US3674008A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Quantitative pulsed transilluminator and method of operation
Assignee: Battelle Development Corp
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Filing: 1970-07-13
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Granted: 1972-07-04
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Expires: 1990-07-13
Abstract
Abstract An instrument is described which quantitatively measures optical density of the transilluminated body portion. The instrument comprises a controllable, relatively low-frequency oscillator generating pulses which are applied to a light source through a first expand and delay circuit. A light-conducting means, such as a fiber optic device, optically couples the light source to one side of the body portion and a similar means optically couples another side of the body portion to a light detector. Alternatively, the light source and detector may be placed directly on the body portion. After compensation for ambient light, the output of the detector is coupled to a sample and hold circuit which is triggered by the controllable oscillator through a second expand and delay circuit. The stored signal in the sample and hold circuit is proportional to transmittance and is converted to a visual indication of optical density by a calibrated display means. Methods of using the instrument in diagnosis are discussed, as are further applications to spectrophotometric determinations.
Inventors
- 👤 Curtis C Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:48
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/0059; A61B5/145; A61B5/1455; A61B5/14551; A61B5/14553; A61B5/40; A61B5/4058; A61B5/4064
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
139 words
An apparatus for measuring the optical density of a human or an animal body portion, comprising: a. means providing a high-intensity light pulse, b. means for conducting said light pulse to a first point on the body portion, c. detecting means providing a first signal whose magnitude is proportional to the light detected at a second point on the body portion, d. means sampling said first signal to remove ambient and noise components therefrom and providing a second signal whose magnitude is proportional to the amount T of said light pulse which is transmitted between said first and second points, and e. means converting said second signal into an output whose magnitude OD is proportional to said optical density and which is related to the amount T represented by said second signal by a relation OD log 1 /T.
Claim 2
Independent Claim
139 words
An apparatus for measuring the optical density of a human or an animal body portion, comprising: a. means providing a high-intensity light pulse, b. means for conducting said light pulse to a first point on the body portion, c. detecting means providing a first signal whose magnitude is proportional to the light detected at a second point on the body portion, d. means sampling said first signal to remove ambient and noise components therefrom and providing a second signal whose magnitude is proportional to the amount T of said light pulse which is transmitted between said first and second points, and e. means converting said second signal into an output whose magnitude OD is proportional to said optical density and which is related to the amount T represented by said second signal by a relation OD log 1 /T.
Claim 3
Dependent Claim
26 words
An apparatus as recited in claim 1 wherein said light pulse providing means comprises a flashlamp, and said conducting means comprises a fiber optic light pipe.
Claim 4
Dependent Claim
36 words
An apparatus as recited in claim 1 wherein said detecting means comprises a fiber optic light pipe and a photomultiplier tube, said light pipe conducting the light present at said second point to said photomultiplier tube.
Claim 5
Dependent Claim
31 words
An apparatus as recited in claim 1 wherein said light pulse providing means and said conducting means comprise a semiconductor light-emitting device, and said detecting means comprises a semiconductor photo-detecting device.
Claim 6
Dependent Claim
30 words
An apparatus as recited in claim 1, wherein said converting means further includes a display means which provides a corresponding visual indication of said output in units of optical density.
Claim 7
Dependent Claim
40 words
An apparatus as recited in claim 1, further including: a. an oscillator providing a series of pulses having a relatively low repetition rate, and b. means controlling the operation of said light pulse providing means in response to said pulses.
Claim 8
Dependent Claim
24 words
An apparatus as recited in claim 1, wherein said sampling means includes a high pass filter removing ambient light components from said first signal.
Claim 9
Dependent Claim
156 words
An apparatus as recited in claim 1, a. further including i. an oscillator providing a series of pulses having a relatively low repetition rate, and ii. a first expand and delay circuit controlling the operation of said light pulse providing means in response to said pulses from said oscillator, b. wherein said sampling means further includes i. a sample and hold circuit having input, output, and control terminals, and operative to store and hold on said output terminal the DC value of any signal present at said input terminal whenever a control signal is applied to said control terminal, ii. a second expand and delay circuit coupling said pulses from said oscillator to said control terminal, and iii. means coupling said first signal to said input terminal of said sample and hold circuit so that said second signal appears on said output terMinal thereof in response to the pulses from said second expand and delay circuit.
Claim 10
Dependent Claim
36 words
An apparatus as recited in claim 8 wherein said light pulse providing means comprises a flashlamp which is connected to said first expand and delay circuit and said conducting means comprises a fiber optic light pipe.
Claim 11
Dependent Claim
47 words
An apparatus as recited in claim 8 wherein said detecting means comprises a fiber optic light pipe and a photomultiplier tube, said light pipe conducting the light present at said second point to said photomultiplier tube and said photomultiplier tube providing in response thereto said first signal.
Claim 12
Dependent Claim
45 words
An apparatus as recited in claim 8 wherein said light pulse providing means and said conducting means comprises a semiconductor, light-emitting device which is connected to said first expand and delay circuit, and said detecting means comprises a semiconductor photo-detecting device providing said first signal.
Claim 13
Dependent Claim
30 words
An apparatus as recited in claim 8, wherein said converting means further includes a display means which provides a corresponding visual indication of said output in units of optical density.
Claim 14
Dependent Claim
28 words
An apparatus as recited in claim 8, wherein said coupling means of said sampling means includes a high pass filter removing ambient light components from said first signal.
Claim 15
Independent Claim
134 words
A method for detecting the onset of hydrocephalus and other conditions involving an increase of fluid within a human or an animal body portion and a corresponding decrease in optical density thereof, comprising the steps of: a. providing a high-intensity light pulse at a first point on the body portion, b. detecting all the light present at a second, separated point on the body portion, c. removing ambient and noise components from the detected light and providing a signal therefrom which is related to the amount of said light pulse that is transmitted through said body portion from said first point to said second point, and d. converting said signal into units of optical density OD by using a relation OD log 1 /T, where T is proportional to the magnitude of said signal.
Claim 16
Independent Claim
134 words
A method for detecting the onset of hydrocephalus and other conditions involving an increase of fluid within a human or an animal body portion and a corresponding decrease in optical density thereof, comprising the steps of: a. providing a high-intensity light pulse at a first point on the body portion, b. detecting all the light present at a second, separated point on the body portion, c. removing ambient and noise components from the detected light and providing a signal therefrom which is related to the amount of said light pulse that is transmitted through said body portion from said first point to said second point, and d. converting said signal into units of optical density OD by using a relation OD log 1 /T, where T is proportional to the magnitude of said signal.
Claim 17
Dependent Claim
21 words
A method as recited in claim 14 wherein said light pulses are continuously provided at a repetition rate of 120 Hz.
Claim 18
Dependent Claim
47 words
A method as recited in claim 14 which is particularly adapted to measurements of the optical density of the membraneous structure of a human skull, further including the step of e. always maintaining said first and second points separated on said skull by a fixed, predetermined distance.
Claim 19
Dependent Claim
50 words
A method as recited in claim 14 which is adapted to longitudinal measurements of the optical density of a human skull having an interior and a posterior, wherein step (a) includes providing said light pulse at the anterior thereof and step (b) includes detecting said light at the posterior thereof.
Claim 20
Dependent Claim
53 words
A method as recited in claim 14 which is particularly adapted to bi-parietal measurements of the optical density of a human skull having a pair of parietals, wherein step (a) includes providing said light pulse at one of the parietals thereof, and step (b) includes detecting said light at the other parietal thereof.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-04 | 1976-01-03 | 1976-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-04 | 1980-01-03 | 1980-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-04 | 1984-01-03 | 1984-07-04 | $7700.00 | Window Closed / Lapsed |