CA2007119A1 - Tool for placement of a monitoring probe in the scalp of a fetus - Google Patents
Tool for placement of a monitoring probe in the scalp of a fetusInfo
- Publication number
- CA2007119A1 CA2007119A1 CA002007119A CA2007119A CA2007119A1 CA 2007119 A1 CA2007119 A1 CA 2007119A1 CA 002007119 A CA002007119 A CA 002007119A CA 2007119 A CA2007119 A CA 2007119A CA 2007119 A1 CA2007119 A1 CA 2007119A1
- Authority
- CA
- Canada
- Prior art keywords
- probe
- drive element
- scalp
- article
- fetus
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
- A61B5/1455—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue using optical sensors, e.g. spectral photometrical oximeters
- A61B5/1464—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue using optical sensors, e.g. spectral photometrical oximeters specially adapted for foetal tissue
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
- A61B5/14542—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue for measuring blood gases
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/24—Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
- A61B5/25—Bioelectric electrodes therefor
- A61B5/279—Bioelectric electrodes therefor specially adapted for particular uses
- A61B5/28—Bioelectric electrodes therefor specially adapted for particular uses for electrocardiography [ECG]
- A61B5/283—Invasive
- A61B5/288—Invasive for foetal cardiography, e.g. scalp electrodes
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/43—Detecting, measuring or recording for evaluating the reproductive systems
- A61B5/4306—Detecting, measuring or recording for evaluating the reproductive systems for evaluating the female reproductive systems, e.g. gynaecological evaluations
- A61B5/4343—Pregnancy and labour monitoring, e.g. for labour onset detection
- A61B5/4362—Assessing foetal parameters
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
- A61B5/6846—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be brought in contact with an internal body part, i.e. invasive
- A61B5/6879—Means for maintaining contact with the body
- A61B5/6882—Anchoring means
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B2503/00—Evaluating a particular growth phase or type of persons or animals
- A61B2503/02—Foetus
Abstract
TOOL FOR PLACEMENT OF A MONITORING PROBE
IN THE SCALP OF A FETUS
Abstract The combination of a rigid, elongated applicator tool (200) and an elongated integral drive rod/probe (202). The drive rod/probe (202) is a rigid cable which includes a monitoring probe (204) with an extending spiral needle (206) at the front end thereof. At the rear end of the cable is a drive knob (236). The applicator tool (200) includes a hood element at the front end thereof which overlies the probe (204) and the needle (206) of the drive rod/probe (202) when the drive rod/probe (202) is positioned within the applicator tool (200). The applicator tool (200) includes a longitudinal slot (208) which permits insertion and removal of the drive rod/probe (202).
IN THE SCALP OF A FETUS
Abstract The combination of a rigid, elongated applicator tool (200) and an elongated integral drive rod/probe (202). The drive rod/probe (202) is a rigid cable which includes a monitoring probe (204) with an extending spiral needle (206) at the front end thereof. At the rear end of the cable is a drive knob (236). The applicator tool (200) includes a hood element at the front end thereof which overlies the probe (204) and the needle (206) of the drive rod/probe (202) when the drive rod/probe (202) is positioned within the applicator tool (200). The applicator tool (200) includes a longitudinal slot (208) which permits insertion and removal of the drive rod/probe (202).
Description
2~0'7~9 Description TOOL FOR PLACEMENT OF A MONITORING PROBE
I~ THE SCALP OF A FE~US
'.!,' 5 Technical Field :
This invention relates generally to the art of fetal monitoring probes, and more particularly concerns an article for placement of such a probe in `. the scalp of a fetus.
' ', 10 Backaround Art The importance of monitoring the physical condition of a fetus during the birth process is well . established. Appropriate remedial action and/or intervention can then be used when indicated. In ~; this regard, the pH of the fetus, as well as the ,s,~~ fetal heart rate, are important indicators of fetal condition. Fetal monitoring eguipment has been ~ developed to obtain, analyze and display such information. Typically, such information is obtained from the f~tus by means of a probe which is attached ~, to the scalp of the fetus in utero and which remains in the scalp tissue throughout the birth process. An example of such a probe is shown in U. S. Patent No.
4,658,825 to Hochberg et al, which is assigned to the same assignee as the present invention.
In order to obtain reliable information, particularly for pH, it is necessary that the end portion of the probe containing the pH sensor be securely positioned in the scalp of the fetus. This is sometimes difficult, since the clinician must accomplish the initial attachment of the probe by feel rather than by sight, and the resulting 7~:~9 attachment must be sufficiently strong to withstand the movement of the fetus and the mother during the . birth process.
Although the particular shape (spiral) of the needle shown and described in the '825 patent has proved to be significant in maintaining the secure attachment of the probe to the fetal scalp, the guidance of the pro~e to, and initial positioning of , the probe on, the fetal scalp is also important, as well as the ability to rotate the probe so that the spiral needle moves into the fetal scalp while maintaining the probe body at an angle which is substantially normal to the scalp. This is often difficult to do under actual conditions.
For that reason, an insertionJplacement tool ; is typically used with the probe to attach the probe to the scalp. While existing insertion tools are typically flexible to accommodate the insertion of the probe through the vagina and csrvix of the woman in labor to the fetal scalp, flexibility alone does not re~ult in proper initial placement and subsequent maintenance of the attachment of the probe to the fetal scalp. In order to accomplish reliable attachment, the applicant has discovered that the forward end o~ the probe must be initially positioned - substantially normal to the fetal scalp, and must be maintained in that position by the insertion tool, while at the same time the tool must be rotatable from its far end ~opposite from the near or fetal scalp end), with the far end of the tool being at a ~, ~ substantial angle relative to the near end which is ; at the fetal scalp.
:~ Use of existing tools have resulted in di~ficulty in properly attaching the probe to the fetal scalp, wh$ch in turn often results in inaccurate or unreliable readings, particularly of pH.
:
2()~`'71~9 ~ 3 :
Discl~s~EQ o th~ Invention The article includes a drive element having a forward end which is adapted to support a probe element, wherein the probe includes a needle extending therefrom, wherein the drive element is flexible along its length, contains connections for the probe and includes means in the vicinity of the rear end thereof for rotating the drive element and hence the probe. The article further includes a ; rigid applicator tool which has a longitudinal slot along one side thereof, adapted to receive the drive element, including the probe, therein. The slot is large enough to accommodate the drive element.
Brief Description of the Drawinas Figure 1 is an elevational, partial cross-sectional view showing the article of one embodiment of the present invention.
Figure 2 is a rear elevational view of the , .:
l front hood element portion of the article of Figure :,,,~ 1.
Figure 2a is a cross-sectional view of the ;~ front hood element of Figures l and 2.
Figure 3 is a front elevational vlew of the drive rod portion of the article of Pigure 1.
Figure 3a is a rear view of the drive rod of i~...l ~j Figures 1 and 3.
Figure 4 shows the details of the flexure ;i 30 joint of the article of Figure 1.
Figure 5 is an isometric view of another embodiment of the insertion tool of the present ~; invention, showing a different flexure joint configuration and a modified front hood element.
3s Figure 6 ls an isometric view of the applicator tool portion of another embodiment of the present invention.
t~r~
ZC~7~19 Figure 7 is a side elevational view of the ! integral drive rod/probe portion of the embodiment of ; Figure 6.
Figure 8 i~ an enlarged cross-section view of a portion of the drive rod/probe shown in Figure 7.
Best M~de For Carryina Out The Invention The insertion/placement tool of the present invention is shown generally at lO in Figure 1, in combination with a fetal probe shown generally at 12.
The tool 10 generally comprises a drive rod 14 and a : hood-like element 16 which is positioned at the front end 18 of the drive rod 14. The fetal probe 12 is shown operatively positioned in the drive rod, with the probe 12 in the embodiment shown generally comprising a body portion 20, an extending needle element 22 and electrical and optical connections 24.
The electrical and optical connections 24, hereinafter referred to simply as cable connections, are in turn connected to a conventional fetal monitoring unit which analyzes and displays the in~ormation obtained by the probe.
In the embodiment shown, the drive rod 14 ~5 comprises a length o~ relative}y stiff plastic, approximately lO inches long and .37 inahes in diameter. An example of suitable material is polypropylene. The drive rod 14 includes a first, forward section 26 which is relatively toward the fetuæ, and a second, rear section 28 which i8 relatively away from the fetus. The forward section 26 i8 hollow while rear section 28 is solid. The forward and rear sections are ~oined by a flexure joint 30 which is shown in more detail in Figure 4 and described below.
The hollow forward section 26 in the embodiment of Figure 1 i5 approximately 2 1/2 inches ~- J
Z()07119 long, and has a longitudinal slot 33 therein which communicates with the hollow interior of section 26 and which extends from the front end 18 of the drive rod approximately 2.40 inches toward the rear end thereof. The slot 33 is wide enough to permit the exit of the cables 24 of the probe from the interior of the drive rod 14. In the embodiment shown, slot 33 is straight; however, it could spiral around the circumference of the forward section of the drive rod, if desired. The solid rear section 28 also includes a longitudinal slot 36 which extends from the rear end 32 thereof approximately 0.80 inches.
Slot 36 is designed to permit the cables 24 to be temporarily secured to the rear end of the drive rod when the probe is in position within the drive rod, and the rod is being inserted into the mother for placement of the probe on the ~calp of the fetus.
At the front end 18 of the drive rod 1~ is a :
hood retaining shoulder or lip 40 which is round in ~ 20 outline and approximately .45 inches in diameter, as : shown in Figures 1 and 3 and also as shown in the ':7 embodiment of Figure 5. The lip 40 extends outwardly ;' from the exterior surface of the drive rod approximately 0.07 inches and is 0.06 inches thick.
,t,'.,J.25 Lip 40 prevents the hood element 16 from coming off the front end of the drive rod.
The interior surface of the drive rod 14, ~-~ from the front end 18 thereof for a distance of approximately 0.20 inches, is square in outline, approximately 0.20 inches on a side. At the rear end of this square portion 42 is a lateral groove 44 in the interior surface of the drive rod 14, ~:~ approximately 0.10 inches wide and 0.28 inches in -~ diameter. The remainder of the forward section 26 has an interior diameter of 0.22 inches. However, ~;;
'~ the interior surface of the drive rod could be square !';;
Z0~7119 ':
: over the entire length of the forward section, if de~ired.
, Referring to Figure 1, the dimensions of the 7' drive rod and the hood are adapted to the dimensions of the probe 12, so that for instance, front portion 46 of probe 12 has a diameter which is ~ust slightly ; smaller than the interior diameter of the front portion of the hood 16, while middle portion 48 of the probe, which is squar~ in cross-sectional outline, has cross-sectional dimensions which are ; slightly less than the dimensions o~ the square portion 42 of the interior surface of drive rod 14.
The probe 12 thus fits securely in the drive rod at the front end thereof.
The front hood element 16 is shown in Figure~ 1 t Z and 2a. In the embodiment shown, the hood element 16 fits around the drive rod 14 at the front thereof, and extends beyond the front end 18 of drive rod 14 a sufficient distance to cover the extending needle portion 22 of the probe when the probe 12 i8 operatively positioned in the drive rod, as shown in Figure 1. The hood element 16 in the embodiment shown is 1.2 inches long and is generally circular in exterior outline, with a diameter o~
;;25 approximately 3/4 inches. A longitudinal slot 50 extends the entire length of the hood element and extends from the exterior surface of the element to ; the hollow interior thereof.
~' The slot 50 i~ wide enough to permit exiting of the cables 24 of the probe therethrough. The hollow interior of the front hood element 16 includes a rear cylindrical portion 52 which is approximately 0.70 inches long and has a diameter of 0.38 inches '~ and a front cylindrical portion 54 which is approximately 0.50 inches long and has a diameter of 0.47 inches. The interior lip 56 defined at the ;! junction of the front and rear portions 52 and 54 ~')07119 abuts against the rear surface of extending lip 40 on the front end 18 of the drive rod 14, which pr~vents further forward movement of th~ hood element 16 relative to the drive rod 14.
In use, the hood element ~6 is grasped by the clinician and inserted into position into the ~ body of the mother, against the head of the fetus, z bringing the drive rod and tho prob~ therealong. The fact that the front hood element 16 extends a slight distance beyond the forward tip of the probe needle 22 prevents the needle from damaging the mother's tissues during insertion of the probe. The front end 59 of the hood element may be serrated or otherwise configured to provide a friction surface. This results in the skin being held taunt to permit better ~ needle penetration.
- To facilitate the insertion of the tool and the probe by means of the hood element, the hood element 16 has three peripherally spaced cut-out !; 20 portions 58, 60 and 62 in the outer surface thereof, I which extend from the rear end 64 of the hood element j 16 to a point which i~ slightly more than half way to s the front end of the element. The three cutout portions 58, 60 and 62 are configured to accommodate the fingers of the clinician. Cutout portions 60 and 62 are spaced 180- relative to each other around the periphery of the hood element, while cutout 58 is at :l 90- to cutouts 60 and 62. Typically, but not 1 necessarily, slot 50 divides cutout 58.
r~ 30 One embodiment of the flexure joint 30 which $s! connects the first and second sections 26 and 28 of ~ ~ the drive rod 14 is shown in Figure 4. The flexure t,~, joint 30 is defined by first and second grooves 66 ~ and 68 and third and fourth grooves 70 and 72. First and second grooves 66 and 68 oppose each other, as ,$ shown in Figure 4 and are somewhat crescent-shaped, ~ extending around the circumference of the drive rod " 8 approximately 160-, toward the rear end thereof, ~; leaving a short span of approx$mately 1/16 inch of ~; material 67 between the respective interior ends of the first and second qrooves 66 and 68. Grooves 66 and 68 at their widest are approximately l/8 inch and narrow toward each end.
1 The third and fourth grooves 70, 72 are cut: in the drive rod slightly to the rear of the first '. and second grooves 66 and 68. Grooves 70 and 72 alsooppose each other and are at 90- relati~e to the first and second grooves. Grooves 70 and 72 are also crescent-shaped, extending toward the front end 18 of i the drive rod, and are positioned relative to each other so that there i8 a small span of material 7 15 between the respective interior ends of each groove.The two sets of grooves are spaced so that there i8 approximately 1/8 inch of material between the respective sets o~ grooves. Also, the interior ends of the four grooves are in the same plane, at points 90- removed ~rom each other. Accordingly, the resulting ~lexure ~oint act~ somewhat like a universal ~oint, permitting the rear section 28 to be ; angled relative to the forward second 26 about ~ relatively small, defined points, and further ;~ 25 permitting rotation of the forward section 26 by ; rotating the rear section 28 without the drive rod being distorted in any way. This is illustrated in Figure 1. The arrangement and configuration of the grooves is also such that rotation of the drive rod i: 30 by the rear section 28 will result in a corresponding rotation of the forward section 26, without lateral ~: movement of the forward sectiGn.
~; Other particular ~lexure joint configurations are possible. One other configuration is described in more detail below. It is important, ~` howev~x, that the flexure be able to permit angling of t~e rear section 2~ relative to the forward Zf)~)7119 section 26, without distortion o~ the first sect~on, and such that rotation o~ the rear section 28 results in a correspondinq rotation of the ~orward section 26. This has the advantageous result that when the rear section 28, which typically extends outwardly ~rom the patient, is rotated by the clinician, the forward section of the probe, which is positioned against the scalp of the fetus, remains substantially normal to the fetal scalp during rotation of the drive rod, which in turn results in the secure attachment of the probe to the scalp of the fetus in a convenient and reliable way, as explained in more detail below.
Figure 5 shows a somewhat different embodiment of the present invention. The drive rod : shown in ~igure 5 includes a ~orward section 80 and a rear portion 82, with the forward section being . hollow and the rear portion 82 beinq solid, as with '. the embodiment of Figures 1-4. The configuration of f 20 the ~orward and rear sections 80 and 82 is also substantlally the same as for the embodiment of Figures 1-4. However, the flexure ~oint 84 is ,~ di~ferent. Joint 84 includes a first pair of grooves 86 and 88 which are approximately 3/16 inch wide, are ~ 25 in registry, and extend approximately halfway through ;~ the drive rod, at right angles to the longitudinal axis o~ the rod, leaving a thin center portion 90 , approximately 1/32nd inch thick so that the rear section 8~ can be moved relative to the forward ~'~'! 30 section 80 about the thin center portion 90-A second set of grooves 92 and 94 is located just to the rear of grooves 86 and 88. Grooves 92 .~ and 94 are oriented a~ 90- to grooves 86 and 88, but otherwise have the same configuration. A thin center ,jA;,'35 portion 96, which is at 90- relative to center ~1 portion 90, re~ains between the two grooves 92 and !.~ 9~, permitting movement of the rear section 82 lo 2~V7119 i; relative to the forward section 80 about center portion 96. The flexure ~oint 84 with the ~, configuration shown permits a substantially universal ~oint function between the rear section 82 and the forward section 80.
v The hood element 98 shown in Figure 5 is also somewhat different than the hood element 16 of Figure 1, in that it includes a lateral slot 100 wh~ch extends through the cross-sectional dimension ;: 10 of the element and also extends from the forward end 102 of the hood 98 to a point somewhat rearward of ` the rear end 103 of the finger depressions. In the embodiment shown, the slot 100 is located on the side ',~!` of the element opposite to finger depression 104, which is designed to accommodate the middle finger of the clinician. A latex band 106 is positioned around the hood element as shown, a portion o~ the band 106 extending through slot 100. The dimension of the latex band 106 is such as to hold the middle finger o~ the clinician in depression 104. The middle finger of the clinician thus acts as a primary guide for the tool a~ it i8 inserted into the patient.
In use of the article of the present invention, in particular, the embodiment of Figure 1, the probe must first be positioned in the drive rod.
The probe cables 24 are first fitted through the longitudinal slot 50 in the hood element, and also : through a portion of the slot 33 in the forward section 26 of the drive rod. The electrical (ECG) - 30 leads are directed through slot 32 at the rear of the - drive rod, while the optical lead ~pH) i9 not extended through the slot 32. The probe body itself is positioned in the open center of the hood element, and is then moved rearwardly so that the portion 48 of the probe is 6eated at the fron~ end of the drive rod and portion 46 of the probe abuts the front , surface of the lip 40 of the drive rod. As stated . ~1 .
Z'~Qt7119 ; a~ove, in such an arrangement, the hood element overlies the extended needle portion 22.
The insertion tool with the probe positioned therein $s now ready for insertion and attachment of the probe onto the scalp of the fetus. To do this, the clinician grasps the hood element 16 in the cutout portions thereof, and guides the hood element and hence the drive xod and probe through the cervix and vagina of the woman in labor to the point where ; 10 the end of the hood element contacts the scalp of the fetus. The hood element is placed against the scalp of the fetus at an angle which is normal thereto by ~udgment of the clinician. In the embodiment of Figure 5, the latex band holds the index ~inger of the clinician in place on the cutout portion of the hood element and thus the index finger can be used as a "pointer" for insertion and proper placement of the ; pro~e.
' While holding the hood element 16 in place, i~ 20 the clinician brings forward pressure at the rear end o~ the drive rod, while at the same time rotating the ~i drive rod. Thi~ forces the probe and the extending ,t needle forwardly and to rotate so that the needle is ;; screwed into the scalp of the fetus. During this process, the hood element 1~ and the flexure arrange~ent 30 prevents the probe from shifting on the scalp. A reliable attachment of the probe to the ~e~ scalp thus occurs.
At the end of this process, the drive rod and hood element are simply pulled away from the .:. 3 probe, with the cables coming out by way of the ~; slots. The insertion tool is then removed.
't Figures 6 through 8 show a further embodiment of the present invention. This embodiment ~, 35 comprises the combination of an elongated applicator ~,,, .; tool shown generally at 200 and an elongated integral j~/ drive rod/probe shown generally at 202. The ,,f~
-12 ~0~7~ 9 .~ drive/rod probe 202, which includes a mon~tor~ng ; probe 204 with an extending spiral needle 206 at the forward end thereof, is initially positioned within - the applicator tool 200. A slot 208 extends for the length of the applicator tool 200, permitting insertion and removal of the drive rod/probe relative to applicator tool 200.
Referring to Figure 6, which shows the applicator tool 200 in detail, the tool includes a guide tube portion 210, which in the embodiment shown has an exterior diameter of .375 inches. The longitudinal slot 208 is .15 inches wide. The guide tube portion 210 in the embodiment shown i5 made of a rigid, clear plastic tubing, such as PVC. It is angled or curved near one end thereof so as to better fit the average female anatomy, thereby facilitating installation of the probe in a directlon perpendicular to the fetal scalp. At the forward end of applicator tool 200 is a hood element 212 which is also made of rigid, clear plastic. The hood 2I2 in the embodiment shown is approximately .8 inches long, and has an external diameter of .54 inches. The hood overlays the forward end of guide tube 210 by '! approximately .4 inches. The hood also includes a longitudinal slot 214 which has a width of .15 inches and which is arranged to be in registry with slot 208 of the guide tube 210. The internal diameter of the hood 212 at its forward end 213 is large enough to accommodate the monitoring probe 204 and needle 206 of the drive rod/probe 202. In the embadiment shown, - the total length of the applicator tool i5 approximately 6.5 inches. As an alternative ~: embodiment, it should be understood that a flexure ~ ~oint could be incorporated in applicator tool 200 at :! 3S a selected point along its length. The joint could ; be arranged to permit flexure in one axis of movement alone or in more than one axis.
, ~ 3 ~
zQ-a7l~9 The integral drive rod/probe is shown in Figures 7 and 8. The probe itsel~ 204 includes an exterior casing or hub portion 215 having on its forward end surface 215 a plurality of spaced gripping feet 218. In the embodi~ent shown, the trailing edge 219 of each foot is relieved from side-to-side 50 that lt extends laterally at an angle of approximately 5 degrees relative to a line ~ormal to the circular peripheral edge of the ~orward end of the probe. The rear part 221 of the upper surface of : each foot is flat, and is approximately .03 inches above the forward end surface 215 of the probe.
Forward of the rear upper surface part 221 is a forward part 223 which ~lopes at an angle of approximately 15- ~165- relative to the rear part ' 221) to the forward end surface 215 o~ the probe. In the embodiment shown, there are three gripping feet 1 positioned at equally spaced intervals around the . .
~;:' forward end surface, although a greater or perhaps fewer number could be used.
~:'' When th~ probe i~ rotated BO that the sloped '. portion 223 of the gripping feet is the leading ~ portion, rotation o~ the probe is relatively easy.
v~; When the probe has been rotated sufficiently that the needle is fully inserted into the f~tal scalp and such that the rear part 221 of each gripping foot presses against the fetal scalp, it is quite 3';~ difficult to rotate the probe in the opposite direction, because the blunt trailing edge (now the leading edge) tends to press into the scalp. The ~eet 218 improve the stability of the probe on the scalp of a fetus, particularly ~calp with hair, and also reduce the possibility of the probe becoming loosened from the scalp after it has been initially attached. The hub 215 is generally circular in ;~ configuration, and in the embodiment shown has a ,~; length of .4 inches. The diameter of rear portion .
ZO~)7119 i' 14 220 o~ the hub is .23 inches, increasing to .46 - inches for front portlon 221. In the embodiment ,; shown the hub 215 i~ made from a plastic material and is filled with epoxy 222.
~", 5 At the rear of hub 215 i8 a re~erence electrode 230 which in the embodiment shown is a thin metal cylinder approximately .~4 inches long and .1~0 .....
l: inches in diameter. The reference electrode 230 has ,.
5~ a front portion 232 which has a slightly smaller ;; 10 exterior diameter than the remainder thereof. The reference electrode 230 is positioned interiorly of - the rear portion 220 of the probe hub 215, with the front portion 232 of the reference electrode ~:~ extPnding almost to the point where the hub 215 begins to increase in diameter, approximately midway ,~;, between the rear and front ends of tha hub. This '~ arrangement results in a small portion of the : reference electrode 230 extending from the rear end - 233 of the hub 215.
jj~ 20 The drive rod portion 234 of the integral drive rod/probe extends axially through reference electrode 230, to a point ~u~t forward o~ the front edge thereof. The drive rod portion 234, which is in the form of a cable, as more clearly described hereinafter, is approximately 7 inches in length. At ;< the rear o~ the cable i8 a drive knob 236 (Figure 7).
Drive knob 236 in the embodiment shown is generally cylindrical in configuration, approximately .31 ; inches in diameter and i8 approximately .6 inches 0 long. Arranged around the exterior surface of the drive knob are a plurality of longitudinal grooves ;~ 240 which are generally configured to permit ,' manipulat~on o~ the drive knob and hence the drive rod by human fingers. The interior of the drive knob ,~i 35 i9 hollow, with the drive rod extending therethrough.
The drive knob 236 is secured to the drive rod 202 so ~;, that the rod is rotated with the drive knob. The :.
Z~)V7~9 forward and rear edges of the drive knob are beveled, at 45- in the embodiment shown.
; The arrangeQent of the drive rod is shownmost clearly in Figure 8. The drive rod, in the form of a flexible cable, includes an outer PVC jacket 24 and an outer braided sleeve conductor element 246 which provides torsional stiffness while maintaining low bend stiffness. The braided ele~ent 246, while an electrical conductor, is not electrically ~ 10 connected to any other element in the cable. The .$ next layer is a thin anti-abrasion layer 248.
Internally of layer 248 is a first internal sleeve 250, which is Teflon in the embodiment shown, around which is wound two alternating wires 252 and 254.
- 15 The wires 252 and 254 provide the electrical connections ~or the probe, and extend out the rear o~
` the integral drive rod~pro~e as shown in Figure 7.
. In the embodiment shown, wire~ 252 and 254, which provide the ECG connection, wind alternately :' 20 around the Te~lon sleeve 250 and then extend outwardly from the front end of the cable within the volume de~ined ~y the hub 215. One wire 254 i8 ~ connected through a solder connection to the spiral needle 206, which extends out from the ~orward end of ~.; 25 the hub 215 and which is held in place within the hub .~ by conventional potting 222. In one embodi~ent, the spiral needle i8 approximately 1 complete turn, and ~ extends approximately 0.16 inches beyond the $orward .~ end o~ the hub 215. The other wire 252 is electrically connected, such as by soldering, to the .:- reference electrode 230. Extending down the middle .~ of the cable is a second internal Teflon sleeve 262.
Within Teflon sleeve 262 is a fiber optic cable 264 . which extends through the center of the spiral needle i~ 35 206 and connects with a pH detector element located near th~ pointed end 258 of the spiral.
,~
, , 16 ~"07~19 In use, ~he integral drive rod/probe 202 i5 '!- po~itioned within the applicator tool 200, the diameter of the drive rod, i.e. cable, being of such a size as to fit into the applicator tool through the slot 208. The hood element 212 at the ~orward end of the applicator tool covers the front end of the hub 215 and the extending needle 206, protecting the patient from possible in~ury during insertion of the probe. As mentioned above, the applicator tool is lo rigid and sufficiently long to allow good control of the tool, and is curved to better fit the ~emale anatomy. When the front end of the hood 212 is ; positioned squarely on the scalp of the fetus, the drive knob 236 is moved forwardly and then rotated so that the needle turns into the fetal scalp. The slot 208 in the guide tube portion of the applicator tool is on one side thereof so as to contain the drive cable in both directions in the plane of the bend.
The ~riction of the cable against the bent portion of the guide tube will tend to roll the cable to the side as it i~ rotated. The slot 208 i8 located in the side opposite from the direction Or the roll.
When the needle has been fully inserted so that the front end of the hub 215 i8 ad~acent the fetal scalp, the applicator tool is removed by moving the drive knob 236 toward the side of the applicator tool and then withdrawing the tool from the drive cable through the longitudinal slot in the tool. The cable may thereafter be used to tighten the probe should it become loose, by rotating the probe in one direction, or to remove the probe, when necessary or desirable, by rotating it in the opposite direction.
- Thus, an article has been described which results in a convenient, reliable and correct (i.e.
the probe is positioned normal to the scalp) attachment of a probe to the scalp of a fetu~.
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~0071~9 Although a preferred embodiment of the invention has been disclosed herein for illustration, it should be understood that variou~ chan~es, mod~fications and substitutions may be incorporated in such embodiment without departing from the spirit of the invention as defined by the claims which ~ollow.
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I~ THE SCALP OF A FE~US
'.!,' 5 Technical Field :
This invention relates generally to the art of fetal monitoring probes, and more particularly concerns an article for placement of such a probe in `. the scalp of a fetus.
' ', 10 Backaround Art The importance of monitoring the physical condition of a fetus during the birth process is well . established. Appropriate remedial action and/or intervention can then be used when indicated. In ~; this regard, the pH of the fetus, as well as the ,s,~~ fetal heart rate, are important indicators of fetal condition. Fetal monitoring eguipment has been ~ developed to obtain, analyze and display such information. Typically, such information is obtained from the f~tus by means of a probe which is attached ~, to the scalp of the fetus in utero and which remains in the scalp tissue throughout the birth process. An example of such a probe is shown in U. S. Patent No.
4,658,825 to Hochberg et al, which is assigned to the same assignee as the present invention.
In order to obtain reliable information, particularly for pH, it is necessary that the end portion of the probe containing the pH sensor be securely positioned in the scalp of the fetus. This is sometimes difficult, since the clinician must accomplish the initial attachment of the probe by feel rather than by sight, and the resulting 7~:~9 attachment must be sufficiently strong to withstand the movement of the fetus and the mother during the . birth process.
Although the particular shape (spiral) of the needle shown and described in the '825 patent has proved to be significant in maintaining the secure attachment of the probe to the fetal scalp, the guidance of the pro~e to, and initial positioning of , the probe on, the fetal scalp is also important, as well as the ability to rotate the probe so that the spiral needle moves into the fetal scalp while maintaining the probe body at an angle which is substantially normal to the scalp. This is often difficult to do under actual conditions.
For that reason, an insertionJplacement tool ; is typically used with the probe to attach the probe to the scalp. While existing insertion tools are typically flexible to accommodate the insertion of the probe through the vagina and csrvix of the woman in labor to the fetal scalp, flexibility alone does not re~ult in proper initial placement and subsequent maintenance of the attachment of the probe to the fetal scalp. In order to accomplish reliable attachment, the applicant has discovered that the forward end o~ the probe must be initially positioned - substantially normal to the fetal scalp, and must be maintained in that position by the insertion tool, while at the same time the tool must be rotatable from its far end ~opposite from the near or fetal scalp end), with the far end of the tool being at a ~, ~ substantial angle relative to the near end which is ; at the fetal scalp.
:~ Use of existing tools have resulted in di~ficulty in properly attaching the probe to the fetal scalp, wh$ch in turn often results in inaccurate or unreliable readings, particularly of pH.
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2()~`'71~9 ~ 3 :
Discl~s~EQ o th~ Invention The article includes a drive element having a forward end which is adapted to support a probe element, wherein the probe includes a needle extending therefrom, wherein the drive element is flexible along its length, contains connections for the probe and includes means in the vicinity of the rear end thereof for rotating the drive element and hence the probe. The article further includes a ; rigid applicator tool which has a longitudinal slot along one side thereof, adapted to receive the drive element, including the probe, therein. The slot is large enough to accommodate the drive element.
Brief Description of the Drawinas Figure 1 is an elevational, partial cross-sectional view showing the article of one embodiment of the present invention.
Figure 2 is a rear elevational view of the , .:
l front hood element portion of the article of Figure :,,,~ 1.
Figure 2a is a cross-sectional view of the ;~ front hood element of Figures l and 2.
Figure 3 is a front elevational vlew of the drive rod portion of the article of Pigure 1.
Figure 3a is a rear view of the drive rod of i~...l ~j Figures 1 and 3.
Figure 4 shows the details of the flexure ;i 30 joint of the article of Figure 1.
Figure 5 is an isometric view of another embodiment of the insertion tool of the present ~; invention, showing a different flexure joint configuration and a modified front hood element.
3s Figure 6 ls an isometric view of the applicator tool portion of another embodiment of the present invention.
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ZC~7~19 Figure 7 is a side elevational view of the ! integral drive rod/probe portion of the embodiment of ; Figure 6.
Figure 8 i~ an enlarged cross-section view of a portion of the drive rod/probe shown in Figure 7.
Best M~de For Carryina Out The Invention The insertion/placement tool of the present invention is shown generally at lO in Figure 1, in combination with a fetal probe shown generally at 12.
The tool 10 generally comprises a drive rod 14 and a : hood-like element 16 which is positioned at the front end 18 of the drive rod 14. The fetal probe 12 is shown operatively positioned in the drive rod, with the probe 12 in the embodiment shown generally comprising a body portion 20, an extending needle element 22 and electrical and optical connections 24.
The electrical and optical connections 24, hereinafter referred to simply as cable connections, are in turn connected to a conventional fetal monitoring unit which analyzes and displays the in~ormation obtained by the probe.
In the embodiment shown, the drive rod 14 ~5 comprises a length o~ relative}y stiff plastic, approximately lO inches long and .37 inahes in diameter. An example of suitable material is polypropylene. The drive rod 14 includes a first, forward section 26 which is relatively toward the fetuæ, and a second, rear section 28 which i8 relatively away from the fetus. The forward section 26 i8 hollow while rear section 28 is solid. The forward and rear sections are ~oined by a flexure joint 30 which is shown in more detail in Figure 4 and described below.
The hollow forward section 26 in the embodiment of Figure 1 i5 approximately 2 1/2 inches ~- J
Z()07119 long, and has a longitudinal slot 33 therein which communicates with the hollow interior of section 26 and which extends from the front end 18 of the drive rod approximately 2.40 inches toward the rear end thereof. The slot 33 is wide enough to permit the exit of the cables 24 of the probe from the interior of the drive rod 14. In the embodiment shown, slot 33 is straight; however, it could spiral around the circumference of the forward section of the drive rod, if desired. The solid rear section 28 also includes a longitudinal slot 36 which extends from the rear end 32 thereof approximately 0.80 inches.
Slot 36 is designed to permit the cables 24 to be temporarily secured to the rear end of the drive rod when the probe is in position within the drive rod, and the rod is being inserted into the mother for placement of the probe on the ~calp of the fetus.
At the front end 18 of the drive rod 1~ is a :
hood retaining shoulder or lip 40 which is round in ~ 20 outline and approximately .45 inches in diameter, as : shown in Figures 1 and 3 and also as shown in the ':7 embodiment of Figure 5. The lip 40 extends outwardly ;' from the exterior surface of the drive rod approximately 0.07 inches and is 0.06 inches thick.
,t,'.,J.25 Lip 40 prevents the hood element 16 from coming off the front end of the drive rod.
The interior surface of the drive rod 14, ~-~ from the front end 18 thereof for a distance of approximately 0.20 inches, is square in outline, approximately 0.20 inches on a side. At the rear end of this square portion 42 is a lateral groove 44 in the interior surface of the drive rod 14, ~:~ approximately 0.10 inches wide and 0.28 inches in -~ diameter. The remainder of the forward section 26 has an interior diameter of 0.22 inches. However, ~;;
'~ the interior surface of the drive rod could be square !';;
Z0~7119 ':
: over the entire length of the forward section, if de~ired.
, Referring to Figure 1, the dimensions of the 7' drive rod and the hood are adapted to the dimensions of the probe 12, so that for instance, front portion 46 of probe 12 has a diameter which is ~ust slightly ; smaller than the interior diameter of the front portion of the hood 16, while middle portion 48 of the probe, which is squar~ in cross-sectional outline, has cross-sectional dimensions which are ; slightly less than the dimensions o~ the square portion 42 of the interior surface of drive rod 14.
The probe 12 thus fits securely in the drive rod at the front end thereof.
The front hood element 16 is shown in Figure~ 1 t Z and 2a. In the embodiment shown, the hood element 16 fits around the drive rod 14 at the front thereof, and extends beyond the front end 18 of drive rod 14 a sufficient distance to cover the extending needle portion 22 of the probe when the probe 12 i8 operatively positioned in the drive rod, as shown in Figure 1. The hood element 16 in the embodiment shown is 1.2 inches long and is generally circular in exterior outline, with a diameter o~
;;25 approximately 3/4 inches. A longitudinal slot 50 extends the entire length of the hood element and extends from the exterior surface of the element to ; the hollow interior thereof.
~' The slot 50 i~ wide enough to permit exiting of the cables 24 of the probe therethrough. The hollow interior of the front hood element 16 includes a rear cylindrical portion 52 which is approximately 0.70 inches long and has a diameter of 0.38 inches '~ and a front cylindrical portion 54 which is approximately 0.50 inches long and has a diameter of 0.47 inches. The interior lip 56 defined at the ;! junction of the front and rear portions 52 and 54 ~')07119 abuts against the rear surface of extending lip 40 on the front end 18 of the drive rod 14, which pr~vents further forward movement of th~ hood element 16 relative to the drive rod 14.
In use, the hood element ~6 is grasped by the clinician and inserted into position into the ~ body of the mother, against the head of the fetus, z bringing the drive rod and tho prob~ therealong. The fact that the front hood element 16 extends a slight distance beyond the forward tip of the probe needle 22 prevents the needle from damaging the mother's tissues during insertion of the probe. The front end 59 of the hood element may be serrated or otherwise configured to provide a friction surface. This results in the skin being held taunt to permit better ~ needle penetration.
- To facilitate the insertion of the tool and the probe by means of the hood element, the hood element 16 has three peripherally spaced cut-out !; 20 portions 58, 60 and 62 in the outer surface thereof, I which extend from the rear end 64 of the hood element j 16 to a point which i~ slightly more than half way to s the front end of the element. The three cutout portions 58, 60 and 62 are configured to accommodate the fingers of the clinician. Cutout portions 60 and 62 are spaced 180- relative to each other around the periphery of the hood element, while cutout 58 is at :l 90- to cutouts 60 and 62. Typically, but not 1 necessarily, slot 50 divides cutout 58.
r~ 30 One embodiment of the flexure joint 30 which $s! connects the first and second sections 26 and 28 of ~ ~ the drive rod 14 is shown in Figure 4. The flexure t,~, joint 30 is defined by first and second grooves 66 ~ and 68 and third and fourth grooves 70 and 72. First and second grooves 66 and 68 oppose each other, as ,$ shown in Figure 4 and are somewhat crescent-shaped, ~ extending around the circumference of the drive rod " 8 approximately 160-, toward the rear end thereof, ~; leaving a short span of approx$mately 1/16 inch of ~; material 67 between the respective interior ends of the first and second qrooves 66 and 68. Grooves 66 and 68 at their widest are approximately l/8 inch and narrow toward each end.
1 The third and fourth grooves 70, 72 are cut: in the drive rod slightly to the rear of the first '. and second grooves 66 and 68. Grooves 70 and 72 alsooppose each other and are at 90- relati~e to the first and second grooves. Grooves 70 and 72 are also crescent-shaped, extending toward the front end 18 of i the drive rod, and are positioned relative to each other so that there i8 a small span of material 7 15 between the respective interior ends of each groove.The two sets of grooves are spaced so that there i8 approximately 1/8 inch of material between the respective sets o~ grooves. Also, the interior ends of the four grooves are in the same plane, at points 90- removed ~rom each other. Accordingly, the resulting ~lexure ~oint act~ somewhat like a universal ~oint, permitting the rear section 28 to be ; angled relative to the forward second 26 about ~ relatively small, defined points, and further ;~ 25 permitting rotation of the forward section 26 by ; rotating the rear section 28 without the drive rod being distorted in any way. This is illustrated in Figure 1. The arrangement and configuration of the grooves is also such that rotation of the drive rod i: 30 by the rear section 28 will result in a corresponding rotation of the forward section 26, without lateral ~: movement of the forward sectiGn.
~; Other particular ~lexure joint configurations are possible. One other configuration is described in more detail below. It is important, ~` howev~x, that the flexure be able to permit angling of t~e rear section 2~ relative to the forward Zf)~)7119 section 26, without distortion o~ the first sect~on, and such that rotation o~ the rear section 28 results in a correspondinq rotation of the ~orward section 26. This has the advantageous result that when the rear section 28, which typically extends outwardly ~rom the patient, is rotated by the clinician, the forward section of the probe, which is positioned against the scalp of the fetus, remains substantially normal to the fetal scalp during rotation of the drive rod, which in turn results in the secure attachment of the probe to the scalp of the fetus in a convenient and reliable way, as explained in more detail below.
Figure 5 shows a somewhat different embodiment of the present invention. The drive rod : shown in ~igure 5 includes a ~orward section 80 and a rear portion 82, with the forward section being . hollow and the rear portion 82 beinq solid, as with '. the embodiment of Figures 1-4. The configuration of f 20 the ~orward and rear sections 80 and 82 is also substantlally the same as for the embodiment of Figures 1-4. However, the flexure ~oint 84 is ,~ di~ferent. Joint 84 includes a first pair of grooves 86 and 88 which are approximately 3/16 inch wide, are ~ 25 in registry, and extend approximately halfway through ;~ the drive rod, at right angles to the longitudinal axis o~ the rod, leaving a thin center portion 90 , approximately 1/32nd inch thick so that the rear section 8~ can be moved relative to the forward ~'~'! 30 section 80 about the thin center portion 90-A second set of grooves 92 and 94 is located just to the rear of grooves 86 and 88. Grooves 92 .~ and 94 are oriented a~ 90- to grooves 86 and 88, but otherwise have the same configuration. A thin center ,jA;,'35 portion 96, which is at 90- relative to center ~1 portion 90, re~ains between the two grooves 92 and !.~ 9~, permitting movement of the rear section 82 lo 2~V7119 i; relative to the forward section 80 about center portion 96. The flexure ~oint 84 with the ~, configuration shown permits a substantially universal ~oint function between the rear section 82 and the forward section 80.
v The hood element 98 shown in Figure 5 is also somewhat different than the hood element 16 of Figure 1, in that it includes a lateral slot 100 wh~ch extends through the cross-sectional dimension ;: 10 of the element and also extends from the forward end 102 of the hood 98 to a point somewhat rearward of ` the rear end 103 of the finger depressions. In the embodiment shown, the slot 100 is located on the side ',~!` of the element opposite to finger depression 104, which is designed to accommodate the middle finger of the clinician. A latex band 106 is positioned around the hood element as shown, a portion o~ the band 106 extending through slot 100. The dimension of the latex band 106 is such as to hold the middle finger o~ the clinician in depression 104. The middle finger of the clinician thus acts as a primary guide for the tool a~ it i8 inserted into the patient.
In use of the article of the present invention, in particular, the embodiment of Figure 1, the probe must first be positioned in the drive rod.
The probe cables 24 are first fitted through the longitudinal slot 50 in the hood element, and also : through a portion of the slot 33 in the forward section 26 of the drive rod. The electrical (ECG) - 30 leads are directed through slot 32 at the rear of the - drive rod, while the optical lead ~pH) i9 not extended through the slot 32. The probe body itself is positioned in the open center of the hood element, and is then moved rearwardly so that the portion 48 of the probe is 6eated at the fron~ end of the drive rod and portion 46 of the probe abuts the front , surface of the lip 40 of the drive rod. As stated . ~1 .
Z'~Qt7119 ; a~ove, in such an arrangement, the hood element overlies the extended needle portion 22.
The insertion tool with the probe positioned therein $s now ready for insertion and attachment of the probe onto the scalp of the fetus. To do this, the clinician grasps the hood element 16 in the cutout portions thereof, and guides the hood element and hence the drive xod and probe through the cervix and vagina of the woman in labor to the point where ; 10 the end of the hood element contacts the scalp of the fetus. The hood element is placed against the scalp of the fetus at an angle which is normal thereto by ~udgment of the clinician. In the embodiment of Figure 5, the latex band holds the index ~inger of the clinician in place on the cutout portion of the hood element and thus the index finger can be used as a "pointer" for insertion and proper placement of the ; pro~e.
' While holding the hood element 16 in place, i~ 20 the clinician brings forward pressure at the rear end o~ the drive rod, while at the same time rotating the ~i drive rod. Thi~ forces the probe and the extending ,t needle forwardly and to rotate so that the needle is ;; screwed into the scalp of the fetus. During this process, the hood element 1~ and the flexure arrange~ent 30 prevents the probe from shifting on the scalp. A reliable attachment of the probe to the ~e~ scalp thus occurs.
At the end of this process, the drive rod and hood element are simply pulled away from the .:. 3 probe, with the cables coming out by way of the ~; slots. The insertion tool is then removed.
't Figures 6 through 8 show a further embodiment of the present invention. This embodiment ~, 35 comprises the combination of an elongated applicator ~,,, .; tool shown generally at 200 and an elongated integral j~/ drive rod/probe shown generally at 202. The ,,f~
-12 ~0~7~ 9 .~ drive/rod probe 202, which includes a mon~tor~ng ; probe 204 with an extending spiral needle 206 at the forward end thereof, is initially positioned within - the applicator tool 200. A slot 208 extends for the length of the applicator tool 200, permitting insertion and removal of the drive rod/probe relative to applicator tool 200.
Referring to Figure 6, which shows the applicator tool 200 in detail, the tool includes a guide tube portion 210, which in the embodiment shown has an exterior diameter of .375 inches. The longitudinal slot 208 is .15 inches wide. The guide tube portion 210 in the embodiment shown i5 made of a rigid, clear plastic tubing, such as PVC. It is angled or curved near one end thereof so as to better fit the average female anatomy, thereby facilitating installation of the probe in a directlon perpendicular to the fetal scalp. At the forward end of applicator tool 200 is a hood element 212 which is also made of rigid, clear plastic. The hood 2I2 in the embodiment shown is approximately .8 inches long, and has an external diameter of .54 inches. The hood overlays the forward end of guide tube 210 by '! approximately .4 inches. The hood also includes a longitudinal slot 214 which has a width of .15 inches and which is arranged to be in registry with slot 208 of the guide tube 210. The internal diameter of the hood 212 at its forward end 213 is large enough to accommodate the monitoring probe 204 and needle 206 of the drive rod/probe 202. In the embadiment shown, - the total length of the applicator tool i5 approximately 6.5 inches. As an alternative ~: embodiment, it should be understood that a flexure ~ ~oint could be incorporated in applicator tool 200 at :! 3S a selected point along its length. The joint could ; be arranged to permit flexure in one axis of movement alone or in more than one axis.
, ~ 3 ~
zQ-a7l~9 The integral drive rod/probe is shown in Figures 7 and 8. The probe itsel~ 204 includes an exterior casing or hub portion 215 having on its forward end surface 215 a plurality of spaced gripping feet 218. In the embodi~ent shown, the trailing edge 219 of each foot is relieved from side-to-side 50 that lt extends laterally at an angle of approximately 5 degrees relative to a line ~ormal to the circular peripheral edge of the ~orward end of the probe. The rear part 221 of the upper surface of : each foot is flat, and is approximately .03 inches above the forward end surface 215 of the probe.
Forward of the rear upper surface part 221 is a forward part 223 which ~lopes at an angle of approximately 15- ~165- relative to the rear part ' 221) to the forward end surface 215 o~ the probe. In the embodiment shown, there are three gripping feet 1 positioned at equally spaced intervals around the . .
~;:' forward end surface, although a greater or perhaps fewer number could be used.
~:'' When th~ probe i~ rotated BO that the sloped '. portion 223 of the gripping feet is the leading ~ portion, rotation o~ the probe is relatively easy.
v~; When the probe has been rotated sufficiently that the needle is fully inserted into the f~tal scalp and such that the rear part 221 of each gripping foot presses against the fetal scalp, it is quite 3';~ difficult to rotate the probe in the opposite direction, because the blunt trailing edge (now the leading edge) tends to press into the scalp. The ~eet 218 improve the stability of the probe on the scalp of a fetus, particularly ~calp with hair, and also reduce the possibility of the probe becoming loosened from the scalp after it has been initially attached. The hub 215 is generally circular in ;~ configuration, and in the embodiment shown has a ,~; length of .4 inches. The diameter of rear portion .
ZO~)7119 i' 14 220 o~ the hub is .23 inches, increasing to .46 - inches for front portlon 221. In the embodiment ,; shown the hub 215 i~ made from a plastic material and is filled with epoxy 222.
~", 5 At the rear of hub 215 i8 a re~erence electrode 230 which in the embodiment shown is a thin metal cylinder approximately .~4 inches long and .1~0 .....
l: inches in diameter. The reference electrode 230 has ,.
5~ a front portion 232 which has a slightly smaller ;; 10 exterior diameter than the remainder thereof. The reference electrode 230 is positioned interiorly of - the rear portion 220 of the probe hub 215, with the front portion 232 of the reference electrode ~:~ extPnding almost to the point where the hub 215 begins to increase in diameter, approximately midway ,~;, between the rear and front ends of tha hub. This '~ arrangement results in a small portion of the : reference electrode 230 extending from the rear end - 233 of the hub 215.
jj~ 20 The drive rod portion 234 of the integral drive rod/probe extends axially through reference electrode 230, to a point ~u~t forward o~ the front edge thereof. The drive rod portion 234, which is in the form of a cable, as more clearly described hereinafter, is approximately 7 inches in length. At ;< the rear o~ the cable i8 a drive knob 236 (Figure 7).
Drive knob 236 in the embodiment shown is generally cylindrical in configuration, approximately .31 ; inches in diameter and i8 approximately .6 inches 0 long. Arranged around the exterior surface of the drive knob are a plurality of longitudinal grooves ;~ 240 which are generally configured to permit ,' manipulat~on o~ the drive knob and hence the drive rod by human fingers. The interior of the drive knob ,~i 35 i9 hollow, with the drive rod extending therethrough.
The drive knob 236 is secured to the drive rod 202 so ~;, that the rod is rotated with the drive knob. The :.
Z~)V7~9 forward and rear edges of the drive knob are beveled, at 45- in the embodiment shown.
; The arrangeQent of the drive rod is shownmost clearly in Figure 8. The drive rod, in the form of a flexible cable, includes an outer PVC jacket 24 and an outer braided sleeve conductor element 246 which provides torsional stiffness while maintaining low bend stiffness. The braided ele~ent 246, while an electrical conductor, is not electrically ~ 10 connected to any other element in the cable. The .$ next layer is a thin anti-abrasion layer 248.
Internally of layer 248 is a first internal sleeve 250, which is Teflon in the embodiment shown, around which is wound two alternating wires 252 and 254.
- 15 The wires 252 and 254 provide the electrical connections ~or the probe, and extend out the rear o~
` the integral drive rod~pro~e as shown in Figure 7.
. In the embodiment shown, wire~ 252 and 254, which provide the ECG connection, wind alternately :' 20 around the Te~lon sleeve 250 and then extend outwardly from the front end of the cable within the volume de~ined ~y the hub 215. One wire 254 i8 ~ connected through a solder connection to the spiral needle 206, which extends out from the ~orward end of ~.; 25 the hub 215 and which is held in place within the hub .~ by conventional potting 222. In one embodi~ent, the spiral needle i8 approximately 1 complete turn, and ~ extends approximately 0.16 inches beyond the $orward .~ end o~ the hub 215. The other wire 252 is electrically connected, such as by soldering, to the .:- reference electrode 230. Extending down the middle .~ of the cable is a second internal Teflon sleeve 262.
Within Teflon sleeve 262 is a fiber optic cable 264 . which extends through the center of the spiral needle i~ 35 206 and connects with a pH detector element located near th~ pointed end 258 of the spiral.
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, , 16 ~"07~19 In use, ~he integral drive rod/probe 202 i5 '!- po~itioned within the applicator tool 200, the diameter of the drive rod, i.e. cable, being of such a size as to fit into the applicator tool through the slot 208. The hood element 212 at the ~orward end of the applicator tool covers the front end of the hub 215 and the extending needle 206, protecting the patient from possible in~ury during insertion of the probe. As mentioned above, the applicator tool is lo rigid and sufficiently long to allow good control of the tool, and is curved to better fit the ~emale anatomy. When the front end of the hood 212 is ; positioned squarely on the scalp of the fetus, the drive knob 236 is moved forwardly and then rotated so that the needle turns into the fetal scalp. The slot 208 in the guide tube portion of the applicator tool is on one side thereof so as to contain the drive cable in both directions in the plane of the bend.
The ~riction of the cable against the bent portion of the guide tube will tend to roll the cable to the side as it i~ rotated. The slot 208 i8 located in the side opposite from the direction Or the roll.
When the needle has been fully inserted so that the front end of the hub 215 i8 ad~acent the fetal scalp, the applicator tool is removed by moving the drive knob 236 toward the side of the applicator tool and then withdrawing the tool from the drive cable through the longitudinal slot in the tool. The cable may thereafter be used to tighten the probe should it become loose, by rotating the probe in one direction, or to remove the probe, when necessary or desirable, by rotating it in the opposite direction.
- Thus, an article has been described which results in a convenient, reliable and correct (i.e.
the probe is positioned normal to the scalp) attachment of a probe to the scalp of a fetu~.
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~0071~9 Although a preferred embodiment of the invention has been disclosed herein for illustration, it should be understood that variou~ chan~es, mod~fications and substitutions may be incorporated in such embodiment without departing from the spirit of the invention as defined by the claims which ~ollow.
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Claims (10)
1. An article for securely attaching a probe to the scalp of a fetus, comprising:
a drive element having a foward end adapted to support a probe, the probe including a spiral needle element extending therefrom, the drive element being flexible along its length and containing therewithin connections for the probe, the drive element including means in the vicinity of the rear end thereof for rotating the drive element and hence the probe;
a rigid applicator tool, having a longitudinal slot along one side thereof, adapted to receive the drive element, including the probe, therewithin, the slot being large enough to accommodate the drive element.
a drive element having a foward end adapted to support a probe, the probe including a spiral needle element extending therefrom, the drive element being flexible along its length and containing therewithin connections for the probe, the drive element including means in the vicinity of the rear end thereof for rotating the drive element and hence the probe;
a rigid applicator tool, having a longitudinal slot along one side thereof, adapted to receive the drive element, including the probe, therewithin, the slot being large enough to accommodate the drive element.
2. An article of Claim 1, wherein the connections include electrical connections for monitoring of ECG, and a fiberoptic connection for monitoring of pH.
3. An article of Claim 2, wherein the probe includes a hub portion from which the spiral needle extends and a reference electrode portion at the rear of the hub portion, wherein the drive element fits securely within the reference electrode and wherein one of the electrical connections includes an electrical conductor connected to the reference electrode and the other electrical connection includes an electrical conductor connected to the spiral needle element.
4. An article of Claim 1, wherein said applicator tool includes a flexure joint at a selected location along its length.
5. An article of Claim 1, including a plurality of gripping feet on a forward end of the probe, wherein the gripping feet have a blunt end and a sloping opposing end, so that rotation of the probe in the direction of the blunt end is difficult when the probe is inserted into the scalp of the fetus.
6. An article for securely attaching a probe to the scalp of a fetus, comprising:
an elongated drive element having a front end thereof adapted to support a probe, wherein the drive element includes a joint along its length which separates the drive element into front and rear portions, wherein the joint is configured to permit the rear portion of the drive element to be angled relative to the front portion thereof without distortion of the front portion and without imparting a bending fordce to the front portion and further such that the rotation of the rear portion results in corresponding rotation of the front portion without lateral movement of the front portion, including the probe, even when the rear portion is angled relative to the forward portion.
an elongated drive element having a front end thereof adapted to support a probe, wherein the drive element includes a joint along its length which separates the drive element into front and rear portions, wherein the joint is configured to permit the rear portion of the drive element to be angled relative to the front portion thereof without distortion of the front portion and without imparting a bending fordce to the front portion and further such that the rotation of the rear portion results in corresponding rotation of the front portion without lateral movement of the front portion, including the probe, even when the rear portion is angled relative to the forward portion.
7. An article of Claim 6, wherein the front portion of the drive element includes a front end, including a hood element which is adapted to fit around the front end of the front portion of the drive element for guiding the drive element and the probe to the scalp of the fetus, wherein the drive element and the hood element are configured and arranged to permit disengagement of the probe from the drive element.
8. An article of Claim 7, wherein the hood element and a portion of the drive element in the vicinity of the front end thereof each include a longitudinal slot for removal of the probe from the drive element.
9. An article of Claim 8, wherein the hood element includes portions in the outer surface thereof configured so as to accommodate the fingers of a clinician user.
10. A probe for monitoring a fetus, comprising:
a probe body having a forward end surface;
a spiral-shaped needle element which extends from the forward end surface of said probe; and a plurality of generally saw-toothed shaped gripping feet members arranged at spaced intervals on the forward end surface of the probe body, the gripping feet each having a sloping leading end and an opposing blunt trailing end, so as to substantially prevent the probe from being turned in a direction opposite from that for insertion of the probe body, following insertion of the probe into the scalp of the fetus.
a probe body having a forward end surface;
a spiral-shaped needle element which extends from the forward end surface of said probe; and a plurality of generally saw-toothed shaped gripping feet members arranged at spaced intervals on the forward end surface of the probe body, the gripping feet each having a sloping leading end and an opposing blunt trailing end, so as to substantially prevent the probe from being turned in a direction opposite from that for insertion of the probe body, following insertion of the probe into the scalp of the fetus.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US293,941 | 1989-01-05 | ||
| US07/293,941 US4913151A (en) | 1989-01-05 | 1989-01-05 | Tool for placement of a monitoring probe in the scalp of a fetus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2007119A1 true CA2007119A1 (en) | 1990-07-05 |
Family
ID=23131221
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002007119A Abandoned CA2007119A1 (en) | 1989-01-05 | 1990-01-04 | Tool for placement of a monitoring probe in the scalp of a fetus |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4913151A (en) |
| EP (1) | EP0377432A1 (en) |
| JP (1) | JPH02234741A (en) |
| AU (2) | AU4739490A (en) |
| CA (1) | CA2007119A1 (en) |
Families Citing this family (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3810008C1 (en) * | 1988-03-24 | 1989-10-26 | Johannes Dr. 8000 Muenchen De Buschmann | |
| US4926517A (en) | 1989-02-24 | 1990-05-22 | Smith Keith E | Sweeper |
| WO1991018549A1 (en) * | 1990-05-29 | 1991-12-12 | Yue Samuel K | Fetal probe apparatus |
| US5199432A (en) * | 1990-10-30 | 1993-04-06 | American Home Products Corporation | Fetal electrode product for use in monitoring fetal heart rate |
| JP3235852B2 (en) * | 1990-10-30 | 2001-12-04 | ジーイー・マーケット・メディカル・システムズ・インコーポレイテッド | Apparatus for electrically connecting electrodes to a support |
| US5222498A (en) * | 1991-02-11 | 1993-06-29 | Neward Theodore C | Spiral electrode with contact retainer |
| US5150709A (en) * | 1991-02-11 | 1992-09-29 | Neward Theodore C | Spiral electrode with contact retainer |
| US5139033A (en) * | 1991-03-04 | 1992-08-18 | Cardiac Pacemakers, Inc. | Sutureless myocardial lead implantation device |
| US5215090A (en) * | 1991-03-12 | 1993-06-01 | Hon Edward H | Fetal electrode |
| US5377677A (en) * | 1992-10-13 | 1995-01-03 | Graphic Controls Corporation | Packaging system for a fetal electrode |
| US5497771A (en) * | 1993-04-02 | 1996-03-12 | Mipm Mammendorfer Institut Fuer Physik Und Medizin Gmbh | Apparatus for measuring the oxygen saturation of fetuses during childbirth |
| US5388579A (en) * | 1993-09-23 | 1995-02-14 | Graphic Controls Corporation | Fetal electrode product with channeled drive mechanism and improved torque characteristics |
| US5411024A (en) * | 1993-12-15 | 1995-05-02 | Corometrics Medical Systems, Inc. | Fetal pulse oximetry sensor |
| DE4427864A1 (en) * | 1994-08-07 | 1996-02-08 | Rall Gerhard | Sensor device for measuring vital parameters of a fetus during childbirth |
| DE4442855B4 (en) * | 1994-12-01 | 2004-04-01 | Gerhard Dipl.-Ing. Rall | Use of a pulse oximetry sensor device |
| US5680859A (en) * | 1995-10-11 | 1997-10-28 | Graphic Controls Corporation | Integrated introducer and drive rod positioning system for a fetal spiral electrode |
| US5671736A (en) * | 1995-10-17 | 1997-09-30 | Graphic Controls Corporation | Fetal electrode product with easy-to-handle connector |
| CA2303803A1 (en) * | 1997-06-17 | 1998-12-23 | Respironics, Inc. | Fetal oximetry system and sensor |
| US20030081310A1 (en) * | 1998-09-09 | 2003-05-01 | Mcmanus Dennis Q. | Microscopy method and apparatus |
| AU5215399A (en) | 1998-09-09 | 2000-03-27 | Dennis Q. Mcmanus | Microscopy method and apparatus |
| WO2021076940A1 (en) | 2019-10-16 | 2021-04-22 | Balman James Robert | Apparatus and method for determining physiological parameters of an infant in-utero |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3910271A (en) * | 1973-06-04 | 1975-10-07 | Theodore C Neward | Method of making a bipolar electrode structure |
| US4320764A (en) * | 1980-06-13 | 1982-03-23 | American Home Products Corporation | Fetal electrode |
| US4658825A (en) * | 1982-09-24 | 1987-04-21 | International Biomedics, Inc. | Spiral probe for simultaneous electrical and chemical monitoring of a fetus |
| JPS5980230A (en) * | 1982-09-24 | 1984-05-09 | アボット・ラボラトリーズ | Connector of electrocardiographic electrode and ph probe |
| DE3446116A1 (en) * | 1984-12-18 | 1986-06-19 | Drägerwerk AG, 2400 Lübeck | Electrode for application onto body parts and a positioning method therefor |
| US4644957A (en) * | 1985-04-08 | 1987-02-24 | Ricciardelli Robert H | Applicator structure for biological needle probes employing spiral-shaped retaining coils |
| US4686996A (en) * | 1985-12-24 | 1987-08-18 | Paul Ulbrich | Electrode assembly for sensing heart activity |
| GB8613687D0 (en) * | 1986-06-05 | 1986-07-09 | Rocket Of London Ltd | Instrument for monitoring foetal heart rate |
-
1989
- 1989-01-05 US US07/293,941 patent/US4913151A/en not_active Expired - Fee Related
- 1989-12-30 JP JP1344984A patent/JPH02234741A/en active Pending
-
1990
- 1990-01-02 AU AU47394/90A patent/AU4739490A/en not_active Abandoned
- 1990-01-02 EP EP90100013A patent/EP0377432A1/en not_active Withdrawn
- 1990-01-04 CA CA002007119A patent/CA2007119A1/en not_active Abandoned
-
1993
- 1993-06-16 AU AU41295/93A patent/AU4129593A/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| US4913151A (en) | 1990-04-03 |
| AU4739490A (en) | 1990-07-12 |
| AU4129593A (en) | 1993-08-26 |
| JPH02234741A (en) | 1990-09-17 |
| EP0377432A1 (en) | 1990-07-11 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |