US3566133A
Expired / Lapsed
US
⏱️ 0.0 years remaining
A hemoglobin measuring method and apparatus having voltage following with feedback
Assignee: Coulter Electronics Inc
•
Filing: 1968-03-18
•
Granted: 1971-02-23
•
Expires: 1988-03-18
Abstract
Abstract Method for determining the hemoglobin content of a sample by the photoelectric monitoring of a reference and the sample and the transducing thereof into a pair of electrical signals representative of the relative light transmission of the two media. The reference signal is applied to a store and, through comparison with the sample signal, an output signal having a duration directly proportional to the hemoglobin content is elicited. Also, apparatus for carrying out such method in which a capacitive storage circuit is charged proportionally to the reference light transmission through use of a monochromatic light and photocell and is discharged to an intermediate value dependent upon the transmission of the sample, the duration of such discharging being the desired output. Interposed in series between the photocell and the storage circuit is an operational amplifier a diode and a switch. The amplifier provides a voltage follower enabling the diode to be a precise comparator between the two signal levels. The time dependent output is taken from the anode side of the diode.
Inventors
- 👤 Ervin L Dorman Jr
- 👤 Walter R Hogg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 01:14
CPC Classifications
G; G01; G01J; G01J1/00; G01J1/10; G01J1/16; G01J1/18
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
111 words
A method for determining the hemoglobin content of a sample comprising the steps of: transducing into a pair of discrete electrical signals the light transmission of said sample and a reference; applying to a store the larger of said pair of signals; applying to comparing means the other of said pair of signals; comparing said signals while emptying the store until said signals are equal; following, in an electrical mode, at a location leading to the comparing means, the other of said transduced signals during its said applying step; feeding back to said location, during said emptying, the signal then in the store; and measuring the time duration of said emptying.
Claim 2
Independent Claim
111 words
A method for determining the hemoglobin content of a sample comprising the steps of: transducing into a pair of discrete electrical signals the light transmission of said sample and a reference; applying to a store the larger of said pair of signals; applying to comparing means the other of said pair of signals; comparing said signals while emptying the store until said signals are equal; following, in an electrical mode, at a location leading to the comparing means, the other of said transduced signals during its said applying step; feeding back to said location, during said emptying, the signal then in the store; and measuring the time duration of said emptying.
Claim 3
Dependent Claim
20 words
The method defined in claim 1 further comprising the step of inhibiting the store from emptying prior to said comparing.
Claim 4
Dependent Claim
41 words
The method defined in claim 1 in which: said following is in a voltage mode and in which; said measuring is enabled by a conflict resulting from an attempted following of a signal which differs significantly from that being fed back.
Claim 5
Dependent Claim
169 words
A hemoglobinometer comprising: a transducer adapted to generate a pair of discrete signals representative of the light transmissions of a reference and a sample; storing means coupled to said transducer to receive and store one of said signals; receiving means coupled on demand to said storing means and, when so coupled, adapted to receive a portion of said one stored signal; control means for enabLing said receiving means subsequent to the storing of said one signal and during the generation of the other of said signals; a biasable circuit interposed between said transducer and said storing means and adapted to be characteristically responsive for the duration that said receiving means is receiving the portion of the one signal, such duration being proportional to the transmission of the sample; a voltage follower interposed between said transducer and the input of said biasable circuit; a feedback path for said voltage follower; and said feedback path being coupled between the output of said biasable circuit and an input of said voltage follower.
Claim 6
Dependent Claim
169 words
A hemoglobinometer comprising: a transducer adapted to generate a pair of discrete signals representative of the light transmissions of a reference and a sample; storing means coupled to said transducer to receive and store one of said signals; receiving means coupled on demand to said storing means and, when so coupled, adapted to receive a portion of said one stored signal; control means for enabLing said receiving means subsequent to the storing of said one signal and during the generation of the other of said signals; a biasable circuit interposed between said transducer and said storing means and adapted to be characteristically responsive for the duration that said receiving means is receiving the portion of the one signal, such duration being proportional to the transmission of the sample; a voltage follower interposed between said transducer and the input of said biasable circuit; a feedback path for said voltage follower; and said feedback path being coupled between the output of said biasable circuit and an input of said voltage follower.
Claim 7
Dependent Claim
62 words
A hemoglobinometer as defined in claim 4 in which said control means includes a switch interposed between said receiving means and said storing means, and said hemoglobinometer further comprises: an output converter coupled to a node which is interposed between said transducer and said biasable circuit, and said output converter adapted to be responsive to the characteristic response of said biasable circuit.
Claim 8
Dependent Claim
51 words
A hemoglobinometer as defined in claim 5 in which: said biasable circuit comprises a first diode and said characteristic response depends upon the bias state of said first diode; a second diode defines an input stage of said output converter; and said diodes being oppositely poled with respect to said node.
Claim 9
Dependent Claim
38 words
A hemoglobinometer as defined in claim 6 in which: said storing and receiving means in combination define an RC circuit; and said output converter includes analogue means enabled by said second diode for the duration of its response.
Claim 10
Dependent Claim
37 words
A hemoglobinometer as defined in claim 4 in which: said voltage follower is an operational amplifier of the balanced differential type; and said feedback path and said transducer being coupled to two separate inputs of said amplifier.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-22 | 1974-08-24 | 1975-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-22 | 1978-08-24 | 1979-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-22 | 1982-08-24 | 1983-02-23 | $7700.00 | Window Closed / Lapsed |