Electrocardiographic recording apparatus

Claim 2

Recording apparatus for electrocardiographic and other physiological signals comprising an input assembly having means for attachment of a multiplicity of conductors such as electrocardiographic leads from a patient, and means for forming said leads into a plurality of signal pairs with said pairs being arranged in sets of at least two lead groups and forming one lead group producing zero voltage, an electrical signal recorder having at least two recording pens for recording said sets of lead groups on a recording chart and a chart drive motor, amplifying means interconnected with each pen, lead group switching means including a plurality of switches in said input assembly for selectively switching each of said lead groups to said pens, logic control circuits including switching means therefore and control means interconnected with said lead group switching means and said logic control circuit for manually, semi-automatically and automatically interconnecting selected lead groups to said amplifiers.

Claim 3

Recording apparatus according to claim 1 wherein said lead group switching means includes means for generating calibrating pulses and means for selectively applying said pulses to said amplifiers upon recordation of each of said sets of lead groups.

Claim 4

Recording apparatus according to claim 2 wherein said imput assembly further includes at least two modulators interconnected with said lead group switching means, signal isolation transformers feeding modulated signals from said input assembly, a power isolation transformer providing operating power for the input assembly and means including a plurality of isolating optoelectronic couplers coupling said logic circuits to said lead group switching means whereby said input assembly is isolated from and electrically floating with respect to the remainder of said recording apparatus.

Claim 5

Recording apparatus according to claim 3 including at least two demodulators interconnecting said signal isolation transformers with said amplifiers and at least two servo amplifiers connected to the first said amplifiers and to said recording pens for operation of said pens.

Claim 6

Recording apparatus according to claim 4 including electrical clamping means interconnected with said amplifiers for clamping the inputs thereof to ground and connections between the last said means and said logic circuits, said logic circuits actuating said clamping means during operation of said lead group switching means to switch from one lead group to the next lead group.

Claim 7

Recording apparaTus for electrocardiographic and other physiological signals comprising an input assembly having means for attachment of a multiplicity of conductors such as electrocardiographic leads from a patient, and means for forming said leads into a plurality of signal pairs with said pairs being arranged in sets of at least two lead groups and forming one lead group producing zero voltage, an electrical signal recorder having at least two recording pens for recording said acts of lead groups on a recording chart and a chart drive motor, amplifying means interconnected with each pen, lead group switching means in said input assembly for selectively switching each of said lead groups to said pens, logic control circuits interconnected with said switching means and control means interconnected with said logic control circuit for manually, semi-automatically and automatically interconnecting selected lead groups to said amplifiers, said lead group switching means including means for generating calibrating pulses and means for selectively applying said pulses to said amplifiers upon recordation of each of said sets of lead groups, said input assembly further including at least two modulators interconnected with said lead group switching means, signal isolation transformers feeding modulated signals from said input assembly, a power isolation transformer providing operating power for the input assembly, means including a plurality of isolating optoelectonic couplers coupling said logic circuits to said lead group switching means whereby said input assembly is isolated from and electrically floating with respect to the remainder of said recording apparatus, at least two demodulators interconnecting said signal isolation transformers with said amplifiers, at least two servo amplifiers connected to the first said amplifiers and to said recording pens for operation of said pens, electrical clamping means interconnected with said amplifiers for clamping the inputs thereof to ground and connections between the last said means and said logic circuits, said logic circuits actuating said clamping means during operation of said lead group switching means to switch from one lead group to the next lead group, said logic circuits further including means operable upon initiation of recording to operate said clamping means, actuate said switching means to switch to said zero voltage lead group, inactivate said clamping means, apply said calibrating pulse, reactivate said clamping means, switch to the lead group to be recorded, inactivate said clamping means to record the last said lead group and terminate said recording after a selected time interval.

Claim 8

Recording apparaTus for electrocardiographic and other physiological signals comprising an input assembly having means for attachment of a multiplicity of conductors such as electrocardiographic leads from a patient, and means for forming said leads into a plurality of signal pairs with said pairs being arranged in sets of at least two lead groups and forming one lead group producing zero voltage, an electrical signal recorder having at least two recording pens for recording said acts of lead groups on a recording chart and a chart drive motor, amplifying means interconnected with each pen, lead group switching means in said input assembly for selectively switching each of said lead groups to said pens, logic control circuits interconnected with said switching means and control means interconnected with said logic control circuit for manually, semi-automatically and automatically interconnecting selected lead groups to said amplifiers, said lead group switching means including means for generating calibrating pulses and means for selectively applying said pulses to said amplifiers upon recordation of each of said sets of lead groups, said input assembly further including at least two modulators interconnected with said lead group switching means, signal isolation transformers feeding modulated signals from said input assembly, a power isolation transformer providing operating power for the input assembly, means including a plurality of isolating optoelectonic couplers coupling said logic circuits to said lead group switching means whereby said input assembly is isolated from and electrically floating with respect to the remainder of said recording apparatus, at least two demodulators interconnecting said signal isolation transformers with said amplifiers, at least two servo amplifiers connected to the first said amplifiers and to said recording pens for operation of said pens, electrical clamping means interconnected with said amplifiers for clamping the inputs thereof to ground and connections between the last said means and said logic circuits, said logic circuits actuating said clamping means during operation of said lead group switching means to switch from one lead group to the next lead group, said logic circuits further including means operable upon initiation of recording to operate said clamping means, actuate said switching means to switch to said zero voltage lead group, inactivate said clamping means, apply said calibrating pulse, reactivate said clamping means, switch to the lead group to be recorded, inactivate said clamping means to record the last said lead group and terminate said recording after a selected time interval.

Claim 9

Recording apparatus according to claim 6 including a chart drive motor control actuated by said logic circuits, means for applying time interval markers on said chart and means actuated by said logic circuits for applying marks on said chart identifying the specific lead group being recorded.

Claim 10

Recording apparatus according to claim 7 wherein said pens include heated stylii, said motor control includes means for preheating said stylii to a low temperature when said chart motor is not running and to a higher normal temperature when said motor is activated.

Claim 11

Recording apparatus for electrocardiographic and other physiological signals comprising an input assembly having means for attachment of a multiplicity of conductors such as electrocardiographic leads from a patient, and means for forming said leads into a plurality of signal pairs with said pairs being arranged in sets of at least two lead groups and forming one lead group producing zero voltage, an electrical signal recorder having at least two recording pens for recording said sets of leads group on a recording chart and a chart drive motor, amplifying means interconnected with each pen, lead group switching means in said input assembly for selectively switching each of said lead groups to said pens, logic control circuits interconnected with said switching means and control means interConnected with said logic control circuits for manually, semi-automatically and automatically interconnecting selected lead groups to said amplifiers, said input assembly including a lead forming network connecting said leads from the patient to said lead switching network, said lead forming network forming at least three sets of lead groups with each set consisting of at least two leads and one of said sets of lead groups producing producing zero voltage and the other of said sets of lead groups producing sets of voltages to be recorded, means interconnected with said logic circuits for electrically clamping said pens when said apparatus is switched from one set of lead groups to another set of lead groups, said lead group switching means further including means for producing calibrating pulses said logic circuits having means responsive to said control means to inactivate said clamping means to observe the motion of said pens when said chart drive motor is not running and upon operation of said control means to record a set of lead groups, said logic circuits activate the drive motor, clamp said pens, switch to said zero voltage lead groups set, unclamp said pens, apply said calibration pulses, again clamp said pens, switch to the selected set of voltage producing lead groups and then unclamp said pens to record the selected lead group.

Claim 12

Recording apparatus for electrocardiographic and other physiological signals comprising an input assembly having means for attachment of a multiplicity of conductors such as electrocardiographic leads from a patient, and means for forming said leads into a plurality of signal pairs with said pairs being arranged in sets of at least two lead groups and forming one lead group producing zero voltage, an electrical signal recorder having at least two recording pens for recording said sets of leads group on a recording chart and a chart drive motor, amplifying means interconnected with each pen, lead group switching means in said input assembly for selectively switching each of said lead groups to said pens, logic control circuits interconnected with said switching means and control means interConnected with said logic control circuits for manually, semi-automatically and automatically interconnecting selected lead groups to said amplifiers, said input assembly including a lead forming network connecting said leads from the patient to said lead switching network, said lead forming network forming at least three sets of lead groups with each set consisting of at least two leads and one of said sets of lead groups producing producing zero voltage and the other of said sets of lead groups producing sets of voltages to be recorded, means interconnected with said logic circuits for electrically clamping said pens when said apparatus is switched from one set of lead groups to another set of lead groups, said lead group switching means further including means for producing calibrating pulses said logic circuits having means responsive to said control means to inactivate said clamping means to observe the motion of said pens when said chart drive motor is not running and upon operation of said control means to record a set of lead groups, said logic circuits activate the drive motor, clamp said pens, switch to said zero voltage lead groups set, unclamp said pens, apply said calibration pulses, again clamp said pens, switch to the selected set of voltage producing lead groups and then unclamp said pens to record the selected lead group.

Claim 13

Recording apparatus according to claim 9 including means in said logic circuits and lead switching circuits for automatically reducing the sensitivity of selected sets of lead groups.

Claim 14

Recording apparatus according to claim 10 including a chart drive motor control actuated by said logic circuits, means for applying time interval markers on said chart and means actuated by said logic circuits for applying marks on said chart identifying the specific lead groups being recorded.

Claim 15

Recording apparatus according to claim 11 wherein said pens include heated styli, said motor control includes means for preheating said styli to a low temperature when said chart motor is not running and to a higher normal temperature when said motor is activated.

Claim 16

Recording apparatus according to claim 10 wherein said input assembly further includes at least two modulators interconnected with said lead group switching means, signal isolation transformers feeding modulated signals from said input assembly, and a power isolation transformer providing operating power for the input assembly and means including a plurality of isolating optoelectronic couplers coupling said logic circuits to said lead group switching means whereby said input assembly is isolated from and electrically floating with respect to the remainder of said recording apparatus.