Ultrasound transducer connector and multiport imaging system receptacle arrangement

A plurality of ultrasound imaging system receptacles are arranged either vertically one above the other or horizontally side-by-side, each receptacle having an insertion slot for receiving the contact pads of an inserted ultrasound transducer connector. All of a number of connectors may be inserted into corresponding receptacles, and the system functions to mutually exclusively engage a single receptacle with its inserted connector. An electrical circuit arrangement is provided for automatically sensing the transducer in use without an operator having to make the selection manually. An interconnect and actuation scheme permits the multiport connector/receptacle arrangement to be manufactured at low cost. The modest size of the connectors and the receptacle assembly allows their placement at convenient locations on the system, and the simple basic design of the connector allows for submersion in liquid disinfectants.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to the field of ultrasound transducers, and in 
particular to an improved ultrasound transducer connector and multiport 
imaging system receptacle assembly of an ultrasound imaging system. 
2. Brief Description of the Prior Art 
Prior art imaging systems have included receptacles for two or three 
different transducer types. That is, two or three transducers are plugged 
into the system at any one time, and the selection of the transducer which 
is to be active is under control of the imaging system in response to 
operator input. The receptacles are normally located in the lower front 
face of the system because of its close proximity to the printed wiring 
board card cage assembly within the system console. 
Existing transducer connectors which have a 256 channel (and higher) 
capacity are large, clumsy, expensive, and not submersible in fluids for 
cleaning and sterilization. The corresponding system receptacles are 
expensive and, in general located on the lower front surface of the 
imaging system because that location is in proximity to the electronics. 
This location is not the most convenient one for the operator, however. 
The industrial designer has little latitude in locating these receptacles. 
Switching between transducers is accomplished in the prior art with 
electrically operated reed relays or FET switches (one for each channel 
and auxiliary function) which are expensive and inherently require a 
significant quantity of printed wiring board real estate. 
There is thus a need in the art for a multiport connector and receptacle 
arrangement in which the transducer in use may be automatically selected 
without need for reed relays or FET switches, and in which the receptacles 
may be located in a more convenient location for the operator, which has 
other important operating features yet is lower in cost, and which employs 
submersible transducer connectors. The present invention fulfills these 
needs. 
SUMMARY OF THE INVENTION 
The present invention overcomes the deficiencies and inconveniences of the 
prior art by providing low cost submersible transducer connectors and 
compatible receptacles, allowing the ultrasound transducer to be strongly 
influenced by ergonomics. Because of the small size of the connectors and 
of the receptacles, the receptacles can be placed up high on the imaging 
system without compromising the desired electrical performance. This 
allows the operator to conveniently change transducers without bending 
over. A high location for the transducer connector and for the transducer 
holder minimizes the chance for system wheel/transducer cable interactions 
which are normally to the detriment of the cable. 
The submersible transducer connector of the present invention is very 
simple and has no moving parts resulting in a low cost connection scheme. 
It is significantly less expensive to manufacture than existing 
connectors, and since each system uses four to five transducers, this 
savings can be quite significant. 
The receptacle assembly is relatively simple and modular, even though it 
can accommodate three transducers at one time. The imaging system cost is 
significantly less than one based on prior art technology. This savings 
takes into account the elimination of transducer selection switches, the 
relatively expensive connector receptacles, and the elimination of safety 
doors, etc. The system of the present invention will allow an imaging 
system to be designed with reduced bulk and weight when compared to 
existing approaches; this aspect of the invention is very appealing to 
potential users. 
In accordance with the invention, there is provided an ultrasound 
transducer connector and multiport ultrasound imaging system receptacle 
arrangement comprising a plurality of receptacles each having a set of 
receptacle contacts, a plurality of connectors each having a set of 
connector contacts, and an engagement actuator for automatically 
contacting only one of the set of receptacle contacts with the set of 
connector contacts of an inserted connector. 
In another aspect of the invention, there is provided an ultrasound 
transducer connector and multiport ultrasound imaging system receptacle 
arrangement comprising a plurality of receptacles each having a set of 
receptacle contacts, the contacts of all receptacles being connected in 
parallel. A plurality of ultrasound transducer connectors are provided, 
each having a set of connector contacts arranged to electrically contact a 
corresponding set of receptacle contacts when the connector is received 
in, and engaged by, one of the receptacles. A connector selector 
exclusively engages the set of connector contacts of any one of the 
connectors with the set of receptacle contacts of the receptacle into 
which it is inserted. 
In yet another aspect of the invention, there is provided an ultrasound 
transducer connector and multiport ultrasound imaging system receptacle 
arrangement comprising a plurality of receptacles each having a set of 
receptacle contacts, and a plurality of transducers each having a 
connector with a set of connector contacts. The plurality of connectors 
are insertable into the plurality of receptacles without mutually engaging 
the receptacle contacts with the connector contacts. An actuator, 
responsive to a transducer being used, engages the set of connector 
contacts of the transducer being used with the receptacle contacts of the 
receptacle into which the connector of the transducer being used is 
inserted.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 shows a typical prior art imaging system transducer connection panel 
1 to which three transducers 9 are connected, via cables 11, to three 
respective ultrasound transducer connectors 7. 
Each imaging system receptacle 5, labeled A, B, and C in FIG. 1, has its 
receptacle-to-relay signal leads 15 routed to a corresponding number of 
FET switches (e.g. electronic relays) 13. For convenience of illustration, 
only two channels are illustrated in FIG. 1, it being understood that, for 
a typical high resolution transducer, 256 channels are required for each 
transducer, i.e. 256 FET switches per transducer receptacle. 
The receptacle signal leads 15 are interrupted at the respective FET 
switches 13 and pass through FET switches 13 only if enabled by a 
transducer select control line 17. Importantly, only one transducer is to 
be active at any one time, and therefore, only one of the control lines 17 
will enable its corresponding set of FET switches 13 at any time. When a 
transducer is to be used, an operator must operate a switch, for example 
(not shown), to energize only one set of control lines 17. When the 
operator wishes to stop using the current transducer and use another 
transducer, he or she must operate the transducer select control switch 
(not shown) to disable the control line 17 for the transducer previously 
used and enable another control line 17 for engaging the connector of the 
newly selected transducer. The operator selector switch arrangement must 
be configured and wired to mutually exclusively select only one of the set 
of FET switches 13 for the desired transducer to be used. Upon selection 
of the desired transducer, the associated set of FET switches 13 are 
effective to connect the signal leads 15 to the relay-to-system connector 
leads 18 which then are routed to the electrical interface connector 19 
for use by the ultrasound imaging system. The interconnections between the 
imaging system receptacles 5, the FET switches 13, and the electrical 
interface connector 19 are made by means of a printed wiring board 3. 
It will be appreciated that the number of receptacles is a matter of design 
choice, and even in the three receptacle arrangement shown in FIG. 1, 
there is required 768 channels, i.e. 256 channels per transducer 
receptacle. 
The present invention avoids the use of FET switches, and provides a means 
for automatically selecting the transducer in use without requiring the 
operator to make the selection. These and other improvements over the 
prior art interconnection system of FIG. 1 will become evident from the 
description of the remaining figures. 
The invention can employ AMP interposer type contacts described in U.S. 
Pat. No. 5,308,252 entitled "Interposer Connector and Contact Element 
Therefor" by R. S. Mroczkowski et al. assigned to AMP Inc., or one of 
several contact methods described in U.S. Pat. No. 5,617,866 entitled 
"Modular Transducer System" by Vaughn Marian assigned to Acuson 
Corporation. 
By eliminating the FET switches and making other design improvements over 
the prior art, the ultrasound transducer connector and multi-port imaging 
system receptacle assembly of the present invention is very low in 
manufacturing cost, is small and ergonomic, yet robust and durable. The 
simple basic design of the connector allows for submersion in liquid 
disinfectants (see U.S. patent application Ser. No. 08/538,780 or 
International Publication WO 97/13300, assigned to Acuson Corporation, for 
details of submersible ultrasound connectors). The electrical 
characteristics are outstanding when compared to all connectors on the 
market with the exception of the MP connector manufactured by AMP, Inc. 
for Acuson Corporation, Mountain View, Calif. The connector extension is 
relatively thin (less than 0.4") and, in one embodiment, is plugged into 
vertical receptacle slots, horizontally aligned, in the imaging system. In 
another embodiment, the receptacle has horizontal slots horizontally 
aligned. 
FIG. 2 is a top view of a 3-port receptacle assembly which may be employed 
in a connector/receptacle arrangement in accordance with the present 
invention. The embodiment of FIG. 2 has three connectors 21A-C inserted in 
the receptacle slots, the connectors 21A-C being vertically oriented and 
horizontally spaced in the receptacle assembly. 
In FIG. 2, all connectors 21A-21C are fully inserted into their respective 
receptacles 40A-C. However, none of the connectors 21A-C are electrically 
connected to its respective receptacle 40A-C. As will be explained 
hereinafter, one of the pressure rollers 31 will be rotated clockwise 
about its pivot axis 34, which action applies upwardly directed rolling 
pressure against pressure plate 35 to rotate nest plate 27 about nest 
plate pivot axis 29. This action moves contact nest 25 upwardly until the 
nest contacts 39 engage corresponding connector printed wiring board 
contacts 37 on one side of the connector printed wiring board 23. The 
contact nest 25 also makes electrical connection with the receptacle 
contacts (not visible) of a receptacle printed wiring board or flex 
circuit 41. Accordingly, when the actuation pressure plate 35 is fully 
closed against the connector extension 38 of one of the connectors 21A-C, 
all 256 contact pads 37 on the connector printed wiring board 23 engage 
with corresponding contact pads on the receptacle printed wiring board or 
flex circuit 41. 
The flex circuit interconnecting scheme of FIG. 2 has the advantage of 
allowing additional flexibility in the placement of the individual ports. 
It can also be used to route the signals into a remotely located card cage 
(not shown) in the imaging system. This gives the industrial design great 
latitude in the imaging system layout. 
Each receptacle 40A-40C has its printed wiring board or flex circuit 41 
routed to a "Z" folded flex circuit 43, the connection being made as shown 
by the dashed lines at 45 in FIG. 2. 
The receptacle assembly illustrated in FIG. 2 can accommodate three 
different connectors plugged in at any particular time. Since the 
connector extensions 38 are small, the width of the slots in the 
receptacles 40A-40C is likewise small. The receptacle is thus inherently 
safe, as fingers cannot access the contacts. Within the receptacle printed 
wiring board or flex circuit 41, contact pads (not visible) for a specific 
channel number are wired electrically in common for the three ports. A 
port which is to be selected is actuated under imaging system control by 
rotation of a selected pressure roller 31; only one transducer assembly 
can be electrically connected to the system at any one time. This 
considerably simplifies the imaging system by eliminating the need for 
electrically operated switches. In effect, a connector 21A-C and its 
receptacle 40A-C becomes a multi-contact relay. 
Of course, with modest redesign, it is possible to accommodate even more 
connectors than the three illustrated, since the assembly, as noted in 
FIG. 2, is modular in construction. The very modest size of the connectors 
and the receptacle assembly allows their placement at convenient locations 
on the system, such as high up on the system console, beside the system 
monitor, or other convenient location. 
Two embodiments of compatible receptacle assemblies are shown in FIGS. 3A 
and 3B in partial cross-sectional representation. Details of a compatible 
connector 21A is shown in FIGS. 5-7. 
From these figures, it will be observed that the connector 21A has 16 
contact pad groups 85, each having 28 contact pads thereon, making a total 
of 448 contact pads, which is quite adequate for a 256 channel ultrasound 
transducer as well as peripheral devices such as motor drive, position 
sensors, etc. The contact pads 85 are on a multi-layer, e.g. 8 layer, 
printed wiring board 81 which also includes coaxial conductor termination 
pads 101. The contact pads 85 are hard gold plated in the same manner as 
those on the MP connector found on the Sequoia.TM.ultrasound imaging 
system manufactured by Acuson Corporation, Mountain View, Calif. The OEM 
supplier is AMP, Inc. of Harrisburg, Pa. Other plating systems may be 
required for greater life expectancies (up to 100,000 cycles). The coaxial 
conductor termination pads 101 are located on both sides of the connector 
printed wiring board 81; they can accommodate coaxial conductors 99 as 
large as 38 gauge. 
The coaxial conductors 99 comprise the flexible cable 11 between the 
transducer connector and the transducer itself, the cable 11 being 
restrained by a cable clamp 95 in a known manner. Also incorporated into 
the design of the connector 21A is a ferrite isolator for rf noise 
immunity. The housing 22 includes two injection molded plastic parts one 
of which, 22A, is shown in FIG. 7, the other part (not shown) removed to 
show the coaxial conductor termination scheme. 
The plastic housing 22 has a retention detent 83 which is engaged by the 
imaging system receptacle 40A-40C. This feature assures that the connector 
extension 87 is properly located within the receptacle 40A-C for proper 
actuation to be accomplished, even before contact engagement is made. The 
"window", i.e. raised frame, 103 around the array of contact pads 85 is 
designed to properly locate the pads 85 with respect to the contacts 39 in 
the receptacle 40A-C during actuation. This "window" technique reduces the 
tolerance required in the other parts of the connector/receptacle 
arrangement, reducing costs and increasing reliability. 
In the embodiment of the connector/receptacle assembly of FIG. 2, a contact 
nest 25 is shown and was described as the element which electrically 
connects the connector contacts to the receptacle contacts. In such an 
embodiment of the receptacle assembly, and in other receptacle embodiments 
in this specification, reference is made to U.S. Pat. Nos. 5,308,252 and 
5,358,411. While these references teach the use of contact springs which 
make a wiping action across the corresponding contact pads on either side 
thereof, thereby establishing a reliable electrical connection between the 
contact pads on either side, other means of contacting the connector 
contacts 37 with the receptacle contacts 39 may be employed in the present 
invention. That is, the invention is not limited to the use of a contact 
nest 25 as shown and described herein. 
FIG. 3A is a partial cross-sectional view of one port of the receptacle 
assembly illustrated in FIG. 2. In this embodiment, a linear actuator 50 
reciprocates the end of an actuation crank 64 (in and out of the paper as 
shown in FIG. 3A), which, in turn, rotates actuator shaft 52. Shaft 52 is 
rotatably supported by the outer two roller bearings 60 fixed relative to 
a framework 66. The middle roller bearing 60 has its axis parallel to the 
axis of shaft 52, the axis of the middle bearing 60 being movable along a 
circular path spaced from the axis of shaft 52. As shaft 52 rotates, the 
middle roller bearing 60 is articulated in the left-right directions as 
viewed in FIG. 3A which, in turn, applies pressure against actuation plate 
56 upon which is mounted the nest plate 58. Movement of nest plate 58 
toward the connector extension 54 serves to electrically connect the 
contacts on connector extension 54 with the nest contacts on nest plate 
58. Rotation of shaft 52 in the opposite direction withdraws the nest 
plate 58 away from connector extension 54 permitting the connector 
extension 54 to be removed from the receptacle slot. 
The flat actuation plate 56 is engaged by the middle roller bearing 60 to 
distribute force over the entire back side of the receptacle printed 
wiring board 70 during actuation. The nest plate 58 and actuation plate 56 
form a sandwich, with the contacts and the printed wiring board, or 
alternative flexible circuit, 70 in between. 
As described, the linear actuator 50 converts linear motion from the 
actuator (which may employ pneumatic, hydraulic, solenoid, screw/motor, or 
other movement actuation means) to rotary motion of the shaft 52. This 
causes the actuation plate 56 and nest plate 58 assembly to displace 
toward the connector extension 54 causing the receptacle contacts to make 
contact with the contact pads on the connector extension. 
The frame 66 ties the components together and supplies the reaction force 
required to compress the contacts into the pads on the connector extension 
54. 
The nest plate 58 and actuation plate 56 assembly moves in an arc about a 
pivot point with respect to the frame 66, in a manner as shown in the 
arrangement of FIG. 2. 
In this connection, as also can be viewed in FIG. 2, the imaging system 
front panel 24 is a molded plastic bezel which funnels the connector 
extension 38 of a connector 21A-C into the vertically oriented ports of 
the receptacle assembly. 
FIG. 3B shows an alternative construction for a receptacle assembly. In 
FIG. 3A, the actuator member 62 presses the nest plate 58 into contact 
with the connector extension 54. In FIG. 3B, the connector extension 65 is 
moved by load plate 57 into contact with the contact nests of the 
receptacle. 
The linear motion of the linear actuator 51 is converted to a rotational 
motion 59 through actuator shaft coupler 33 in a manner similar to that 
described in connection with FIG. 3A. Actuator shaft 34 is supported by 
roller bearings 55 which in turn rotates actuator member 68 moving 
pressure roller bearing 31 into pressing engagement with load plate 57. 
Connector extension 65 is biased away from the contact nests 69 of the 
receptacle by means of a pair of compression springs 75 which may be in 
the form of leaf springs or coiled compression springs. When pressure 
roller bearing 31 moves load plate 57 against the connector extension 65, 
the top and bottom edges of connector extension 65 press against the 
shoulder 74 of a moving frame 63 against the bias of springs 75 and 
collapses springs 75 to bring the connector printed wiring board 67 of 
connector extension 65 into contact with the contact nests 69 of the 
receptacle. A receptacle printed wiring board or flex circuit 71 carries 
signals from the contact nests 69 to the ultrasound imaging system 
electronics. Thus, in the embodiment of FIG. 3B, although the connector 
extension 65 is translated by the actuator 51, the receptacle printed 
wiring board or flex circuit 71, the nest plate 72, and contact nests 69 
remain stationary in the receptacle, being fixed in place by bolster plate 
73 attached at both of its ends to the receptacle frame 61. 
FIGS. 4-7 show one example of an appropriate connector 21A which may be 
adapted to fit into the receptacles shown and described in FIGS. 2, 3A, 
and 3B. Many other forms of the connector are envisioned, and the 
particular designs shown in FIGS. 4-7 are to be treated as exemplary only. 
The connector 21A of this embodiment includes a housing 22 the rear end of 
which serves as a hand grip, the forward end being narrowed to define the 
connector extension 87. A retention detent 83 is formed on the top of the 
connector and cooperates with a resiliently biased bar or dog (not shown) 
in the system receptacle. When a connector 21A is inserted into a system 
receptacle, this features assures that the connector extension is properly 
located and retained within the receptacle for proper actuation to be 
accomplished, i.e. for appropriate registration of the contact pads 85 on 
connector printed wiring board 81 with the corresponding pads of the 
contact nests 69 of the receptacle (the FIG. 3B as an example). 
The contact pads 85 are arranged in groups of 28, there being 16 contact 
pad groups on the connector printed wiring board 81, as shown. The 448 
contact pads are sufficient in number to permit 256 channel ultrasound 
transducer operation, including contact pads to route signals for 
peripheral devices such as motor drives, position sensors, etc. 
The connector printed wiring board 81 is preferably an eight layer printed 
wiring board which also includes coaxial conductor etermination pads 101. 
The termination pads 101 are connected to respective contact pads 85 
through the multilayer printed wiring board 81. The multi-coaxial 
conductor cable 11 from the transducer enters the housing 22 and passes 
through a ferrite isolator 93 providing rf noise immunity. The cable 11 
then is passed through a securing cable clamp 95 for strain relief and 
cable attachment to the housing 22. After passing through cable clamp 95, 
the outer insulation and ground shield layers (not shown) are stripped 
away leaving individual coaxial conductors 99 to follow an appropriate 
layout pattern for connection to the coaxial conductor termination pads 
101. The center conductor of each coaxial conductor 99 is thus connected 
to an assigned contact pad 85, and the ground shield of each coaxial 
conductor (not shown) may be soldered to a ground plane 100. The shield 
solder connections and center conductor solder connections for each 
coaxial conductor are not shown in the drawing, as these are commonly 
understood construction details for ultrasound transducer connectors. 
To assist in proper alignment of the contact pads 85 with the corresponding 
contact nests of the receptacle, a window frame 103 around the contact 
pads 85 is provided. A complementary interengaging window frame (actually 
a rabbet 98 around the edge of the contact nest plate 58, such as that 
shown in FIG. 3A) is provided within the receptacle arrangement, so that 
when the connector extension 87 is brought into contact with the contact 
nests of the receptacle, the making of the conductor and receptacle window 
frames automatically align the contact pads for proper registration. 
FIG. 8 is a representation in partial cross-section of an alternate 
embodiment of an ultrasound transducer connector 111 having a connector 
printed wiring board 114 within housing 115 having a housing extension 
115A. A connector extension locking lug 119 and the end 119A of the 
extension 119 establish a reference (left to right) for the connector when 
it is mated in the receptacle described below with reference to FIGS. 9 
and 10. Correct alignment of the contact pads in the connector 111 with 
corresponding pads within the receptacle 121 is required for proper 
functioning of the connector/receptacle system. Single or multiple 
openings 117 molded into the housing extension 115A provide mechanical and 
electrical access to contact pads on the back side of the printed wiring 
board 114. The shape of opening 117 together with the mechanical design of 
the mating components in the receptacle 121 (described below) serve the 
same purpose as the retention detent 83 described in connection with FIGS. 
4-7; the connector is assured to be correctly located within the 
receptacle 121 before electrical engagement of the signal contacts between 
the connector printed wiring board 114 and the contact nest 127 of the 
receptacle 121 has been effected. 
As may be appreciated by reference to the drawing of FIGS. 8 and 9, as the 
rounded blunt nose of the connector extension 115A enters receptacle slot 
123, the conductive detent roller 131 is pushed slightly downwardly to 
pivot about nest plate pivot 125A, such pivoting action being slightly 
resisted by the spring plunger assembly 141 applying a resilient force 
against the "L" bracket detent frame 145 by plunger 142. After the distal 
end of housing extension 115A passes by the axis of conductive detent 
roller 131, roller 131 is permitted to return upwardly to engage the 
ground plane 113 of connector 111 due to the detent roller 131 moving into 
opening 117 on the side of connector 111 opposite the connector extension 
hook 119. As a result of this action, the connector extension locking lug 
119 engages corresponding features (not visible in FIGS. 9 and 10--to be 
detailed with reference to FIGS. 11 and 12 which follows) on the sides of 
the contact nest plate 125 so as to properly locate (left and right 
directions) the contact pads on printed wiring board 114 to contacts 
within the contact nest 127. 
In the condition in which the connector and receptacle signal contacts are 
not engaged, if an operator wishes to pull the connector 111 out of 
engagement with the receptacle 121, a moderate pulling force will bias 
conductive detent roller 131 downwardly due to the sloping edges of 
opening 117 in the connector 111 to accommodate the withdrawal. 
After insertion of the connector 111 into receptacle slot 123, conductive 
detent roller 131, as mentioned, electrically contacts the ground plane 
113 of the connector 111 through opening 117. This is an important feature 
of the invention, in that, although the electrical imaging contact pads 
have not yet been mutually engaged between connector and receptacle, a 
ground connection (and other connections, as desired) is made between 
these two members to enable automatic detection by the ultrasound imaging 
system as to which transducer is being used. Details of this feature of 
the invention will be described hereinafter. 
In FIGS. 9 and 10, it will be observed that a "transducer-in-use" spade lug 
connector 137 is electrically coupled to the conductive detent roller 131, 
the roller 131 assembly being mounted on "L" bracket detent frame 145 by 
means of a screw 137. An insulator 133 electrically isolates the spade lug 
connector 137 with respect to the detent frame 145. 
The nest plate 125 supports the contact nest 127 and pivots about nest 
plate pivot 125A when an actuator shaft 129 is operated to pivot the nest 
plate 125 downwardly from the position shown in FIG. 9 to the position 
shown in FIG. 10, the latter demonstrating a full engagement of the 
connector 111 in the receptacle 121 with the contact pads of the connector 
printed wiring board 114 being in registration contact with the contact 
nest 127. 
In the reverse operation, the release of connector 111 is effected by 
movement of actuator shaft 129 upwardly, acting against the return frame 
146 to pivot nest plate 125 upwardly about nest plate pivot 125A, i.e. 
returning the nest plate 125 to the FIG. 9 position. 
Microswitch 139 detects the presence of a connector in the receptacle in 
the clamped condition. That is, when the nest plate 125 is in the position 
shown in FIG. 10, "L" bracket detent frame 145 is pivoted about nest plate 
pivot 128 sufficiently to actuate the plunger on microswitch 139, and 
spade lugs 147 conveys this sensed information to the system via the flex 
circuit 153. In FIGS. 9 and 10, the dotted lines encompassing 
"Transducer-in-use" spade lug connector 137 and microswitch spade lugs 147 
indicate that the electrical connections to these spade lugs are made to 
the flex circuit 153 in an appropriate and known manner. 
FIGS. 11 and 12 show yet another, and preferred, embodiment of a receptacle 
compatible with the design of the transducer connector 111 shown in FIG. 
8. In FIGS. 11 and 12, the portion of the connector housing 111 having an 
opening 117 (FIG. 8), and the conductive detent roller 131 (FIG. 9) are 
not shown for convenience, as these elements operate in the same manner as 
was described in connection with FIGS. 8-10. The details of FIGS. 11 and 
12 are thus offered to show an alternative connector clamping scheme. 
In this connection, FIGS. 11 and 12 show the locating features described 
broadly with reference to FIGS. 8 and 9. When connector 111 is initially 
inserted into a receptacle 102, it is pushed forward until the nose of 
extension 115A abuts stop bracket 155 which limits the insertion depth. In 
this position, the signal contact pads on the connector printed wiring 
board 114 are spaced from the contacts of the contact nest 106. As contact 
next 106 is pivoted downwardly by actuator 112, the sloping distal edge 
157 of the contact nest plate 104 slides against and pushes the connector 
extension locking lug 119 toward the insertion direction, while the 
sloping edge 151 of the contact next plate 104 continues to move 
downwardly until it is seated against the sloping wall 149 of the 
connector extension 115A. This causes a wedging effect in which the 
forward most end on each side of the contact nest plate 104 precisely fits 
into a complementary shaped cutout defined by locking lug 119 and sloping 
wall 149. This is best observed in FIG. 12 where it is clear that such 
wedging effect aligns the connector 111 and receptacle 102 longitudinally 
in the insertion direction. Interengaging window frames guide and maintain 
the connector 111 and receptacle 102 laterally of the insertion direction 
in the manner described with reference to FIGS. 3A and 7. 
In FIG. 11, an air cylinder actuator 112 is mounted to the receptacle 102 
by means of an air cylinder pivot axle 136. The plunger 116 moves in and 
out of air cylinder actuator 112 under ultrasound system control. In turn, 
the distal end of plunger 116 is fixed to a roller yoke 118 pivotally 
coupled to a roller axle 120. obviously, other types of actuators, or a 
manually actuated lever, could be used in place of the air cylinder 
actuator 112 shown. Examples are a hydraulic cylinder, a solenoid, lead 
screw and motor arrangement, etc. 
The roller axle 120 has a roller 44 journaled thereon to roll against the 
top surface of nest plate 104. Alternatively, with the proper choice of 
materials for the top of nest plate 104 and the end of roller yoke 118, a 
roller may be eliminated, and the rounded distal end of roller yoke 118 
may apply a low-friction sliding pressure against the top of nest plate 
104 to rotate nest plate 104 about nest plate pivot 110 in order to engage 
the contact nest 106 of the receptacle with the connector printed wiring 
board 114 of the connector 111. 
When the plunger 116 is fully extended from the air cylinder actuator 112, 
the roller link 124 has rotated clockwise until release trigger 132 
engages and is stopped by the manual ejection button 134. In this 
configuration, the roller link 124 has rotated slightly over center with 
respect to roller link pivot axis 122 and roller axis 120. Thus, when the 
air is removed from the air cylinder actuator 112, the nest plate 104 
remains clamped. 
The fully clamped condition as just described is shown in FIG. 12. In the 
clamped condition, the contact nest 106 are connected to the system via a 
flex circuit 128. When the transducer associated with transducer connector 
111 is not in use, the receptacle 102 must return to its unclamped 
condition. To do so, the system detects the non-use of the transducer 
involved and pulls back on plunger 116 from the FIG. 12 position to the 
FIG. 11 position. In doing so, the roller 44 is pulled back against the 
"Z" shaped extractor 126 which pulls the nest plate 104 upwardly to pivot 
about nest plate pivot 110 and return to the FIG. 11 condition. The 
extractor 126 forces the nest plate 104 to follow the roller link 124 when 
disengaging. Also, when disengaging, the connector extension retainer 130 
keeps the connector 111 from following nest plate 104. After return of the 
nest plate 104 to the FIG. 11 position, the connector 111 may be removed 
from the receptacle 102 as hereinbefore described in connection with FIGS. 
8-10. 
In the event of a malfunction of the air cylinder actuator 112, or for any 
other reason, a manual ejection button 134 is provided. With reference to 
FIG. 12, the roller link 124, pivotable about roller link pivot axis 122, 
is provided with a release trigger 132 extending toward the system front 
panel 148. When manual ejection button 134 is pressed into the panel 148, 
it engages release trigger 132 and forces roller link 124 to pivot 
counterclockwise and move roller yoke 118 rearwardly, releasing the 
pressure against nest plate 104 and allowing it to be pivoted back to its 
unclamped condition shown in FIG. 11 for easy removal of connector 111 
from receptacle 102. 
An alternative layout for the three receptacle ports is illustrated in FIG. 
13. In this arrangement, the ports are oriented in a horizontal manner and 
horizontally spaced, so that all three mechanisms are serviced by one 
shaft 165. This arrangement has several advantages which include only a 
single rotary actuator 163, which may be implemented by a geared, or 
stepper, motor 163 for all three ports. Each port has a pair of bearings 
(e.g., Torrington bearings) 169 within which the common shaft 165 rotates. 
Each port is also provided with a pair of cams 167 fixed to shaft 165 and 
spaced angularly 120 degrees. This ensures that only one connector is 
engaged by its respective receptacle at any time. As with the previously 
described port arrangement, the imaging system provides the proper drive 
signal to the actuator 163 responsive to either a manually selected 
transducer selection or automatically by the operator picking up a 
transducer to be used. 
In FIG. 13, the horizontally oriented multiport receptacle assembly 161 is 
provided with three identical receptacles 180A, B, and C. Each receptacle 
180A-C is configured the same as that shown and described in connection 
with FIG. 3B. That is, each receptacle 180A-C has a moving pressure platen 
171 movable by the cams 167 for applying a pressure against the connector 
extension 179 having a connector printed wiring board 181 on one side 
surface facing a contact nest 185 of a nest plate 187. The nest plate 187 
makes multiple contact with the registered contact pads of a system 
printed wiring board 183. When the cam 167 of a particular receptacle 
180A-C is moved to the unclamped rotational position, a pair of leaf or 
coil compression springs 177 presses against a horizontal offset shoulder 
184 to return the moving frame 182 to an open condition, and this, in 
turn, moves the connector extension 179 and moving pressure platen 171 
away from the contact nest 185 in order that the connector extension 179 
may be removed from the receptacle 180A-C. 
As noted above, since the cams 167 for three ports are oriented 120 degrees 
apart on the shaft 165, only one port can be actuated at any particular 
time. Thus, the required exclusivity is implemented mechanically in the 
receptacle assembly instead of electronically in the imaging system 
controller. The cost of such an arrangement will thus be typically lower 
than the vertical configuration shown in FIG. 2. However, the flexibility 
of this arrangement for the industrial designer is somewhat reduced. 
A conceptual design for a receptacle flex circuit 201 is illustrated in 
FIG. 14. Flex circuit 201 is a four layer Kapton (Trademark of DuPont, 
Inc.) based flexible circuit which electrically interconnects the contact 
pads 211 of a receptacle printed wiring board contact pad extension 203 to 
system connectors 221 which are interfaced to mating receptacles in the 
imaging system chassis (not shown). The contact pads 211 connect to a 
trace group 209. The traces of trace group 209 make electrical connection 
to corresponding ones of the traces of connector routing traces 223. 
Connections between layers and between the trace groups and routing traces 
of flex circuit 201 are accomplished by standard plated through vias. 
The schematic diagram of FIG. 15 is one example of a "transducer-in-use" 
detecting system which has been described generally herein to this point. 
FIG. 16 shows signal waveforms and the timing thereof for the circuit of 
FIG. 15. 
A 50 KHz oscillator 301 provides an rf signal source for the 
"transducer-in-use" detecting system. For example, the signal from 
oscillator 301 may be about 12 volts peak-to-peak and sinusoidal. This rf 
signal at point A of the schematic of FIG. 15 is rectified by diode 337 
and filtered by the RC network 339, 341. The time constant of the RC 
network 339, 341 is great as compared to the frequency of the rf signal 
source 301, and thus the negative input of comparator 343 has a DC 
reference voltage as one of its inputs. 
The rf signal at point A is also conveyed to the transducer 9 through a 
contact roller 303 within the receptacle (not shown), making contact with 
sense signal injection line 305. Injection line 305 is the center 
conductor of a coaxial conductor 99 leading to the transducer 9 and is 
electrically coupled there to a sense signal electrode (e.g., plate) 307. 
A second, detection line electrode (e.g., plate) 315 lies adjacent the 
sense signal electrode 307, such that when an operator 311 picks up the 
transducer 9 for usage, the operator 311 provides a capacitive coupling 
between the two electrodes. 
That is, a capacitive coupling 309 exists between the operator 311 and 
sense signal electrode 307, and also a capacitive coupling 313 exists 
between the operator 311 and the detection line electrode 315. Thus, when 
the operator picks up the transducer 9 for usage, a capacitive coupling 
path between the two coaxial conductors 99 in the cable assembly 11 
exists, and due to the high frequency of the rf signal source 301, the 
small capacitance that the operator 311 possesses with respect to the 
electrodes 307 and 315 produces a "transducer-in-use" detection signal on 
the detection line 317 which is electrically in contact with contact 
roller 319. The signal on contact roller 319 is developed across resistor 
325 and is shown in the timing diagram of FIG. 16 as waveform C. Waveform 
C is amplified by amplifier 327 which has a gain control 329 that the 
operator may adjust to set the threshold for the comparator 343 (to be 
described later). 
The output of amplifier 327 passes through diode 331 to be rectified and 
filtered by the RC network of resister 333 and capacitor 335 to produce 
signal B as shown in FIG. 16. Although signal C is somewhat less in 
amplitude than signal A due to losses and capacitive coupling to ground, 
the amplitude of the signal from amplifier 327 is greater than signal A, 
so that, when rectified, the DC voltage at point D is greater than the DC 
voltage at point B. Since the signal at D is applied to the positive 
terminal of comparator 343, and since the comparator 343 is an inverting 
circuit, when the DC signal level at point D is greater than that at point 
B, the output E of comparator 343 goes to a low level. This occurs when 
the operator 311 holds transducer 9 to provide the capacitive coupling 
309, 313. 
When the operator 311 releases the transducer 9, and capacitive couplings 
309, 313 no longer exist, the voltage on detection line 317 drops 
significantly. The input to amplifier 327 is thus a small 50 KHz signal 
which, when rectified at point D is less than that of the DC level at 
point B. In such a case, the negative input to comparator 343 is greater 
than that on the positive input, and the inverting comparator provides a 
high level output, typically 5 volts at point E. Thus, as FIG. 16 
indicates, when the operator 311 is not touching transducer 9, the output 
at E is at about 5 volts, and when the operator is holding the transducer 
9, the output E from comparator 343 is approximately 0.7 volts. 
The schematic diagram of FIG. 15 and waveform chart of FIG. 16 represents 
only a single detection scheme for indicating to the imaging system that a 
particular transducer is being used. A number of other schemes may be used 
instead. For example, a simplified "transducer-in-use" detection scheme 
may only detect the difference in noise picked up on a ground line in the 
transducer cable 11 when the operator is holding a transducer and when he 
or she is not holding the transducer. When held, there would be a larger 
level of noise picked up on the ground line, and this increase could be 
detected to produce a "transducer-inuse" signal. 
FIG. 17 is a simple logic circuit arrangement designed to eliminate the 
possibility of two receptacles being clamped and in operating engagement 
with their respective connectors. As mentioned, it is essential for only 
one receptacle to be clamped at any one time. The circuit of FIG. 15 will 
meet this requirement for so long as the operator (or different 
operators/personnel) does not pick up and hold two transducers at the same 
time. The circuit of FIG. 17 gives priority to the first transducer picked 
up, and will retain priority for that transducer even if another 
transducer is subsequently picked up before the first transducer is 
released. 
Assume transducer 1 is picked up in FIG. 17. The touching by the operator 
produces a positive level "transducer-in-use" signal as seen in FIG. 16. 
This high level is sent as one input to AND gate 354 and is also inverted 
by inverter 351 and applied to the reset input of flip-flop 357 as well as 
to the inputs to AND gates 355 and 356 related to transducers 2 and 3. 
Flip-flop 357 can only be set by all three inputs to AND gate 354 going 
positive. This can only happen if transducer 1 is touched and transducers 
2 and 3 are not being touched. Thus, exclusively, if transducer 1 is 
touched and transducers 2 and 3 are not touched, flip-flop 357 is set, and 
its output is sent to receptacle 360 to clamp the inserted connector of 
transducer 1 in receptacle 1. 
Note that when the conditions of the preceding paragraph are met, the 
inputs to AND gates 355 and 356 necessarily are low, preventing flip-flops 
358 and 359 from setting and clamping receptacles 2 and 3. Also, 
necessarily, with transducers 2 and 3 not being touched, the outputs of 
inverters 352 and 353 are high, resetting flip-flops 358 and 359. 
In the event that another transducer, e.g. transducer 2 is touched, the 
middle input of AND gate 355 goes high, but the lower input to gate 355 is 
low due to transducer 1 being previously touched. Therefore, even though 
flip-flop 358 is no longer being reset, it cannot be set until transducer 
1 is released. At that time, all three inputs to AND gate 355 are high; 
flip-flop 357 is reset via inverter 351; and flip-flop 358 is set by the 
output of AND gate 355. 
The same analysis applies to other conditions of touching and non-touching 
of the three transducers. Importantly, in order for any receptacle 360, 
361, or 362 to be clamped, it requires that the transducer connected to 
the connector inserted in it must be touched and the other two transducers 
not touched. 
If the transducer-in-use detection system is used, transducer selection is 
automatic, as described. However, operation of the receptacles may be 
optionally under the control of the imaging system. A particular 
transducer can be selected by the operator manually, providing an input to 
the control panel of the imaging system. To implement this function, OR 
logic gates 348-350 and a manual/automatic switch 347 are provided. Switch 
347 has three sets of single-pole double-throw switch contact sets 344-346 
which, when switch 347 is in the manual position, disconnects the 
transducer-in-use signals from all three OR gates 348-350. In order to get 
any one transducer connector to be engaged with the receptacle into which 
it is inserted, any one of the manual enable inputs, ME1-ME3, are brought 
to a high logic level (e.g., +5 volts), and this replaces the automatic +5 
volt enabling signal from the transducer-in-use circuit of FIG. 15. 
Whether the inputs to OR gates 348-350 are from the transducer-in-use 
circuits or are manually applied, the feature of not permitting more than 
one transducer connector to be engaged is equally effective. If desired, 
simple additional switching circuitry can be employed to select only 
automatic operation or manual operation. Using the circuit of FIG. 17, any 
transducer may be manually activated by bringing a selected one of inputs 
ME1-ME3 high independent of whether switch 347 is in the automatic or 
manual mode. In such a case, only the automatic selection may be disabled; 
the manual selection remains available at any time. This may be 
advantageous in certain situations. 
FIGS. 18-40 depict variations on the design of the connectors and/or 
receptacles, using the basic and general concepts described in connection 
with FIGS. 1-17 and the corresponding text in this specification. 
In FIGS. 18-21, a connector 381 is inserted into a horizontal slot in front 
panel 380, connector 381 exposing the contact pads 383 of a connector 
printed wiring board 402. The receptacle in FIG. 18 is in the locked, or 
clamped, condition in which the receptacle nest plate 382 has exposed 
contact nests 406 facing downwardly, each contact nest having typically 
408 contacts (12 groups of 34 contacts each). A rigid aluminum bolster 389 
is fixed to the frame 394 and front panel 380 and supports the receptacle 
printed wiring board 392 in a fixed position. 
The connector 381 is moved from the unclamped condition of FIG. 21 to the 
clamped condition of FIG. 18 by rotation of a connector actuator arm 393 
in the direction of rotation indicated by numeral 388. Arm 393 is moved to 
the clamped position by a linear actuator 395 having a plunger 401 
linearly reciprocating horizontally. A connecting linkage 399 pivotally 
attaches to the end of plunger 401 at one end thereof and through 
Torrington roller bearings 398 to an actuator link 397 which is pivotable 
about an actuator link pivot 384. Actuator link 397 has an actuation 
roller 386 journaled on a hardened pin shaft 385. 
In FIG. 18, the plunger 401 is withdrawn into linear actuator 395, pulling 
the bottom of actuator link 97 to cause actuation roller 386 to move to 
the left in FIG. 18 and apply pressure to the connector actuator arm 393 
to move the extension of the connector 381 upwardly for making contact 
with the contact nests 406 of the receptacle. 
As will be appreciated by reference to FIG. 21, extending the plunger 401 
out of linear actuator 395 rotates actuator link 397 clockwise as 
indicated by arrow 396. As actuation roller 386 moves to the right in FIG. 
21, it engages the inner surface of an extraction extension 387 fixed to 
the connector actuator arm 393. With the plunger 401 fully extended, 
actuation roller 386 has moved downwardly relative to its pivot axis 384 
permitting the connector 381 to be released from electrical contact with 
the nest plate 382 of the receptacle. To ensure that connector 381 is 
fully withdrawn and out of contact with nest plate 382, roller 386 pushes 
downwardly on the lower end of extraction extension 387. Under these 
circumstances, the connector 381 may be easily removed from the 
receptacle. 
FIGS. 19 and 20 illustrate additional details of this connector 381 in 
which a connector printed wiring board 402 is supported in the connector 
body. A snap-in strain relief assembly 405 is provided at the cable entry 
end of the connector 381, and a standard cable clamp 404 and ferrite 
isolator 403 is provided. 
FIG. 20 is a cross-sectional view taken along the lines 20--20 in FIG. 19 
and shows a keying channel 388 which is keyed to a horizontal bar or rails 
388A on the connector actuator arm 393. The engagement of bar or rails 
388A in channel 388 ensures that the connector 381 will not fall out of 
the receptacle in the open or unlocked condition shown in FIG. 21. 
FIGS. 22 and 23 show graphs of the load requirement for the engagement of 
the connector printed wiring board 402 and the receptacle nest plate 382 
as a function of solenoid displacement for both the clamped and unclamped 
condition. FIGS. 24-27 illustrate yet a further variation of an ultrasound 
transducer connector 450 which has lighted nomenclature 451 as shown in 
FIG. 25 for easy identification by the operator as to the type of 
transducer to which the connector is attached. The lighted nomenclature 
451 is illuminated by light panels 452 powered from the ultrasound system 
through cable 458. As cable 458 enters the injection molded housing 457 of 
connector 450, it passes through a standard cable clamp 456 and a ferrite 
isolator 455, the coaxial conductors of the cable 458 being soldered to 
the printed wiring board 453 at coaxial conductor termination pads 454. 
The connector pads 459, in the embodiment of the connector shown in FIGS. 
24-27, face downwardly from the horizontal extension of connector 450, 
opposite in direction to the facing of the connector pads in the connector 
variation shown in FIGS. 18-21. 
FIG. 28 is a basic representation of a three-port receptacle assembly 
provided with individual linear actuators 465 acting upon shoes 466, each 
shoe 466 shown to have the extension of a connector 464 mechanically held 
in place and ready for making contact with the nest plates 462 of the 
receptacle. The frame 460 provides the pressure support for the linear 
actuators 465 and includes a bolster plate 461 upon which the printed 
wiring board 463 of the receptacle is fixed. Nest plates 462 are provided 
in a manner similar to the already-described connector/receptacle 
variations. 
FIGS. 29 and 30 illustrate yet another transducer connector 470 terminating 
a cable 471 through a strain relief 472 and through a ferrite isolator 
473, the coaxial conductor 474 terminating at a coaxial conductor 
termination 475. 
The connector printed wiring board 478 is provided with 64 0.1".times.0.1" 
inductors on 0.175" centers, 64 of each such inductors placed on each side 
of printed wiring board 478. Inductors are frequently used in ultrasound 
systems to improve the energy transfer from the transducer to the imaging 
system, or to improve the frequency response characteristics of the 
transducer; other passive components such as transformers, capacitors, and 
resistors can be used for the same purpose. Active components can also be 
used; amplifiers can increase the receive signal levels for improved 
imaging performance, while multiplexers can allow use of imaging 
transducers with high channel counts (improved resolution) on imaging 
systems having limited channel processing capability. 
A flash memory chip 477 may be provided on the printed wiring board 478. 
This device can be read by the imaging system; it can also be written to 
by the imaging system. The flash memory can be programmed during the 
transducer manufacturing process with such important information as the 
transducer identification (type of transducer), the serial number of the 
transducer, or any calibration or compensation information about the 
imaging stack. A programmable "Read Only Memory" can also be used for this 
transducer information. 
The flash memory chip 477, or a separate flash memory chip, can also store 
information written to it by the imaging system. This information, which 
may include imaging system control settings, would decrease the amount of 
time required to acquire good diagnostic images the next time the 
transducer is used. In addition, text relating to the idiosyncrasies of 
the particular transducer may prove useful to other diagnosticians. 
As with other connector variations described, there is provided 408 contact 
pads 481 accessible on one side of the connector (see FIG. 30), and a 
detent feature 479. 
FIGS. 31-33 show yet another version of a transducer connector 480 having 
408 contact pads 481 accessible on the top of the connector (see FIG. 32). 
A cable 482 enters the connector 480 with the coaxial conductors terminated 
at 484. The plastic housing 483 of connector 480 has an oval shape portion 
diminishing in dimension to the extension 486 of the connector 480 at 
which the printed wiring board 485 is exposed for contact engagement. 
FIGS. 34 and 35 show a mechanism for engaging the receptacle module 489 
with either one of a pair of connectors 480 inserted into the receptacle 
opening. The connectors 480 are spaced from one another by a plate 493 
which is attached to a rotating carriage 495 within imaging system front 
panel 494. 
With the two connectors 480 inserted in the rotating carriage, the 
receptacle module 489 may be pivoted in the direction of arrow 491 about 
pivot axis 490 until the contact nests 496 of the nest plate 497 engages 
the printed wiring board of the top connector 480. Electrical continuity 
through the connector 480 to the system board is provided by a flex 
circuit 492. 
When another connector is to be connected to the system, the receptacle 
module 489 is rotated upwardly, and the rotating carriage 495 is rotated 
as indicated by arrow 488 until the bottom connector 480 is now on the 
top. At this time, the system commands the receptacle module 489 to again 
pivot downwardly and make contact with the newly selected transducer. 
FIG. 36 also employs a dual connector 480 arrangement in which the 
connectors are separated by a plate 487 and inserted into a receptacle 
slot in the imaging system front panel 496. In this embodiment, rather 
than rotating the connectors, the system receptacle is provided with a 
pair of receptacle modules 500 and 502. The contact nests of each 
receptacle module 500, 502 have their contacts wired in parallel through 
the flex circuit 505 leading to the system board. 
As shown in FIG. 36, the bottom connector 480 is connected to the system 
because of the clamping of the lower receptacle module 502 to the 
connector extension 486 of the lower connector 480. When the upper 
connector is to be connected to the system, an actuator (not shown) 
rotates receptacle modules 500, 502 in the direction of arrow 506 about 
respective pivot points 501, 503, the link 504 moving the lower receptacle 
module 502 out of contact with the lower connector 480 and moving the 
upper receptacle module 500 into contact with the inserted upper 
connector. 
FIGS. 38-40 show an arrangement in which a series of transducer connectors 
550 are arranged horizontally in fixed positions, and a moving receptacle 
module with appropriate contact nests is translated linearly by each of 
the assembled connectors and clamped to a selected one of them by a 
camming action. In FIG. 38, a receptacle module 551 is out of contact with 
the connector 550 and resting against a stop 552. FIG. 39 shows the 
rotation of the pin 558 in a direction to pivot the receptacle module 551 
about a screw 555 and into contact with the connector 550. 
A flex circuit 556 connected to the receptacle module 551 permits module 
551 to be translated linearly across a number of selectable transducer 
connectors, e.g. a series of six transducer connectors, under software 
control. 
A cam 552 may be provided adjacent each connector placement position, and a 
stepping motor 554 rotates screw 555 to translate receptacle module 551 
linearly, module 551 having female threads corresponding to the male 
threads of screw 555. 
Another stepper motor or geared motor 553, under software control of the 
imaging system, rotates a cam set 552 which are angularly aligned in 
parallel, i.e. stepper/gear motor 553 selectively rotates the cam 552 to 
only one of two positions, a clamped position and an unclamped position. 
The clamped position is selected when the receptacle module 551 is 
translated to a new connector position, and when that selected transducer 
is used, the cam 552 is rotated to depress the receptacle module 551 into 
contact with the printed wiring board of the selected connector. 
Shown in FIGS. 41-43 are partial cross sections of a connection arrangement 
using a contact nest 560 connecting the contacts 564 of a receptacle 
printed wiring board 561 to a flex circuit 562 of an imaging system. FIG. 
42 is a partial cross sectional side view of the arrangement depicted in 
FIG. 41, taken along the line 42--42 in FIG. 41 and showing a spring 
contact 563. Contact 563 is shown to make sliding electrical contact with 
printed wiring board contacts 564 on the receptacle printed wiring board 
561 and signal contacts 565 on the top side of flex circuit 562. 
FIG. 43 is a magnified view of the lower portion of the cross sectional 
view enclosed within the line 43 in FIG. 41. Using a two-sided flex 
circuit 562, FIG. 43 shows a way of connecting ground contacts 569 with a 
ground plane 566 on the bottom side of flex circuit 562. This is made 
possible by providing an aperture 567 through the flex circuit exposing 
the ground plane 566 through the aperture 567. The spring contacts 563 are 
sufficiently resilient that good and reliable electrical connections are 
made at both the signal contacts 565 and the ground plane 566 due to the 
thin dielectric of the flex circuit between. It should be noted that 
either a flexible circuit or a printed wiring board can be used in the 
receptacle assembly, and that the showing of a printed wiring board 561 is 
exemplary only. 
By this scheme, the contacts assigned to signals are contact pads 565 on 
the top side of the flex circuit 562, and those contacts 569 assigned to 
ground contact the ground plane 566 on the bottom side of the flex circuit 
562 through apertures 567 in the flex circuit substrate. This 
interconnection scheme could, for example, be used in making the 
multi-path connections between the printed wiring board 37 of connectors 
21A-21C and the flex circuit 41 through contact nest 25 in FIG. 2. 
It will be understood that the apertures 567 could be formed to provide 
access to the signal contacts 565 through the substrate 561, but the 
former configuration is preferred with the aperture(s) exposing the groung 
contact(s) through the substrate 561. 
While only certain embodiments of the invention have been set forth above, 
alternative embodiments and various modifications will be apparent from 
the above description and the accompanying drawing to those skilled in the 
art. For example, imaging system operator control settings may be stored 
in a flash memory in the connector. When initializing a transducer, this 
information is read by the imaging system. When switching to that 
transducer in the future, the previous settings are restored by the 
imaging system, reducing the time required to acquire diagnostically 
useful images. Additionally, operator inputted information may be stored 
in a flash memory for use by other operators or to enable recall of 
special information aabout the idiosyncrasies of the transducer. These and 
other alternatives are considered equivalents and within the spirit and 
scope of the present invention.