to a digital pulse output. The pulse rate is proportional to the instantaneous intensity. The pulses are counted to accumulate the total ultraviolet energy per unit area received by the subject. The apparatus is so controlled that when the total energy received by the subject reaches a predetermined preset value, the subject or doctor is alerted or notified either audibly or visually, e.g., when an ultraviolet lamp source is employed the lamp or lamps may automatically be turned off. In an improved embodiment a minute timer is provided in the circuit and has a switch to turn off the lamps after a predetermined period of time has elapsed as a safety precaution in case of failure of the ultraviolet light sensor and integration system. Additional safety features are provided to turn off lamps if fault occurs or when the ultraviolet sensor is accidentally obscured by the hand of the subject. In further improved embodiments, a manual switch is provided for turning the lamps on momentarily for measuring the intensity of the ultraviolet light acting on the photoelectric cell prior to treatment, and a reset circuit is provided for preventing identical dosages from being given inadvertently to successive patients.

Claims

1. Apparatus for rendering more safe the exposure of the skin of a subject to ultraviolet light radiation, comprising means for monitoring the ultraviolet light radiation energy per unit area impinging upon the subject, and providing notification when a predetermined amount of energy per unit area has impinged upon the subject, said monitoring means comprising:

photoelectric means providing an analog electrical signal proportional to the intensity of the ultraviolet light which impinges thereon,

solid state integrated circuit signal converting means for converting the analog electrical signal from said photoelectric means to a digital electrical signal having a frequency proportional to the intensity of the analog electrical signal,

solid state integrated circuit counting means receiving said digital signal and counting the pulses of said signal to provide a measure of the total amount of ultraviolet energy received per unit area during a measured period of time, and

means operatively connected to said circuit counting means adapted to be set to the desired amount of radiation applied per unit area of the subject and to provide notification when the set amount of total energy per unit area has been attained,

wherein said apparatus includes one or more ultraviolet lamps and means for electrically energizing said lamps, wherein said photoelectric means is adapted to be mounted on the body of said subject, and which includes a control switch having associated digital display for setting the total amount of ultraviolet light radiation per unit area desired to be applied to the subject, said control switch being operatively connected to said counting means and being so operatively connected that counted pulses of said counting means gradually reduces the reading on the display to indicate the total amount of energy per unit area still remaining to be applied, means for generating an electrical signal when the reading on said display reaches zero, and means actuated by said latter electrical signal adapted to turn off said ultraviolet lamps.

2. Apparatus of claim 1, wherein a solid state operational amplifier is associated with said photoelectric means to amplify the signal from said photoelectric means and to provide an amplified signal to said signal converting means.

3. Apparatus of claim 1, comprising filter means adapted to pass substantially only ultraviolet light to said photoelectric means.

4. Apparatus of claim 3, additionally having means for temporarily turning on said lamps prior to treatment, and metering means for measuring the strength of the signal derived from said photoelectric means to determine the intensity of the radiated ultraviolet light from said lamps.

5. Apparatus of claim 1, wherein the display of the actual energy remaining to be applied is calibrated in terms of joules/cm².

6. Apparatus of claim 1, having means for detecting faults in the monitoring means, and means for turning off said lamps when a fault is detected.

7. Apparatus of claim 6, having means for detecting an abnormal drop in the signal from said photoelectric means and for turning off said lamps when such a drop is detected.

8. Apparatus of claim 1, additionally having an independent timing means for turning off said lamps when a preset period of time has elapsed.

9. Apparatus of claim 8, having digital readout means provided for displaying the actual remaining time.

10. Apparatus of claim 1, additionally having means for temporarily turning on said lamps prior to exposure of a subject thereto, and metering means for measuring the strength of the signal derived from said photoelectric means to determine the intensity of the ultraviolet light radiated from said lamps.

11. An apparatus for rendering more safe the exposure of the skin of a subject to ultraviolet light radiation, comprising means for monitoring the ultraviolet light radiation energy per unit area impinging upon the subject, and providing notification when a predetermined amount of energy per unit area has impinged upon the subject, said monitoring means comprising:

means for applying ultraviolet light radiation with a particular dosage setting,

photoelectric means providing an analog electrical signal proportional to the intensity of the ultraviolet light which impinges thereon,

means for converting the analog electrical signal to a digital electrical signal having a frequency proportional to the intensity of the analog electrical signal,

means for counting the pulses of said digital electrical signal to provide a measure of the total amount of the ultraviolet energy received by the subject per unit area during the period of exposure,

means operatively connected to said counting means for providing notification when the total amount of ultraviolet light radiation applied per unit area of the subject reaches a predetermined value,

means for remembering the radiation dosage setting for a first subject,

means for comparing the next subsequent dosage setting with the dosage setting for said first subject, and

means responsive to said comparing means for blocking the continued operation of said apparatus when said comparing means shows identical dosage settings for precluding a next preceding dosage from inadvertently being given to a subject immediately following said first subject.

12. Apparatus of claim 11, wherein said means for remembering is an integrated circuit containing a data register.

13. Apparatus of claim 11, wherein said means for comparing is an integrated circuit containing a comparator.

14. Apparatus of claim 11, wherein said means for blocking is an integrated circuit having means for removal of an enabling signal.