the verress - type needle 100 , of this invention comprises a hollow outer needle with a sharpened tip 12 maintained in a handle 2 . the handle 2 has inserted into it the blunt inner needle 4 with a blunt tip 42 , which has a smaller diameter than the hollow outer needle 1 . thus , the blunt inner needle 4 can fit within the outer needle 1 with interior passage therethrough . the inner needle 4 is spring - loaded at the end 72 of a spring 7 against a viewing tube 8 . the other end 74 of spring 7 is placed against cone shaped end 62 of positive indicator 6 . positive indicator 6 slides over inner needle 4 to abut negative indicator 5 , as will be later explained herein . viewing tube 8 fits with flanges 82 against walls 22 of handle 2 . handle 2 has a hollow interior bore 24 extending for a portion of the length of handle 2 containing narrow walls 26 , in a generally cylindrical fashion . outer needle 1 is anchored to handle 2 within the bore 24 at walls 26 . also , inner needle 4 is hollow , for insufflation through end 44 and from sufflation holes 46 . therefore , when properly assembled , the blunt tip 42 of inner needle 4 is caused by the force of the spring 7 to extend past the tip 12 of the sharpened hollow outer needle 1 . when inserted into the body , pressure is exerted first against the blunt tip 42 of the inner needle 4 . needle 4 is caused to retract into the handle 2 of instrument 100 , and then the body wall contacts the sharpened tip 12 of the outer needle 1 . when the outer needle 1 is inserted into the body , it pierces the body wall . then , the force of spring 7 is greater than any tissue force , so that spring 7 pushes the blunt inner needle 4 , whereby the blunt inner needle 4 is caused to surpass the tip 12 of the sharpened outer needle 1 . in this way , the blunt inner needle 4 protects the internal abdominal cavity from damage by the hollow sharpened outer needle 1 . various aspects of this type of verress - needle will now be discussed . first , it is to be noticed that the outer walls 28 on handle 2 are cone shaped . there is contained within these walls 28 of the handle 2 a hollowed out portion 29 toward the rear of the handle . this hollowed out portion 29 acts as a sound amplification means . in this way , after the blunt inner needle 4 is caused return to its initial position by the force of the spring 7 , the force of the negative indicator 5 ( attached to the blunt inner needle 4 ) against inner wall 21 of the handle bore 24 , causes a vibration within handle 2 . this vibration is amplified by the hollowed out area 29 at the rear of handle 2 . in this way , the user is able to audibly verify the fact that the blunt inner needle 4 has been caused to move into a protective position , so that it is able to protect the abdominal cavity from injury by outer needle 1 . optionally , and ideally , this sound amplification arrangement is magnified by the opaque washer 3 emplaced within the bore 24 of the handle 2 . thus , when the negative indicator 5 is forced by spring 7 to move against inner wall 21 , the washer 3 is also vibrated , and this increased vibration is amplified by the cone shaped hollow portion 29 of handle 2 . also , there are provided visual means for indication that the blunt inner needle 4 is being forced against the handle 2 , such that the tip 42 of blunt inner end 4 extends past the end 12 of the sharpened hollow outer needle 1 . this is accomplished by the indicator system 5 , 6 attached to the blunt inner needle 4 , near the spring 7 which exerts force on the blunt inner needle 4 . the spring 7 is located at the rear 84 of the viewing tube 8 . this viewing tube 8 is hollow and made of opaque plastic and held within the widened walls 23 of the bore 24 contained in handle 2 . the viewing tube 8 has a clear window 86 located toward its distal end , which serves to indicate whether the inner needle 4 is exposed past the length of the outer needle 1 . the visual indication means is a two part indicator 5 , 6 which is attached to the inner needle 4 . the lower portion 5 of the inner needle is colored in a negative fashion , such as red . the upper portion 6 , most closely attached to the spring 7 , is colored in a positive manner , such as green . in this way , when the inner needle 4 is in its initial postion , it is fully extended past the sharpened end 12 of the outer needle 1 . only the green positive indicator 6 is exposed in the window 86 of the viewing tube 8 . negative indicator 5 is obscured by opaque washer 3 . however , when the needle 4 is retracted , by force applied to the blunt tip 42 of inner needle 4 , the lower , negative indicator 5 is exposed so that the observer sees red in the viewing window 86 . positive indicator 6 is obscured by opaque viewing tube 8 . in this fashion , the viewer knows that the sharpened outer needle end 12 is exposed , and that there is a likelihood of harm to the patient if the inner needle 4 does not return to its initial position . ( alternately , the viewer can see both red and green at this point , if window 86 is made larger than indicated . this visual stimulus will elicit a similar reaction for the user .) one additional visual mechanism is contained in the handle 2 at cap 10 . cap 10 is attached to the rear of the handle 2 by sliding walls 102 over walls 22 . cap 10 contains a hollow tube 104 with a colored ball 9 contained therein . this colored ball 9 rises or falls within the tube 104 depending upon liquid level within the tube 104 and , ultimately , inner needle 4 . therefore , the user may insert saline solution through the end 106 of cap 10 . it will be caused to flow into inner needle 4 , and then into the abdominal cavity . if there has been proper insertion of the needle 100 , ball 9 , which is less dense than saline solution , will float toward the rear 106 of cap 10 , for so long as saline remains to that level in needle 100 . once saline has drained into the abdominal cavity , so that cap 10 empties , ball 9 will begin to flow to the forward end of cap 10 , abutting end 88 of tube 8 . this procedure will work similarly , if liquid flow is in an opposite direction . at the end 106 of the cap 10 , there is a luer connector 108 , which may be connected to a stopcock or valve . with a stopcock in the closed position , the internal abdominal pressure is sealed , so that pneumoperitoneum is maintained . as is further seen in fig3 there is disclosed a verress - type needle 200 similar to the embodiment in fig1 except that it contains an acoustical mechanism on its forward part of the handle 202 which is slightly different from that described in fig1 and 2 . this acoustical mechanism can also be seen in fig4 . there , the rear of the mechanism is horn - shaped as at 214 , so that when the washers 203 vibrate by motion of the inner needle 204 against the handle 202 , the sound is further amplified . other portions of the needle 200 are identical in function to those of needle 100 . that is there are described an outer needle 201 , a pair of washers 203 , an inner needle 204 , indicating means 205 , 206 , a spring 207 , and a viewing window 208 , held within handle 202 . this viewing window 208 is obscured , except for a narrow opening 218 , through which positive viewing means 206 and negative viewing means 205 may be observed . a two piece cap 209 , 211 is attached to handle 202 , and floating ball 210 is maintained within the cap 209 , 211 . there is also a luer lock 212 at the end of the cap . as can be further seen in fig4 a , the portion of the acoustical mechanism 214 on fig4 has been enhanced in handle 202a . while the acoustical horn 214 in fig4 is created so that there is maintained a cylindrical lens 216 on the acoustical horn 214 , fig4 a now contains acoustical mechansim 216a containing magnifying lenses 216b around its periphery . the cylindrical lens 216 and magnifying lenses 216a visually enhance the colored indicators 205 , 206 as they pass through the focal point of each of the lenses , so that the user may more clearly see the color change as indicators 205 , 206 move with inner needle 204 . in this fashion , the user can determine more clearly which the puncture has been made by the sharpened outer needle 201 . this invention has been described with a number of preferred embodiments , all of which accomplish the aforementioned objects of the invention . it is to be understood that the invention is to be derived from the following claims and their equivalents .
a verres - type needle which has a sharpened outer needle and allows passage of a blunt inner needle within the outer needle . the verress needle also contains a position indicator to indicate the position of the inner needle within the outer needle , so that the user knows whether the inner needle is in a protective or non - protective position . further , a liquid level indicator demonstrates the path of liquid flow within the verress - type needle . finally , there is an acoustical enhancment mechanism , which allows the user to know whether the blunt inner needle has sprung forward within the abdominal cavity , to its most forward , protective position .